u n 6^-^ l^ iO = ^ s ^ r^ = = CO ■■"i — r^ o^s ^s i-n r S^ r-q = i n- r D fY\ n- PROTOZOOLOGY PROTOZOOLOGY <^1 ^^' By RICHARD ROKSABRO KUDO, D.Sc. Associate Professor of Zoology The University of Illinois Enlarged and completely rewritten edition of HANDBOOK OF PROTOZOOLOGY With two hundred and ninety-one illustrations n 3^ CHARLES C THOMAS • PUBLISHER SPRINGFIELD- ILLINOIS • BALTIMORE • MARYLAND COPYRIGHT, 1931, BY CHARLES C THOMAS COPYRIGHT, 1939, BY CHARLES C THOMAS Printed in the United States of A merica All rights reserved. This book may not be re- produced, in whole or in part, in any form (ex- cept by reviewers for the public press), with- out written permission from the publisher. " The revelations of the Microscope are perhaps not excelled in importance by those of the telescope. While exciting our curiosity, our wonder and admiration, they have proved of infinite service in advancing our knowledge of things around us." Leidy Preface THE present work is similar in its primary aim to that of its predecessor, Handbook of Protozoology (1931), in presenting "introductory information on the common and representative genera of all groups of both free-living and parasitic Protozoa," to advanced undergraduate and graduate students in zoology in colleges and universities. With the expansion of courses in proto- zoology at the University of Illinois and elsewhere, it seemed ad- visable to incorporate more material for lecture and discussion, in addition to the enlargement of the taxonomic section. The change of the text-contents has, therefore, been so extensive that a new title. Protozoology , is now given. Chapters 1 to 6 deal with introduction, ecology, morphology, physiology, reproduction, and variation and heredity, of Proto- zoa, Each subject-matter has been considered in the light of more recent investigations as fully as the space permitted. Selection of material from so great a number of references has been a very difficult task. If any important papers have been omitted, it was entirely through over-sight on the part of the author. The taxonomic portion (Chapters 7 to 43) has also been com- pletely rewritten and enlarged. Numerous genera and species, both old and new, have been added; synonymy of genera and species has as far as possible been brought down to date; new taxonomic arrangement of major and minor subdivisions in each class has resulted in numerous changes. The class Ciliata has completely been reclassified, following Kahl's admirable work on free-living ciliates (1930-1935); however, unlike the latter, all parasitic ciliates have also been considered in the present work. The author continues to believe that good illustrations are in- dispensable in this kind of work, since they are far more easily comprehended than lengthy descriptions. Therefore, many old illustrations have been replaced by more suitable ones and nu- merous new illustrations have further been added. All illustrations were especially prepared for this work and in the case of those which have been redrawn from illustrations found in published papers, the indebtedness of the author is indicated by mention- ing the names of the investigators from whose works the illustra- viii PR?:FACK tions were taken. In order to increase the reference value, all figures are accompanied by scales of magnification which are uni- formly somewhat greater than those of Handbook of Protozool- ogy, since the microscope now used in the class-room has been improved upon in recent years. The list of references appended to the end of each chapter has been enlarged and is meant to aid those who wish to obtain fuller information than that w^hich is given in this volume. Since com- prehensive monographs on various groups of Protozoa are widely scattered and ordinarily not easily accessible, the author has en- deavored to provide for each group as complete an information as possible for general reference purpose within the limited space, and hopes that the present work has reference value for teachers of biology, field workers in pure and applied biological sciences, veterinarians, physicians, public health workers, laboratory tech- nicians, and others. The author is under obligation to numerous writers for their valuable contributions which have been incorporated in the text. Special thanks are due Professor L. R. Cleveland, Harvard Uni- versity; Professor R. P. Hall, New York University; Professor H. Kirby, Jr., University of California; Professor L. E. Noland, University of Wisconsin; Professor H. J. Van Cleave, University of Illinois; Professor D. H. Wenrich, University of Pennsylvania; and Professor L. L. Woodruff, Yale University, for their valued criticisms and suggestions. The author further wishes to express his appreciation to Mr. Charles C Thomas, for his patient and kind cooperation which has aided greatly in the completion and ap- pearance of the present work. R.R.K. Urbana, Illinois, U.S.A. July, 1939 Contents Preface ^^ Chapter 1 Introduction ^ Relationship of protozoology to other fields of biological science, p. 5; the history of proto- zoology, p. 9. 2 Ecology 1^ The free-living Protozoa, p. 16; the parasitic Protozoa, p. 23. 3 Morphology ^1 The nucleus, p. 32; the cytosome, p. 36; loco- motor organellae, p. 40; fibrillar structures, p. 51 ;protective or supportive organellae,p. 59; hold-fast organellae, p. 65; the parabasal ap- paratus, p. 66; the blepharoplast or centriole, p. 67; the Golgi apparatus, p. 69; the chon- driosomes, p. 71; the contractile and other vacuoles, p. 73; the chromatophore and asso- ciated organellae, p. 78. 4 Physiology ^^ Nutrition, p. 84; the reserve food matter, p. 94; respiration, p. 96; excretion and secretion, p. 98; movements, p. 101; irritability, p. 109; regeneration, p. 114. 5 Reproduction 11° Nuclear division, p. 118; cytosomic division, p. 137; colony formation, p. 140; asexual re- production, p. 142; sexual reproduction and life-cycles, p. 143. 6 Variation and heredity 162 7 Phylum Protozoa 1^1 Subphylum 1 Plasmodroma 171 Class 1 Mastigophora 171 Subclass 1 Phytomastigina 173 Order 1 Chrysomonadina 173 ix CONTENTS 8 Order 2 Cryptomonadina 184 9 Order 3 Phytomonadina 188 10 Order 4 Euglenoidina 203 Order 5 Chloromonadina 213 11 Order 6 Dinoflagellata 216 12 Subclass 2 Zoomastigina 235 Order 1 Rhizomastigina 235 13 Order 2 Protomonadina 239 14 Order 3 Polymastigina 260 15 Order 4 Hypermastigina 277 16 Class 2 Sarcodina 288 Subclass 1 Rhizopoda 289 Order 1 Proteomyxa 289 17 Order 2 Mycetozoa 296 18 Order 3 Amoebina 304 19 Order 4 Testacea 323 20 Order 5 Foraminifera 344 21 Subclass 2 Actinopoda 356 Order 1 Heliozoa 356 22 Order 2 Radiolaria 367 23 Class 3 Sporozoa 377 Subclass 1 Telosporidia 378 Order 1 Gregarinida 378 24 Order 2 Coccidia 415 25 Order 3 Haemosporidia 434 26 Subclass 2 Acnidosporidia 446 Order 1 Sarcosporidia 446 Order 2 Haplosporidia 448 27 Subclass 3 Cnidosporidia 453 Order 1 Myxosporidia 454 Order 2 Actinomyxidia 468 28 Order 3 Microsporidia 472 Order 4 Helicosporidia 479 29 Subphylum 2 Ciliophora 481 Class 1 Ciliata 481 Subclass 1 Protociliata 483 30 Subclass 2 Euciliata 487 Order 1 Holotricha 487 Suborder 1 Astomata 488 31 Suborder 2 Gymnostomata 496 CONTENTS xi Tribe 1 Prostomata 496 32 Tribe 2 Pleurostomata 517 Tribe 3 Hypostomata 522 33 Suborder 3 Trichostomata 531 34 Suborder 4 Hymenostomata 547 35 Suborder 5 Thigmotricha 560 36 Suborder 6 Apostomea 567 37 Order 2 Spirotricha 573 Suborder 1 Heterotricha 573 38 Suborder 2 Oligotricha 587 39 Suborder 3 Ctenostomata 600 40 Suborder 4 Hypotricha 603 41 Order 3 Chonotricha 614 42 Order 4 Peritricha 616 43 Class 2 Suctoria 628 Author and Subject Index 643 PROTOZOOLOGY Chapter 1 Introduction PROTOZOA are unicellular animals. The body of a protozoan is morphologically a single cell and manifests all character- istics common to the Hving thing. The various activities which make up the phenomena of life are carried on by parts within the body or cell. These parts are comparable with the organs of a metazoan which are composed of a large number of cells grouped into tissues and are called organellae or cell-organs. Thus one sees that the one-celled protozoan is a complete organism some- what unhke the cell of a metazoan, each of which is dependent upon other cells and cannot live independently. From this view- point, certain students of protozoology maintain that the Proto- zoa are non-cellular, and not unicellular, organisms. Dobell (1911) for example, points out that the "cell" is employed to designate 1) the whole protozoan body, 2) a part of an organism and, 3) a potential whole organism (a fertilized egg) which consequently re- sulted in a confused state of knowledge regarding living things, and, therefore, proposed to define a cell as a mass of protoplasm composing part of an organism, and further considered that the protozoan is a non-cellular but complete organism, differently organized as compared with cellular organisms, the Metazoa and Metaphyta. The great majority of protozoologists, however, con- tinue to consider the Protozoa as unicellular animals. Through the processes of organic evolution, they have undergone cyto- logical differentiation and the Metazoa histological differentia- tion. In being unicellular, the Protozoa and the Protophyta are alike. The majority of the Protozoa are quite clearly distinguish- able from the majority of the Protophyta on the basis of nuclear condition, method of nutrition, direction of division-plane, etc. While numerous Protophyta appear to possess scattered nuclear material or none at all, the Protozoa contain at least one nu- cleus. It is generally considered that the binary fission of the Protozoa and the Protophyta is longitudinal and transverse, re- spectively. A great majority of CiUata, however, multiply by transverse division. In general the nutrition of Protozoa is holo- 4 I'ROTOZOOLOGY zoic and of Protophyta, holophytic; but there are large numbers of Protozoa which nourish themselves by holo})hytic method. Thus an absolute and clean-cut separation of the two groups of unicellular organisms is not possible. Haeckel coined the name Protista to include these organisms in a single group, but this is not generally adopted, since it includes undoubted animals and plants, thus creating an equal amount of confusion between it and the animal or the plant. Recently Calkins (1933) excluded chromatophore-bearing Mastigophora from his treatment of Pro- tozoa, thus placing organisms similar in every way, except the presence or absence of chromatophores, in two different groups. This intermingling of characteristics between the two groups of microorganisms shows clearly their close interrelationship and suggests strongly their common ancestry. Although the majority of Protozoa are solitary and the body is composed of a single cell, there are a few forms in which the body is made up of more than one cell. These forms, which are called colonial Protozoa, are well represented by the members of Phytomastigina, in which the individuals are either joined by cytoplasmic threads or embedded in a common matrix. These cells are alike both in structure and in function, although in several genera there may be differentiation of the individuals into reproductive and vegetative cells. Unlike the cells in a metazoan which form tissues, these vegetative cells of colonial Protozoa are not dependent upon other cells; therefore, they do not form any tissue. The reproductive cells produce zygotes through sexual fusion, which subsequently undergo repeated division and may produce a stage comparable with the blastula stage of a meta- zoan, but never reaching the gastrula stage. Thus colonial Pro- tozoa are'only cell-aggregates without histological differentiation and may thus be distinguished from the Metazoa. Between 15,000 and 20,000 species of Protozoa are known to man. From comparatively simple forms such as Amoeba, up to highly complicated organisms as represented by numerous cili- ates, the Protozoa vary exceedingly in their body organization, morphological characteristics, behavior, habitat, etc., which ne- cessitates a taxonomic arrangement for proper consideration as set forth in detail in chapters 7 to 43. INTRODUCTION 5 Relationship of protozoology to other fields of biological science A brief consideration of the relationship of Protozoology to other fields of biology and its possible applications may not be out of place here. Since the Protozoa are single-celled animals manifesting the characteristics common to all living things, they have been studied by numerous investigators with a view to dis- covering the nature and mechanism of various phenomena, the sum-total of which is known collectively as life. Though the in- vestigators generally have been disappointed in the results, in- asmuch as the assumed simphcity of unicellular organisms has proved to be offset by the complexity of their cell-structure, nevertheless any discussion of biological principles today must take into account the information obtained from studies of Pro- tozoa. It is now commonly recognized that adequate information on various types of Protozoa is a prerequisite to a thorough com- prehension of biology and to proper application of biological prin- ciples. Practically all students agree in holding that the higher types of animals have been derived from organisms which existed in the remote past and which probably were somewhat similar to the Protozoa of the present day. Since there is no sharp distinction between the Protozoa and the Protophyta or between the Pro- tozoa and the Metazoa, and since there are intermediate forms between the major classes of the Protozoa themselves, progress in protozoology contributes toward the advancement of our knowledge of the steps by which living things in general evolved. Geneticists have undertaken studies on heredity and variation among Protozoa. "Unicellular animals," wrote Jennings (1909), "present all the problems of heredity and variation in miniature. The struggle for existence in a fauna of untold thousands showing as much variety of form and function as any higher group, works itself out, with ultimate survival of the fittest, in a few days under our eyes, in a finger bowl. For studying heredity and varia- tion we get a generation a day, and we may keep unlimited num- bers of pedigreed stock in a watch glass that can be placed under the microscope." Morphological variations are encountered com- monly in all forms. Whether variation is due to germinal or en- vironmental conditions, is often difficult to determine. The recent discovery of the sex reaction types in Paramecium aurelia (Son- / 6 PROTOZOOLOGY neborn; Kimbell) and in P. hursaria (Jennings) will probably assist in bringing to light many genetic problems of Protozoa which have remained obscure in the past. Parasitic Protozoa are limited to one or more specific hosts. Through studies of the forms belonging to one and the same genus or species, the phylogenetic relation among the host ani- mals may be established or verified. The mosquitoes belonging to the genera Culex and Anopheles, for instance, are known to transmit avian and human Plasmodium respectively. They are further infected by specific microsporidian parasites. For in- stance, Thelohania legeri has been found widely in many species of anopheline mosquitoes only; T. opacita has, on the other hand, been found in culicine mosquitoes, although the larvae of the species belonging to these two genera live frequently in the same body of water. By observing certain intestinal Protozoa in some monkeys, Hegner obtained evidence of the probable phylogenetic relationship between them and other higher mammals. The re- lation of various Protozoa of the wood-roach to those of the ter- mite, as revealed by Cleveland and his associates, gives further proof that the Blattidae and the Isoptera are of the common origin. Study of a particular group of parasitic Protozoa and their hosts may throw light on the geographic condition of the earth in the remote past. The members of the genus Zelleriella are usually found in the colon of the frogs belonging to the family Leptodactylidae. Through an extensive study of these amphibi- ans from South America and Australia, Metcalf found that the species of Zelleriella occurring in the frogs of the two continents are almost identical. He finds it more difficult to conceive of con- vergent or parallel evolution of both the hosts and the parasites, than to assume that there once existed between Patagonia and Australia a land connection over which frogs, containing Zelleri- ella, migrated. Experimental studies of large Protozoa have thrown light on the relation between the nucleus and the cytoplasm, and have furnished a basis for an understanding of regeneration in animals. In Protozoa we find various gradations of nuclear division ranging from a simple amitotic division to a complex process comparable in every detail with the typical metazoan mitosis, so that a great part of our knowledge of cytology is based upon studies of pro- tozoan cells. INTRODUCTION 7 Through the studies of various investigators in the past forty years, it has now become known that numerous parasitic Protozoa occur in man. Entamoeba histolytica, Balantidium coli, and three species of Plasmodium, all of which are pathogenic to man, are ^\'idely distributed throughout the world. In certain restricted areas are found other pathogenic forms, such as Trypanosoma and Leishmania. Since all parasitic Protozoa presumably have originated in free-living forms and since our knowledge of the morphology, physiology and reproduction of the parasitic forms has largely been obtained through studies of the free-living organisms, a general knowledge of the entire phylum is necessary to understand the parasitic forms. Recent studies have further revealed that almost all domestic animals are hosts to numerous parasitic Protozoa, many of which are responsible for serious infectious diseases. Many of the forms found in domestic animals are morphologically indistinguishable from those occurring in man. Balantidium coli is now generally considered as a parasite of swine, and man is its secondary host. Knowledge of protozoan parasites is useful to medical practi- tioners, just as it is essential to veterinarians inasmuch as certain diseases in animals, such as Texas fever, dourine, nagana, black- head, coccidiosis, etc., are caused by protozoans. Sanitary betterment and improvement are fundamental re- quirements in the modern civilized world. One of man's necessi- ties is safe drinking water. The majority of Protozoa live freely in various bodies of water and some of them seem to be responsi- ble, if present in sufficiently large numbers, for giving certain odors to the waters of reservoirs or ponds (p. 95). But these Protozoa which are occasionally harmful are relatively small in number compared with those which are beneficial to man. It is generally understood that bacteria feed on various waste materi- als present in polluted water, but that upon reaching a certain population, they would cease to multiply and would allow the excess organic substances to undergo decomposition. Numerous holozoic Protozoa, however, feed on the bacteria and prevent them from reaching the saturation population. Protozoa thus seem to help indirectly in the purification of the water. Proto- zoology therefore must be considered as an important part of modern sanitary science. Young fish feed extensively on small aquatic organisms, such 8 PROTOZOOLOGY as larvae of insects, small crustaceans, annelids, etc., all of which depend largely upon Protozoa and Protophyta as sources of food supply. Thus the fish are indirectly dependent upon Protozoa as food material. On the other hand, there are numbers of Protozoa which live at the expense of fish. The Myxosporidia are almost exclusively parasites of fish and often cause death to large num- bers of commercially important fishes. Success in fish-culture, therefore, requires among other things a thorough knowledge of Protozoa. Since Russel and Hutchinson suggested some thirty years ago that Protozoa are probably a cause of limitation of the numbers, and therefore the activities of bacteria in the soil and thus tend to decrease the amount of nitrogen which is given to the soil by the nitrifying bacteria, several investigators have brought out the fact that in the soils of temperate climates Protozoa are present commonly and active throughout the year. The exact relation between specific protozoans and bacteria in the soil is a matter which still awaits future investigations, although numerous ex- periments and observations have already been made. All soil in- vestigators should be acquainted with the biology and taxonomy of free-living protozoans. It is a matter of common knowledge that the silkworm and the honey bee suffer from protozoan infection known as micro- sporidiosis. Sericulture in southern Europe suffered great damages in the middle of the nineteenth century because of the "pebrine" disease, caused by the microsporidian, Nosema hombycis. During the first decade of the present century, another microsporidian, Nosema apis, was found to destroy a large number of honey bees. Methods of control have been developed and put into practice so that these microsporidian infections are at present not serious, even though they still occur. On the other hand, other Micro- sporidia are now known to infect certain insects, such as mosqui- toes and lepidopterous pests, which, when heavily infected, die sooner or later. Methods of destruction of these insects by means of chemicals are more and more used, but attention should also be given to utilization of the parasitic Protozoa and Protophyta for this purpose. While the majority of Protozoa lack permanent skeletal struc- tures and their fossil forms are unknown, there are at least two large groups in the Sarcodina which possess conspicuous shells INTRODUCTION 9 and which are found as fossils. They are Foraminifera and Ra- diolaria. From early palaeozoic times down to the present day, the carbonate of lime which makes up the skeletons of numerous Foraminifera has been left embedded in various rock strata. Al- though there is no distinctive foraminiferan fauna characteristic of a given geologic period, there are certain peculiarities of fossil Foraminifera which distinguish one formation from the other. From this fact one can understand that knowledge of foraminifer- ous rocks is highly useful in checking up logs in well drilling. The skeletons of the Radiolaria are the main constituent of the ooze of littoral and deep-sea regions. They have been found abun- dantly in siliceous rocks of the palaeozoic and the mesozoic, and are also identified with the clays and other formations of the miocene. Thus knowledge of these two orders of Sarcodina, at least, is essential for the student of geology and paleontology. The history of protozoology Aside from a comparatively small number of large forms. Pro- tozoa are unobservable with the naked eye, so that we can easily understand why they were unknown prior to the invention of the microscope. Antony van Leeuwenhoek (1632-1723) is commonly recognized as the father of protozoology. Grinding lenses himself, Leeuwenhoek made more than four hundred microscopes, includ- ing one which, it is said, had a magnification of 270 times (Hart- ing). Among the many things he discovered were various Proto- zoa. According to Dobell (1932), Leeuwenhoek saw for the first time in history, free-living Protozoa in fresh water in 1674. Among them, he observed bodies "green in the middle, and before and behind white," w^hich Dobell interprets were Euglena. Between 1674 and 1716 he apparently observed numerous microscopic or- ganisms which he communicated to the Royal Society of London and which, as Dobell considered, were Vorticella, Stylonychia, Carchesium, Volvox, Haematococcus, Coleps, Kerona, Antho- physa, Elphidium, Polytoma, etc. According to Dobell, Huy- gens gave in 1678 "unmistakable descriptions of Chilodon(ella), Paramecium, Astasia and Vorticella, all found in infusions." Colpoda was seen by Bouonanni (1691) and Harris (1696) re- discovered Euglena. In 1718 there appeared the first treatise on microscopic organisms, particularly of Protozoa, by Joblot who emphasized the non-existence of abiogenesis by using boiled hay- 10 PROTOZOOLOGY infusions in which no Infusoria developed without exposure to the atmosphere. This experiment confirmed that of Redi who, twenty years before, had made his well-known experiments by excluding flies from meat. Joblot illustrated, according to Woodruff (1937), Paramecium, the slipper animalcule, with the first identifiable figure. Trembly (1715) studied division in some ciliates, including probably Paramecium, which generic name was coined by Hill in 1752. Noctiluca was first described by Baker (1753). Rosel (1755) observed an amoeba, possibly Amoeba proteus or an allied form, which he called "der kleine Proteus," and also Vorticella, Stentor, and Volvox. Ledermiiller is said to have coined the term "Infusoria" in 1763 (Biitschli). By using the juice of geranium, Ellis (1770) caused the extrusion of the 'fins' (trichocysts) in Paramecium. Eichhorn (1783) observed the helio- zoan, Actinosphaerium, which now bears his name. O. F. Miiller described Ceratium a little later and published two works on the Infusoria (1786). Although he included unavoidably some Meta- zoa and Protophyta in his monographs, some of his descriptions and figures of Ciliata were so well done that they are of value even at the present time. At the beginning of the nineteenth century the cyclosis in Paramecium was brought to light by Gruithuisen. Goldfuss (1817) coined the term "Protozoa," including in it the coelente- rates. Ten years later there appeared d'Orbigny's systematic study of the Foraminifera, which he considered as microscopical cephalopods. In 1828 Ehrenberg began publishing his observa- tions on Protozoa and 1838 he summarized his contributions in Die Infusionsthierchen als vollkommene Organismen, in which he diagnosed genera and species so well that many of them still hold good. Ehrenberg excluded Rotatoria and Cercaria from Infu- soria. Through the studies of Ehrenberg the number of known Protozoa increased greatly; he, however, proposed the term "Polygastricha," under which he placed Mastigophora, Rhizo- poda, Ciliata, Suctoria, desmids, etc., since he believed that the food vacuoles present in them were stomachs. This hypothesis became immediately the center of controversy, which inciden- tally, together with the then-propounded cell theory and improve- ments in microscopy, stimulated researches on Protozoa. Dujardin (1835) took pains in studying the protoplasm of various Protozoa and found it ahke in all. He named it "sarcode." INTRODUCTION 11 In 1841 he published an extensive monograph of various Protozoa which came under his observations. The term "Rhizopoda" was coined by this investigator. The commonly used term "proto- plasm" was coined by Purkinje in 1840. The Protozoa was given a distinct definition by Siebold in 1845, as follows: "Die Thiere, in welchen die verschiedenen Systeme der Organe nicht scharf ausgeschieden sind, und deren unregelmassige Form und einfache Organization sich auf eine Zelle reduzieren lassen." Siebold sub- divided Protozoa into Infusoria and Rhizopoda. The sharp dif- ferentiation of Protozoa as a group certainly inspired numerous microscopists. As a result, various students brought forward several group names, such as Radiolaria (J. Miiller, 1858), Ciliata (Perty, 1852), Flagellata (Cohn, 1853), Suctoria (Claparede and Lachmann, 1858), Heliozoa, Protista (Haeckel, 1862, 1866), Mastigophora (Diesing, 1865), etc. Of Suctoria, Stein failed to see the real nature (1849), but his two monographs on CiUata and Mastigophora (1854, 1859-1883) contain concise descriptions and excellent illustrations of numerous species. Haeckel (1873), who went a step further than Siebold by distinguishing between Pro- tozoa and Metazoa, devoted ten years to his study of Radiolaria, especially those of the Challenger collection, and described in his celebrated monographs more than 4000 species. In 1879 the first comprehensive monograph on the Protozoa of North America was put forw^ard by Leidy under the title of Freshwater Rhizopods of North America, which showed the wide distribution of many known forms of Europe and revealed a number of new and interesting forms. This w^ork was followed by Stokes' The freshwater Infusoria of the United States, which ap- peared in 1888. Blitschli (1880-1889) estabHshed Sarcodina and made an excellent contribution to the taxonomy of the then- known species of Protozoa, which is still considered as one of the most important works on general protozoology. The painstaking researches by Maupas, on the conjugation of ciliates, corrected erroneous interpretation of the phenomenon observed by Balbi- ani some thirty years before and gave impetus to a renewed cyto- logical study of Protozoa. The variety in form and structure of the protozoan nuclei became the subject of intensive studies by several cytologists. Weismann (1881) put into words the immor- tality of the Protozoa. Schaudinn contributed much toward the cytological and developmental studies of Protozoa. 12 PROTOZOOLOGY In the first year of the present century, Calkins in the United States and Doflein in Germany wrote modern textbooks on pro- tozoology deahng with the biology as well as the taxonomy. Cal- kins initiated the so-called isolation pedigree culture of ciHates in order to study the physiology of conjugation and other phe- nomena connected with the life-history of the ciHates. The appli- cation of this method has been found very popular in recent years. Today the Protozoa are more and more intensively and exten- sively studied from both the biological and the parasitological sides, and important contributions appear continuously. Since all parasitic Protozoa appear to have originated in free-living forms, the comprehension of the morphology, physiology, and develop- ment of the latter group obviously is fundamentally important for a thorough understanding of the former group. Compared with the advancement of our knowledge on free- living Protozoa, that on parasitic forms has been very slow. This is to be expected, of course, since the vast majority of them are so minute that the discovery of their presence has been made possible only through improvements in the microscope and in technique. Here again Leeuwenhoek seems to have been the first to ob- serve a parasitic protozoan, for he observed, according to Dobell, in the fall of 1674, the oocysts of the coccidian, Eimeria stiedae, in the contents of the gall bladder of an old rabbit; in 1681, Giardia intestinalis in his own diarrhcsic stools; and in 1683, Opalina and Nyctotherus in the gut contents of frogs. There is no record of anyone having seen Protozoa living in other organ- isms until 1828, when Dufour's account of the gregarine from the intestine of coleopterous insects appeared. Some ten years later, Hake rediscovered the oocysts of Eimeria stiedae. A flagellate was observed in the blood of salmon by Valentin in 1841, and the frog trypanosome was discovered by Gluge and Gruby (1842), the latter author creating the genus Trypanosoma for it. The gregarines were a httle later given attention by Siebold (1839), Kolliker (1848) and Stein (1848). The year 1849 marks the first record of an amoeba being found in man, for Gros then observed Entamoeba gingivalis in the human mouth. Five years later, Davaine found in the stools of cholera patients two flagel- lates (Trichomonas and Chilomastix). Kloss in 1855 observed the INTRODUCTION 13 coccidian, Klossia helicina, in the excretory organ of Helix and Eimer (]870) made an extensive study of Coccidia occurring in various animals. Balantidium coli was discovered by Malm- sten in 1857. Lewis in 1870 observed Entamoeba coli in India, and Losch in 1875 found Entamoeba histolytica in Russia. At the be- ginning of the last century, an epidemic disease, pebrine, of the silkworm appeared in Italy and France, and a number of biolo- gists became engaged in its investigation. Foremost of all, Pas- teur (1870) made an extensive report on the nature of the causa- tive organism, now known as Nosema bombycis, and also on the method of control and prevention. Perhaps this is the first scien- tific study of a parasitic protozoan to result in an effective prac- tical method of control of its infection. Lewis observed in 1878 an organism which is since known as Trypanosoma lewisi in the blood of rats. In 1879 Leuckart created the group ''Sporozoa," including in it the gregarines and coccidi- ans. The groups under Sporozoa were soon definitely designated. They are Myxosporidia (Biitschli, 1881), Microsporidia (Balbi- ani, 1882) and Sarcosporidia (Balbiani, 1882). Parasitic protozoology received a far-reaching stimulus when Laveran (1880) discovered the malarial parasite in the human blood. Smith and Kilborne (1893) demonstrated that the Babe- sia of the Texas fever of cattle in the southern United States was transmitted by cattle ticks from host to host, and thus brought to light for the first time the close relationship which exists be- tween an arthropod and a parasitic protozoan. Two years later, Bruce discovered Trypanosoma brucei in the blood of horses and cattle suffering from "nagana" disease in Africa, and in the fol- lowing year he showed by experiments that the tsetse fly trans- mits the trypanosome from host to host. Studies of malarial dis- eases continued and several important contributions appeared. Golgi (1886, 1889) studied the schizogony and its relation to the occurrence of fever and was able to distinguish two types of fever. MacCallum (1897-1898) found in the United States the union of a microgamete and a macrogamete of Haemoproteus of birds. Almost at the same time, Schaudinn and Siedlecki (1897) showed that anisogamy results in the production of zygotes in Coccidia. The latter author published later correct observations on the Ufe-cycle of Coccidia (1898, 1899). Ross (1898) showed how Plasmodium praecox was carried by 14 PROTOZOOLOGY Culex fatigans and described its life-cycle. Since that time several investigators have brought to light imi)ortant observations con- cerning the biology and development of these organisms and their relation to man. In the present century, Forde and Dutton (1901) observed that the sleeping sickness in Africa is due to an infection by Trypanosoma gamhiense. In 1903 Leishman and Donovan recognized Leishmania of "kala-azar." Artificial cultivation of bacteria had contributed toward a very rapid advancemtnt in bacteriology, and it was natural, as the number of known parasitic Protozoa rapidly increased, that at- tempts to cultivate them in vitro should be made. Musgrave and Clegg (1904) cultivated, on bouillon-agar, small free-living amoe- bae from old fecal matter. In 1905 Novy and McNeal cultivated successfully the trypanosome of birds in blood-agar medium, which remained free from bacterial contamination and in which the organisms underwent multiplication. Almost all species of Trypanosoma and Leishmania have since been cultivated in a similar manner. This serves for detection of a mild infection and also identification of the species involved. It was found, further, that the changes which these organisms underwent in the culture media were imitative of those that took place in the invertebrate host, thus contributing toward the life-cycle studies of them. Bass (1911), and Bass and Johns (1912) demonstrated that Plasmodium of man could be cultivated in vitro for a few genera- tions. During and since the World War, it became known that numerous intestinal Protozoa of man are widely present through- out the tropical, subtropical and temperate zones. Taxonomic, morphological and developmental studies on these forms have therefore appeared in an enormous number. Cutler (1918) seems to have succeeded in cultivating Entamoeba histolytica, though his experiment was not repeated by others. Barret and Yarborough (1921) cultivated Balantidium coli and Boeck (1921) also culti- vated Chilomastix mesnili. Boeck and Drbohlav (1925) succeeded in cultivating Entamoeba histolytica, and their work was repeated and improved upon by several investigators. While the cultiva- tion has not yet thrown much light on this and similar amoebae, it reveals certain evidences that there is no sexual reproduction in these amoebae. Since that time, almost all intestinal Protozoa of both vertebrates and invertebrates have been cultivated by nu- merous investigators. INTRODUCTION 15 References BiJTSCHLi, O. 1887-1889 Bronn's Klassen und Ordnungen des Thier-reichs. Vol. 1, Part 3. Calkins, G. N. 1933 The biology of the Protozoa. 2 ed. Phila- delphia. Cole, F. J. 1926 The history of protozoology . London. DoBELL, C. 1911 The principles of protistology. Arch. f. Protis- tenk., Vol. 23. 1932 Antony van Leeuwenhoek and his "little animals." New York. DoFLEiN, F. and E, Reichenow. 1929 Lehrbuch der Protozoen- kunde. 5 ed. Jena. NoEDENSKiOLD, E. 1928 The history of biology. New York. Woodruff, L. L. 1937 Louis Joblot and the Protozoa. Sci. Monthly, Vol. 94. Chapter 2 Ecology WITH regard to their habitats, the Protozoa may be divided into free-Uving forms and those Hving on (epizoic) or in (cndozoic) other organisms. The free-living Protozoa The vegetative or trophic stage of free-hving Protozoa have been found in every type of fresh and salt water, soil and decay- ing organic matter. In the circumpolar regions or at extremely high altitudes, certain Protozoa occur at times in fairly large numbers. The factors, which influence their distribution in a giv- en body of water, are temperature, light, chemical composition, acidity, kind and amount of food, and degree of adaptabihty of the individual protozoans to various environmental changes. Their early appearance as living organisms, their adaptability to various habitats and their capacity to remain viable in encysted condition possibly account for the wide distribution of the Pro- tozoa throughout the world. The common free-living amoebae, numerous testaceans and others, to mention a few, of fresh wa- ters, have been observed in innumerable parts of the world. Temperature. The majority of Protozoa are able to live only within a small range of temperature variation, although in the encysted state they can withstand a far greater temperature fluctuation. The lower Hmit of the temperature is marked by the freezing of the protoplasm, and the upper limit by the destructive chemical change within the body. The temperature toleration seems to vary among different species of Protozoa; and even in the same species under different conditions. For example. Chalk- ley (1930) placed Paramecium caudatum in 4 culture media (bal- anced saline, saline with potassium excess, saline with calcium excess, and saline with sodium excess), all with pH from 5.8 or 6 to 8.4 or 8.6, at 40°C. for 2-16 minutes and found that 1) the re- sistance varies with the hydrogen-ion concentration, maxima ap- pearing in the alkaline and acid ranges, and a minimum at or near about 7.0; 2) in a balanced saline, and in saline with an excess of sodium or potassium, the alkaline maximum is the higher, while 16 ECOLOGY 17 in saline with an excess of calcium, the acid maximum is the higher; 3) in general acidity decreases and alkalinity increases re- sistance; and 4) between pH 6.6 and 7.6, excess of potassium de- creases resistance and excess of calcium increases resistance. Glaser and Coria (1933) cultivated Paramecium caudatum on dead yeast free from living organisms at 20-28°C. (optimum 25°C.) and noted that at 30°C. the organisms were killed. Doudoroff (1936), on the other hand, found that in P. multimicronucleata its resistance to raised temperature was low in the presence of food, but rose to a maximum when the food was exhausted, and there was no appreciable difference in the resistance between single and conjugating individuals. The thermal waters of hot springs have been known to contain living organisms including Protozoa. Glaser and Coria obtained from the thermal springs of Virginia, several species of Mastigo- phora, Ciliata, and an amoeba which were living in the water, the temperature of which was 34-36°C., but did not notice any pro- tozoan in the water which showed 39-4 1°C. Uyemura and his co-workers made a series of studies on Protozoa living in various thermal waters of Japan, and reported that many species lived at unexpectedly high temperatures. Some of the Protozoa ob- served and the temperatures of the water in which they were found are as follows: Amoeba sp., Vahlkampfia Umax, A. radiosa, 30-51°C.; Amoeba verrucosa, Chilodonella sp., Lionotus fasciola, Paramecium caudatum, 36-40°C.; Oxytricha fallax, 30-56°C. Under experimental conditions, it has been shown repeatedly that many protozoans become accustomed to a very high tem- perature if the change be made gradually. Dallinger and Drysdale showed a long time ago that Tetramitus rostratus and two other species of flagellates could be cultivated in temperatures ranging from 16° to 70°C. In nature, however, the thermal death point of most of the free-living Protozoa appears to lie between 36° and 40°C. and the optimum temperature, between 16° and 25°C. On the other hand, the low temperature seems to be less detri- mental to Protozoa than the higher ones. Many protozoans have been found to live in water under ice, and several haematochrome- bearing Phytomastigina undergo vigorous multiplication on snow in high altitudes, producing the so-called ''red snow." Efimoff (1924) demonstrated that Paramecium, Frontonia, Colpidium and other ciliates die quickly at — 4°C., but by a quick and short 18 PROTOZOOLOGY overcooling (not lower than — 9°C.) no injury is brought about. At 0°C., Paramecium was able to multiply once in about 13 days. Wolfson (1935) studied Paramecium sp. in gradually descending subzero-temperature, and observed that as the temperature de- creases the organisms often swim backward, its bodily move- ments cease and its cilia finally stop beating. If the low tempera- ture exposure has not been of sufficient intensity or duration, warming induces a resumption of movement. Kept for 10-15 minutes at 10°C., the organism increases its body volume and be- comes rounded, from which condition it may recover if the tem- perature rises, but which otherwise is followed rapidly by a com- plete disintegration. When the water in which the ciliates are kept freezes, the organisms do not survive. Light. In the Phytomastigina which include chromatophore- bearing flagellates, the sun light is essential to photosynthesis (p. 92). The sun light further plays an important role in those protozoans which are dependent upon chromatophore-possessing organisms as chief source of food supply. Hence the light is an- other factor concerned with the distribution of free-living pro- tozoans in the water. Chemical composition of water. The chemical nature of the water is another important factor which influences the very exist- ence of Protozoa in a given body of water. Different Protozoa show different morphological as well as physiological character- istics. As numerous cultural experiments indicate that individual protozoan species requires a certain chemical composition of the water in which it is cultivated under experimental conditions, al- though this may be more or less variable among different forms (Needham et al.). In their "biological analysis of water" Kolkwitz and Marsson (1908, 1909) distinguished four types of habitats for many aquatic plant, and a few animal, organisms, which were based upon the kind and amount of inorganic and organic matter and amount of oxygen present in the water: namely, katharobic, oligosapro- bic, mesosaprobic, and polysaprobic. Katharobic protozoans are those which live in mountain springs, brooks, or ponds, the water of which is rich in oxygen, but free from organic matter. Oligosa- probic forms are those that inhabit waters which are rich in min- eral matter, but in which no purification processes are taking place. Many Phytomastigina, various testaceans and many cih- ECOLOGY 19 ates, such as Frontonia, Lacrymaria, Oxytricha, Stylonychia, Vorticella, etc., inhabit such waters. Mesosaprobic protozoans live in waters in which active oxidation and decomposition of organic matter are taking place. The majority of freshwater pro- tozoans belong to this group : namely, numerous Phytomastigina, Hehozoa, Zoomastigina, and all orders of Cihata. Finally poly- saprobic forms are capable of living in waters which, because of dominance of reduction and cleavage processes of organic matter, contain at most a very small amount of oxygen and are rich in carbonic acid gas and nitrogenous decomposition products. The black bottom shme contains usually an abundance of ferrous sul- phide and other sulphurous substances. Lauterborn (1901) called this sapropelic. Examples of polysaprobic protozoans are Pelo- myxa palustris, Eughjpha alveolata, Pamphagus armatus, Mastig- amoeba, Trepomonas agilis, Hexamita inflata, Rhynchomonas nasuta, Heteronema acus, Bodo, Cercomonas, Dactylochlamys, Ctenostomata, etc. The so-called "sewage organisms" abound in such habitat (Lackey). Certain free-hving Protozoa which inhabit waters rich in de- composing organic matter are frequently found in the fecal mat- ter of various animals. Their cysts either pass through the aU- mentary canal of the animal unharmed or are introduced after the feces are voided, and undergo development and multiplica- tion in the fecal infusion. Such forms are collectively called copro- zoic Protozoa. The coprozoic protozoans grow easily in suspension of old fecal matter which are rich in decomposed organic matter and thus show a strikingly strong capacity of adapting themselves to conditions different from those of the water in which they normally live. Some of the Protozoa which have been referred to as coprozoic and which are mentioned in the present work are, as follows: Scytomonas pusilla, Rhynchomonas nasuta, Cercomonas longicauda, C. crassicauda, Trepomonas agilis, Dimastig amoeba gruheri, Hartmanella hyalina, Chlamydophrys stercorea and Tilli- na magna. As a rule, the presence of sodium chloride in the sea water pre- vents the occurrence of the large number of fresh-water inhabi- tants. Certain species, however, have been known to live in both fresh and brackish or salt water. Among the species mentioned in the present work, the following species have been reported to oc- cur in both fresh and salt waters: Mastigophora: Amphidinium 20 PROTOZOOLOGY lacustris, Ceratium hirundinella; Sarcodina: Lieberkuhnia wag- neri] Ciliata: Mesodinium pulex, Prorodon discolor, Lacrymaria olor, Amphileptus claparedei, Lionotus fasciola, Nassula aurea, Trochilioides recta, Chilodonella cucullulus, Trimyema compressum, Paramecium calkinsi, Colpidium campylum, Platynematum sociale, Cinetochilum margaritaceum, Pleuronema coronatum, Caenomorpha medusula, Spirostomum minus, S. teres, Climacostomum virens, and Thuricola folliculata; Suctoria: Metacineta mystacina, En- dosphaera engelmanni. It seems probable that many other protozoans are able to live in both fresh and salt water, judging from the observations such as that made by Finley (1930) who subjected some fifty species of freshwater Protozoa of Wisconsin to various concentrations of sea water, either by direct transfer or by gradual addition of the sea water. He found that Bodo uncinatus, Uronema marina, Pleu- ronema jaculans and Colpoda aspera are able to live and reproduce even when directly transferred to sea water, that Amoeba verru- cosa, Euglena, Phacus, Monas, Cyclidium, Euplotes, Lionotus, Paramecium, Stylonychia, etc., tolerate only a low salinity when directly transferred, but, if the sahnity is gradually increased, they live in 100 per cent sea water, and that Arcella, Cyphoderia, Aspidisca, Blepharisma, Colpoda cucullus, Halteria, etc., could not tolerate 10 per cent sea water even when the change was gradual. Finley noted no morphological changes in the experi- mental protozoans which might be attributed to the presence of the salt in the water, except Amoeba verrucosa, in which certain structural and physiological changes were observed as follows: as the salinity increased, the pulsation of the contractile vacuole became slower. The body activity continued up to 44 per cent sea water and the vacuole pulsated only once in 40 minutes, and after systol, it did not reappear for 10-15 minutes. The organism became less active above this concentration and in 84 per cent sea water the vacuole disappeared, but there was still a tendency to form the characteristic ridges, even in 91 per cent sea water, in which the organism was less fan-shaped and the cytoplasm seemed to be more viscous. Yocom (1934) found that Euplotes patella was able to live normally and multiply up to 66 per cent of sea water; above that concentration no division was noticed, though the organism lived for a few days in up to 100 per cent salt water, and Paramecium caudatum and Spirostomum amhigu- ECOLOGY 21 um were less adaptive to salt water, rarely living in 60 per cent sea water. Hydrogen-ion concentration. Closely related to the chemical composition is the hydrogen-ion concentration (pH) of the water which influences the distribution of Protozoa. The hydrogen-ion concentration of freshwater bodies vary a great deal between highly acid bog waters in which various testaceans may frequent- ly be present, to highly alkaline water in which such forms as Acanthocystis, Hyalobryon, etc., occur. In standing deep fresh water, the bottom region is often acid because of the decomposing organic matter, while the surface water is less acid or slightly alkaline due to the photosynthesis of green plants which utilize carbon dioxide. Several investigators have recently made obser- vations on the pH range of the water or medium in which certain protozoans live, grow, and multiply, which data are collected in a table on page 22. Seemingly various Protozoa require a definite pH value in order to carry on maximum metabolic activities. As a matter of fact, Pringsheim, Hall, Loefer, Johnson, and others, found that sodium acetate may increase or decrease the growth rate of various Phytomastigina subject to the hydrogen-ion concentration of the culture media. Food. The kind and amount of food available in a given body of water also controls the distribution of Protozoa. The food is ordinarily one of the deciding factors of the number of Protozoa in a natural habitat. Species of Paramecium and many other holozoic protozoans cannot live in waters in which bacteria or mi- nute protozoans do not occur. If other conditions are favorable, then the greater the number of food bacteria, the greater the number of these protozoans. Didinium nasutum feeds almost ex- clusively on Paramecium, hence it cannot live in the absence of the latter ciliate. Euryphagous protozoans are widely distributed and stenophagous forms are limited in their distribution. Some protozoans inhabit soil of various types and localities. Under ordinary circumstances, they occur near the surface, their maximum abundance being found at a depth of about 10-12 cm. (Sandon, 1927). It is said that a very few protozoans occur in the subsoil. Here also one notices a very wide geographical distribu- tion of apparently one and the same species. For example, San- don found Amoeba proteus in samples of soil collected from Green- 22 PROTOZOOLOGY pH range of Protozoa medium in which Optimum Observers growth occurs range In bacteria-free cultures Euglena gracilis 3.5-9.0 — Dusi 3.0-7.7 6.7 Alexander 3.9-9.9 6.6 Jahn E. deses 6.5-8.0 7.0 Dusi 5.3-8.0 7.0 Hall E. pisciformis 6.0-8.0 6.5-7.5 Dusi 5.4-7.5 6.8 Hall Chilomonas Paramecium 4.1-8.4 4.9;7.0 Loefer Chlorogonium euchlorutn 4.8-8.7 7.1-7.5 Loefer C. elongaturn Colpidium striatum 4.0-8.9 5.5-5.7 Elliott C. campylum 4.0-8.9 6.5 Elliott Glaucoma pyriformis 4.0-8.9 4.8-5.3 Johnson G. ficaria 4.0-9.5 5.1-6.0 Johnson Paramecium bursaria 5.3-8.0 6.7-6.8 Loefer In cultures containing bacteria Carteria obtusa — 3.5-4.5 Wermel Acanthocystis aculeata 7 .4 or above 8.1 Stern Paramecium caudatum 5.3-8.2 7.0 Darby 6.0-9.5 7.0 Morea P. aurelia 5.7-7.8 6.7 Morea 5.9-8.2 — Phelps P. multimicronucleata 4.8-8.3 7.0 Jones P. sp. — 7.8-8.0 Saunders 7.0-8.5 7.8-8.0 Pruthi Colpidiuvi sp. 6.0-8.5 — Pruthi Colpoda cucullus 5.5-9.5 6.5;7.5 Morea Holophyra sp. 6.5-7.4 — Pruthi Plagiopyla sp. 6.9-7.5 — Pruthi Amphilepius sp. 6.8-7.5 7.1-7.3 Pruthi Spirostomum ambiguum 6.8-7.5 7.4 Saunders 5. sp. 6.5-8.0 7.5 Morea Blepharisma xmdulans — 6.5 Moore Gastrostyla sp. 6.0-8.5 — Pruthi Stylonychia pustulata 6.0-8.0 6.7;8.0 Darby land, Tristan da Cimha, Goiigh Island, England, Mauritius, Africa, India, and Argentina. This amoeba is known to occur in various parts of North America, Europe, Japan, and Australia. The majority of Testacea inhabit moist soil in abundance. Sandon observed Trinema enchelys in the soils of Spitzbergen, ECOLOGY 23 Greenland, England, Japan, Australia, St. Helena, Barbados, Mauritius, Africa, and Argentina. The parasitic Protozoa Some Protozoa belonging to all groups live on or in other or- ganisms. The Sporozoa are made up exclusively of such forms. The relationships between the host and the protozoan differ in various ways, which make the basis for distinguishing the associa- tions into three types as follows : commensalism, symbiosis, and parasitism. The commensalism is an association in which an organism, the commensal, is benefited, while the host is neither injured nor benefited. Depending upon the location of the commensal in the host body, the ectocommensalism or endocommensalism is used. The ectocommensalism is often represented by Protozoa which may attach themselves to any aquatic animals that inhabit the same body of water, as shown by various species of Chonotricha, Peritricha, and Suctoria. In other cases, there is a definite rela- tionship between the commensal and the host. For example, Kerona polyporum is found on various species of Hydra, and the ciliates placed in Thigmotricha (p. 560) are inseparably associated with certain species of the mussels. The endocommensalism is often difficult to distinguish from the endoparasitism, since the effect of the presence of the com- mensal upon the host cannot be easily understood. On the whole, the protozoans which live in the lumen of the alimentary canal of the host may be looked upon as endocommensals. These proto- zoans use undoubtedly part of the food material which could be used by the host, but they do not invade the host tissue. As examples of endocommensals may be mentioned: Endamoeba hlattae, Lophomonas hlattaru7n, L. striata, Nyctotherus ovalis, etc., of the cockroach; Entamoeba coli, lodamoeba butschlii, Endolimax nana, Dientamoeba fragilis, Chilomastix mesnili, Giardia intesti- nalis, etc., of the human intestine; numerous species of Proto- ciliata of Anura, etc. Because of the difficulties mentioned above, the term parasitic Protozoa, in its broad sense, includes the commensals also. The symbiosis on the other hand is an association of two species of organisms which is of mutual benefit. The cryptomonads be- longing to Chrysidella ("zooxanthellae") containing yellow or 24 PROTOZOOLOGY brown chromatophores, which Uvc in Foraminifera and Radio- laria, and certain algae belonging to Chlorella ("zoochlorellae") containing green chromatophores, which occur in some fresh- water protozoans, such as Paramecium bursaria, Stentor amethys- tinus, etc., are looked upon as holding symbiotic relationship with the respective protozoan host. Several species of the highly in- teresting Hypermastigina, which are present commonly and abundantly in various species of the termite and the woodroach Cryptocercus,have been demonstrated by Cleveland to digest the cellulose material which makes up the bulk of wood-chips the host animals take in and to transform it into glycogenous sub- stances which are used partly by the host insects. If deprived of these flagellates by being subjected to oxygen under pressure or to a high temperature, the termites lose the flagellates and die, even though the intestine is filled with wood-chips. If removed from the gut of the termite, the flagellates die. Thus the associa- tion here may be said to be an absolute symbiosis. The parasitism is an association in which one organism (the parasite) lives at the expense of the other (the host). Here also ectoparasitism and endoparasitism occur, although the former is not commonly found. Hydramoeha hydroxena (p. 321) feeds on ectodermal cells of Hydra which, according to Reynolds and Looper, die on an average in 6.8 days as a result of the infection and the amoebae disappear in from 4 to 10 days if removed from a host Hydra. Costia necatrix (p. 264) often occurs in an enormous number, attached to various freshwater fishes especially in an aquarium, by piercing through the epidermal cells and ajipears to disturb the normal functions of the host tissue. Ichthyophthirius multifiliis (p. 504), another ectoparasite of freshwater fishes, goes further by completely burying themselves in the epidermis and feeds on the host's tissue cells and, not infrequently, contributes toward the cause of the death of the host fishes. The endoparasites absorb by osmosis the vital body fluid, feed on the host cells or cell-fragments by pseudopodia or cytostome, or enter the host tissues or cells themselves, living on the cytoplasm or in some cases on the nucleus. Consequently they bring about abnormal or pathological conditions upon the host which often succumbs to the infection. Endoparasitic Protozoa of man are Entamoeba histolytica, Balantidium coli, species of Plasmodium and Leishmania, Trypanosoma gambiense, etc. The Sporozoa, as ECOLOGY 25 was stated before, are without exception coelozoic, histozoic, or cytozoic parasites. Because of their modes of Uving, the endoparasitic Protozoa cause certain morphological changes in the cells, tissues, or organs of the host. The active growth of Entamoeba histolytica in the glands of the colon of the victim, produces slightly raised nodules first which develop into abscesses and the ulcers formed by the rupture of abscesses, may reach 2 cm. or more in diameter, com- pletely destroying the tissues of the colon wall. Similar patho- logical changes are also noticed in the case of infection by Bala?itidium coli. In Leishmania donovani, the victim shows an increase in number of the large macrophages and mononuclears and also an extreme enlargement of the spleen. Trypanosoma cruzi brings about the degeneration of the infected host cells and an abundance of leucocytes in the infected tissues, followed by an increase of fibrous tissue. T. gamhiense, the causative organ- ism of African sleeping sickness, causes enlargement of lymphatic glands and spleen, followed by changes in meninges and an in- crease of cerebro-spinal fluid. Its most characteristic changes are the thickening of the arterial coat and the round-celled infiltra- tion around the blood vessels of the central nervous system. Von Brand's (1938) summary of the carbohydrate metabolism of the pathogenic trypanosomes tends to show that the sugar is only partially oxidized in the presence of oxygen and that the carbo- hydrate metabolism of the infected host is disturbed, as shown mainly by the unbalanced condition of the blood sugar, by lower- ing of the glycogen reserves, and by reduced ability to build glycogen from sugar. Malarial infection is invariably accom- panied by an enormous enlargement of the spleen ("spleen index"); the blood becomes watery; the erythrocytes decrease in number; the leucocytes, subnormal; but mononuclear cells in- crease in number; pigment granules which are set free in the blood plasma at the time of merozoite-liberation are engulfed by leucocytes; and enlarged spleen contains large amount of pig- ments which are lodged in leucocytes and endothelial cells. In Plamodium falciparum, the blood capillaries of brain, spleen and other viscera may completely be blocked by infected erythro- cytes. In Myxosporidia which are either histozoic or coelozoic para- sites of fishes, the tissue cells that are in direct contact with highly 26 PROTOZOOLOGY enlarged parasites, undergo various morphological changes. For example, the circular muscle fibers of the small intestine of Pomoxis sparoides, which surround Myxobolus intestinalis, a myxosporidian, become modified a great deal and turn about 90° from the original direction, due undoubtedly to the stimulation exercised by the myxosporidian parasite (Fig. 1, a). In the case of another myxosporidian, Thelohanellus notatus, the connective tissue cells of the host fish surrounding the protozoan body, trans- ?^fl^^^S^SS!f:^^. ks^-yy--- Fig. 1. Histological changes in host fish caused by myxosporidian, infection, X1920 (Kudo), a, portion of a cyst of Mijxoholus intestinalis, surrounded by peri-intestinal muscle of the black crappie; b, part of a cyst of Thelohanellus notatus, enveloped by the connective tissue of the blunt-nosed minnow. form themselves into "epithelial cells" (Fig. 1, 6), a state com- parable to the formation of the ciliated epithelium from a layer of fibroblasts lining a cyst formed around a piece of ovary in- planted into the adductor muscle of Pecten as observed by Drew (1911). Practically all Microsporidia are cytozoic, and the infected cells become hypertrophied enormously, producing in one genus the so-called Glugea cysts (Fig. 220). In many cases, the hyper- trophy of the nucleus of the infected cell is far more conspicuous than that of the cytoplasm (Fig. 218). Information concerning ECOLOGY 27 toxic substances produced by parasitic Protozoa is meager. Sarcosporidia appear to produce a certain toxic substance which, when injected in the blood vessel, is highly toxic to experimental animals. This was named sarcocystine (Laveran and Mesnil) or sarcosporidiotoxin (Teichmann and Braun). As in bacterial in- fection, the reaction and resistance of the host to protozoan in- fection apparently differ among different individuals. Taliaferro demonstrated that there occur in the blood of animals suffering from trypanosomiasis or malaria, certain agents which would either inhibit the rate of multiplication of the parasites or destroy the parasites themselves. With regard to the origin of parasitic Protozoa, it is generally agreed among biologists that the parasite in general evolved from the free-living form. The protozoan association with other organ- isms was begun when various protozoans which lived attached to, or by crawling on, submerged objects happened to transfer themselves to various invertebrates which occur in the same water. These Protozoa benefit by change in location as the host animal moves about, and thus enlarging the opportunity to ob- tain a continued supply of food material. Examples of such ectocommensals abound everywhere. The ectocommensalism may next lead into ectoparasitism as in the case of Costia or Hydra- moeba, and then again instead of confining themselves to the body surface, the Protozoa may bore into the body wall from out- side and actually acquire the habit of feeding on tissue cells of the attached animals as in the case of Ichthyophthirius. The next step in the evolution of parasitism must have been reached when Protozoa, accidentally or passively, were taken into the digestive system of the Metazoa. Such a sudden change in habitat appears to be fatal to most protozoans. But certain others possess extraordinary capacity to adapt themselves to an entirely different environment. For example, Dobell (1918) ob- served in the tad-pole gut, a typical free-living limax amoeba, with characteristic nucleus, contractile vacuoles, etc., which was found in numbers in the water containing the fecal matter of the tadpole. Glaucoma pyriformis (p. 548), a free-living ciliate, was found to occur in the body cavity of the larvae of Theohaldia annulata (after MacArthur) and in the larvae of Chironomus plumosus (after Treillard and Lwoff). Lwoff successfully inocu- lated this ciliate into the larvae of Galleria niellonella which died 28 I'ROTOZOOLOGY later from the infection. Recently Janda and Jlrovec (1937) in- jected bacteria-free culture of this ciliate into annelids, molluscs, crustaceans, insects, fishes, and amphibians, and found that only- insects — all of 14 species (both larvae and adults) — became in- fected by this ciliate. In a few days after injection the haemocoele became filled with the ciliates. Of various organs, the ciliates were most abundantly found in the adipose tissue. The organisms were much larger than those present in the original culture. The insects, into which the ciliates were injected, died from the in- fection in a few days. The course of development of the ciliate within an experimental insect depended not only on the amount of the culture injected, but also on the temperature. At 1-4°C. the development was much slower than at 26°C.; but if an in- fected insect was kept at 32-36°C. for 0.5-3 hours, the ciliates were apparently killed and the insect continued to live. When Glaucoma taken from Dixippus morosus were placed in ordinary water, they continued to live and underwent multiplication. The ciliate showed a remarkable power of withstanding the artificial digestion; namely, at 18°C. they lived 4 days in artificial gastric juice with pH 4.2; 2-3 days in a juice with pH 3.6; and a few hours in a juice with pH 1.0. Cleveland (1928) observed Tri- trichomonas fecalis in feces of a single human subject for three years which grew well in feces diluted with tap water, in hay in- fusions with or without free-living protozoans or in tap water with tissues at —3° to 37°C., and which, when fed per os, was able to live indefinitely in the gut of frogs and tadpoles. Reynolds (1936) found that Colpoda steini, a free-living ciliate of fresh water, occurs naturally in the intestine and other viscera of the land slug, Agriolimax agrestis, the slug forms being much larger than the free-living individuals. It may further be speculated that Vahlkampfia, Hydramoeba, Schizamoeba, and Endamoeba, are the different stages of the course the intestinal amoebae might have taken during their evolution. Obviously endocommensalism in the alimentary canal was the initial phase of endoparasitism. When these endocom- mensals began to consume an excessive amount of food or to feed on the tissue cells of the host gut, they became the true endo- parasities. Destroying or penetrating through the intestinal wall, they became first established in body cavities or organ cavities and then invaded tissues, cells or even nuclei, thus developing ECOLOGY 29 into pathogenic Protozoa. The endoparasites developing in in- vertebrates which feed upon the blood of vertebrates as source of food supply, will have opportunities to establish themselves in the higher animals. References Chalkley, H. W. 1930 Resistance of Paramecium to heat as affected by changes in hydrogen-ion concentration and in inorganic salt balance in surrounding medium. U. S. Publ. Health, Rep. Vol. 45. Cleveland, L. R. 1926 Symbiosis among animals with special reference to termites and their intestinal flagellates. Quart. Rev. Biol., Vol. 1. 1928 Tritrichomonas fecalis nov. sp. of man; its ability to grow and multiply indefinitely in faeces diluted with tap water and in frogs and tadpoles. Amer. Jour. Hyg., Vol. 8. DoBELL, C. 1918 Are Entamoeba histolytica and Entamoeba ranarum the same species? Parasitology, Vol. 10. DouDOROFF, M. 1936 Studies in thermal death in Paramecium. Jour. Exp. ZooL, Vol. 72. Efimoff, W. W. 1924 Ueber Ausfrieren und Ueberkaltung der Protozoen. Arch. f. Protistenk., Vol. 49. FiNLEY, H. E. 1930 Toleration of freshwater Protozoa to in- creased salinity. Ecology, Vol. 11. Glaser, R. W. and N. A. Coria 1933 The culture of Parame- cium caudatum free from living microorganisms. Jour. Parasit. Vol. 20. Janda, V. and O. JIrovec 1937 Ueber kiinstlich hervorgerufenen Parasitismus eines freilebenden Ciliaten Glaucoma piriformis und Infektionsversuche mit Euglena gracilis und Spirochaeta biflexa. Mem. soc. zool. tehee, de Prague, Vol. 5. KoLKWiTZ, R. and M. Marsson 1909 Oekologie der tierischen Saprobien. Intern. Rev. Ges. Hydrobiol. u. Hydrogr., Vol. 2. Kudo, R. R. 1929 Histozoic Myxosporidia found in freshwater fishes of Illinois, U.S.A. Arch. f. Protistenk., Vol. 65. Lackey, J. B. 1925 The fauna of Imhof tanks. Bull. New Jersey Agr. Exp. Stat., No. 417. Lauterborn, R. 1901 Die "sapropelische" Lebewelt. Zool. Anz., Vol. 24. Needhum, J. G., P. S. Galtsoff, F. E. Lutz and P. S. Welch. 1937 Culture methods for invertebrate animals. Ithaca. NoLAND, L. E. 1925 Factors influencing the distribution of freshwater ciliates. Ecology, Vol. 6. Reynolds, B. D. 1936 Colpoda steini, a facultative parasite of the land slug, Agriolimax agrestis. Jour. Parasit., Vol. 22. and J. B, Looper 1928 Infection experiments with Hydramoeba hydroxena nov. gen. Ibid., Vol. 15. 30 PROTOZOOLOGY Sandon, H. 1927 The composition and distribution of the proto- zoan fauna of the soil. Edinburgh, Taliaferro, W. H. 1926 Host resistance and types of infections in trypanosomiasis and malaria. Quart. Rev. Biol., Vol. 1. VON Brand, T. 1938 The metabolism of pathogenic trypano- somes and the carbohydrate metabolism of their hosts. Ibid., Vol. 13. Wenyon, C, M. 1926 Protozoology. 2 vols. London and New York. WoLFSON, C. 1935 Observations on Paramecium during ex- posure to sub-zero temperatures. Ecology, Vol. 16. YocoM, H. B. 1934 Observations on the experimental adapta- tion of certain freshwater ciliates to sea water. Biol. Bull., Vol. 67. Chapter 3 Morphology PROTOZOA range in size from ultramicroscopic to macro- scopic, though they are on the whole minute microscopic animals. The parasitic forms, especially cytozoic parasites, are often extremely small, while free-living protozoans are usually of much larger dimensions. Noctiluca, Foraminifera, Radiolaria, many ciliates such as Stentor, Bursaria, etc., represent larger forms. Colonial protozoans such as Carchesium, Zoothamnium, Ophrydium, etc., are even greater than the solitary forms. Plas- modium, Leishmania, and microsporidian spores may be men- tioned as examples of the smallest forms. The unit of measure- ment employed in protozoology is, as in general microscopy, 1 micron (/x) which is equal to 0.001 mm. The body forms of Protozoa are even more varied, and fre- quently, because of its extreme plasticity it does not remain constant. From a small simple spheroidal mass up to large highly complex forms, all possible body forms occur. Although the great majority are without symmetry, there are some which pos- sess a definite symmetry. Thus bilateral symmetry is noted in all members of Diplomonadina (p. 272); radial symmetry in Gon- ium, Cyclonexis, etc.; and universal symmetry, in certain Helio- zoa, Volvox, etc. The fundamental component of the protozoan body is the pro- toplasm which is without exception difTerentiated into the nucleus and the cytosome. Haeckel's monera are now considered as nonexistent, since improved microscopic technique failed in recent years to reveal any anucleated protozoans. The nucleus and the cytosome are inseparably important to the well-being of a protozoan, as has been shown by numerous investigators since Verworn's pioneer work. In all cases, successful regenera- tion of the body is only accomplished by the nucleus-bearing portions and enucleate parts degenerate soon or later. On the other hand, when the nucleus is taken out of a cell, both the nucleus and cytosome degenerate, which indicate their intimate association in carrying on the activities of the body. It appears certain that the nucleus controls the assimilative phase of metab- 31 32 PROTOZOOLOGY olism which takes place in the cytosome in normal animals, while the cytosome is capable of carrying on catabolic phase of the metabolism. Aside from the importance as the controlling center of metabolism, evidences point to the conclusion that the nucleus contains the genes or hereditary factors which character- ize each species of protozoans from generation to generation, as in the cells of multicellular animals and plants. The nucleus Because of a great variety of external body forms and of con- sequent body organizations, the protozoan nuclei are of various forms, sizes and structures. At one extreme there is a small nucleus and, at the other, a large voluminous one and, between these extremes, is found every conceivable variety of form and structure. The majority of Protozoa contain a single nucleus, though many may possess two or more throughout the greater part of their life-cycle. In several species, each individual pos- sesses two similar nuclei, as in Pelomyxa hinucleata, Arcella vulgaris, Diplomonadina, Protoopalina and Zelleriella. In Eucil- iata and Suctoria, two dissimilar nuclei, a macronucleus and a micronucleus, are typically present. The macronucleus is always larger than the micronucleus, and controls the trophic activities of the organism, while the micronucleus is concerned with the reproductive acti\dty. Certain Protozoa possess numerous nuclei of similar structure, as for example, in Mycetozoa, Actino- sphaerium, Opalina, Cepedea, Myxosporidia, Microsporidia, etc. Dileptus anser contains many small macronuclei, a condition not observed in other euciliates. The essential components of the protozoan nucleus are the nuclear membrane, chromatin, plastin and nucleoplasm. Their interrelationship varies sometimes from one developmental stage to another, and vastly among different species. Structurally, they fall in general into one of the two types: vesicular and compact. The vesicular nucleus (Fig. 2, a) consists of a nuclear mem- brane which is sometimes very delicate, but distinct, nucleo- plasm and chromatin. Besides there is an intranuclear body which is, as a rule, more or less spherical and which appears to be of dif- ferent make-ups, as judged by its staining reactions among dif- ferent nuclei. It may be composed of chromatin, of plastin, or of a mixture of both. The first type is sometimes called karyosome MORPHOLOGY 33 and the second, nucleolus or plasmosome. Absolute distinction between these two terms cannot be made as they are based upon the difference in affinity to nuclear stains which cannot be stand- ardized and hence do not give uniformly the same result. Fol- lowing Minchin and others, the term endosome is advocated here to designate one or more conspicuous bodies other than the chromatin granules, present within the nuclear membrane. When viewed in life, the nucleoplasm is ordinarily homo- geneous and structureless. But, upon fixation, there appear in- variably plastin strands or networks which seem to connect the Nuclear membrane Endosome Achromatic strand Chromatin granules a b Fig. 2. a, vesicular nucleus; b, compact nucleus (diagrams). endosome and the nuclear membrane. Some investigators hold that these strands or networks exist naturally in life, but due to the similarity of refractive indices of the strands and of the nucleoplasm, they are not visible and that, when fixed, they be- come readily recognizable because of a change in these indices. In some nuclei, however, certain strands have been observed in life, as for example in the nucleus of the species of Barbu- lanympha (Fig. 131, c), according to Cleveland and his associates (1934). Others maintain that the achromatic structures promi- nent in fixed vesicular nuclei are mere artifacts brought about by fixation and do not exist in life and that the nucleoplasm is a homogeneous liquid matrix of the nucleus. The chromatin substance is ordinarily present as small granules although at times they may be in block forms. Precise knowledge of chromatin is still lacking. At present the determination of the chromatin depends upon the following tests: 1) artificial digestion which does not destroy this substance, while non-chromatinic parts of the nucleus are completely dissolved; 2) acidified methyl green which stains the chromatin bright green; 3) 10 per cent sodium chloride solution which dissolves, or causes swelling of, chromatin granules, while nuclear membrane and achromatic substances remain unattacked; and 4) in the fixed condition 34 PROTOZOOLOGY Feulgen's niicleal reaction. The vesicular nucleus is most com- monly present in various orders of the Sarcodina and Mastig- ophora. The compact nucleus (Fig. 2, b), on the other hand, contains a large amount of chromatin substance and a comparatively small amount of nucleoplasm, and is thus massive. The macronucleus of the Ciliophora is almost always of this kind. The variety of forms of the compact nuclei is indeed remarkable. It may be spherical, ovate, cylindrical, club-shaped, band-form, moniliform, horseshoe-form, filamentous, or root-like. The nuclear membrane is always distinct, and the chromatin substance is usually spheroidal, varying in size among different species and often even in the same nucleus. In the majority of species, the chromatin granules are small and compact, though in some forms, such as Nydotherus ovalis (Fig. 3), they may reach 20^ or more in diame- ter, and while the smaller chromatin granules seem to be solid, larger forms contain alveoli of different sizes in which smaller chromatin granules are suspended (Kudo, 1936). There is no sharp demarcation between the vesicular and compact nuclei, since there are numerous nuclei the structures of which are intermediate between the two. Moreover what appears to be a vesicular nucleus in hfe, may approach a compact nucleus when fixed and stained as in the case of Euglenoidina. Several experimental observations show that the number, size, and structure of the endosomes in the vesicular nucleus, and the amount and arrangement of the chromatin in the compact nu- cleus, vary according to the physiological state of the protozoan concerned. The macronucleus may be divided into two or more parts with or without connections among them and in Dileptiis anser into more than 200 small nuclei, each of which is "composed of a plastin core and a chromatin cortex" (Calkins; Hayes). In general, the chromatin granules or spherules fill the intra- nuclear space compactly, in which one or more endosomes may occur. In many nuclei these chromatin granules appear to be suspended freely, while in others a reticulum appears to make the background. The chromatin of compact nuclei gives a strong posi- tive Feulgen's nucleal reaction. The macronuclear and micro- nuclear chromatin substance responds differently to Feulgen's nucleal reaction or to the so-called nuclear stains, as judged by the difference in the intensity or tone of color. In Paramecium MORPHOLOGY 35 caudatum, P. aiirelia, Chilodonella, Nydotherus ovalis, etc., the macronuclear chromatin is colored more deeply than the micro- nuclear chromatin, while in Colpoda, Urostyla, Euplotes, Sty- lonychia, and others, the reverse seems to be the case, which may support the validity of assumption that the two types of the Fig. 3. Four macronuclei of Nydotherus ovalis, s^liuwing chromatin spherules of different sizes, X650 (Kudo). nuclei of Euciliata and Suctoria are made up of different chroma- tin substances — idiochromatin in the micronucleus and tropho- chromatin in the macronucleus — and in other classes of Protozoa, the two kinds of chromatin are present together in a single nucleus. Chromidia. Since the detection of chromatin had solely de- pended on its affinity to nuclear stains, several investigators 36 PROTOZOOLOGY found extranuclear chromatin granules in many protozoans. Finding such granules in the cytosome of Actinosyhaerium eich- horni, Arcella vulgaris, and others, Hertwig (1902) called them chromidia, and maintained that under certain circumstances, such as lack of food material, the nuclei disappear and the chro- matin granules become scattered throughout the cytosome. In the case of Arcella vulgaris, the two nuclei break down completely to produce a chromidial-net which later reforms into smaller secondary nuclei. It has, however, been found by Belaf that the lack of food caused the encystment rather than chromidia- formation in Actinosphaerium and, according to Reichenow, Jollos observed that in Arcella the nuclei persisted, but were thickly covered by chromidial-net which could be cleared away by artificial digestion to reveal the two nuclei. In Difflugia, the chromidial-net is vacuolated or alveolated in the fall and in each alveolus appear glycogen granules which seem to serve as reserve food material for the reproduction that takes place during that season (Zuelzer), and the chromidia occurring in Actinosphaerium appear to be of a combination of a carbohydrate and a protein (Rumjantzew and Wermel). Apparently the widely distributed volutin (p. 95), and many inclusions or cytozoic parasites, such as Sphaerita, which occur occasionally in different Sarcodina, have in some cases been called chromidia. By using Feulgen's nucleal reaction, Reichenow (1928) obtained a .diffused violet- stained zone in Chlamydomonas and held them to be dissolved volutin. Calkins (1933) found the chromidia of Arcella vulgaris negative to the nucleal reaction, but by omitting acid-hydrolysis and treating with fuchsin-sulphurous acid for 8-14 hours, the chromidia and the secondary nuclei were found to show a typical positive reaction and believed that the chromidia are chromatin. Thus at present the real nature of chromidia is still not clearly known, although many protozoologists are inclined to think that the substance is not chromatinic, but, in some way, is connected with the metabolism of the protozoan. The cytosome The extranuclear part of the protozoan body is the cytosome. It is composed of the cytoplasm, a colloidal system, which may be homogenous, granulated, vacuolated, reticulated, or fibrillar in optical texture, and is almost ahvays colorless. The chromato- MORPHOLOGY 37 phore-bearing Protozoa are variously colored, and those with symbiotic algae or cryptomonads are also greenish or brownish in color. Furthermore, pigment or crystals which are produced in the body, may give protozoans various colorations. In several forms pigments are diffused throughout the cytoplasm. For ex- ample, many dinoflagellates are beautifully colored which, ac- cording to Kofoid and Swezy, is due to a thorough diffusion of pigment in the cytoplasm. Stentor coeruleus is ordinarily blue- colored, the pigment responsible for which was called Stentorin (Lankester) and is lodged in granules between the surface striae; and rose- or purple-coloration of several species of Blepharisma appears to be due to a special pigment, zoopurpurin (Arci- chovskij) which is lodged in the ectoplasmic granules often called protrichocysts (p. 65). The development of zoopurpurin is definitely correlated with the sun-light, as shown by Giese. Deeply pink specimens will lose color completely in a few hours when exposed to strong sun-light and the recoloration takes place in darkness very slowly. The extent and nature of the cytosomic differentiation differs greatly among various groups. In the majority of Protozoa, the cytoplasm is differentiated into the ectoplasm and the endo- plasm. The ectoplasm is the cortical zone which is hyaline and homogeneous. In the Ciliophora, it is a permanent and distinct part of the body and contains several organellae; in the Sarcodina and the Sporozoa, it is more or less a temporarily differentiated zone and hence varies greatly at different times and, in the Mastigophora, it seems to be more or less permanent. The endo- plasm is more voluminous and fluid. It is granulated or alveo- lated and contains various organellae. While the alveolated cytoplasm is normal in forms such as the members of Heliozoa and Radiolaria, in other cases the alveolation of normally gran- ulated or vacuolated cytoplasm indicates invariably the degen- eration of the protozoan body. In numerous Sarcodina and certain Mastigophora, the body surface is naked and not protected by any form-giving organella. According to observations by Kite, Howland, and others, the surface layer is not only elastic, but solid, and therefore the name plasma-membrane may be applied to it. Such forms are capable of undergoing amoeboid movement by formation of pseudopodia and by continuous change of form due to the movement of the 38 PROTOZOOLOGY cytoplasm which is more fluid. However, the majority of Proto- zoa possess a characteristic and constant body form due to the development of a special envelope, the pellicle. In Amoeba striata and A. verrucosa, there is an extremely thin pellicle. The same is true with some flagellates, such as certain species of Euglena, Peranema, and Astasia, in which it is elastic and expansible so that the organisms possess a great deal of plasticity. The pellicle of a ciliate is much thicker and more definite, and often variously ridged or sculptured. In many, linear furrows and ridges run longitudinally, obliquely, or spirally; and, in others, the ridges are combined with hexagonal or rectangular depressed areas. Still in others, such as Coleps, elevated platelets are arranged parallel to the longitudinal axis of the body as four girdles. In certain peritrichous ciliates, such as Vorticella moni- lata, Carchesium granulatum, etc., the pellicle may possess nodu- lar thickenings arranged in more or less parallel rows at right angles to the body axis. While the pellicle always covers the protozoan body closely, there are other kinds of protective envelopes produced by Proto- zoa which may cover the body rather loosely. These are the shell, test, lorica or envelope. The shell of various Phytomastigina is mainly made up of cellulose, a carbohydrate, which is widely dis- tributed among the plant kingdom. It may be composed of a single or several layers, and may possess ridges or markings of various patterns on it. In addition to the shell, gelatinous sub- stance may in many forms be produced to surround the shelled body or in the members of Volvocidae to form the matrix of the entire colony in which the individuals are imbedded. In the dino- flagellates, the shell is highly developed, and often composed of numerous plates which are variously sculptured. In other Protozoa, the shell is made up of chitin or pseudo- chitin (tectin). Common examples are found in the testaceans; for example, in Arcella and allied forms, the shell is made up of chitinous material, constructed in particular w^ays which char- acterize the different genera. Newly formed shell is colorless, but older ones become brownish, because of the presence of iron oxide. Difflugia and related genera form shells by glueing together small sand-grains, diatom-shells, debris, etc., with chitinous or pseudo- chitinous substances which they secrete. Many foraminiferans seem to possess a remarkable selective power in the use of foreign MORPHOLOGY 39 material for the construction of their shells. According to Cush- man, Psammos'phaera fusca uses sand-grains of uniform color but of different sizes, while P. parva uses grains of more or less uniform size but adds, as a rule, a single large acerose sponge spicule which is built into the test and which extends out both ways considerably. Cushman thinks that this is not accidental, since the specimens without the spicules are few and those with a short or broken spicules are not found. P. howmanni, on the other hand, uses only mica flakes which are found in a comparatively small amount, and P. rustica uses acerose sponge spicules for the Fig. 4. Diagram of the shell of Peneroplis pertusus, X about 35 (Carpenter), ep, external pore; s, septum; sc, stolon canal. framework of the shell, skillfully fitting smaller broken pieces into polygonal areas. Other foraminiferans combine chitinous secre- tion with calcium carbonate and produce beautifully complicated shells (Fig. 4) with one or numerous pores. In the Coccolithidae, variously shaped platelets of calcium carbonate ornament the shell. The silica is present further in the shells of various Protozoa. In Euglypha and related testaceans, siliceous scales or platelets are produced in the endoplasm and compose a new shell at the time of fission or of encystment together with the chitinous secre- tion. In many heliozoans, siliceous substance forms spicules, platelets, or combination of both which are embedded in the mucilaginous envelope which surrounds the body and, in some 40 PROTOZOOLOGY cases, a special clathrate shell composed of silica, is to be found. In some Radiolaria, isolated siliceous spicules occur as in Helio- zoa, while in others the lateral development of the spines results in production of highly complex and most beautiful shells with various ornamentations or incorporation of foreign material. Many pelagic radiolarians possess numerous conspicuous radiat- ing spines in connection with the skeleton, which apparently aid the organisms to maintain their existence in the open sea. Some flagellates may be encased in a chitinous lorica or house and in addition there is occasionally a collar developed at one end. The lorica found in the Ciliophora is mostly composed of chitinous substance alone, especially in Peritricha, although some produce a house made up of gelatinous secretion containing foreign material as in Stentor (p. 581). In the Tintinnidiidae, the loricae are either solely chitinous in numerous marine forms not mentioned in the present work or composed of sand-grains or coccoliths cemented together by chitinous secretion. Locomotor organellae Closely associated with the body surface are the organellae of locomotion: pseudopodia, flagella, and cilia. These organellae are not confined to Protozoa alone and occur in various cells of Metazoa. All protoplasmic masses are capable of movement which may result in change of their forms. Pseudopodia. A pseudopodium is a temporary projection of part of the cytoplasm of those protozoans which do not possess a definite pellicle. Pseudopodia are therefore a characteristic organella of Sarcodina, though many Mastigophora and certain Sporozoa, which lack a pellicle, are able also to produce them. According to their form and structure, four kinds of pseudopodia are distinguished. 1). The lobopodium is formed by an extension of the ecto- plasm and by a flow of endoplasm as is commonly found in Amoeba proteus (Figs. 42; 140). It is finger- or tongue-like, some- times branched, and its distal end is typically rounded. It is quickly formed and equally quickly retracted. In many cases, there are many pseudopodia formed from the entire body surface, in which the largest one will counteract the smaller ones and the organism will move in one direction; while in others, there may be a single pseudopodium formed, as in Amoeba striata, A. guttula, MORPHOLOGY 41 Vahlkampfia Umax, Pyxidicula operculata, etc., in which case it is a broadly tongue-like extension of the body in one direction and the progressive movement of the organisms is comparatively rapid. The lobopodia may occasionally be conical in general shape, as in Amoeba spumosa. Although ordinarily the formation of lobopodia is by general flow of the cytoplasm, in some it is sudden and "eruptive," as in Endamoeha hlattae or Entamoeba histolytica in which the flow of the endoplasm presses against the inner zone of the ectoplasm and the accumulated pressure finally causes breaks through the line, resulting in a sudden ex- tension of the endoplasmic flow at that point. 2). The filopodium is a more or less filamentous projection com- posed almost exclusively of the ectoplasm. It may sometimes be branched, but the branches do not anastomose. Many testaceans, such as Lecythium, Boderia, Plagiophrys, Pamphagus, Euglypha, etc., form this type of pseudopodia. The pseudopodia of Aynoeba radiosa may be considered as approaching this type more than the lobopodia. 3). The rhizopodium is also filamentous, but branching and anastomosing. It is found in numerous Foraminifera, such as Elphidium, Peneroplis (Fig. 5), etc., and in certain testaceans, such as Lieberkuhnia, Myxotheca, etc. The abundantly branch- ing and anastomosing rhizopodia often produce a large network which serve almost exclusively for capturing prey. 4). The axopodium is, unlike the other three types, a more or less semi-permanent structure and composed of axial rod and cytoplasmic envelope. The axopodia are found in many Heliozoa, such as Actinophrys, Actinosphaerium, Camptonema, Sphaera- strum, and Acanthocystis. The axial rod, which is composed of fibrils (Doflein; Roskin), arises from the central body or the nucleus located in the approximate center of the body, from each of the nuclei in multinucleate forms, or from the zone between the ectoplasm and endoplasm (Fig. 6). Although semipermanent in structure, the axial rod is easily absorbed and reformed. In the genera of Heliozoa, not mentioned above and in numerous radio- larians, the radiating filamentous pseudopodia are so extremely delicate that it is difficult to determine whether an axial rod exists in each or not, although they resemble axopodia in general ap- pearance. There is no sharp demarcation between the four types of 42 PROTOZOOLOGY psciidopodia, as there are transitional pseiidopodia between any two of them. For example, the pseudopodia formed by Arcella, Lesquereusia, Hyalosphaenia, etc., resemble more lobopodia '■t'V^'>'^"'' V 'i" ,'.,:•-'. ,•:■■. '.'■ 'I'M', ' > ;V/' ^^/< 7,'/ /./•■•/T / '(■/.<.i./.,-^' V/ii nil i \ ■ / ■■ ' /ill ' • ^ //J /^h \ \ Fig. 5. Pseudopodia of Elphidium strigilata, X about 50 (Schulze from Kiihn). than filopodia, though composed of the ectoplasm only. The pseudopodia of Actinomonas, Elaeorhanis, Clathrulina, etc., may be looked upon as transitional between rhizopodia and axopodia. MORPHOLOGY 43 While the pseudopodia formed by an individual are usually of characteristic form and appearance, they may show an entirely different appearance under different circumstances. According to the often-quoted experiment of Verworn, limax amoebae change into radiosa amoebae upon addition of potassium hydrate to the water (Fig. 7). Mast has recently shown that when Amoeba proteus or A. dubia is transferred into pure water, the amoeba produced radiating pseudopodia, and when transferred to a salt Fig. 6. Portion of Actinosphaerium eichhorni, X800 (Kiihn). ar, axial rod; cv, contractile vacuole; ec, ectoplasm; en, endoplasm; n, nucleus. medium, it changed into monopodial form, which change, he was inclined to attribute to the difference in the water contents of the amoeba. In some cases during and after certain internal changes, an amoeba may show conspicuous differences in pseudopodia (Neresheimer). As was stated before, pseudopodia occur widely in forms which are placed under classes other than Sarcodina during a part of their life-cycle. Care, therefore, should be exer- cised in using them for taxonomic consideration of the Protozoa. Flagella. The flagellum is a filamentous extension of the cyto- plasm and is ordinarily extremely fine and highly vibratile, so 44 PROTOZOOLOGY that it is difficult to recognize it in life under the microscope with a moderate magnification. In a number of species, the flagellum, however, can be seen in life as a long filament, as for example in Peranema. As a rule, the number of flagella present in a single individual is small, varying from one to eight, but in Hyper- mastigina there are numerous flagella. A flagellum appears to be composed of at least two parts (Fig. 8, a, h). An axial filament which is elastic, takes its origin directly, or indirectly through d e f Fig. 7. Form-change in a limax-amoeba (Verworn). a, b, contracted forms; c, individual showing typical form; d-f, radiosa-forms, after addition of KOH solution to the water. basal granule, in the blepharoplast. Surrounding this filament there is a sheath of contractile cytoplasm which varies in thick- ness alternately on the opposite sides of the filament. The flagellum ordinarily tapers toward its distal end where the axial filament is said to be frequently exposed. Recently Vlk found, besides the kind above mentioned which he called the whip-flagellum, another form named by him as the ciliary flagellum. The latter is said to be uniformly thick, but possesses dense ciliary projections which are arranged on a flagellum in one or two spiral rows (Fig. 8, c, d). Vlk found the whip-flagellum in Chlamydomonas, Polytoma uvella(e), Cercomonas MORPHOLOGY 45 axial filament cytoplasmic sheath \ / Fig. 8. Diagrams of flagella. a, flagellum of Euglena (Biitschli); b, flagellum of Trachelomonas (Plenge); c, ciliary flagellum with one row of cilia; d, a ciliary flagellum with two rows of cilia; e, whip- flagella of Pohjtoma uvella; f, ciliary flagellum of Urceolus cyclostomus; g, the flagella of Monas socialis (Vlk) . 46 PROTOZOOLOGY crassicauda, Trcpomonas rotans, T. agilis, Hexamita injlata, Urophagus rostratus, etc.; the ciliary flagcllum, in JMallomonas, Chromulina, Trachclomonas, Urccolus (/), Phaciis, Euglena, Astasia, Distigma, etc.; and both kinds in Syniira, Uroglena, Dinobryon, Monas (g), etc. The flagcllum is most frequently inserted near the anterior end of the body and directed forward, its movement pulling the organism forward. Combined with this, there may be a trailing flagellum which is directed i)osteriorly and which serves to steer Fliigellum Undulatinji membrane Nucleus Basal granule Blepharoplast Anterior flagellum Basal granule Blepharoplast Rhizoplast Nucleus Parabasal body Posterior flagellum Fig. 9. Diagrams of two flagellates, showing their structures (Kiihn). a, Trypanosoma brucei; b, Proteromonas lacertae. the course of movement or to push the body forward to a certain extent. In a comparatively small niunber of flagellates, the flagel- lum is inserted near the posterior end of the body and would push the body forward by its -snbration. Lankester coined tractella and pulsella for pulling and pushing flagella respectively. In certain parasitic Mastigophora, such as Trjrpanosoma (Fig. 9, o), Trichomonas, etc., there is a very delicate membrane extending out from the side of the body, a flagellum bordering its outer margin. When this membrane vibrates, it shows a characteristic undulating movement, as will easily be seen in Trypanosoma rotaforiutn of the frog, and is called the undulating membrane. In many of the dinoflagellates, the transverse flagel- lum seems to be similarly constructed (Kofoid and Swezy) (Fig. 101, d, /). MORPHOLOGY 47 Cilia. The cilia are the organella of locomotion and food- capturing found in the Ciliophora. They seem to serve often as a tactile organella. The cilia are fine and more or less short proc- esses of ectoplasm and occur in large numbers in the majority of the Holotricha. They may be uniformly long, as in Protocihata, or may be of different lengths, being longer at the extremities, on certain surfaces, in peristome or in circumoral areas. Ordinarily the cilia are arranged in longitudinal, oblique, or spiral rows, being inserted on either the ridges or the furrows. Again the cilia may be confined to certain parts or zones of the body. Each cilium originates in a basal granule situated in the deeper part of the ectoplasm and, in a few species, a cilium is found to be made up of an elastic axial filament arising from the basal granule and contractile sheath. Gelei observed in flagella and cilia, lipoid substance in granular or rod-like forms which differed even among different individuals of the same species; and Klein found in many cilia of Colpidium colpoda, an argentophilous substance in granular form much resembling the lipoid structure of Gelei and called them "cross-striation" of the contractile component (Fig. 10). The cilia are often present in a certain area more densely than in other parts of body and, consequently, such an area stands out conspicuously, and is sometimes referred to as a cihary field. If this area is in the form of a zone, it may be called a ciliary zone. Some authors use pectinellae for short longitudinal rows or trans- verse bands of close-set cilia. In a number of forms, such as Coleps Stentor, etc., there occur, mingled among the vibratile cilia, immobile stiff cilia which are apparently solely tactile in function. In the Hypotricha, the ciHa are largely replaced by cirri, al- though in some species both may occur. A cirrus is composed of a number of cilia arranged in 2 to 3 rows which fused into one structure completely (Figs. 11, 12), which was demonstrated by Taylor. Klein also showed by desiccation that each marginal cirrus of Stylonychia was composed of 7 to 8 ciha. In some in- stances, the distal portion of a cirrus may show two or more branches. The cirri are confined to the ventral surface in Hypo- tricha, and called frontal, ventral, anal, caudal, and marginal cirri, according to their location (Fig. 11). Unhke the cilia, the cirri may beat in any direction so that the organisms bearing them, show various ways of locomotion. Oxytricha, Stylonychia, 48 PROTOZOOLOGY etc., walk on frontals, ventrals, and anals, while swimming move- ment by other species is of different types. In all euciliates except Holotricha, there are adoral membranel- lae. A membranella is composed of a double ciliary lamella, fused completely into a plate (Fig. 12). A number of these membranel- lae occur on a margin of the peristome, forming the adoral zone Fig. 10. Diagrams of cilia (Klein), a, Coleps; b, Cyclidium glaucoma; c, Colpidiu7n colpoda. af, axial filament; bg, basal granule; of, circular fibril; cs, cross-striation; sg, secondary granule. of membranellae, which serves for bringing the food particles to the cytostome. The frontal portion of the zone, the so-called frontal membrane, appears to serve for locomotion and Kahl considers that it is probably made up of three lamellae. The membranes which are often found in Holotricha and Hetero- tricha, are transparent thin membranous structures composed of one or two rows of cilia, which are more or less strongly fused. MORPHOLOGY 49 Cirrus fiber Ectoplasmic granules Basal plate of the cirrus Basal granules of component cilia Adoral zone Frontal cirri Undulating membrane Marginal cirri Ventral cirri Anal cirri Caudal cirri Fig. 11. a, five anal cirri of Euplotes patella (Taylor); b, schematic ventral view of Stylonychia to show the distribution of the cirri. 50 PROTOZOOLOGY The membranes, located in the lower end of the peristome, are sometimes called perioral membranes, and those in the cyto- pharynx, undulating membranes. In Suctoria, cilia are present only during the developmental stages, and, as the organisms become mature, tentacles are de- veloped. The tentacles are concerned with food-capturing, and are either prehensile or usually suctorial. In a few instances the cpg Fig. 12. Diagrams of cirrus and membranella of Euplotes pateUoi X1450 (Taylor), a, an anal cirrus in side view; b, a membranella; bg- basal granule; cpg, coagulated protoplasmic granules; cr, ciliary root; fp, fiber plate. tentacles are tubular and this type is interpreted by Collin as possibly derived from a cytostome and cytopharynx of the ciliate (Fig. 13). Although the vast majority of Protozoa possess only one of the three organellae of locomotion mentioned above, a few may possess pseudopodia in one phase and fiagella in another phase during their life-cycle. Among many examples, may be men- tioned Dimastigamoebidae (Fig. 139), Tetramitus rostratus (Fig. 122), etc. Furthermore, there are some protozoans which possess two types of organellae at the same time. Flagellum or fiagella MORPHOLOGY 51 and pseudopodia occur in many Phytomastigina and Rhizomasti- gina, and a flagellum and cilia are present in Ileonema (Fig. 235, b, c). In the cytosome of Protozoa there occur various organellae, each of which will be considered briefly here. Fibrillar structures One of the characteristics of the protoplasm is its contractility. If a fully expanded Amoeba proteus is subjected to a mechanical pressure, it retracts its pseudopodia and contracts into a more or less spherical form. In this response there is no special organella, and the whole body reacts. But in certain other Protozoa, there Fig. 13. Diagrams showing the possible development of a suctorian tentacle from a cytostome and cytopharynx of a ciliate (Collin). are special organellae of contraction. Many Ciliophora are able to contract instantaneously when subjected to mechanical pres- sure, as will easily be noticed by following the movement of Stentor, Spirostomum, Trachelocerca, Vorticella, etc., under a dissecting microscope. The earliest observer of the contractile elements of Protozoa was Lieberkiihn (1857) who noted "muscle fibers" in the ectoplasm of Stentor which were later named myonemes (Haeckel) or Neurophanes (Neresheimer). The myonemes of Stentor have been studied by several in- vestigators. According to Schroder (1906), there is a canal be- tween each two longitudinal striae and in it occurs a long banded myoneme which measures in cross-section 3-7 fx high by about 1m wide and which appears cross-striated (Fig. 14). Roskin (1923) considers that the myoneme is a homogeneous cytoplasm (kino- plasm) and the wall of the canal is highly elastic and counteracts 52 PROTOZOOLOGY the contraction of the myonemes. All observers agree that the myoneme is a highly contractile organella. Many stalked peritrichous ciliates have well-developed myo- nemes not only in the body proper, but also in the stalk. Koltzoff's studies show that the stalk is a pseudochitinous tube, enclosing an inner tube filled with granulated thecoplasm, surrounding a cl m mc m bg gis Fig. 14. Myonemes in Stentor coeruleus (Schroder), a, cross-section of ectoplasm; b, surface view of three myonemes; c, two isolated myonemes; bg, basal granules; cl, cilium; gis, granules between striae; m, myonemes; mc, myoneme canal. central rod, composed of kinoplasm, on the surface of which are arranged skeletal fibrils (Fig. 15). The contraction of the stalk is brought about by the action of kinoplasm and walls, while elastic rods will lead to extension of the stalk. Myonemes present in the cihates aid in the contraction of body, but those which occur in many Gregarinida aid apparently in locomotion, being arranged longitudinally, transversely and probably spirally (Fig. 15). In certain Radiolaria, such as Acanthometron elasticum MORPHOLOGY 53 (Fig. 168, c), etc., each axial spine is connected with 10-30 myo- nemes (myophrisks) originating in the body surface. When these myonemes contract, the body volume is increased, thus in this case functioning as a hydrostatic organella. In Isoiricha prostoma and /. iritestinalis, Schuberg (1888) observed that the nucleus is suspended by ectoplasmic fibrils and Fig. 15. a, b, fibrillar structures of the stalk of Zoothamnium (Kolt- zoff); 0, myonemes in Gregarina (Schneider), ef, elastic fiber; ie, inner envelope; k, kinoplasm; oe, outer envelope; t, thecoplasm. called the apparatus karyophores. In some forms these fibrils are replaced by ectoplasmic membranes as in Nyctotherus ovalis (Zuluta; Kudo), ten Kate (1927) studied fibrillar systems in Opalina, Nyctotherus, Ichthyophthirius, Didinium, and Balantid- ium, and found that there are numerous fibrils, each of which originates in a basal granule of a cilium and takes a transverse or oblique course through the endoplasm, ending in a basal granule located on the other side of body. He further noted that the cyto- 54 PROTOZOOLOGY Fig 16. A composite drawing from three median sagittal sections of Evidinium ecaudatum, fixed in Zenker and stained with Ma lory s connective tissue stain, X1200 (Sharp), am, adoral membranellae; c cytostome; cp, cytopharynx; cpg, cytopyge; cpr, circumpharyngeal ring- dd, dorsal disk; dm, dorsal membrane; ec, ectoplasm; en, encio- plasm; m, motorium; oc, oral cilia; od, oral disk; oef, oesophageal fibers; of, opercular fibers; p, pellicle; prs, pharyngeal retractor strands; si, skeletal laminae; vs, ventral skeletal area. MORPHOLOGY 55 pharynx and nucleus are also connected with these fibrils, ten Kate suggested morphonemes for them, since he believed that the majority were form-retaining fibrils. The well-coordinated movement of cilia in the ciliate has long been recognized, but it was Sharp (1914) who definitely showed that this ciliary coordination is made possible by a certain fibrillar system which he discovered in Epidinium {Diplodiniutn) ecaudatum (Fig. 16). Sharp recognized in this ciHate a complicated fibrillar system, connecting all the motor organellae of the cyto- stomal region, and thinking that it was "probably nervous in function," as its size, arrangement and location did not suggest supporting or contractile function, he gave the name neuromotor apparatus to the whole system. This apparatus consists of a central motor mass, the motorium (which is stained red with Zenker fixation and modified Mallory's connective tissue stain- ing), located very deeply in the ectoplasm just above the base of the left skeletal area, from which definite strands radiate : namely, one to the roots of the dorsal membranellae (a dorsal motor strand); one to the roots of the adoral membranellae (a ventral motor strand); one to the cytopharynx (a circum-oesophageal ring and oesophageal fibers); and several strands into the ecto- plasm of the operculum (opercular fibers). A similar apparatus has since been observed in many other ciliates: Euplotes (Yocom; Taylor), Balantidium (McDonald), Paramecium (Rees; Brown; Lund), Tintinnopsis (Cambell), Boveria (Pickard), Dileptus (Visscher), Chlamydodon (MacDougall), Entorhipidium and Lechriopyla (Lynch), Eupoterion (MacLennan and Connell), Metopus (Lucas), Troglodytella (Robertson), Oxytricha (Lund), Ancistruma and Conchophthirus (Kidder), etc. Euplotes patella, a common free-living hypotrichous ciliate, has been known for nearly 50 years to possess definite fibrils connecting the anal cirri with the anterior part of the body. Engelmann suggested that their function was somewhat nerve- like, while others maintained that they were supporting or con- tracting in function. Yocom (1918) traced the fibrils to the mo- torium, a very small bilobed body (about S^t by 2yu) located close to the right anterior corner of the triangular cytostome (Fig. 17). Joining with its left end are five long fibers from the anal cirri which converge and appear to unite with the motorium as a single strand. From the right end of the motorium extends the mem- 56 PROTOZOOLOGY ^ — mfp Fig. 17. Diagrams showing the neuromotor apparatus of Euplotes patella (Taylor), a, diagrammatic dorsal view of the entire apparatus, X1600; b, dissected portion of disintegrating membranella fiber plates attached to the membranella fiber; c, a dissociated fiber plate of a frontal cirrus with its attached fibers, X1450. acf, anal cirrus fiber; afp, anal fiber plate; eg, small and large ectoplasmic granules; m, motorium; mf, membranella fiber; mfp, membranella fiber plate. branella-fiber anteriorly, and then to left along the proximal bor- der of the oral lip and the bases of all membranellae. Yocom further noticed that within the lip there was a latticework struc- ture whose bases very closely approximate the cytostomal fiber. Taylor (1920) recognized two additional groups of fibrils in the same organism: 1) membranella fiber plates, each of which is contiguous with a membranella basal plate, and is attached at one end to the membranella fiber; 2) dissociated fiber plates contiguous with the basal plates of the frontal, ventral and marginal cirri, to each of which are attached the dissociated fibers (c). By means of microdissection needles, Taylor demonstrated that these fibers have nothing to do with the maintainance of body form since there results no deformity when Euplotes is cut fully two-thirds its width, thus cutting the fibers, and that when the motorium is destroyed or its attached fibers are cut, there is no coordination in the movements of the adoral mem- branellae and anal cirri. Turner (1933) however is inclined to think that there is no motorium in this protozoan. MORPHOLOGY 57 Fig. 18. The silverline system of Ancistruma mytili, XlOOO (Kidder), a, ventral view; b, dorsal view. A striking feature common to all neuromotor systems, is that there seems to be a central motorium from which radiate fibers to different ciliary structures and that, at the bases of such motor organellae, are found the basal granules or plates to which the "nerve" fibers from the motorium are attached. Independent of the studies on the neuromotor system of American investigators, Klein (1926) introduced the silver-im- pregnation method which had first been used by Golgi in 1873 to demonstrate various fibrillar structures of metazoan cells, to Protozoa in order to demonstrate the cortical fibers present in ciliates, by dry-fixation and impregnating with silver nitrate. K,lein (1926-1930) subjected the ciliates of numerous genera and species to this method, and observed that there was a fibrillar system in the ectoplasm at the level of the basal granules which cannot be demonstrated by other methods. Ivlein (1927) named the fibers silver lines and the whole complex, the silverline sys- tem, which is characteristic of each species (Fig. 18). Chatton 58 PROTOZOOLOGY and Lwoff, Gelci, Jirovec, Lynch, Jacobson, Kidder, Lund, and others, applied the silver-impregnation methods to many other ciliates and confirmed Klein's observations. Chatton and Lwoff (1935) found in Apostomea, the system remains even after the embryonic cilia have entirely disappeared and, therefore, named it infraciliature. The question whether the neuromotor apparatus and the silver- line system are independent structures or different aspects of the same structure has been raised frequently. Turner (1933) found that in Euplotes patella the silverline system is a regular latticework on the dorsal surface and a more irregular network on the ventral surface. These lines are associated with rows of rosettes from which bristles extend. These bristles are held to be sensory in function and the network, a sensory conductor system, which is connected with the neuromotor system. Turner main- tains that the neuromotor apparatus in Euplotes patella is augmented by a distinct but connected external network of sensory fibrils. Lund (1933) also made a comparative study of the two systems in Paramecium multimicronucleata, and observed that the silver- line system of this ciliate consists of two parts. One portion is made up of a series of closely-set polygons, usually hexagons, but flattened into rhomboids or other quadrilaterals in the regions of the cytostome, cytopyge, and sutures. This system of lines stains if the organisms are well dried. Usually the lines appear solid, but frequently they are interrupted to appear double at the ver- tices of the polygons which Klein called "indirectly connected" (pellicular) conductile system. In the middle of the anterior and posterior sides of the hexagons is found one granule or a cluster of 2-4 granules, which marks the outer end of the trichocyst. The second part which Klein called "directly connected" (subpel- licular) conductile system consists essentially of the longitudinal lines connecting all basal granules in a longitudinal row of hexa- gons and of delicate transverse fibrils connecting granules of adjacent rows especially in the cytostomal region (Fig. 19). By using Sharp's technique, Lund found the neuromotor sys- tem of Paramecium multimicronucleata constructed as follows: The subpellicular portion of the system is the longitudinal fibrils which connect the basal granules. In the cytostomal region, the fibrils of right and left sides curve inward forming complete cir- cuits (the circular cytosomal fibrils) (Fig. 20). The postoral MORPHOLOGY 59 suture is separated at the point where the cytopyge is situated. Usually 40-50 fibrils radiate outward from the cytostome (the radial cytostomal fibrils). The pharyngeal portion is more com- plex and consists of 1) the oesophageal network, 2) the motorium and associated fibrils, 3) penniculus which is composed of 8 rows of basal granules, thus forming a heavy band of cilia in the Fig. 19. Diagram of the cortical region of Paramecium multimicronu- cleata, showing various organellae, x7300 (Lund), bg, basal granule; c, cilia; et, tip of trichocyst; If, longitudinal fibril; p, pellicle; t, tricho- cyst; tf, transverse fibril. cytopharynx, 4) oesophageal process, 5) paraoesophageal fibrils, 6) posterior neuromotor chain, and 7) postoesophageal fibrils. Lund concludes that the so-called silverline system includes three structures: namely, the peculiarly ridged pellicle; trichocysts which have no fibrillar connections among them or with fibrils, hence not conductile; and the subpellicular system, the last of which is that part of the neuromotor system that concerns with the body ciHa. ten Kate (1927) suggested that sensomotor ap- paratus is a better term than the neuromotor apparatus. Protective or supportive organellae The external structures as found among various Protozoa which serve for body protection have already been considered 60 PROTOZOOLOGY Fig. 20. The neuromotor system of Paramecium multimicronudeata (Lund), a, oral network; b, motorium, X1670. aep, anterior end of penniculus; c, cytopyge; ccf, circular cytostomal fibril; cof, circular oesophageal fibril; cpf, circular phar3aigeal fibril; ef, endoplasmic fibrils; Ibf, longitudinal body fibril; lof, longitudinal oesophageal fibrils; Ipf, longitudinal pharyngeal fibril; m, motorium; oo, opening of eosophagus; op, oesophageal process; paf, paraoesophageal fibrils; pep, posterior end of penniculus; pnc, posterior neuromotor chain; pof, postoesophageal fibrils; rcf, radial cytostomal fibril; s, suture. MORPHOLOGY 61 (p. 38). Here certain internal structures will be discussed. The greater part of the shell of Foraminifera is to be looked upon as endoskeleton and thus supportive in function. In Radiolaria, there is a membranous structure, the central capsule, which divides the body into a central region and a peripheral zone. The intracapsular portion contains the nucleus or nuclei, and is the seat of reproductive processes, and thus the capsule is to be con- sidered as a protective organella. The endoskeletal structures of Radiolaria vary in chemical composition and forms, and are ar- ranged with a remarkable regularity (pp. 371-376). In some of the astomous euciliates, there are certain structures which seem to serve for attaching the body to the host's organ, but which seem to be supportive to a certain extent also. The pecuhar organella, furcula, observed by Lynch in Lechriopyla (p. 536) is said to be concerned with either the neuromotor system or protection. The members of the family Ophryoscolecidae, which are common commensals of the stomach of ruminants, have conspicuous endoskeletal plates which arise in the oral region and extend posteriorly. Dogiel (1923) believed that the skeletal plates of Cycloposthium and Ophryoscolecidae are made up of hemicellulose, "ophryoscolecin," which was also observed by Strelkow (1929). MacLennan found that the skeletal plates of Polyplastron multivesiculatuni were composed of small, roughly prismatic blocks of glycogen, each possessing a central granule. In certain Polymastigina and Hypermastigina, there occurs a flexible structure known as the axostyle, which varies from a filamentous structure as in several Trichomonas, to a very con- spicuous rod-like structure occurring in Parajoenia, Giganto- monas, etc. The anterior end of the axostyle is very close to the anterior tip of the body, and it extends lengthwise through the cytoplasm, ending near the posterior end or extending beyond the body surface. In other cases, the axostyle is replaced by a bundle of axostylar filaments which have connections with the flagella as seen in Polymonadina and certain Hypermastigina such as Lophomonas. Kirby showed that in Trichomonas tennop- sidis, the axostyle and the granules occurring in it, are of glycog- enous substance. In trichomonad flagellates there is often present along the at- tachment of the undulating membrane a rod-like structure which has been known as costa (Kunstler) and which, according to 62 PROTOZOOLOGY Kirby's extensive study, appears to be the most highly developed in Pseudotrypanosoma and Trichomonas. The staining reaction indicates that its chemical composition is different from that of fiagella, blepharoplast, parabasal body, or chromatin. In the gymnostomous cihates, the cytopharynx is often sur- rounded by rod-hke bodies, and the entire apparatus is often called oral or pharyngeal basket, which is considered as sup- portive in function. The rod-like bodies appear in most cases to Fig. 21. a, trichites in Spathidium spathula, X300 (Woodruff and Spencer); b, trichites in Enchelyodon farctus, X400 (Roux). be trichites which may have been derived from the trichocysts, but which do not explode as do the latter. For example, in Chilodonella cucullulus the oral basket is composed of 12 trichites which are so completely fused in part that the lower portion ap- pears as a smooth tube and in Enchelyodon farctus (Fig. 21, b) much longer trichites form the basket, with reserve structures scattered throughout the cytoplasm (Engelmann). In Spathidium spathula (Fig. 21, a), trichites are imbedded hke a paling in the thickened rim of the anterior end. They are also distributed throughout the endoplasm and, according to Woodruff and Spencer, "some of these are apparently newly formed and being transported to the oral region, while others may well be trichites which have been torn away during the process of prey ingestion." MORPHOLOGY 63 Whether the numerous 12-20^ long needle-Hke endoskeletal structures which Kahl observed in Remanella (p. 522) are modi- fied trichites or not, is not known. In numerous ciliates, there is another ectoplasmic organella, the trichocyst, which is much shorter, though somewhat similar in general form. As seen in a Paramecium, the refractile fusiform trichocysts are embedded in the ectoplasm and arranged at right angles to the body surface, while in forms, such as Cyclogramma they are situated obliquely (Fig. 240, c). In Frontonia leucas (Fig. 22), Tonniges found that the trichocysts originated in the chromatinic endosomes of the macronucleus and development takes place during their migration to the ectoplasm; on the other hand, Brodsky believes that the trichocysts are composed of colloidal excretory substances and are first formed in the vicinity of the macronucleus, becoming fully formed during the course of their migration toward the periphery of the body. In species of Prorodon, Kriiger recently observed that the rod-like trichocysts of these ciliates are composed of a cylindrical sac containing a long filament which is arranged in a manner somewhat similar to the polar capsule of cnidosporidian spores. The end facing the body surface is filamentous and connected with the pellicle. The extrusion of the trichocysts is easily induced by means of mechanical pressure or chemical (acid or alkaline) stimulation, though the mechanism of extrusion is not well understood in all forms. Brodsky maintains that the fundamental force is not the mechanical pressure, but that the expansion of the colloidal sub- stances results under the influence of certain stimuli in the ex- trusion of the trichocysts through the pellicle. The fully extruded trichocysts are needle-like in general form. The trichocysts of Frontonia leucas are about G/j, long, but when extruded, measure 50-60/x in length, and those of Paramecium caudatum may reach 40m ill length. Dileptus anser feeds on various ciliates through the cytostome, located at the base of the proboscis, which possesses a band of long trichocysts on its ventral side. When food organisms come in contact with the ventral side of the proboscis, they give a violent jerk, and remain motionless. Visscher saw no formed elements discharged from the trichocysts, and, therefore, considered that these trichocysts contained a toxic fluid and named them toxi- cytes. Recently Hayes found that the exploded trichocysts (Fig. 64 PROTOZOOLOGY ill thr WW extr •I I ! trb P trg trb rt en Fig. 22. a, b, cortical region of Frontonia leucas, with embedded and extruded trichocysts (Tonniges) ; c, d, embedded and discharged tricho- cysts of Dileptus anser, X4200 (Hayes); e, two extruded trichocysts of Paramecium caudatutn, X1530. ci, cilium; ec, ectoplasm; en, endo- plasm; extr, extruded trichocyst; p, pellicle; rt, root of trichocyst; thr, thread of trichocyst; tr, trichocyst; trb, bulb of trichocyst; trg, trichocyst granule. MORPHOLOGY 65 22) could be distinctly seen and suggested that these trichocysts themselves may be toxic. Although the trichocyst was first discovered by Elhs (1769) and so named by Allman (1855), nothing concrete is yet known as to their function. Ordinarily the trichocysts are considered as a defensive organella as in the case of the oft-quoted example Paramecium, but, as Mast demonstrated, the extruded tricho- cysts of this ciUate do not have any effect upon Didinium other than forming a viscid mass about the former to hamper the latter. Penard considers that some trichocysts may be secretory organel- le to produce material for loricae or envelope,, with which view Kahl concurs, as granular to rod-shaped trichocysts occur in Metopus, Amphileptus, etc. Klein has called these ectoplasmic granules protrichocysts, and in Prorodon, Kriiger observed, be- sides typical tubular trichocysts, torpedo-like forms to which he applied the same name. To this group may belong the trichocysts recognized by Kidder in Conchophthirus mytUi. The trichocysts present in certain Cryptomonadina (Chilomonas and Cyatho- monas) are probably homologous with the protrichocysts. The pigments, which give a beautiful coloration to certain ciliates such as Stentor and Blepharisma, are said to be lodged in the protrichocysts. Hold-fast organellae In the Mastigophora, Ciliophora, and a few Sarcodina, there are forms which possess a stalk supporting the body or the lorica. With the stalk the organism is attached to a solid surface. In some cases, as in Anthophysa, Maryna, etc., the dendritic stalks are made up of gelatinous substances rich in iron, which gives to it a reddish color. In parasitic Protozoa, there are special organellae developed for attachment. Many genera of cephaline gregarines are provided with an epimerite of different structures (Figs. 181- 183), by w^hich the organisms are able to attach themselves to the gut epithelium of the host. In Astomata, such as Intoshellina, Maupasella, Lachmannella, etc., simple or complex protrusible chitinous structures are often present in the anterior region; or a certain area of the body may be concave and serves for adhesion to the host, as in Rhizocaryum, Perezella, etc.; or, again, there may be a distinctive sucker-hke organella near the anterior ex- tremity of the body, as in Haptophyra, Steinella, etc. A sucker is also present on the antero-ventral part of Giardia intestinalis. 66 PROTOZOOLOGY In the Myxosporidia and Actinomyxidia, there appear, during the development of s})ore, 1-4 special cells which develop into 1-4 polar capsules, each, when fully formed, enclosing a more or less long spirally coiled hollow thread, the polar filament (Fig. 221). The polar filament is considered as a temporary anchoring or- ganella of the spore at the time of its germination after it gained entrance into the alimentary canal of a suitable host. The nema- tocysts (Fig. 104, b) of certain dinoflagellates belonging to Nema- toidium and Polykrikos, are almost identical in structure with those found in the coelenterates. They are distributed through the cytoplasm, and various developmental stages were noticed by Chatton, and Kofoid and Swezy, which indicates that they are characteristic structures of these dinoflagellates and not foreign in origin as had been held by some. The function of the nemato- cysts in these protozoans is not understood. The parabasal apparatus In the cytosome of many parasitic flagellates, there is frequent- ly present a conspicuous structure known as the parabasal ap- paratus (Janicki), consisting of the parabasal body and the thread (Cleveland), which latter may be absent in some cases. This structure varies greatly among different genera and species in appearance, structure and position within the body. It is usually connected with the blepharoplast and located very close to the nucleus, though not directly connected with it. It may be single, double, or multiple, and may be pyriform, straight or curved rod-like, bandform, spirally coiled or collar-like (Fig. 23). Kofoid and Swezy considered that the parabasal body is derived from the nuclear chromatin, varies in size according to the meta- bolic demands of the organism, and is a "kinetic reservoir." On the other hand, Duboscq and Grasse maintain that this body is the Golgi apparatus, since 1) acetic acid destroys both the para- basal body and the Golgi apparatus; 2) both are demonstrable with the same technique; 3) the parabasal body is made up of chromophile and chromophobe parts as is the Golgi apparatus; and 4) there is a strong evidence that the parabasal body is secre- tory in function. According to Kirby, who has made an extensive study of this organella, the parabasal body could be stained with Delafield's haematoxylin or Mallory's triple stain after fixation with acetic acid-containing fixatives and the body does not show MORPHOLOGY 67 any evidence to indicate that it is a secretory organella. Moreover the parabasal body is discarded or absorbed at the time of divi- sion of the body and two new ones are formed. In the parabasal body of LopJwmonas hlattarum to which the name was originally applied, the structure is discarded when the organism divides and two new ones are reformed from the cen- triole or blepharoplast (Fig. 59), and its function appears to be Fig. 23. Parabasal apparatus in: a, Lophomonas hlattarum (Kudo); b, Metadevescovina debilis; c, Devescovina sp. (Kirby). af, axostylar filaments; bl, blepharoplast; f, food particles; fl, flagella; n, nucleus; pa, parabasal apparatus. supportive. Possibly not all so-called parabasal bodies are homol- ogous or analogous and a fuller comprehension of the function of the organella rests with further investigations. The blepharoplast or centriole In the jMastigophora or in other groups in which flagellate stages occur, the flagellum ends internally in a basal granule, which, in turn, is sometimes connected by a much larger body. This latter organella has been called the centriole or blepharo- 68 PROTOZOOLOGY plast. In many instances they appear to be combined in one. The blepharoplast is further connected by a fibril, the rhizoplast, with the nucleus (Fig. 24). The blepharoplast and centriole are con- l4':5 hJ Fig. 24. Flagellar attachment in Euglenoidina (Hall and Jahn). a, Euglena deses, X2025; b, E. acus, X750; c, E. spirogyra, X720; d, Menoidium incurvum, X1550. sidered synonymous by Minchin, Cleveland, and others, since this organella gives rise to the kinetic element. Woodcock and Minchin held, on the other hand, that the blepharoplast was a nucleus holding a special relation with locomotor organellae, and MORPHOLOGY 69 called it kinetonucleus. In recent years it has become known that the blepharoplast of many flagellates responds positively to Feulgen's nucleal reaction which indicates the presence of thymo- nucleic acid or chromatin in this structure. The Golgi apparatus With the discovery of a wide distribution of the so-called Golgi apparatus in metazoan cells, a number of protozoologists also re- ported a homologous structure from many protozoans. It seems impossible at present to indicate just exactly what is the Golgi Fig. 25. The Golgi bodies in Amoeba proteus (Brown). apparatus, since the so-called Golgi techniques, the important ones of which are based upon the assumption that the Golgi ma- terial is osmiophile and argentophile, and possesses a strong affin- ity to neutral red, are not specific and the results obtained by using the same method often vary a great deal. Some of the ex- amples of the Golgi apparatus reported from various Protozoa are mentioned on page 70. It appears thus that the Golgi bodies occurring in Protozoa are small osmiophilic granules or larger spherules which are composed of osmiophile cortical and osmiophobe central substances. Fre- 70 PROTOZOOLOGY Protozoa Golgi apparatus Observers Monocystis, Gregarina Spheres, rings, crescents Hirschler Endamoeba blattae Spheres, rings, crescents Hirschler Adelea Crescents, beaded grains King and Gatenby Entamoeba gingivalis Rings, crescents to network Causey Vorticella, Lionotus, The membrane of con- Nassonov Paramecium, Dogi- tractile vacuole and col- ella, Nassula, Chilo- lecting canals monas, Chilodonella Holomastigotes, Pyr- Parabasal bodies Dubocsq and sonympha, etc. Grasse Aggregata, gregarines Crescents, rings Joyet- Lavergne Euglenoidina Stigma Grass^ Chilomonas Granules, vacuoles Hall Peranema Rings, globules, granules Hall Chromulina, Astasia Rings, spherules with a dark rim Hall Amoeba proteus (Fig. 25) Rings, crescents, globules, granules Brown Pyrsonympha, Di- Rings, crescents, spherules; Brown nenympha granules break down to form network near pos- terior end Euglena gracilis Spherical, discoidal with dark rim; tend to group around or near nucleus Brown Blepharisma undulans Rings in the cytoplasm Moore quently the cortical layer is of unequal thickness, and, therefore, crescentic forms appear. Ringform apparatus was noted in Chilo- donella and Dogiella by Nassonov and network-like forms were observed by Brown in Pyrsonympha and Dinenympha. The numerous observations on the Golgi apparatus of Protozoa as well as of Metazoa, indicate that it is composed of a lipoidal ma- terial in combination with a protein. In line with the suggestion made for the metazoan cell, the Golgi apparatus of Protozoa is considered as having something to do with secretion or excretion. Nassonov considers that osmio- philic lipoidal substance, which he observed in the neighborhood of the walls of the contractile vacuole and its collecting canals in many ciliates and flagellates, is homologous with the meta- MORPHOLOGY 71 zoan Golgi apparatus and secretes the fluid waste material into the vacuole from which it is excreted to the exterior. According to Brown, there is no blackening by osmic impregnation of the contractile vacuole in Amoeba proteus, but fusion of minute vacu- oles associated with crescentic Golgi bodies produces the vacuole. Duboscq and Grasse who hold that the parabasal body is the Golgi apparatus, maintain that this body is a source of energy which is utilized by the motor organellae. Joyet-Lavergne pointed out that in certain sporozoans the Golgi apparatus is granular and may be the center of enzyme production. The exact morpho- logical and physiological information of the Golgi apparatus must be looked for in future observations. The chondriosomes Widely distributed in many metazoan cells, the chondriosomes have also been recognized in various Protozoa. The chondriosomes possess a low refractive index, and are composed of substances easily soluble in alcohol, acetic acid, etc. Janus green B stains them even in 1 : 500,000 solution, but stains also other inclusions, such as the Golgi bodies (in some cases) and certain bacteria. Ac- cording to Horning (1926), janus red is said to be a more exclusive chondriosome stain, as it does not stain bacteria. The chemical composition of the chondriosome seems to be somewhat similar to that of the Golgi body; namely, it is a protein compounded with a lipoidal substance. If the protein is small in amount, it is said to be unstable and easily attacked by reagents; on the other hand, if the protein is relatively abundant, it is more stable and resist- ant to reagents. The chondriosomes occur as small spherical to oval granules, rod-like or filamentous bodies, and show a tendency to adhere to or remain near protoplasmic surfaces. In many cases they are dis- tributed without any definite order; in others, as in Paramecium or Opalina, they are regularly arranged between the basal gran- ules of cilia (Horning). In Peranema trichophorum (Fig. 26), ac- cording to Hall, the chondriosomes are said to be located along the spiral striae of the pellicle. Causey (1925) noticed in Leish- mania hrasiliensis usually eight spherical chondriosomes in each individual, which become rod-shaped when the organism divides. He further observed spherical and rod-like chondriosomes in Noctiluca scintillans. 72 PROTOZOOLOGY In certain Protozoa, the chondriosomcs are not always demon- strable. For example, Horning states in Monocystis the chondrio- somes present throughout the asexual Hfe-cycle as rod-shaped bodies, but at the beginning of the spore formation they decrease in size and number, and in the spore none exists. The chondrio- somcs appear as soon as the sporozoites are set free. Thus it would appear that the chondriosomcs were reformed de novo. On the other hand, Faure-Fremiet, the first student of the chondrio- somcs in Protozoa, maintained that they reproduce by division, v» /» » .» » .'A' A VM ~ « » * N^ \' "\v>: Fig. 26. The chrondriosomes in Peranema trichophorum, X1750 (Hall)' a, b, surface views and c, optical section of a single individual. which has since been confirmed by many observers. As a matter of fact, Horning found in Opalina, the chondriosomcs are twisted filamentous structures and underwent multiple longitudinal fis- sion in asexual division phase. Before encystment, the chondrio- somcs divide repeatedly transversely and become spherical bodies which persist during encystment and in the gametes. In zygotes, these spherical bodies fuse to produce longer forms which break up into elongate filamentous structures. Richardson and Horning further succeeded in bringing about division of the chondriosomcs in Opalina by changing pH of the medium. As to the function of chondriosomcs, opinions vary. A number of observers hold that they are concerned with the digestive process. After studying the relationship between the chondrio- MORPHOLOGY 73 somes and food vacuoles of Amoeba and Paramecium, Horning suggested that the chondriosomes are the seat of enzyme activity and it is even probable that they actually give up their own sub- stance for this purpose. The view that the chondriosomes may have something to do with the cell-respiration expressed by Kingsbury was further elaborated by Joyet-Lavergne through his studies on certain Sporozoa. That the chondriosomes are ac- tively concerned with the development of the gametes of the Metazoa is well known. Zweibaum's observation, showing an in- crease in the amount of fatty acid in Paramecium just prior to conjugation, appears to suggest this function. On the other hand, Calkins found that in Uroleptus, the chondriosomes became abundant in exconjugants, due to transformation of the macro- nuclear material into the chondriosomes. It may be stated that the chondriosomes appear to be associated with the formation of enzymes which participate actively in the processes of catalysis or synthesis in the protozoan body. The author agrees with McBride and Hewer who wrote: "it is a remarkable thing that so Httle is known positively about one of the 'best known' proto- plasmic inclusions." The contractile and other vacuoles The majority of Protozoa possess one or more vacuoles known as pulsating or contractile vacuoles. They occur regularly in all freshwater inhabiting Sarcodina and Mastigophora, and in Cilio- phora regardless of habitat. In the Sporozoa, which are all para- sitic, and the Sarcodina and Mastigophora, which live either in salt water or in the body of other animals, there is no contractile vacuole. In various species of free-living amoebae, the contractile vacu- ole is formed by accumulation of water in one or more droplets which finally fuse into one. It enlarges itself continuously until it reaches a maximum size (diastole) and suddenly bursts through the thin cytoplasmic layer above it (systole), discharging its con- tents to outside. The location of the vacuole is not definite in such forms and, therefore, it moves about with the cytoplasmic move- ments; and, as a rule, it is confined to the temporary posterior region of the body. Although almost spherical in form, it may oc- casionally be irregular in shape, as in Amoeba striata (Fig. 140, /). In many testaceans and heliozoans, the contractile vacuoles 74 PROTOZOOLOGY ,y X' Fig. 27. Diagrams showing the contractile vacuole, the accessory vacuoles and the aperture, during diastole and systole in Conchoph- thirus (Kidder). which are variable in number, are formed in the ectoplasm and the body surface bulges out above the vacuoles at diastole. In the Mastigophora, the contractile vacuole appears to be more or less constant in position. In Phytomastigina, they are usually located near the anterior region and, in Zoomastigina, as a rule, in the posterior half of the body. The number of the vacuoles present in an individual varies from one to several. In Euglenoidina, one or more vacuoles are sometimes arranged near the reservoir which opens to "cytopharynx." In the Ciliophora, except Protociliata, there occur one to many contractile vacuoles, which seem to be located in the deepest part of the ectoplasm and therefore constant in position. Directly above each vacuole is found a pore in the pellicle, through which the contents of the vacuole are discharged to outside. In the spe- cies of Conchophthirus, Kidder (1934) observed a narrow slit in the pellicle just posterior to the vacuole on the dorsal surface (Fig. 27). The margin of the slit is thickened and highly refrac- tile. During diastole, the slit is nearly closed and, at systole, the wall of the contractile vacuole appears to break and the slit opens suddenly, the vacuolar contents pouring out slowly. When there is only one contractile vacuole, it is usually located either near the cytopharynx or, more often, in the posterior part of the body. When several to many vacuoles are present, they may be dis- tributed without apparent order, in linear series, or along the body outline. When the contractile vacuoles are deeply seated, there is a delicate duct which connects the vacuole with the pore on the pellicle as in Paramecium woodruffi or in Ophryoscolecidae. In Balantidium, Nyctotherus, etc., the contractile vacuole is formed very close to the permanent cytopyge located at the posterior extremity, through which it empties its contents. MORPHOLOGY 75 In a number of ciliates there occur radiating or collecting canals besides the main contractile vacuole. These canals radiate from the central vacuole in Paramecium, Frontonia, Disemato- stoma, etc. But when the vacuole is terminal, the collecting canals of course do not radiate, in which case the number of the canals varies among different species: one in Spirostomum, Stentor, etc., 2 in Climacostomum, Eschaneustyla, etc., and several in Tillina. In Peritricha, the contractile vacuole occurs near the posterior region of the peristome and its contents are discharged through a canal into the vestibule. \.y o= <=>!^3^^ <^f^'%Z> \Z7 \ vU =>o FiG. 28. Diagrams showing the successive stages in the formation of the contractile vacuole in Paramecimn rnultimicronucleata (King) ; upper figures are side views; lower figures front views; solid lines indi- cate permanent structures; dotted lines temporary structures, a, full diastole; b-d, stages of systole; e, contents of ampulla passing into injection canal; f, formation of vesicles from injection canals; g, fusion of vesicles to form contractile vacuole; h, full diastole. Of numerous observations concerning the operation of the con- tractile vacuole, that of King (1935) on Paramecimn multimi- croniicleata (Figs. 28, 29) may be quoted here. In this ciliate, there are 2 to 7 contractile vacuoles which are located below the ecto- plasm on the aboral side. There is a permanent pore above each vacuole. Leading to the pore is a short tube-like invagination of the pellicle, with inner end of which the temporary membrane of the vacuole is in contact (Fig. 28, a). Each vacuole has 5-10 long 76 PROTOZOOLOGY Fig. 29. Contractile vacuoles of Paramechivi multimicrouudeata, X1200 (King), a, early systole, side view; b, diastole, front view; c, complete systole, front view; d, systole, side view. MORPHOLOGY 77 collecting canals with strongly osmiophile walls (Fig. 29), and each canal is made up of terminal portion, a proximal injection canal, and an ampulla between them. Surrounding the distal por- tion, there is osmiophilic cytoplasm which may be granulated or finely reticulated, and which Nassonov interpreted as homologous to the Golgi apparatus of the metazoan cell. The injection canal extends up to the pore. The ampulla becomes distended first with fluid transported discontinuously down the canal and the fluid next moves into the injection canal. The fluid now is expelled into the cytoplasm just beneath the pore as a vesicle, the membrane of which is derived from a membrane which closed the end of the injection canal. These fluid vesicles coalesce presently to form the contractile vacuole in full diastole and the fluid is discharged to exterior through the pore, which becomes closed by the remains of the membrane of the discharged vacuole. The function of the contractile vacuole is considered in the following chapter (p. 98). Various other vacuoles or vesicles occur in different Protozoa. In the ciliates belonging to Loxodidae, there are variable numbers of Miiller's vesicles or bodies arranged in 1-2 rows along the aboral surface. These vesicles (Fig. 30, a-c) vary in diameter from 5 to 8.5/i and contain a clear fluid in which one large spherule or several small highly refractile spherules are suspended. In some, there is a filamentous connection between the spherules and the wall of the vesicle. Penard maintains that these bodies are balanc- ing cell-organs and called the vesicle, the statocyst, and the spher- ules, the statoliths. Another vacuole, known as concrement vacuole, is a character- istic organella in Butschliidae and Paraisotrichidae. As a rule, there is a single vacuole present in an individual at the anterior third of body. It is spherical to oval and its structure appears to be highly complex. According to Dogiel, the vacuole is composed of a pelhcular cap, a permanent vacuolar wall, concrement grains and two fibrillar systems (Fig. 30, d). When the organism divides, the anterior daughter individual retains it, and the posterior in- dividual develops a new one from the pellicle into which concre- ment grains enter after first appearing in the endoplasm. This vacuole shows no external pore. Dogiel believes that its function is sensory and has named the vacuole, the statocyst, and the en- closed grains, the statoliths. Food vacuoles are conspicuously present in the holozoic Pro- 78 PROTOZOOLOGY Fig. 30. a-c, Mtiller's vesicles in Loxodes (a, b) and in Remanella (c) (a, Penard; b, c, Kahl); d, concrement vacuole of Blepharoprosth- ium (Dogiel). cf, centripetal fibril; eg, concrement grains; cp, cap; fw, fibrils of wall; p, pellicle; vp, vacuolar pore; w, wall. tozoa which take in whole or parts of other organisms as food. The food vacuole is a space in the cytoplasm, containing the fluid medium which surrounds the protozoans and in which are sus- pended the food matter, such as various Protophyta, other Pro- tozoa or small Metazoa. In the Sarcodina, the Mastigophora and the Suctoria, which do not possess a cytostome, the food vacuoles assume the shape of the food particles and, when these particles are large, it is difficult to make out the thin film which surrounds them. When minute food particles are taken through a cyto- stome, as is the case with the majority of euciliates, the food vacu- oles are usually spherical and of approximately the same size within a single protozoan. In the saprozoic Protozoa, which ab- sorb fluid substances through the body surface, food vacuoles containing solid food, of course, do not occur. The chromatophore and associated organellae In the Phytomastigina and certain other forms which are green-colored, one to many chromatophores (Fig. 31) or chloro- plasts containing chlorophyll occur in the cytosome. The chroma- I MORPHOLOGY 79 t ophores vary in form among different species ; namely, discoidal, ovoid, band-form, rod-like, cup-like, network or irregularly dif- fused. The color of the chromatophore depends upon the amount and kinds of pigment which envelops the underlying chlorophyll substance. Thus the chromatophores of Chrysomonadina are brown or orange, as they contain one or more accessory pigments, including phycochrysin, and those of Cryptomonadina are of various types of brown with very diverse pigmentation. In Chla- romonadina, the chromatophores are bright green, containing an excess of xanthophyll. In dinoflagellates, they are dark yellow or brown, because of the presence of pigments: carotin, phylloxan- thin, and peridinin (Kylin), the last of which is said to give the brown coloration. A few species of Gymnodinium contain blue- green chromatophores for which phycocyanin is held to be re- sponsible The chromatophores of Phytomonadina and Euglenoi- dina are free from any pigmentation, and therefore green. Aside from various pigments associated with the chromatophores, there are carotinoid pigments which occur often outside the chrom- atophores, and are collectively known as haematochrome. The haematochrome occurs in Haematococcus pluvialis, Euglena sanguinea, Chlamydomonas, etc. In Haematococcus, it increases in volume and in intensity when there is a deficiency in phosphorus and especially in nitrogen; and when nitrogen and phosphorus are sufficiently present in the culture medium, the haematochrome loses its color completely (Reichenow; Pringsheim). Steinecke also noticed that the frequent yellow coloration of phytomonads in moorland pools is due to a development of carotin in the chro- matophores as a result of deficiency in nitrogen. In association with the chromatophores are found the pyre- noids (Fig. 31) which are usually embedded in them. The pyre- noid is a viscous structureless mass of protein (Czurda), and may or may not be covered by tightly fitting starch-envelope, com- posed of several pieces or grains which appear to grow by apposi- tion of new material on the external surface. A pyrenoid divides when it reaches a certain size, and also at the time of the division of the organism in which it occurs. As to its function, it is gen- erally agreed that the pyrenoid is concerned with the formation of the starch and allied anabolic products of photosynthesis. Chromatophore-bearing Protozoa usually possess also a stigma (Fig. 31) or eye-spot. The stigma may occur in exceptional cases in colorless forms, as in Khawkinea according to Jahn. It is ordi- 80 PROTOZOOLOGY narily situated in the anterior region and appears as a reddish or brownish red spot or rod, embedded in the cortical layer of the cytoplasm. The color of the stigma is due to the presence of drop- lets of haematochrome in a cytoplasmic network. The stigma is incapable of division and a new one is formed de novo at the time of cell division. In many species, the stigma possesses no acces- sory parts, but, according to Mast, the pigment mass in Chlamy- Flagella Stigma Pyrenoids Chromatophores — Nucleus Shell Chromatophores Pyrenoids Fig. 31. a, Trachelomonas hispida, X530 (Doflein); b, c, living and stained reproductive cells of Pleodorina illinoisensis, XlOOO (Merton) ; d-f, terminal cells of Hydrur us foetid us, showing division of chromato- phore and pyrenoid (Geitler); g-i, Chlamydomonas sp., showing the division of pyrenoid (Geitler). domonas, Pandorina, Eudorina, Euglena, Trachelomonas, etc., is in cup-form, the concavity being deeper in the colonial than in solitary forms. There is a colorless mass in the concavity, which appears to function as a lens. In certain dinoflagellates, there is an ocellus (Fig. 101,c, d,(j,h) M'hich is composed of amyloid lens and a dark pigment mass (melanosome) that is sometimes capable of amoeboid change of form. The stigma is, in general, regarded as an organella for the perception of light intensity. Mast considers MORPHOLOGY 81 that the stigma in the Volvocidae is an organella which deter- mines the direction of the movement. References Belar, K. 1926 Der Formwechsel der Protistenkerne. Ergebn, u. Fortschr. Zool., Vol. 6. Brodsky, a. 1924 Die Trichocysten der Infusorien. Arch. rus. protist., Vol. 3. Brown, V. E. 1930 The Golgi apparatus of Amoeba proteus. Biol. Bull., Vol. 59. 1930 The Golgi apparatus of Pyrsonympha and Dine- nympha. Arch. f. Protistenk., Vol. 71. Chatton, E. and A. Lwoff 1935 Les cilies apostomes. Arch. zool. exp. et gen.. Vol. 77. Causey, D. 1925-1926 Mitochondria and Golgi bodies in Endamoeba gingivalis. Mitochondria in Leishmania hrasilien- sis. Mitochondria in Noctiluca scintillans. Univ. Calif. Publ. Zool., Vol. 28. Cleveland, L. R., S. R. Hall, E. P. Sanders and J. Collier 1934 The wood-feeding roach Cryptocercus, its Protozoa, and the symbiosis between Protozoa and roach. Mem. Amer. Acad. Arts Sci., Vol. 17. Cushman, J. A. 1933 Foraminifera: their classification and eco- nomic use. Second edition. Sharon, Mass. Doflein, F. 1916 Studien zur Naturgeschichte der Protozoen. VII. Zool. Jahrb. Abt. Anat., Vol. 39. Dogiel, V. 1923 Cellulose als Bestandteil des Skellettes bei einigen Infusorien. Biol. Zentralbl., Vol. 43. 1929 Die sog. "Konkrementenvakuole" der Infusorien als eine Statocyste betrachtet. Arch. f. Protistenk., Vol. 68. DuBoscQ, O. and P. P. Grasse 1933 L'appareil parabasal des flagelles. Arch. zool. exp. et gen.. Vol. 63. Gelei, J. VON 1926 Zur Kenntnis des Wimperapparates. Zeitschr. f. ges. Anat., Abt. I, Vol. 81. Giese, a. C. 1938 Reversible bleaching of Blepharisma. Trans. Amer. Micr. Soc, Vol. 57. Hall, R. P. 1929 Reaction of certain cytoplasmic inclusions to vital dyes and their relation to mitochondria and Golgi ap- paratus in the flagellate Peranema trichophorum. Jour. Morph. Physiol., Vol. 48. and T. L. Jahn 1929 On the comparative cytology of certain euglenoid flagellates and the systematic position of the families Euglenidae and Astasiidae. Trans. Amer. Micro. Soc, Vol. 48. Hayes, M. L. 1938 Cytological studies on Dileptus anser. Ibid., Vol. 57. Hertwig, R. 1902 Die Protozoen und die Zelltheorie. Arch. f. Protistenk., Vol. 1. 82 PROTOZOOLOGY Horning, E. S, 1926 Observations on mitochondria. Austral. Jour. Exp. Biol. Med. Sci., Vol. 3. 1927 On the orientation of mitochondria on the surface cytoplasm of infusorians. Ibid., Vol. 4. 1929 Mitochondrial behavior during the life cycle of a sporozoan (Monocystis). Quart. Jour. Micr, Sci., Vol. 73. Janicki, C. v. 1911 Zur Kenntnis des Parabasalapparates bei parasitischen Flagellaten. Biol. Zentralbl., Vol. 31. Kidder, G. W. 1933 On the genus Ancistruma Strand (Ancis- trum Maupas). Biol. Bull., Vol. 64. 1933 Conchophthirus caryoclada sp. nov. Ibid., Vol. 65, 1934 Studies on the ciliates from freshwater mussels. Ibid., Vol. 66. King, R. L. 1935 The contractile vacuole of Paramecium multi- micronucleata. Jour. Morph., Vol. 58. KiRBY, Jr., H. 1931 The parabasal body in trichomonad flagel- lates. Trans. Amer. Micr. Soc, Vol. 50. Klein, B. M. 1926 Ergebnisse mit einer Silbermethode bei Ciliaten. Arch. f. Protistenk., Vol. 56. 1927 Die Silverliniensystem der Ciliaten. Ibid., Vol. 58. — 1929 Weitere Beitrage zur Kenntnis des Silberlinien- systems der Ciliaten. Ibid., Vol. 65. 1930 Das Silberliniensystem der Ciliaten. Ibid., Vol. 69. KoFOiD, C. A. and Olive Swezy 1921 The free-living un- armored Dinoflagellata. Mem. Univ. California. Vol. 5. KoLTZOFF, N. K. 1911 Untersuchung iiber die Kontraktilitat des Stieles von Zoothamnium alternans. Biol. Zeitschr. Mos- kau., Vol. 2. Kruger, F. 1934 Untersuchungen liber die Trichocysten einiger Prorodon-Arten. Arch. f. Protistenk., Vol. 83. Kudo, R. R. 1924 A biologic and taxonomic study of the Micro- sporidia. Illinois Biol. Monogr., Vol. 9. 1926 Observations on Lophomonas hlattarum, a flagel- late inhabiting the colon of the cockroach, Blatta orientalis. Arch. f. Protistenk., Vol. 53. 1936 Studies on Nydotherus ovalis Leidy, with special reference to its nuclear structure. Ibid., Vol. 87. Lund, E. E. 1933 A correlation of the silverline and neuromotor systems of Paramecium. Univ. Calif. Publ. ZooL, Vol. 39. Lynch, J. E. 1930 Studies on the ciliates from the intestine of Strongylocentrotus. II Lechriopylamijsta.r, gen. nov., sp. nov. Ibid. Vol. 33. Mast, S. O. 1928 Structure and function of the eye-spot in unicellular and colonial organisms. Arch. f. Protistenk., Vol. 60. Nassonov, D. 1924 Der Exkretionsapparat (kontraktile Vaku- ole) der Protozoen als Homologen des Golgischen Apparatus der Metazoenzelle. Arch. mikr. Anat., Vol. 103. MORPHOLOGY 83 Penard, E. 1922 Etudes sur les infusoires d'eau douce. Geneva. PiNEY, A. 1931 Recent advances in microscopy. London. Pringsheim, E. 1914 Die Ernahrung von Haematococcus pluvi- alis. Beitr. Biol. Pflanzen, Vol. 12. Reichenow, E. 1909 Untersuchungen an Haematococcus pluvi~ alis nebst Bemerkungen liber andere Flagellaten. Arch, kaiserl, Gesundheitsamt., Vol. 33. 1928 Ergebnisse mit der Nuklealfarbung bei Protozoen. Arch. f. Protistenk., Vol. 61. Richardson, K. C. and E. S. Horning 1931 Cytoplasmic struc- tures in binucleate opalinids with special reference to the Golgi apparatus. Jour. Morph. Physiol., Vol. 52. RosKiN, G. 1923 La structure des Myonemes des infusoires. Bull. biol. France et Belg., Vol. 57. ■ 1925 Ueber die Axopodien der Heliozoa und die Greift- entakel der Ephelotidae. Arch. f. Protistenk., Vol. 52. Rumjantzew, a. and E. Wermel 1925 Untersuchungen ueber den Protoplasmabau von Actinosphaerium eichhorni. Ibid., Vol. 52. Schroder, O. 1906 Beitrage zur Kenntnis von Stentor coeruleus und St. roeselii. Ibid., Vol. 8. Schuberg, a. 1888 Die Protozoen des Wiederkauermagens. I. Zool. Jahrb. Abt. System., Vol. 3. Sharp, R. 1914 Diplodinium ecaudatum with an account of its neuromotor apparatus. Univ. Calif. Publ. Zool., Vol. 13. Strelkow, a. 1929 Morphologische Studien liber oHgotriche Infusorien aus dem Darme des Pferdes. I. Arch. f. Protist- enk., Vol. 68. Taylor, C. V. 1920 Demonstration of the function of the neuro- motor apparatus in Euplotes by the method of micro-dissec- tion. Univ. Calif. Publ. Zool., Vol. 19. ten Kate, C. G. B. 1927 Ueber das Fibrillensystem der Ciha- ten. Arch. f. Protistenk., Vol. 57. Tonniges, C. 1914 Die Trichocysten von Frontonia leucas und ihr chromidialer Ursprung. Ibid., Vol. 32. Turner, J. P. 1933 The external fibrillar system of Euplotes with notes on the neuromotor apparatus. Biol. Bull. Vol. 64. Verworn, M. 1903 Allgemeine Physiologic. Fourth edition. Jena. VisscHER, J. P. 1926 Feeding reactions in the ciliate Dileptus gigas, with special reference to the trichocysts. Biol. Bull, Vol. 45. Vlk, W. 1938 Ueber den Bau der Geissel. Arch. f. Protistenk., Vol. 90. Woodruff, L. L. and H. Spencer 1922 Studies on Spathidium spathula. I. Jour. Exp. Zool., Vol. 35. YocoM, H. B. 1918 The neuromotor apparatus of Euplotes patella. Univ. Calif. Publ. Zool, Vol. 18. Chapter 4 Physiology THE morphological consideration which has been given in the last chapter, is, though necessarily brief, indicative of the oc- currence of various and often complex organellae in Protozoa. The physiological activity of the whole protozoan is the sum-total of all the functions which are carried on by numerous minute parts or organellae of the cell body, unlike the condition found in a metazoan. Indeed, as Calkins (1933) stated, "physiological problems (of Protozoa) for the most part begin where similar problems of the Metazoa leave off, namely the ultimate processes of the single cell. Here the functional activities have to do with the action and interaction of different substances which enter into the make-up of protoplasm and, for the most part, these are be- yond our powers of analysis." A full discussion of various physio- logical problems pertaining to Protozoa is out of question in the present work and, therefore, a general consideration on protozoan physiology will suffice for our purpose. Nutrition The Protozoa obtain nourishment in manifold ways, which may be placed under three types: holozoic, holophytic, and sapro- zoic. Holozoic (zootrophic, heterotrophic) nutrition. This is the method by which all higher animals obtain their nourishment; namely, the protozoan uses other animals or plants as sources of food. It involves the food-capture and ingestion, the digestion and assimilation, and rejection of indigestible portions. The methods of food-capture vary among different forms. In the Sarcodina, the food organisms are captured and taken into the body at any point. The methods however vary. According to Rhumbler's oft-quotied observations, four methods of food-inges- tion occur in amoebae (Fig. 32) ; namely, 1) by "import," in which the food is taken into the body upon contact, with very little movement on the part of the amoeba (a); by "circumfluence," in which the cytoplasm flows around the food organism as soon as it comes in contact with it on all sides and engulfs it (b); 3) by "cir- 84 PHYSIOLOGY 85 cumvallation," in which the amoeba without contact with the food, forms pseuclopodia which surround the food on all sides and ingest it (c); 4) by "invagination," in which the amoeba touches and adheres to the food, and the ectoplasm in contact with it is Fig. 32. Various waj's by which amoebae capture food organisms. a, Amoeba verrucosa feeding on Oscillatoria by 'import' (Rhumbler); b, A. proteus feeding on bacterial glea by 'circumfluence'; c, on Para- mecium by 'circumvollation' (Kepner and Whitlock); d-h, A. ver- rucosa ingesting a food particle by 'invagination' (Gross- Allermann). invaginated into the endoplasm as a tube, the cytoplasmic mem- brane later liquefies and disappears {d-h). Jennings, Kepner, Schaeffer and others, have made studies with reference to the food-ingestion in amoebae. In certain testaceans, such as Gromia, several rhizopodia co- operate in engulfing the prey and, in Lieberkuhnia (Fig. 33), Ver- worn noted cihates are captured and digested in the rhizopodium. 86 PROTOZOOLOGY Fig. 33. A filopodium of Lieberkuhnia, capturing and digesting Colpidium colpoda (Verworn). Similar observation was made by Schaudinn in the heliozoan Camptonema in which several axopodia anastomose to capture a prey (Fig. 163, d). In the holozoic Mastigophora, such as Hyper- mastigina, which do not possess cytostome, the food-ingestion is by pseudopodia also. The food particles become attached to the pseudopodium and are held there on account of the viscid nature of the pseudopodi- um. The sudden immobility of active organisms upon coming in contact with pseudopodia of certain forms, such as Actinophrys, Actinosphaerium, Gromia, Elphidium, etc., suggests, however, probable discharge of poisonous substances. In the Suctoria which lack a cytostome, the tentacles serve as food-capturing organel- lae. The suctorial tentacle bears on its distal end a rounded knob which, when it comes in contact with an actively swimming cili- ate, stops the latter immediately (Parapodophrya typha, Fig. 287, a). The prehensile tentacles of Ephelotidae are said to be similar in structure to the axopodia, in that each possesses a bun- dle of axial filaments around a cytoplasmic core (Roskin). These tentacles are capable of piercing through the body of a prey. In some suctorians, such as Choanophrya (Fig. 291, a), the tentacles are said to be tubular, and both solid and liquid food materials are sucked in through the cavity. The rapidity with which a tentacle of a suctorian stops a very actively swimming ciliate is attributed to a certain substance secreted by the tentacles which paralyzes the prey. PHYSIOLOGY 87 In the cytostome-bearing Mastigophora, the lashing of flagella will aid in bringing about the food-particles to the cytostome, where it is taken into the endoplasm. In the ciliates there are nu- merous types of cytostomes and associated organellae. But food- capturing seems to be in general of two kinds. When the cytostome is permanently open, the organism ingests food-particles which are small enough to pass the cytostome and cytopharynx, as in the case of Paramecium. Another type is one, such as noted in Coleps, Didinium, etc., where the ciliate attacks other organism and sucks in the body substance of the latter through the en- larged cytostome. The ingested food-particles are always surrounded by a film of fluid which envelops the organism and the whole is known as the food vacuole (p. 77). The quantity of fluid taken in with the food varies greatly and, generally speaking, seems to be inversely proportional to the size, but proportional to the activity, of the food organisms. Food vacuoles composed entirely of surrounding liquid medium have occasionally been observed. Edwards (1925) observed ingestion of fluid-medium by an amoeba by forming food-cups under changed chemical composition. Brug (1928) re- ports seeing Entamoeba hystolytica engulf liquid culture medium by formation of lip-Uke elevation of the ectoplasm and Kirby (1932) figures ingestion of the brine containing no visible organ- isms by the cytostome of Rhopalophrya salina. Mast and Doyle (1934) stated that if Amoeba proteus, A. dubia, A. dofleini, or A. radiosa is placed in an albumin solution, a hypertonic balanced salt solution or a hypertonic solution of calcium gluconate, it rap- idly decreases in volume, and forms numerous tubes filled with fluid, which disintegrate sooner or later and release their fluid content in the cytoplasm. At times 50 or more such tubes may be present, which indicate that the organism ingests considerable quantities of fluid in this way. The two authors consider that it is "a biological adaptation which serves to compensate for the rapid loss of water." The food vacuoles finally reach the endoplasm and in forms such as Amoebina, the vacuoles are carried about by the moving endoplasm. In the ciliates, the fluid endoplasm often shows a definite rotation movement. In Paramecium, the general direction is along one side up to the anterior end and down the other side, with a short cyclosis in the posterior half of the body. In Carchesium, according to Greenwood, the food-vacuoles pass 88 PROTOZOOLOGY down to one end of the macronucleus and then move close to its concave surface to near the anterior end of the nucleus where def- ecation to the vestibule takes place (Fig. 34). As stated above, in a number of species the food organisms are paralyzed or killed upon contact with pseudopodia, tentacles or exploded trichocysts. In numerous other cases, the captured or- FiG. 34. Diagram showing the digestion within the food vacuoles in Carchesium polypimim (Greenwood), a, digestion area; b, region of little change; c, region of acid reaction; d, region of neutral reaction; e, defecation area. ganism is taken into the food-vacuole alive, as will easily be noted by observing Chilomonas taken in by Amoeba proteus or actively moving bacteria ingested by Paramecium. But the prey ceases to move in a very short time. Apparently some substances are se- creted into the food vacuole by the protoplasm of the organisms to stop the activity of the prey within the food vacuole. Engel- mann (1878) demonstrated that the granules of blue litmus, when ingested by Paramecium or Amoeba, became red in a few minutes. PHYSIOLOGY 89 Brandt (1881) examined the staining reactions of amoebae by means of haematoxylin, and found that the watery vacuoles con- tained acid. Metschnikoff (1889) also showed that there appears an acid secretion around the ingested litmus grains in Myceto- zoa. Greenwood and Saunders (1884) found in Carchesium that ingestion of food particles stimulated the cytoplasm to secrete a cv cv Fig. 35. Diagram showing changes in reactions in food-vacuoks of Paramecium caudatum, after ingesting litmus (Shapiro), b, blue; cv, contractile vacuole; lb, light blue; Ir, light red; r, red. mineral acid (Fig. 34). According to Nirenstein (1925), the food vacuole in Paramecium undergoes change in reaction which can be grouped in two periods. The first is acid reaction and the sec- ond alkaline reaction, in which albumin digestion takes place. On the other hand, Khainsky (1910) observed that the food vacuole of ciliates, such as Paramecium, is acid during the entire period of protein digestion, and becomes neutral to finally alkaline when the solution of the food substance is ended. Metalnikoff (1912) 90 PROTOZOOLOGY found in tlie food vacuoles of Paramecium, besides acid-alkaline reaction change, that some vacuoles never show acid reaction and others occasionally show sustained acid reaction. According to Shapiro (1927), who observed reaction change of the food vacu- oles in Paramecium caudatum (Fig. 35) by using phenol red, neu- tral red, Congo red, and litmus, when the organism is kept in a medium with pH 7, its food vacuoles are first alkaline (pH 7.6), soon reach a maximum acidity (pH 4.0), while still in the poste- rior half of the body. Later, the vacuoles show a decreased acidity, finally reaching pH 7.0 prior to excretion. In Vorticella sp. and Stylonychia pustulata, the range of pH observed in the food vacu- oles was said to be 4.5-7.0 and 4.8-7.0 respectively. The food vacuoles of Actinosphaerium, according to Rowland (1928), pos- sess at the beginning pH 6.0-7.0 for 5 to 10 minutes, but this soon changes to acid (pH 4.3) in which digestion appears to be carried on. In older food vacuoles which are of less acid (pH 5.4-5.6), the digestion appears to be at an end. Just exactly what processes take place in the food vacuole have been observed only in a few cases. Nirenstein noticed the appear- ance of numerous neutral red-stainable granules around the food vacuole which pass into the inside of the vacuole, and regarded them as carriers of a tryptic ferment, while Roskin and Levinsohn demonstrated the oxidase reaction in these granules. A number of enzymes have been reported in the Protozoa, some of which are mentioned on page 91. These findings suffice to indicate that the digestion in Protozoa is carried on also by enzymes and its course appears to vary among different Protozoa. The albuminous substances are di- gested and decomposed into simpler compounds by enzymes and absorbed by the surrounding cytoplasm. The power to digest starch into soluble sugars is widely found among various Protozoa. It has been reported in Mycetozoa, Foraminifera, Pelomyxa, Amoeba, Entamoeba, Ophryoscolecidae and other ciliates by sev- eral investigators. In Pelomyxa, Stole (1900) found that the so- called refractile bodies are intimately associated with the carbo- hydrate metabolism in that they are filled with glycogen which amount is proportionate to the food matter the organism ob- tains. The members of Vampyrella (p. 291) are known to dissolve the cellulose wall of algae, especially Spirogyra in order to feed on PHYSIOLOGY 91 Protozoa Enzymes Observers Aethalium septicum Pelomyxa palustris Soil amoebae Balantidium coli Glaucoma pyriformis Colpidium striatum Poly- and Hyper- mastigina in wood roach Pepsin-like enzyme, dis- solving albumins in acid medium Pepsin-like and diastatic enzymes "Amoebodiastase": tryp- sin-like, active in neutral or slightly alkaline me- dium, liquefies gelatin, coagulates albumin, in- active at 60°C. Diastatic enzyme Proteolytic enzyme, ca- pable of hj^drolyzing casein Proteolytic enzyme, ca- pable of hydrolyzing casein Cellulase; Cellobiase Krukenberg (1886) Hartog and Dixon (1893) Mouton (1902) Glaessner (19081 Lwoff (1932) Elliott (1933) Cleveland et al. (1934) their contents. Pelomyxa (Stole), Foraminifera (Schaudinn), Amoeba (Rhumbler), Hypermastigina, Polymastigina (Cleve- land), etc., have also been known for possessing the power of cellulose digestion. Many of the Hypermastigina and Polymasti- gina which lead symbiotic life in the intestine of the termite and the wood roach, as demonstrated by Cleveland and his cowork- ers, digest by enzymes the cellulose which the host insect ingests. The assimilation products produced by an enormous number of these flagellates are seemingly sufficient to support the protozoans as well as the host. The ciliate commensals inhabiting the stomach of ruminants also apparently digest the cellulose, since the fecal matter as a rule does not contain this substance. The digestion of fat by Protozoa had not been known, although oils and fat have been observed in numerous Protozoa, until Dawson and Belkin (1928) injected different oils into Amoeba duhia and found that from 1.4 to 8.3 per cent of the injected oil was digested. The indigestible residue of the food is extruded from the body. The extrusion may take place at any point on the surface in many Sarcodina by a reverse process of ingestion of food. But in pelli- 92 PROTOZOOLOGY cle-bearing forms, the defecation takes place either through the cytopyge located in the posterior region of the body or through an aperture to the vestibule (in Carchesium). Permanent cyto- pyge is lacking in some forms. In Fabrea salina, Kirby (1934) no- ticed that a large opening is formed at the posterior end, the con- tents of food vacuoles discharged, and the opening closes over. At first the margin of the body is left uneven, but soon the evenly rounded outline is restored. The same seems to be the case with Spirostomum (Fig. 36), Blepharisma, etc. Fig. 36. Outline sketches showing the defecation process in Spirostoni^un ambiguum (Blattner). Holophytic (autotrophic, phytotrophic) nutrition. This is the type of nutrition in which the Protozoa are able to decompose carbon dioxide by means of chlorophyll contained in chromato- phores (p. 78) in the presence of the sunUght, liberating the oxy- gen and combining the carbon with other elements derived from water and inorganic salts. The pyrenoids (p. 79) are inseparably connected with the reserve carbohydrate formation in this nutri- tion. Aside from the Phytomastigina, chromatophores were defi- nitely observed in Cyclotnchium meunieri (Fig. 230, o) by Powers. In a number of other cases, the organism itself is without chro- matophores but is apparently not holozoic, because of the presence of chlorophyll-bearing organisms within it. For example, in the testacean Paulinella (Fig. 155, c) in which occur no food vacuoles, chromatophores of peculiar shape are always present. The latter appear to be a species of algae which holds a symbiotic relation- ship with the testacean, and perhaps it acts for the sarcodinan as the chromatophores of the Phytomastigina. Saprozoic (saprophytic) nutrition. In this nutrition, the Proto- zoa obtain nourishment by diffusion through the body surface. This is accomplished without any special organellae. Perhaps the PHYSIOLOGY 93 only instance in which the saprozoic nutrition is accompHshed through a special organella is the pusules (Figs. 101, 102) in ma- rine dinoflagellates which, according to Kofoid and Swezy, ap- pear to contain decomposed organic matter and aid the organ- isms in carrying on this process. The dissolved food matters are simpler compounds which have originated in animal or vegetable matter due to the decomposing activities of bacterial organisms. Numerous free-living Zoomastigina nourish themselves with this method. Recently a number of investigators found that saprozoic Protozoa could be cultivated in bacteria-free media of known compositions. For example, Pringsheim observed in Polytoma uvella (Fig. 91, h) that sodium acetate is needed from which the starch among others is produced, and carbohydrates have no di- rect bearing upon the nutrition, but fatty acids derived from them participate in the metabolism. Hall, Jahn, Loefer and oth- ers are following the same line of work which may lead to a better understanding of saprozoic nutrition as found in Protozoa. The Protozoa which live within the body of another organism are able to nourish themselves by absorbing the digested or de- composed substances of the host and could be considered as sap- rozoic though parasitic has sometimes been used. Coelozoic Pro- tozoa belong to this group, as for example, Protociliata, astomous ciliates, Trypanosomidae, etc. In the case of cytozoic or certain histozoic forms, such as Cnidosporidia, the host cytoplasm is ap- parently liquefied or hydrolyzed by enzymes (?) before being ab- sorbed by the latter. The parasitic Protozoa, which actually feed on host tissue cells, such as Entamoeba histolytica, Balantidium coli, etc., or endocommensals, employ, of course, the holozoic nu- trition. Many Protozoa nourish themselves by more than one method at the same or different times, subject to a change in external conditions. This is sometimes referred to as mixo trophic nutrition (Pfeiffer). For example, Euglena gracilis, according to Zumstein (1889) and Lwoff (1932) loses its green coloration and becomes Astasia-like in the dark, or even in the light when the culture me- dium is very abundant in decomposed organic substances, which would indicate that this organism is capable of carrying on both holophytic and saprozoic nutrition. On the other hand Chloro- gonium euchlorum and C. elongatum are said, according to Loefer (1934), to retain their green coloration after a year of cultivation 94 PROTOZOOLOGY in total darkness, although the chromatophores appear somewhat modified. The reserve food matter The anabolic activities of Protozoa result in the growth and in- crease in volume of the organism, and also in the formation and storage of reserve food-substances which are deposited in the cy- toplasm to be utilized later for growth or reproduction. The re- serve food stuff is ordinarily glycogen or glycogenous substances, which seem to be present widely. Thus, in saprozoic Gregarinida, there occur in the cytoplasm numerous refractile bodies which stain brown to brownish- violet in Lugol's solution; are insoluble in cold water, alcohol, ether; become swollen and later dissolved in boiling water; and are reduced to a sugar by boiHng in dilute sulphuric acid. This substance which composes the refractile bodies is called paraglycogen (Biitschli) or zooamylum. The abun- dant glycogen bodies of Pelomyxa have already been mentioned (p. 90). Rumjantzew and Wermel demonstrated glycogen in Actinosphaerium. In lodamoeba, glycogen body is conspicuously present and is taken as a characteristic feature of the organism. The iodinophile vacuole of the spores of Myxobolidae is a con- spicuously well-defined vacuole containing glycogenous substance and is also considered as possessing a taxonomic value. In many cihates, both free-living (Paramecium, Glaucoma, Vorticella, etc.) and endozoic (Ophryoscolecidae, Nyctotherus, Balantidi- um, etc.), glycogenous bodies are always present. The anabolic products of the holophytic nutrition are starch, paramylon, oil and fats. The paramylon bodies are of various forms among different species, but appear to maintain a certain characteristic form within a species and can be used to a certain extent in taxonomic consideration. According to Heidt (1937), the paramylon of Euglena sanguinea (Fig. 37) is spirally coiled which confirms BiitschU's observation. The paramylon appears to be a polysaccharide which is insoluble in boiling water, but dis- solves in concentrated sulphuric acid, potassium hydroxide, and slowly in formaldehyde. It does not stain with either iodine or chlor-zinc-iodide and when treated with a dilute potassium hy- droxide, the paramylon bodies become enlarged and frequently exhibit a concentric stratification. In the Chrysomonadina, the reserve food material is in the form of refractile bodies which are collectively called leucosin, PHYSIOLOGY 95 probably a carbohydrate. Oils occur in various Protozoa and when there is a sufficient number of oil producing forms in a body of water, the water may develop various odors. Whipple lists the following Protozoa, each of which if present in large numbers, may produce an offensive odor: Cryptomonas (candied violets), Mallomonas (aromatic, violets, fishy), Synura (ripe cucumber, muskmelon, bitter and spicy taste), Uroglenopsis (fishy, cod-liver oil-like), Dinobryon (fishy, like rockweed), Chlamydomonas (fishy, unpleasant or aromatic), Eudorina (faintly fishy), Pando- rina (faintly fishy), Volvox (fishy), Ceratium (vile stench, rusty Fig. 37. a-d, two types of paramylon present in Euglena gracilis (Biitschli); e-h, paramylon of E. sanguined, XllOO (Heidt). e, natural appearance; dried forms; h, strongly pressed bodies. brown color), Glenodinium (fishy), Peridinium (fishy, like clam- shells), and Bursaria (Irish moss, salt marsh, fishy). Fats have also been detected in many Protozoa, such as Myxo- sporidia, Protociliata, certain Euciliata, Trypanosoma, etc. Ac- cording to Panzer, the fat contents of Eimeria gadi was 3.55 per cent and Pratje reports that 12 per cent of the dry matter of Noc- tiluca scintillans appeared to be the fatty substance present in granular forms and which are said to give phosphorescence upon mechanical or chemical stimulation. A number of other dinoflag- ellates, such as Peridinium, Ceratium, Gonyaulax, Gymnodini- um, etc., also emit phosphorescence. In other forms the fats may be hydrostatic in function, as is the case with a number of pelagic Radiolaria. Another reserve food-stuff which occurs widely in Protozoa, excepting Ciliophora, is the so-called volutin or metachromatic granules. It is apparently equally widely present in Protophyta. In fact it was first discovered in the protophytan Spirillum volu- tans. Meyer coined the name and held it to be made up of a nu- 96 PROTOZOOLOGY cleic acid. It stains deeply with nuclear dyes. Reichenow (1909) demonstrated that if Haematococais pluvialis (Fig. 38) was culti- vated in phosphorus-free medium the volutin is quickly used up and does not reappear. If however, the organisms are cultivated in a medium rich in phosphorus, the volutin increases greatly in volume and, as the culture becomes old, it gradually breaks down. In Polytomella agilis (Fig. 92, c, r/), Doflein showed that an addi- tion of sodium phosphate resulted in an increase of volutin. Reichenow, Schumacher, and others, hold that the volutin appears Fig. 38. Haematococcus phivialis, showing the development of volu- tin in the medium rich in phosphorus and its disintegration in ex- hausted medium, X570 (Reichenow). a, second daj^; b, third day; c, fourth da}'; d, e, sixth day; f, eighth day. to be a free nucleic acid, and is a special reserve food material for the nuclear substance. Recently Sassuchin (1935) studied the volutin in Spirillu?n volutans and Sarcina flava and found that the volutin appears during the period of strong growth, nourishment and multiplication, disappears in unfavorable condition of nour- ishment and gives a series of characteristic carbohydrate reac- tions. Sassuchin considers that the volutin is not related to the nucleus, but is reserve food material of the cell, which is compos- ed of glykoproteid. Respiration In order to carry on various vital activities, the Protozoa, like all other organisms, must transform the potential energy stored in highly complex chemical compounds present in the cytoplasm, into various forms of active energy by oxidation. The oxygen in- volved in this process appears to be brought into contact with the substances in two ways in Protozoa. The great majority of free- living, epizoic and certain endozoic forms absorb free molecular oxygen from the surrounding media. The absorption of oxygen appears to be carried on by the permeable body surface, since there is no special organella for this purpose. The polysaprobic Protozoa are known to live in water containing no free oxygen. PHYSIOLOGY 97 For example, Noland (1927) observed Metopus es in a pool, 6 feet in diameter and 18 inches deep, filled with dead leaves which gave a strong odor of hydrogen sulphide. The water in it showed pH 7.2 at 14°C., and contained no dissolved oxygen, 14.9 c.c. per liter of free carbon dioxide, and 78.7 c.c. per liter of fixed carbon dioxide. It is considered that endozoic Protozoa of metazoan digestive systems live also in a medium containing no dissolved oxygen. All these forms appear to possess capacity of splitting complex oxy- gen-bearing substances present in the body to produce necessary oxygen. The liberation of energy is accompanied by production of water and carbon dioxide. Several investigators studied the influence of abundance or lack of oxygen upon different Protozoa. For example. Putter dem- onstrated that several ciliates reacted differently when subjected to anaerobic condition, some perishing rapidly, others living for a considerable length of time. Death is said by Lohner to be brought about by a volume-increase due to accumulation of the waste products. When first starved for a few days and then placed in anaerobic environment, Paramecium and Colpidium died much more rapidly than unstarved individuals. Putter, therefore, sup- posed that the difference in longevity of aerobic Protozoa in ana- erobic conditions was correlated with that of the amount of reserve food material such as protein, glycogen and paraglycogen present in the body. Noting Paramecium is less affected by anaerobic con- ditions than Spirostomum in a small amount of water, Putter maintained that the smaller the size of Protozoa and the more elaborate the contractile vacuole system, they suffer the less lack of oxygen in the water, since the removal of catabolic waste de- pends upon these factors. The variety of habitats and results of artificial cultivations of various Protozoa clearly indicate that the oxygen requirements vary a great deal among different forms. Attempts were made in recent years to determine the oxygen requirement of Protozoa. The results of the observations are not always convincing. The oxygen consumption of Paramecium is said, according to Lund (1918) and Amberson (1928), to be fairly constant over a wide range of oxygen concentration. Specht (1934) considers the meas- urements of the oxygen consumption and carbon dioxide produc- tion in Spirostomum amhiguum vary because of the presence of a base produced by the organism. Soule (1925) observed in the cul- 98 PROTOZOOLOGY tural tubes of Trypanosoma lewisi and Leishmania tropica, the oxygen contained in about 100 c.e. of air of the test tube is used up in about 12 and 6 days respectively. A single Paramecium caudatum is said to consume in one hour at 21°C. from 0.0052 c.c. (Kalmus) to 0.00049 c.c. (Rowland and Bernstein) of oxygen. Amoeba proteus, according to Hulpieu (1930), succumbs slowly when the amount of oxygen in water is less than 0.005 per cent and also in excess, which latter confirms Putter's observation of Spirostomum. The Hypermastigina of the termite are killed, ac- cording to Cleveland, when the host animals are kept in an excess of oxygen. Jahn (1935) found that Chilomonas Paramecium in bacteria-free cultures in heavily buffered peptone-phosphate media at pH 6.0 required for rapid growth carbon dioxide which apparently brings about a favorable intracellular hydrogen-ion concentration. Excretion and secretion The catabolic waste material composed of w^ater, carbon diox- ide, urea and other nitrogenous compounds, all of which are solu- ble, pass out of the body by diffusion through the surface or by means of the contractile vacuole (p. 73). The protoplasm of the Protozoa is generally considered to possess a molecular make-up which appears to be similar among those living in various habi- tats. In the freshwater Protozoa, the water diffuses through the body surface and so increases the water contents of the body pro- toplasm as to interfere with its normal function. The contractile vacuole, which is invariably present in all freshwater forms, is the means of getting rid of this excess water from the body. On the other hand, marine or endozoic. Protozoa live in isotonic media and there is no excess of water entering the body, hence the con- tractile vacuoles are not found in them. Just exactly why all eucili- ates and suctorians possess the contractile vacuole regardless of habitat, has not been explained. There are accumulating evidences to indicate that the pellicle of the ciliate is impermeable to water and salts, and that the water enters the ciliate body through the cytostome and cytopharynx only. Frisch (1937) observed recently such is the case in Paramecium vmltimicronucleata. If this is true in all ciliates, it is quite easy to understand the universal occur- rence of the contractile vacuole in the cytostome-bearing ciliates. However, it does not explain all cases, as a number of astomous ciliates with a definite peUicle possess contractile vacuoles (p. 488). PHYSIOLOGY 99 That the ehmination of excess amount of water from the body is one of the functions of the contractile vacuole appears to be beyond doubt judging from the observations of Zuelzer (1907), Finley (1930) and others, on Amoeba verrucosa which lost gradu- ally its contractile vacuole as sodium chloride was added to the water, losing the organella completely in the seawater concentra- tion. Herf (1922) studied the pulsation of the contractile vacuoles of Paramecium caudatum in fresh water as well as various salt concentrations, and obtained the following measurements : Per cent NaCl in water 0 0 . 25 0.5 0 . 75 1 . 00 Contraction period in second 6.2 9.3 18.4 24.8 163.0 Excretion per hour in body volumes 4.8 2.82 1.38 1.08 0.16 The contractile vacuole also serves to remove from the body part of soluble catabolic wastes, judged by numerous observa- tions. Weatherby (1929) showed that the contractile vacuoles of Paramecium and Spirostomum contain urea, and that of Didini- um contains ammonia and occasionally trace of uric acid. The number of the contractile vacuoles present in a given species as in various species of Paramecium, is not always constant. Nor is its size constant. According to Taylor (1920) the average size of the contractile vacuole of Euplotes patella is 29/i at maximum dias- tole, but may become 45-50^ in diameter upon disturbance or after incision. The rate of pulsation is subject to changes with temperature, physiological state of the organism, amount of food substances present in the water, etc. For example, Rossbach ob- served in the three ciliates mentioned below that the pulsation of the contractile vacuole increased first rapidly and then more slowly with the rise of the temperature of the water: Time in seconds between two systoles at different temperature (C.) 5° 10° 15° 20° 25° 30° 61 48 31 28 22 23 18 14 10-11 6-8 5-6 4 9 7 5 4 4 — Euplotes char on Stylonychia pustulata Chilodonella cuculhdus Aside from the soluble forms, there often occur in the protozoan body insoluble catabolic products in the forms of crystals and granules of various kinds. Schewiakoff (1893) first noticed that Paramecium often contains crystals (Fig. 39) composed of calcium 100 PROTOZOOLOGY phosphate, which disappeared completely in 1-2 days when the organisms were starved, and reappeared when food was given. Schewiakoff did not see the extrusion of these crystals, but con- sidered that these crystals were first dissolved and excreted by the contractile vacuoles, as they were seen collected around the vacuoles. In Amoeba proteus, Schubotz (1905) noted that the crys- tals were of similar chemical composition and of usually bipyram- idal or rhombic form, and that they measure about 2-5^ in length and doubly refractile. Schaeffer (1920) observed calcium phosphate crystals in three species of Amoeba and was inclined to think that the form and dimensions of these crystals were Fig. 39. Examples of crystals present in Protozoa, a-e, in Parame- cium caudatum (Schewiakoff), (a-d, XlOOO, e, X2600); f, in Amoeba proteus; g, in A. discoides; h, in A. dubia (Schaeffer). characteristic of each species. Thus in Amoeba proteus, they are truncate bipyramids, rarely flat plates, up to 4.5/i long; in A. dis- coides, abundant, truncate bipyramids, up to 2.5At long; and in A. dubia, variously shaped (4 kinds) few, but large, up to IOjjl, 12/x, 30m long (Fig. 39). Rowland detected uric acid in Paramecium caudatum and Amoeba verrucosa. Luce and Pohl (1935) noticed that at certain times amoebae in culture are clear and contain relatively a few crystals but, as the culture grows older and the water becomes more neutral, the crystals become abundant and the organisms become opaque to transmitted light. These crystals are tubular and six-sided, and vary in length from 0.5 to 3.5)U. They consid- ered the crystals were composed of calcium chlorphosphate. Mast and Doyle (1935), on the other hand, noted in Amoeba proteus two kinds of crystals, plate-like and bipyramidal, which vary in size up to Ifj, in length and which are suspended in alkaline fluid to viscous vacuoles. These two authors believe that the plate-like PHYSIOLOGY 101 crystals are probably leucine, while the bipyramidal crystals con- sist of a magnesium salt of a substituted glycine. Other crystals are said to be composed of urate, carbonate, oxalate, etc. Another catabolic product is the melanin grains which occur in many haemosporidians and which appear to be composed of a derivative of the haemoglobin of the infected erythrocyte. In cer- tain Radiolaria, there occurs a brownish amorphous mass which is considered as catabolic waste material and, in Foraminifera, the cytoplasm is frequently loaded with masses of brown granules which appear also to be catabolic waste and are extruded from body periodically. While intracellular secretions are usually difficult to recognize, because the majority remain in fluid form except those which pro- duce endoskeletal structures occurring in Heliozoa, Radiolaria, certain parasitic ciliates, etc., the extracellular secretions are eas- ily recognizable as loricae, shells, envelopes, stalks, collars, mu- cous substance, pigments which give the body a characteristic coloration (p. 37), etc. Furthermore, many Protozoa secrete, as was stated before, certain substances through the pseudopodia, tentacles or trichocysts which possess paralyzing effect upon the preys. Movements The Protozoa move about by means of the pseudopodia, flagel- la, or cilia, which may be combined with internal contractile or- ganellae. Movement by pseudopodia. The amoeboid movements have long been studied by numerous observers. The first attempt to explain the movement was by Berthold (1886), who held that the difference in the surface tension was the cause of amoeboid move- ments, which view was supported by the observations and ex- periments of Btitschli (1894) and Rhumbler (1898). According to this view, when an amoeba forms a pseudopodium, there prob- ably occurs a diminution of the surface tension of the cytoplasm at that point, due to certain internal changes which are continu- ously going on within the body and possibly to external causes, and the internal pressure of the cytoplasm will then cause the stream- ing of the cytoplasm. This results in the formation of a pseudo- podium which becomes attached to the substratum and an in- crease in tension of the plasma-membrane draws up the posterior 102 PROTOZOOLOGY -fe Fig. 40. a, diagram showing the movement of Amoeba verrucosa in side view (Jennings) ; b, a marine limax-amoeba in locomotion (Pantin from Reichenow). ac, area of conversion; cet, contracting ectoplasmic tube; fe, fiuid ectoplasm; ge, gelated ectoplasm. end of the amoeba, thus bringing about the movement of the whole body. Jennings (1904) found that the movement of Amoeba verrucosa (Fig. 40, a) could not be explained by the surface tension theory, since he observed "in an advancing amoeba substance flows for- ward on the upper surface, rolls over at the anterior edge, coming in contact with the substratum, then remains quiet until the body of the amoeba has passed over it. It then moves upward at the posterior end, and forward again on the upper surface, continuing in rotation as long as the amoeba continues to progress." Thus Amoeba verrucosa may be compared with an elastic sac filled with fluid. Bellinger (1906) studied the movement of Amoeba proteus, A. verrucosa and Difflugia spiralis. Studying in side view, he found that the amoeba (Fig. 41) extends a pseudopod, "swings it about, brings it into the line of advance, and attached it" to the substratum and that there is then a concentration of the sub- stance back of this point and a flow of the substance toward the anterior end. Bellinger held thus that "the movements of amoe- bae are due to the presence of a contractile substance," which was said to be located in the endoplasm as a coarse reticulum. PHYSIOLOGY 103 > Fig. 41. Outline sketches of photomicrographs of Amoeba proteus dur- ing locomotion, as viewed from side (Bellinger). In the face of advancement of our knowledge on the nature of protoplasm, Rhumbler realized the difficulties of the surface ten- sion theory and later suggested that the conversion of the ecto- plasm to endoplasm and vice versa were the cause of the cyto- plasmic movements, which was much extended by Hyman (1917). Hyman considered that: 1) a gradient in susceptibility to potas- sium cyanide exists in each pseudopodium, being the greatest at the distal end, and the most recent pseudopodium, the most sus- ceptible; 2) the susceptibility gradient (or metabolic gradient arises in the amoebae before the pseudopodium appears and hence the metabolic change which produces increased susceptibility, is the primary cause of pseudopodium formation; and 3) since the surface is in a state of gelation, amoeboid movement must be due to alterations of the colloidal state. Solation, which is brought about by the metabolic change, is regarded as the cause of the ex- tension of a pseudopodium, and gelation of the withdrawal of pseudopodia and of active contraction. Schaeffer (1920) mentions the importance of the surface layer which is a true surface tension film, the ectoplasm, and the streaming of endoplasm in the amoe- boid movement. Pantin (1923) studied a marine hmax-type amoeba (Fig. 40, h) and came to recognize acid secretion and absorption of water at the place where the pseudopodium was formed. This results in swelling of the cytoplasm and the pseudopodium is formed. Because of the acidity, the surface tension increases and to lower or reduce this, concentration of substances in the "wall" of the pseudopodium follows. This leads to the formation of a gelatinous ectoplasmic tube which, as the pseudopodium, ex- tends moves toward the posterior region where the acid condition is lost, gives up water and contracts, finally becoming trans- formed into endoplasm near the posterior end. The contraction of 104 PROTOZOOLOGY Fig. 42. Diagram of Amoeba proteus, showing the solation and gela- tion of the cytoplasm during amoeboid movement (Mast), c, crystal; cv, contractile vacuole; f, food vacuole; he, hyaline cap; n, nucleus; pg, plasmagel; pgs, plasmagel sheet; pi, plasmalemma; ps, plasmasol. PHYSIOLOGY 105 the ectoplasmic tube forces the endoplasmic streaming to the front. This observation is in agreement vnth that of Mast (1923, 1926, 1931) who after a series of carefully conducted observations on Amoeba proteus came to hold that the amoeboid movement is brought about by ''four primary processes; namely, attachment to the substratum, gelation of plasmasol at the anterior end, solation of plasmagel at the posterior end and the contraction of the plas- magel at the posterior end" (Fig. 42). As to how these processes work, Mast states: "The gelation of the plasmasol at the anterior Fig. 43. Diagrams of varied cytoplasmic movements at the tip of a pseudopodium in Amoeba proteus (Mast), g, plasmagel; he, hyaline cap; hi, hyaline layer; pi, plasmalemma; s, plasmasol. end extends ordinarily the plasmagel tube forward as rapidly as it is broken down at the posterior end by solation and the contrac- tion of the plasmagel tube at the posterior end drives the plas- masol forward. The plasmagel tube is sometimes open at the anterior end and the plasmasol extends forward and comes in con- tact with the plasmalemma at this end (Fig. 43, a), but at other times it is closed by a thin sheet of gel which prevents the plas- masol from reaching the anterior end (6). This gel sheet at times persists intact for considerable periods, being built up by gelation as rapidly as it is broken down by stretching, owing to the pres- sure of the plasmagel against it. Usually it breaks periodically at various places. Sometimes the breaks are small and only a few granules of plasmasol pass through and these gelate immediately and close the openings (d). At other times the breaks are large and plasmasol streams through, filling the hyaline cap (c), after which the sol adjoining the plasmalemma gelates forming a new gel sheet. An amoeba is a turgid system, and the plasmagel is under continuous tension. The plasmagel is elastic and, consequently, is 106 PROTOZOOLOGY pushed out at the region where its elasticity is weakest and this results in pseudopodial formation. When an amoeba is elongated and undergoing movement, the elastic strength of the plasmagel is the highest at its sides, lowest at the anterior end and inter- mediate at the posterior end, which results in continuity of the elongated form and in extension of the anterior end. If pressure is brought against the anterior end, the direction of streaming of plasmasol is immediately reversed, and a new hyaline cap is formed at the posterior end which is thus changed into a new an- terior end." Flagellar movement. The flagellar movement is only in a few instances observable as in Peranema, but in most cases it is very difficult to observe in hfe. Since there is difference in the number, location, size, and probably structure (p. 45) of fliagella occurring in Protozoa, it is supposed that there are varieties of flagellar movements. The first explanation was advanced by Biitschli, who observed that the flagellum undergoes a series of lateral move- ments and, in so doing, a pressure is exerted on the water at right angles to its surface. This pressure can be resolved into two forces : one directed parallel, and the other at right angles, to the main body axis. The former will drive the organism forward, while the latter will tend to rotate the animal on its own axis. Gray (1928), who gave an excellent account of the movement of flagella, points out that "in order to produce propulsion there must be a force which is always applied to the water in the same direction and which is independent of the phase of lateral move- ment. There can be little doubt that this condition is satisfied in flagellated organisms not because each particle of the flagellum is moving laterally to and fro but by the transmission of the waves from one end of the flagellum to the other, and because the direc- tion of the transmission is always the same. A stationary wave, as apparently contemplated by Biitschli, could not effect propul- sion since the forces acting on the water are equal and opposite during the two phases of the movement. If however the waves are being transmitted in one direction only, definite propulsive forces are present which always act in a direction opposite to that of the waves." Because of the nature of the flagellar movement, the actual process has often not been observed. Verworn observed long ago that in Peranema trichoyhoruni the undulation of the distal por- PHYSIOLOGY 107 tion of flagellum is accomplished by a slow forward movement, while undulation along the entire length by a rapid forward move- ment. Recently Krijgsman (1925) studied Monas sp. (Fig. 44) which he found in soil cultures, under the darkfield microscope and stated: 1) when the organism moves forward with the maxi- mum speed, the flagellum starting from cl , with the wave begin- ning at the base, stretches back (c 1-6), and then waves back {d, e), which brings about the forward movement. Another type is Fig. 44. Diagrams illustrating flagellar niovemengs of Monas sp. (Krijgsman). a-g, rapid forward movement (a, b, optical image of the movement in front and side view; c, preparatory and d, e, effective stroke; f, preparatory and g, effective stroke); h-j, moderate forward movement (h, optical image; i, preparatory and j, effective stroke); k-o, undulator}' movement of the flagellum in backward movement; p, lateral movement; q, turning movement. one in which the flagellum bends back beginning at its base (/) until it coincides with the body axis, and in its effective stroke waves back as a more or less rigid structure (g) ; 2) when the or- ganism moves forward with moderate speed, the tip of the flagel- lum passes through 45° or less (h-j); 3) when the animal moves backward, the flagellum undergoes undulation which begins at its base (k-o) ; 4) when the animal moves to one side, the flagellum becomes bent at right angles to the body and undulation passes along it from its base to tip (p); and 5) when the organism under- goes a slight lateral movement, the distal end of the flagellum only undulates (q). 108 PROTOZOOLOGY Ciliary movement. The cilia are the locomotor organella pres- ent liermanently in the ciliates and vary in size and distribution among different species. Just as flagellates show various types of movements, so do the ciliates. Individual cilium on a progressing ciliate bends throughout its length and strike the water so that the organism tends to move in a direction opposite to that of the effective beat, while the water moves in the direction of the beat (Fig. 45, a-d). In the Protociliata and the majority of holotrich- ous and heterotrichous ciliates, the cilia are arranged in longi- ..i f /"\ :a 9 Fig. 45. Diagrams illustrating ciliary movements (Verworn). a-d, movement of a marginal cilium of Urostyla grandis (a, preparatory and b, effective stroke, resulting in rapid movement; c, preparatory, and d, effective stroke, bringing about moderate speed); e, metachronous movements of cilia in a longitudinal row. tudinal, or oblique rows and it is clearly noticeable that the ciUa are not beating in the same phase, although they are moving at the same rate. A cilium (Fig. 45, e) in a single row is slightly in advance of the cilium behind it and slightly behind the one just in front of it, thus the cilia on the same longitudinal row beat metachronously. On the other hand, the cilia on the same trans- verse row beat synchronously, the condition clearly being recog- nizable on Opalina among others, which is much like the waves passing over a wheat field on a windy day. The organized move- ments of cilia, cirri, membranellae and undulating membranes are probably controlled by the neuromotor system (p. 55) which PHYSIOLOGY 109 appears to be condiictile as judged by the results of micro-dissec- tion experiments of Taylor (p. 56). The Protozoa which possess myonemes are able to move by contraction of the body or of stalk, and others combine this with the secretion of mucous substance as was found in Haemogrega- rina and Gregarinida. Irritability Under natural conditions, the Protozoa do not behave always in the same manner, because several stimuli act upon them usu- ally in combination and predominating stimulus or stimuli vary under different circumstances. Many investigators have, up to the present time, studied the reactions of various Protozoa to external stimulations, full discussion of which is beyond the scope of the present work. Here one or two examples in connection with the reactions to each of the various stimuli will only be men- tioned. Of various responses expressed by a protozoan against a stimulus, movement is the most clearly recognizable one and, therefore, free-swimming forms, particularly ciliates, have been the favorite objects of study. We consider the reaction to a stimu- lus in protozoans as the movement response, and this appears in one of the two directions: namely, toward, or away from, the source of the stimulus. Here we speak of positive or negative re- action. In forms such as Amoeba, the external stimulation is first received by the body surface and then by the whole protoplasmic body. In flagellated or ciliated Protozoa, these processes act in part sensory, in fact in a number of ciliates are found non-vibra- tile ciha which appear to be sensory in function. In a compara- tively small number of forms, there are sensory organellae such as stigma (p. 79), ocellus (p. 80), statocysts (p. 77), concretion vacuoles (p. 77), etc. In general, the reaction of a protozoan to any external stimulus depends upon its intensity so that a certain chemical substance may bring about entirely opposite reactions on the part of the protozoans in different concentrations and, even under identical conditions, different individuals of a given species may react dif- ferently. Reaction to mechanical stimuli. One of the most common stimuli a protozoan would encounter in the natural habitat is that which comes from contact with a solid object. When an amoeba which Jennings observed, came in contact with the end 110 PROTOZOOLOGY of a doad algal filament at the middle of its anterior surface (Fig. 46, a), the amoeboid movements proceeded on both sides of the filament (b), but soon motion ceased on one side, while it contin- ued on the other, and the organism avoided the obstacle by re- versing a part of the current and flowing in another direction (c). When an amoeba is stimulated mechanically by the tip of a glass rod (d), it turns away from the side touched, by changing endo- plasmic streaming and forming new pseudopodia (e). Positive re- FiG. 46. Reactions of amoebae to mechanical stimuli (Jennings), a-c, an amoeba avoiding an obstacle; d, e, negative reaction to mechan- ical stimulation; f-h, positive reaction of a floating amoeba. actions are also often noted, when a suspended amoeba (/) comes in contact with a sohd surface with the tip of a pseudopodium, the latter adheres to it by spreading out (g). Streaming of the cytoplasm follows and it becomes a creeping form (h). Positive reactions toward solid bodies account of course for the ingestion of food particles. In Paramecium, according to Jennings, the anterior end is more sensitive than any other parts, and while swimming, if it comes in contact with a solid object, the response may be either negative or positive. In the former case, avoiding movement (Fig. 47, c) follows and in the latter case, the organism rests with its anterior PHYSIOLOGY 111 end or the whole side in direct contact with the object, in which position it ingests food particles through the cytostome. Reaction to gravity. The reaction to gravity varies among dif- ferent Protozoa, according to body organization, locomotor or- ganellae, etc. Amoebae, Testacea and others which are usually found attached to the bottom of the container, react as a rule positively toward gravity, while others manifest negative reac- FiG. 47. Reactions of Paramecium (Jennings), a, collecting in a drop of 0.02% acetic acid; b, ring-formation around a drop of a stronger solution of the acid; c, avoiding reaction. tion as in the case of Paramecium (Jensen; Jennings), which ex- plains in part why Paramecium in a culture jar are found just be- low the surface film en mass, although, according to Dembowski (1929) the vertical movement of Paramecium caudatum is influ- enced by various factors. Reaction to current. Free-swimming Protozoa appear to move or orientate themselves against the current of water. In the case of Paramecium, Jennings observed the majority place them- selves in line with the current, with anterior end upstream. The myoetozoan is said to exhibit also a well-marked positive reaction. 112 PROTOZOOLOGY Reaction to chemical stimuli. When methylgreen, methylene blue, or sodium chloride is brought in contact with an advancing amoeba, the latter organism reacts negatively (Jennings). Jen- nings further observed various reactions of Paramecium against chemical stimulation. This ciliate shows positive reaction to weak solutions of many acids and negative reactions above certain con- centrations. For example, Paramecium enters and stays within the area of a drop of 0.02 per cent acetic acid introduced to the preparation (Fig. 47, a); and if stronger acid is used, the organ- isms collect about its periphery where the acid is diluted by the surrounding water (Fig. 47, h). The reaction to chemical stimuli is probably of the greatest importance for the existence of Proto- zoa, since it leads them to proper food substances, the ingestion of which is the foundation of metabolic activities. In the case of parasitic Protozoa, possibly the reaction to chemical stimuli re- sults in their finding specific host animals and their distribution in different organs and tissues within the host body. Reaction to light stimuli. Most Protozoa seem to be indifferent to the ordinary fight, but when the fight intensity is suddenly in- creased, there is usually a negative reaction. Verworn saw the direction of movements of an amoeba reversed when its anterior end was given a sudden ilfiimination ; Rhumbler observed that an amoeba, which was in the act of feeding, stopped feeding when it was subjected to strong light. According to Mast, Amoeba -pro- teus ceases to move when suddenly strongly illuminated, but con- tinues to move if the increase in intensity is gradual and if the illumination remains constant, the amoeba begins to move. Ac- cording to Jennings, Stentor coeruleus reacts negatively against fight. The positive reaction to light is most clearly shown in stigma- bearing Mastigophora, as is well demonstrated by a jar contain- ing Euglena, Phacus, etc., in which the organisms collect at the place where the strongest light reaches. If the light is excluded completely, the organisms become scattered throughout the con- tainer, inactive and sometimes encysted, although the mixotroph- ic forms would continue activities by saprozoic methods. The positive reaction to light by chromatophore-bearing forms en- ables them to find places in the water where photosynthesis can be carried on to the maximum degree. All Protozoa seem to be more sensitive to ultraviolet rays. In- PHYSIOLOGY 113 man found that amoebae show a greater reaction to the rays and Hertel observed that Paramecium which were indifferent to an ordinary hght, showed an immediate response (negative reac- tion) to the rays. MacDougall brought about mutations in Chilo- donella by means of these rays (p. 164). When ciUates are vitally stained with eosin, erythrosin, etc., they react sometimes posi- tively or negatively, as in Paramecium (Metzner), or always neg- atively, as in Spirostomum (Blattner). According to Efimoff, this "induced phototaxis" is not limited to fluorescent dyes, but also is possessed by all vital-staining dyes. Zuelzer (1905) studied the effects of radium rays upon various Protozoa and found that the effect was not the same among different species. For example, limax amoeba was more resistant than others. In all cases, how- ever, long exposure to the rays was fatal to Protozoa, the first ef- fect of exposure being shown by accelerated movement. Halber- staedter and Luntz (1929) studied injuries and death of Eudorina elegans by exposure to radium rays. Joseph and Prowazek (1902) found Paramecium and Volvox gave negative response to the rontgen-ray. Reaction to temperature stimuli. As was stated before, there seems to be an optimum temperature range for each protozoan, although it can withstand temperatures which are lower or higher than that range. As a general rule, the higher the temperature, the greater the metabolic activities, and the latter condition results in turn in a more rapid growth and more frequent repro- duction. It has been suggested that change to different phases in the life-cycle of a protozoan in association with the seasonal change may be largely due to temperature changes of the environ- ment. In the case of parasitic Protozoa which pass their life-cycle in warm-blooded and cold-blooded host animals, such as Plasmo- dium and mammalian trypanosomes, the change in body tem- perature of host animals may bring about specific stages in their development. Reaction to electrical stimuli. Since Verworn's experiments, several investigators studied the effects of electric current which is passed through Protozoa in water. Amoeba shows negative reaction to the anode and moves toward the cathode either by reversing the cytoplasmic streaming (Verworn) or by turning around the body (Jennings). The free-swimming ciliates move mostly toward the cathode, but a few may take a transverse 114 PROTOZOOLOGY position (Spirostomiim) or swim to the anode (Paramecium, Stentor, etc.). Of flagellates, Verworn noticed that Trachelo- monas and Peridinium moved to the cathode, while Chilomonas Cryptomonas, and Polytomella, swam to the anode. Regeneration The power of regenerating the lost parts of the body is char- acteristic of all Protozoa from simple forms to those with highly complex organization, as shown by observations of numerous investigators. The general procedure of the experiment is to cut the body of a protozoan into two or more parts and observe how far each part regenerates. It is now well established that only the parts which contain the whole or part of the nucleus are able to regenerate completely under favorable circumstances. A re- markably small portion of a protozoan is known to regenerate completely. For example, Sokoloff found 1/53-1/69 of Spiro- stomum and 1/70-1/75 of Dileptus were able to regenerate. Ac- cording to Philps, portions down to 1/80 of an amoeba are able to regenerate. Burnside (1929) cut 27 specimens of Stentor coeruleus belonging to a single clone, into two or more parts in such a way that some of the pieces contained a large portion of the nucleus while others a small portion. These fragments re- generated and multiplied, giving rise to 268 individuals. No dimensional differences resulted from the different amounts of nuclear material present in the cut specimens. Apparently regula- tory processes took place and in all cases normal size was restored, no matter what was the amount of the nuclear material in an- cestral pieces. Thus, in this ciliate, biotypes of diverse size are not produced by causing inequalities in the proportions of nuclear material in different individuals. The parts which do not contain nuclear material, may continue to show certain activities, such as locomotion, contraction of the contractile vacuole, etc., for some time. For example, Penard observed enucleated amoebae lived eight days, Stole and Gruber found amoebae without nuclear material were able to live up to 30 days, and enucleated pieces of A. verrucosa were seen to remain alive for 20 to 25 days (Grosse-Allermann). At the time of reproduction of all Protozoa, the various organel- lae, such as cilia, flagella, cytostome, contractile vacuole, etc., are completely regenerated before the separation of body occurs. PHYSIOLOGY 115 References Berthold, C. 1886 Studien iiber Protoplasmamechanik. Leipzig. Brug, S. L. 1928 Observations on a culture of Entamoeba histo- lytica. Med. Dienst Volksges. Ned. Indie. BuRNSiDE, L. H. 1929 Relation of body size to nuclear size in Stentor coeruleus. Jour. Exper. Zool., Vol. 54. Cleveland, L. R. 1925 Toxicity of oxygen for Protozoa in vivo and in vitro. Animals defaunated without injury. Biol. Bull., Vol. 48. , S. R. Hall, E. P. Sanders and J. Collier 1934 The wood-feeding roach Cryptocercus, its Protozoa, and the symbiosis between Protozoa and roach. Mem. Amer. Acad. Arts and Sci., Vol. 17. Dawson, J. A. and M. Belkin 1928 The digestion of oil by Amoeba dubia. Proc. Soc. Exp. Biol, and Med., Vol. 25. Bellinger, O. P. 1906 Locomotion of amoebae and allied forms. Jour. Exp. Zool., Vol. 3. Dembowski, J. 1929 Die Vertikalbewegungen von Paramecium caudatum. IL Arch. f. Protistenk., Vol. 68. DoFLEiN, F. 1918 Ueber Polytomella agilis Aragao. Zool. Jahrb. Abt. Anat., Vol. 41. Frisch, J. A. 1937 The rate of pulsation and the function of the contractile vacuole in Paramecium multimicronucleatum. Arch. f. Protistenk., Vol. 90. Gray, J. 1928 Ciliary movement. Cambridge. Greenwood, M. 1894 Constitution and formation of "food- vacuoles" in Infusoria. Phil. Trans. (B). Vol. 185, and E. R. Saunders 1884 The role of acid in protozoan digestion. Jour. Physiol., Vol. 16. Heidt, K. 1937 Form und Struktur der Paramylonkorner von Euglena sanguinea. Arch. f. Protistenk., Vol. 88. Herfs, a. 1922 Die pulsierende Vakuole der Protozoen, ein Schutzorgan gegen Ausslissung. Ibid., Vol. 44. Rowland, R. B. 1928 The pH of gastric vacuoles. Protoplasma, Vol. 5. and A. Bernstein 1931 A method for determining the oxygen consumption of a single cell. Jour. Gen. Physiol., Vol. 14. HuLPiEu, H. R. 1930 The effect of oxygen on Amoeba proteus. Jour. Exp. Zool., Vol. 56, Hyman, L. H. 1917 Metabolic gradients in amoeba and their relation to the mechanism of amoeboid movement. Jour. Exp. Zool., Vol. 24. Jennings, H. S. 1904 Contributions to the study of the be- havior of the lower organisms. Publ. Carnegie Inst. Washing- ton, No. 16. 1906 Behavior of the lower organisms. New York. Khainsky, a. 1910 Zur Morphologie und Physiologic einiger 116 PROTOZOOLOGY Infusorien {Paramecium caudatum) auf Grund einer neuen histologischen Methode, Arch. f. Protistenk., Vol. 21. KiRBY, H. Jr., 1934 Some ciliates from salt marshes in Cali- fornia. Ibid., Vol. 82. KoFOiD, C. A. and 0. Swezy 1921 The free-living unarmored Dinofiagellata. Mem. Univ. Calif., Vol. 5. KoRSCHELT, E. 1927 Regeneration und Transplantation. Vol. 1. Berlin. Krijgsman, B. J. 1925 Beitrage zum Problem der Geisselbe- wegung. Arch. f. Protistenk., Vol. 52. Kudo, R. R. 1921 On the nature of structures characteristic of cnidosporidan spores. Trans. Amer. Micr. Soc, Vol. 40. Mast, S. O. 1923 Mechanics of locomotion in amoeba. Proc. Nat. Acad. Sci. Vol. 9. 1926 Structure, movement, locomotion, and stimulation in amoeba. Jour. Morph. Physiol., Vol. 41. 1931 Locomotion in Amoeba proteus. Protoplasma, Vol. 14. and W. L. Doyle 1934 Ingestion of fluid by amoeba. Ibid., Vol. 20. 1935 Structure, origin and function of cytoplas- mic constituents in Amoeba proteus with special reference to mitochondria and Golgi substance. Arch. f. Protistenk., Vol. 86. Meldrum, N. U. 1934 Cellular respiration. London. Metalnikoff, S. 1912 Contribution a I'etude de la digestion intracellulaire chez les protozoaires. Arch. zool. exp. (ser. 5), Vol. 9. Mouton, H. 1902 Recherches sur la digestion chez les amibes et sur leur diastase intracellulaire. Ann. Inst. Pasteur. Vol. 16. Nirenstein, E. 1925 Ueber die Natur und Starke der Saure- bildung in den Nahrungsvakuolen von Paramecium cauda- tum. Zeitschr. wiss. Zool., Vol. 125. NoLAND, L. E. 1927 Conjugation in the ciliate Metopus sig- moides. Jour. Morph. Physiol., Vol. 44. Pantin, C. F. a. 1923 On the physiology of amoeboid move- ment I. Marine Biol. Ass. Plymouth, N. S., Vol. 13. Panzer, T. 1913 Beitrag zur Biochemie der Protozoen. Hoppe- Seylers Zeitschr. phys. Chemie, Vol. 86. Powers, P. B. A. 1932 Cyclotrichium meunieri sp. nov.; cause of red water in the gulf of Maine. Biol. Bull., Vol, 63. Pratje, a. 1921 Makrochemische, quantitative Bestimmung des Fettes und Cholesterins, sowie ihrer Kennzahlen bei Noctiluca miliaris. Biol. Zentralbl., Vol. 21. Pringsheim, E. G. 1923 Zur Physiologie saprophytischer Flagellaten. Beitr. allg. Bot., Vol. 2. Putter, A. 1905 Die Atmung der Protozoen. Zeitschr. allg. Physiol., Vol. 5. PHYSIOLOGY 117 1908 Methoden zur Erforschung des Lebens der Pro- tistenk. Tigerstedt's Handb. physiol. Methodik, Vol. 1. RosKiN, G. and L, Levinsohn 1926 Die Oxydasen und Per- oxydasen bei Protozoen. Arch. f. Protistenk., Vol. 56. Rhumbler, L. 1910 Die verschiedenartigen Nahrungsaiifnah- men bei Amoeben als Folge verschiedener Colloidalzustande ihrer Oberflachen. Arch. Entw. Organism., Vol. 30. Sassuchin, D. N, 1935 Zum Studium der Protisten- und Bak- terien-kerne. Arch. f. Protistenk., Vol. 84. ScHAEFFER, A. A. 1920 Amoehoid movement. Princeton. ScHEWiAKOFF, W. 1894 Ueber die Natur der sogenannten Ex- kretkorner der Infusorien. Zeitschr, wiss. Zool., Vol. 57. Shapiro, N. N. 1927 The cycle of hydrogen-ion concentration in the food vacuoles of Paramecium, Vorticella, and Stylony- chia. Trans. Amer. Micro. Soc, Vol. 46. SoKOLOFF, B. 1924. Das Regenerationsproblem bei Protozoen. Arch. f. Protistenk., Vol. 47. SouLE, M. H. 1925 Respiration of Ti^ypanosoma lewisi and Leishmania tropica. Jour. Inf. Dis., Vol. 36. Stolc, a. 1900 Beobachtungen und Versuche ueber die Ver- dauung und Bildung der Kohlenhydrate bei einen amoeben- artigen Organismen, Pelomyxa palustris. Zeitschr. wiss. Zool. Vol. 68. Verworn, M. 1889 Psycho-physiologische Protisten-studien. Jena. 1903 Allgemeine Physiologie. 4te Aufi. Jena. Wetherby, J. H. 1929 Excretion of nitrogenous substances in Protozoa. Physiol. Zool., Vol. 2, Whipple, G. C. 1927 The microscopy of drinking water. 4 ed. New York, Zuelzer, M. 1907 Ueber den Einfluss des Meerwassers auf die pulsierende Vacuole. Berlin. Sitz.-Ber. Ges. naturf. Freunde. ZuMSTEiN, H. 1899 Zur Morphologie und Physiologie der Eu- glena gracilis Klebs. Pringsheims Jahrb. wiss. Botanik Vol. 34. Chapter 5 Reproduction THE mode of reproduction in Protozoa is highly variable among different groups, although it is primarily a cell divi- sion. The reproduction is initiated by the nuclear division in all cases, which will therefore be considered first. Nuclear division Between a simple direct division on the one hand and a com- plicated indirect division which is comparable with the typical metazoan mitosis on the other hand, all types of nuclear division are to be encountered. Direct nuclear division. While not so widely found as it was thought to be in former years, amitosis occurs normally and regu- larly in many forms. The macronuclear division of the Ciliophora is without exception direct. The macronucleus elongates itself without any particular changes in its internal structure and be- comes divided through the middle, resulting in formation of two daughter nuclei as seen commonly in Paramecium (Fig. 48). It is assumed that the nuclear components undergo solation during division, since the formed particles of nucleus which are stationary in the resting stage, manifest a very active Brownian movement as was observed m vivo in Endamoeha hlattac (Fig. 49). Furthermore, in some cases the nuclear components may undergo phase reversal, that is to say, the chromatin granules which are dispersed phase in the non-staining fiuid dispersion medium in the resting nucleus, become dispersion medium in which the latter is suspended as dispersed phase. By using Feulgen's nucleal reaction, Reichenow (1928) demonstrated this reversal phenome- non in the division of the macronucleus of Chilodonella cucullulus (Fig. 50). When the macronucleus is elongated as in Spirostomum, Stentor, Euplotes, etc., the nucleus becomes condensed into a rounded form prior to its division. When the macronuclear ma- terial is distributed throughout the cytoplasm as numerous grains as in Dileptus anser (Fig. 239, c), "each granule divides where it happens to be and with the majority of granules both halves 118 REPRODUCTION 119 remain in one daughter cell after division" (Calkins). Hayes noticed a similar division, but at the time of simultaneous divi- sion prior to cell division, each macronucleus become elongated and breaks into several small nuclei. Fig. 48. Nuclear and cj'tosomic division of Paramecium caudatum as seen in stained smears, X260 (Kudo). The macronucleus becomes at the time of its division somewhat enlarged and its chromatin granules are more deeply stained than before. Since the number of chromatin granules appear ap- proximately the same in the macronuclei of different generations 120 PROTOZOOLOGY of a given species, the reduced number of chromatin granules must be restored sometime before the next division takes place. Calkins (1926) is of the opinion that "each granule elongates and divides into two parts, thus doubling the number of chromo- FiG. 49. Division of Endamoeha blaltae as seen in life, X250 (Kudo). The entire process took one hour and seven minutes. meres." Reichenow (1928) found that in Chilodonella cucullulus the lightly Feulgen positive endosome appeared to form chroma- tin granules and Kudo (1936) maintained that the large chroma- tin spherules of the macronucleus of Nyctotherus ovalis probably produce smaller spherules in their alveoli. In the elongated or miniliform macronuclei of a number of ciliates, there occur, prior to and during division, 1-2 character- istic zones which have been called by various names, such as nuclear clefts, reconstruction bands, reorganization bands, etc. In Euplotes patella, Turner (1930) observed before division, a reorganization band consisting of an unstained zone ("reconstruc- REPRODUCTION 121 Fig. 50. The solation of chromatin during the macronuclear division of Chilodonella cuculhilus, positive to Feulgen's nucleal reaction, X1800 (Reichenow). tion plane") and a stained zone (''solution plane"), appears at each end of the macronucleus (Fig. 51, a) and as each moves toward the middle, a more chromatinic area is left behind (h-d). According to Summers (1935), a similar change occurs in Dio- FiG. 51. Macronuclear reorganization before division in Euplotes patella, X240 (Turner), a, reorganization band appearing at a tip of the macronucleus; b-d, later stages. 122 PROTOZOOLOGY phrys appendtculata and Styloyiychia pustulata; but in Aspidisca lynceus (P'ig. 52) a reorganization band ai)peared first near the middle region of the macronucleus (b), divided into two and each moved toward an end, leaving between them a greater chroma- tinic contents of the reticula (c-i). Summers suggested that "the Fig. 52. Macronuclear reorganization prior to division in Aspidisca lynceus, X1400 (Summers), a, resting nucleus; b-i, successive stages in reorganization process; j, a daughter macronucleus shortly after division. reorganization bands are local regions of karyolysis and re- synthesis of macronuclear materials with the possibility of an elimination of physically or possibly chemically modified non- staining substances into the cytoplasm." The discarding of a certain portion of the macronuclear material during division has been observed in a number of species. REPRODUCTION 123 In Uroleptus halseyi, Calkins actually noticed each of the eight macronuclei is "purified" by discarding a reorganization band and an "x-body" into the cytoplasm before fusing into a single macronucleus which then di\'ides into two nuclei. In the more or less rounded macronucleus which is commonly found in many ciHates, no reorganization band has been recognized. A number of observers have however noted during the nuclear division there appears and persists a small body within the nuclear figures, ■mMim^mmf^m Fig. 53. Macronuclear division in Conchophthirus mytili, X440 (Kidder). located at the division plane as in the case of Loxocephalus (Behrend), Eupoterion (MacLennan and Connell) and even in the widely different protozoan, Endamoeba hlattae (Kudo) (Fig. 49). We owe Kidder for a careful comparative study of this body. Kidder (1933) observed that during the division of the macro- nucleus of Conchophthirus mytili (Fig. 53), the nucleus ''casts out a part of its chromatin at every vegetative division," which "is broken down and disappears in the cytoplasm of either daughter organism." A similar phenomenon has since been found 124 PROTOZOOLOGY further in C. anodontae, C. curtus, C. magna (Kidder), Uro- centrum turbo, Colpidium colpoda, C. campylum, Glaucoma scintillans (Kidder and Diller), and Allosphaerium convexa (Kidder and Summers). Kidder and his associates beheve that the process is probably eHmination of waste substances of the prolonged cell-division, since chromatin extrusion does not take place during a few divisions subsequent to reorganization after conjugation in Conchophthirus mytili and since in Colpidium and Glaucoma, the chromatin elimination appears to be the cause of high division rate and infrequency of conjugation. Other examples of amitosis are found in the vesicular nuclei in the trophozoite of Myxosporidia, as for example, Myxosoma catostomi (Fig. 54), Thelohanellus notatus (Debaisieux), etc., in which the endosome divides first, followed by the nuclear con- striction. In Streblomastix strix, the compact elongated nucleus was found to undergo a simple division by Kofoid and Swezy. tf^^-j/^^ W^'^W^ f^^^^^H ffr'M^'^0 "A^S^tW a b c d e Fig. 54. Amitosis in the trophozoite of Myxosoma catostomi, X2250 (Kudo). Indirect nuclear division. The indirect division which occurs in the protozoan nuclei is of manifold types as compared with the mitosis in the metazoan cell, in which, aside from minor varia- tions, the change is of a uniform pattern. Chatton, Alexeieff and others, have proposed several terms to designate the various types of indirect nuclear division, but no one of these types is sharply defined. For our purpose, mentioning of examples will suffice. A veritable mitosis was noted by Dobell in the heliozoan Oxnerella maritima (Fig. 55), which possesses an eccentrically situated nucleus containing a large endosome and a central centroplast or centriole, from which radiate many axopodia (a). The first sign of the nuclear division is the shght enlargement, and migration toward the centriole, of the nucleus. The centriole first divides into two (c, d) and the nucleus becomes located be- tween the two centrioles (e). Presently spindle fibers are formed REPRODUCTION 125 and the nuclear membrane disappears (/, g). After passing through an equatorial-plate stage, the two groups of the chromo- somes move toward the opposite poles {g-i). As the spindle fibers become indistinct, radiation around the centrioles becomes con- spicuous and the two daughter nuclei are completely recon- •■#i«^fe Fig. 55. Nuclear and cytosomic division in Oxnerella maritima, X about 1000 (Dobell). a, a living individual; b, stained specimen; c-g, prophase; h, metaphase; i, anaphase; j, k, telophase; 1, division completed. structed to assume the resting phase (j-l). The mitosis of another heliozoan Acanthocystis aculeata is, according to Schaudinn and Stern, very similar to the above. Aside from these two species, 126 PROTOZOOLOGY the centriolc has been r('])()rte(l in many others, such as Hart- mannella (Arndt), Euglypha, Monocystis (Belaf), Aggregata (Dobell, Belaf, and Naville), various Hyi)ermastigina (Kofoid; Duboscq, Grasse; Kirby; Cleveland and his associates). In numerous species the division of the centriole (or blepharo- ])last) and a connecting strand between them, which have been called desmose, centrodesmose or paradesmose, have been ob- served. According to Kofoid and Swezy (1919), in Trichonympha campanula (Fig. 56), the prophase begins early, during which 52 chromosomes are formed and become split. The nucleus moves nearer the anterior end where the centriole divides into two, be- tw^een which develops a desmose. From the posterior end of each centriole, astral rays extend out and the split chromosomes form loops, pass through "tangled skein" stage, and emerge as 26 chromosomes. In the metaphase, the equatorial plate is made up of V-shaped chromosomes as each of the split chromosomes are still connected at one end, which finally becomes separate in anaphase, followed by formation of two daughter nuclei. As to the origin and development of the achromatic figure, various observations and interpretations have been advanced. Certain Hypermastigina possess very large filiform centrioles and a large rounded nucleus. In Barbulanympha (Fig. 57), Cleveland (1938) found that the centrioles vary from 15 to 30/x in length in the four species of the genus which he studied. They can be seen, according to Cleveland, in life as made up of a dense hyahne protoplasm. When stained, it becomes apparent that the two centrioles are joined at their anterior ends by a desmose and their distal ends 20 to 30^ apart, each of which is surrounded by a special centrosome (a). In the resting stage no fibers extend from either centriole, but in the prophase, astral rays begin to grow out from the distal end of each centriole (6). As the rays grow longer (c), the two sets soon meet and the individual rays or fibers join, grow along one another and overlap to form the central spindle (d). In the resting nucleus, there are large irregular chromatin granules which are connected by fibrils with one an- other and also with the nuclear membrane. As the achromatic figure is formed and approaches the nucleus, the chromatin be- comes arranged in a single spireme imbedded in matrix. The spireme soon divides longitudinally and the double spireme presently breaks up transversely into paired chromosomes. The REPRODUCTION 127 Fig. 56. Mitosis in Trichonyinpha campanula, XSOO (Kofoid and Swezy). a, resting nucleus; b-g, prophase; h, metaphase; i, j, anaphase; k, telophase; 1, a daughter nucleus being reconstructed. central spindle begins to depress the nuclear membrane and the chromosomes become shorter and move apart. The intra- and 128 PROTOZOOLOGY Fig. 57. Development of spindle and astray rays during the mitosis in Barbulanympha, x930 (Cleveland), a, interphase centrioles and centrosomes; b, prophase centrioles with astral rays developing from their distal ends through the centrosomes; c, meeting of astral rays from two centrioles; d, astral rays developing into the early central spindle; e, a later stage showing the entire nuclear figure. extranuclear fibrils unite as the process goes on (e), the central spindle now assumes an axial position, and two groups of V-shaped chromosomes are drawn to opposite poles. In the telophase, the chromosomes elongate and becomes branched, thus assuming conditions seen in the resting nucleus. REPRODUCTION 129 In the unique resting nucleus of Spirotrichonympha polygyra (Fig. 58), Cleveland (1938) found four chromosomes, each of which contains a distinct coil within a sheath and its one end con- nected with the anterior margin of the nuclear membrane by an Fig. 58. Mitosis in Spirotrichonympha polygyra (Cleveland), a, resting nucleus with 4 chromosomes; b, c, prophase; d, chromosomes mo\ang apart; e, elongation of nucleus; f, telophase; g, a daughter nucleus in which the chromosomes are splitting, a-e, X3800; f, g, X2400. intranuclear chromosomal fiber, and the other with a deeply staining endosome (a). The spindle fibers appear between the separating flagellar bands which come in contact with the nuclear membrane. Soon some of the astral rays become connected mth the intranuclear chromosomal fibers and one long and one short 130 'RUTOZOOLOGY chromosomes which become thicker and shorter move toward each pole. During the telophase, each chromosome spHts length- wise and forms the resting nucleus (g). In Lophotnonas blattarum, the nuclear division (Fig. 59) is initiated by the migration of the nucleus out of the calyx. On the nuclear membrane is attached the centriole which probably originates in the blepharoplast ring; Fig. 59. Nuclear division in Lophomonas blattarum, X1530 (Kudo), a, resting nucleus; b, c, prophase; d, metaphase; e-h, anaphase; i-k. telophase. the centriole divides and the desmose which grows, now stains very deeply, the centrioles becoming more conspicuous in the anaphase when new flagella develop from them. Chromatin granules become larger and form a spireme, from which 6-8 chromosomes are produced. Two groups of chromosomes move toward the opposite poles, and when the division is completed, each centriole becomes the center of formation of all motor organellae. REPRODUCTION 131 In some forms, such as Noctiluca (Calkins), Actinophrys (Belaf), etc., there may appear at each pole, a structureless mass of cytoplasm (centrosphere), but in a very large number of species there appear no special structures at poles and the spindle fibers become stretched seemingly between the two extremities of the elongating nuclear membrane. Such is the condition found in Cryptomonas (Belaf), Rhizochrysis (Doflein), Aulacantha (Borgert), and in micronuclear division of the majority of Euciliata and Suctoria. The behavior of the endosome during the mitosis differs among different species as are probably their functions. In Eimeria schuhergi (Schaudinn), Euglena viridis (Tschenzoff), Oxyrrhis marina (Hall), Colacium vesiculosum (Johnson), Haplosporidium limnodrili (Granata), etc., the conspicuously staining endosome divides by elongation and constriction along with other chromat- ic elements, but in many other cases, it disappears during the early part of division and reappears when the daughter nuclei are reconstructed as observed in Monocystis, Dimorpha, Eu- glypha, Pamphagus (Belaf), Acanthocystis (Stern), Chilomonas (Doflein), Dinenympha (Kirby), etc. In the vegetative division of the micronucleus of Concho- phthirus anodontae (Fig. 60), Kidder (1934) found that prior to division the micronucleus moves out of the pocket in the macro- nucleus and the chromatin becomes irregularly disposed in a reticulum; swelling continues and the chromatin condenses into a twisted band, a spireme, which breaks into many small seg- ments, each composed of large chromatin granules. With the rapid development of the spindle fibers, the twelve bands become arranged in the equatorial plane and condense. Each chromosome now splits longitudinally and two groups of 12 daughter chromo- somes move to opposite poles and transform themselves into two compact daughter nuclei. In Zelleriella intermedia (Fig. 61), Chen (1936) saw the formation of 24 chromosomes, each of which is connected with a fiber of the intranuclear spindle and splits lengthwise in the metaphase. While in the majority of protozoan mitosis, the chromosomes split longitudinally, there are observa- tions which suggest a transverse division. As examples may be mentioned the chromosomal divisions in Astasia laevis (Belaf), Entosiphon sulcatum (Lackey), and a number of ciliates. In a small number of species observations vary, as, for example, in 132 PROTOZOOLOGY Peranema trichophorum in which the chromosomes were observed to divide transversely (Hartmann and Chagas) as well as longi- tudinally (Hall and Powell; Brown). It is inconceivable that the division of the chromosome in a single species of organism is haphazard. The apparent transverse division might be explained SP^ 1^ T2 Fig. 60. Mitosis of the micronucleus of Concho'phthirus anodontae, X2640 (Kidder), a-c, prophase; d, e, metaphase; f, g, anaphase; h, i, telophase. by assuming, as Hail (1937) showed in Euglena gracilis, that the splitting is not completed at once and the pulling force acting upon them soon after division brings forth the long chromosomes still connected at one end. Thus the chromosomes remain to- gether before the anaphase begins. In the instances considered on the preceding pages, the so- called chromosomes found in them, appear to be essentially REPRODUCTION 133 similar in structure and behavior to typical metazoan chromo- somes. In many other cases, the so-called chromosomes or "pseudochromosomes" are slightly enlarged chromatin granules which differ from the ordinary chromatin granules in their time of appearance and movement only. In these cases it is of course Fig. 61. Stages in mitosis in Zelleriella intermedia, X1840 (Chen), a, early prophase; b, metaphase; c, anaphase; d, telophase. not possible at present to determine how and when their division occurs before separating to the respective division pole. In the following table are listed the number of the "chromosomes" which have been reported by various investigators in the Proto- zoa that are mentioned in the present work : Protozoa Number of chromosomes Observers Rhizochrysis scherffeli 22 Doflein Haematococnis pluvialis 20-30 Elhott Polytomella agilis 5 Doflein Chlamydomonas spp. 10 (haploid) Pascher Euglena -piscijormis 12-15(?) Dangeard E. viridis 30 or more Dangeard Phacus pyrum 30-40 Dangeard Menoidium incurvum About 12 Hall Vacuolaria virescens About 30 Fott Syndiniuvi turbo 5 Chatton Anthophytha vegetans 8-10 Dangeard Cercomonas longicauda 4-5 Dangeard Collodidyon triciliatum About 20 Belaf 134 PROTOZOOLOGY Protozoa Number of chromosomes Observers Chilomastix gallinarum About 12 Boeck and Tanabe Eutricho7nastix ser'penlis 5 Kofoid and Swezy Dinenympha fimbricata 25-30 Kirby Metadevescovina debilis About 4 Light Trichomonas elongatum 3 Hinshaw T. batrachorum 4 or 8 Kuczynski 6 Bishop T. augusta 6 Bishop Hexatnita salmonis 5 or 6 Davis Giardia mlestinalis 4 Kofoid and Swezy G. muris 4 Kofoid and Christi- ansen Calonympha grassii 4 or 5 Janicki Spirotrichonympha polygyra 2 doubles Cup 2 Cleveland Lophomonas blattarum 16 or 8 doubles Janicki 8 or 6 Kudo 12 or 6 doubles Belaf L. striata 12 or 6 doubles Belaf Barbulanymph a laurabxida 40 Cleveland B. uf alula 50 Cleveland Rhynchonympha tarda 19 Cleveland Urinympha talea 14 Cleveland Staurojoenia assimilis 24 Kirby Trichonympha campamda 52 or 26 doubles Kofoid and Swezy T. grandis 22 Cleveland Dim astigaynoeba bistadialis 16-IS Kiihn Endamoeba disparata About 12 Kirby Entamoeba histolytica 6 Kofoid and Swezy; Uribe E. coli 6 Swezy; Stabler Hydramoeba hydroxena 8 Revnolds and Threl- keld Actinophrys sol 44 (diploid) ; 22 (haploid) Belaf Oxnerella maritima About 24 Dobell Thalassicolla nucleata 4 Belaf A ulacantha scolymantha More than 1600 Borgert 4 in gamogony Belaf Zygosoma globosimi 12 (diploid); 6 (haploid) Noble Diplocystis schneideri 6 (diploid) ; 3 (haploid) Jameson REPRODUCTION 135 Protozoa Number of chromosomes Observers Nina gracilis 5 (haploid) Leger and Duboscq Aggregata eberthi 12 (diploid) ; Dobell and Jameson; 6 (haploid) Belaf; Naville Adelea ovata 8-10 (diploid); 4-5 (haploid) Greiner Orcheobius hcrpobdeUae 10-12 Kunze Chloromijxwm leydigi 4 (diploid); 2 (haploid) Naville Myxidium lieberkuhni 4 Bremer Sphaeromyxa sabrazesi 6 Debaisieux; Belaf 4 Naville S. bolbianii 4 Naville Myxobolus pfeijferi 4 Keysselitz; Mercier; Georgevitch Protoopalina intestinalis 8 (diploid) ; 4 (haploid) Metcalf Zelleriella antilliensis 2(?) Metcalf Z. intermedia 24 Chen Didinium nasidum 16 (diploid); 8 (haploid) Prandtl Chilodonella uncinata 4 (diploid); 2 (haploid) Enrique; McDougall C. uncinata (tetraploid) 8;4 McDougall ConchopJithirus anodontae 12 (diploid) Kidder C. mytili 16 (diploid); 8 (haploid) Kidder Ancistruma isseli About 5 (haploid) Kidder Paramecium aurelia 30-40 Diller Slentor coeruleus 28 (diploid) ; 14 (haploid) Mulsow Oxytricha fallax 24 (diploid); 12 (haploid) Gregory Uroleptus halseyi 24 (diploid); 12 (haploid) Calkins Pleurotricha lanceolata About 40 (dipl.); 20 (hapl.) Man well Stylonychia pustidata 6 Prowazek Euplotes patella 6 (diploid) Yocom; Ivanic 8 (diploid) ; Turner 4 (haploid) Carchesium polypinum 16 (diploid); 8 (haploid) Popoff Trichodina sp. 4-6 Diller 136 PROTOZOOLOGY In many other Protozoa, the division figure, especially the achromatic figure, suggests strongly a mitosis, but the chromatin substance which makes up the equatorial plate can hardly be called chromosomes. A typical example of this type is found in the nuclear division of Amoeba proteus (Fig, 62). According to Chalkley and Daniel (1933), the conspicuous granules present in the resting nucleus, under the membrane contain very little chromatin, while abundant chromatin is lodged in the central Fig. 62. Nuclear division in Amoeba proteus, X180 (Chalkley and Daniel), a, resting stage; b-d, prophase; e, metaphase; f, g, anaphase; h, a daughter nucleus. area. The peripheral granules appear to give rise to achromatic figure. At the beginning of division, the chromatin granules become aggregated in a zone (6); they then assume a ring-form along the periphery of the central mass of network (c); at this stage, the cytoplasm around the nucleus is much vacuolated. A little later appears a discoid equatorial plate or ring which is connected with the nuclear membrane by numerous fibrils, and the nucleus becomes markedly flattened with its membrane still intact (d), which is considered as the end of the prophase. In the metaphase, the nuclear membrane becomes extremely faint and the portion over one side of the plate is without it (e). At the REPRODUCTION 137 anaphase the membrane completely disappears, the equatorial plate sphts and each half contracts in the plane of the plate, pro- ducing two daughter-plates. In some specimens a faint spindle formation was noted. At about this time, vacuolated condition of the perinuclear cytoplasm disappears (/). In later phases of anaphase the plates are more widely separated and are slightly less in diameter as compared with earlier stages. There are dis- tinct polar caps of fibrillar material at the poles of the spindle (g), finally each plate transforms itself into a resting nucleus (h). The two investigators added that if the chromatin granules located in the equatorial plate are chromosomes, ''they must be extremely numerous." Liesche (1938) recently estimates the number of these granules which he called chromosomes as between 500 and 600. C5rtosomic division Binary fission. As in metazoan cells, the binary fission occurs very widely among the Protozoa. It is a division of the body through middle of the extended long axis into two nearly equal daughter individuals (Fig. 49). In Amoeba proteus, Chalkley and Daniel found that there is a definite correlation between the stages of nuclear division and external morphological changes (Fig. 63). During the prophase, the organism is rounded, studded with fine pseudopodia and exhibits under reflected light a clearly defined hyaline area at its center (a), which disappears in the metaphase (b, c). During the anaphase the pseudopodia rapidly become coarser; in the telophase the elongation of body, cleft formation, and return to normal pseudopodia, take place. In Testacea, one of the daughter individuals remains, as a rule, within the old test, while the other moves into a newly formed one, as in Arcella, Pyxidicula, Euglypha, etc. According to Doflein, the division plane coincides with the axis of body in Cochliopodium, Pseudodifflugia, etc., and the delicate homo- geneous test also divides into two parts. In the majority of the Mastigophora, the division is longitudinal, as is shown by that of Menoidium incurvum (Fig. 64). In certain dinoflagellates, such as Cefatium, Cochliodinium, etc., the division plane is oblique, while in forms such as Oxyrrhis (Dunkerly; Hall), the fission is transverse. In Strehlomastix strix (Kofoid and Swezy), Lopho- monas striata (Kudo), Spirotrichonympha hispira (Cleveland), etc., the division takes place transversely but the polarity of the 138 PROTOZOOT-OGY posterior individual is reversed so that the posterior end of the parent organism becomes the anterior end of the posterior daughter individual. In the ciliate Bursaria, Lund (1917), ob- served reversal of polarity in one of the daughter organisms at the time of division of normal individuals and also in those which regenerated after being cut into one-half the normal size. In the Ciliophora the division is as a rule transverse (Fig. 48), ^ ''4 Fig. 63. External morphological changes during division of Amoeba protetis, as viewed in life in reflected light, X about 20 (Chalkley and Daniel), a, shortly before the formation of the division sphere; b, a later stage; c, prior to elongation; d, further elongation; e, division al- most completed. in which the cytostome without any enlargement or elongation divides by constriction through the middle so that the two daughter individuals are about half as large at the end of division. Both individuals retain their polarity except in a few cases. Multiple division. In multiple division the body divides into a number of daughter individuals, with or without residua^ cyto- plasmic masses of the parent body. In this process the nucleus may undergo either simultaneous multiple division, as in Ag- gregata, or more commonly, repeated binary fission, as in Plasmo- dium (Fig. 198) to produce large numbers of nuclei, each of which REPRODUCTION 139 becomes the center of a new individual. The number of daughter individuals often varies, not only among the different species, but also within one and the same species. Multiple division occurs commonly in the Foraminifera (Fig. 157), the Radiolaria (Fig. 167), a few Mastigophora such as Trypanosoma lewisi (Fig. 112), T. cruzi, and many Hypermastigina. It is very common among various groups of Sporozoa in which the trophozoite multiplies abundantly by this method. Fig. 64. Nuclear and cytosomic division in Menoidium incurvum, X about 1400 (Hall), a, resting stage; b, c, prophase; d, equatorial plate; e, f, anaphase; g, telophase. Budding. Multiplication by budding which occurs in the Proto- zoa is the formation of one or more smaller individuals from the parent organism. It is either exogenous or endogenous, depend- ing upon the location of the developing buds or gemmules. Exogenous budding has been reported in Acanthocystis, Nocti- luca (Fig. 101), Myxosporidia (Fig. 65, h), astomous ciliates (Fig. 228), Chonotricha, Suctoria (Fig. 289, k), etc. Endogenous budding has been found in Testacea, Gregarinida, Myxosporidia (Figs. 212, e; 214, j), and other Sporozoa as well as Suctoria (Fig. 289, h). Collin observed a unique budding in Tokophrya 140 PROTOZOOLOGY cyclopum in which the entire body, excepting the stalk and pelHcle, transforms itself into a young ciliated bud which leaves sooner or later the parent pellicle as a swarmer. Plasmotomy. Occasionally the multinucleate body of a proto- zoan divides into two or more small, multinucleate individuals, .•:-if.<-Joi-;.(>i V-.f(t«i'?»-».-. pa Mm 'l^ Fig. 65. a, b, budding in Myxidium lieberkuhni; c, d, plasmotomy in Chloromyxum leydigi; e, plasmotomy in Sphaeromyxa halbianii. the cytosomic division taking place independently of nuclear division. This has been called plasmotomy by Doflein. It has been observed in the trophozoites of several coelozoic myxo- sporidians, such as Chloromyxum leydigi (Fig. 65), Sphaeromyxa halbianii (Fig. 65), etc. It occurs further in Mycetozoa (Fig. 135), Foraminifera and ProtociHata. Colony formation When the division is repeated without a complete separation of the daughter individuals, a colonial form is produced. The REPRODUCTION 141 component indi\'idiials of a colony may either have protoplasmic connections among them or be grouped within a gelatinous enve- lope if completely separated. Or, in the case of loricate or stalked forms, these exoskeletal structures may become attached to one another. Although varied in appearance, the arrangement and relationship of the component individuals are constant, and this makes the basis for distinguishing the types of protozoan colonies, as follows: Catenoid or linear colony. The daughter individuals are at- tached endwise, forming a chain of several individuals. It is of comparatively rare occurrence. Examples : Astomous ciliates such as Radiophrya (Fig. 228), Protoradiophrya (Fig. 228) and dino- fiagellates such as Ceratium, Haplozoon (Fig. 103) and Poly- krikos(Fig. 104). Arboroid or dendritic colony. The individuals remain connected with one another in a tree-form. The attachment may be by means of the lorica, stalk or gelatinous secretions. It is a very common colony found in different groups. Examples : Dinobryon (Fig. 87), Hyalobryon (Fig. 87), etc. (connection by lorica); Colacium (Fig. 96), many Peritricha (Figs. 280; 282), etc. (by stalk); Poteriodendron (Fig. 109), Stylobryon (Fig. 119), etc. (by lorica and stalk); Hydrurus (Fig. 88), Spongomonas (Fig. 118), Cladomonas (Fig. 118) and Anthophysa (Fig. 119) (by gelatinous secretions). Discoid colony. A small number of individuals are arranged in a single plane and grouped together by a gelatinous substance. Examples: Cyclonexis (Fig. 87), Gonium (Fig. 93), Platydorina (Fig. 94), Protospongia (Fig. 108), Bicosoeca (Fig. 109), etc. Spheroid colony. The individuals are grouped in a spherical form. Usually enveloped by a distinct gelatinous mass, the com- ponent individuals may possess protoplasmic connections among them. Examples: Uroglena (Fig. 87, c), Uroglenopsis (Fig. 87, d), Volvox (Fig. 93), Pandorina (Fig. 94, /), Eudorina (Fig. 94, h), etc. Such forms as Stephanoon (Fig. 94, a) appear to be inter- mediate between this and the discoid type. The component cells of some spheroid colonies show a distinct differentiation into somatic and reproductive individuals, the latter apparently de- veloping from certain somatic cells during the course of develop- ment. The gregaloid colony, which is sometimes spoken of, is a loose 142 PROTOZOOLOGY Fig. 66. Encystment of Lophomonas hlattarum, X1150 (Kudo). group of individuals of one species, usually of Sarcodina, which become attached to one another by means of pseudopodia in an irregular form. Asexual reproduction The Protozoa nourish themselves by certain methods, grow and multiply by the methods described in the preceding pages. This phase of the life-cycle of a protozoan is the vegetative stage or the trophozoite. The trophozoite repeats its asexual reproduc- tion process under favorable circumstances. Generally speaking, the Sporozoa increase to a much greater number by schizogony and the trophozoites are called schizonts. Under certain conditions, the trophozoite undergoes encyst- ment (Fig. 66). Prior to encystment, the trophozoites cease to ingest, and extrude remains of, food particles, resulting in some- what smaller forms which are usually rounded and inactive. This is often called the precystic stage. The organism presently secretes substances which become solidified into the cyst wall and thus the cyst is formed. In this condition, the protozoan ap- parently is able to maintain its vitality for a certain length of time under unfavorable conditions. The causes of encystment are still the matter which many investigators are attempting to com- prehend. It appears certain at least in some cases that the encyst- ment is brought about by changes in temperature, desiccation, and chemical composition, amount of food material, accumulation of catabolic wastes, etc., in the medium in which the organisms REPRODUCTION 143 Fig. 67. Encystment of Exiglypha acanthophora, X320 (Klihn). live. In some cases, the organisms encyst temporarily in order to undergo nuclear reorganization and multiplication. Because of the latter condition and also of the failure in attempting to cause certain Protozoa to encyst under experimental conditions, some suppose that certain internal factors play as great a part as do the external conditions in the phenomenon of encystment. Ordinarily a single cyst wall seems to be sufficient to protect the protoplasm against unfavorable external conditions. In some cases there may be a double cyst wall, the inner one usually being more delicate. The cyst wall is generally composed of homo- geneous substances, but it may contain calcareous scales as in Euglypha (Fig. 67). While chitin is the common material of which the cyst wall is composed, cellulose makes up the cyst envelope of numerous Phytomastigina. The capacity of Protozoa to produce the cyst is probably one of the reasons why they are so widely distributed over the surface of the globe. The minute protozoan cysts are easily carried from place to place by wind, attached to soil particles, debris, etc., by the flowing water of rivers or the current in oceans or by insects, birds, other animals to which they become readily attached. When a cyst encounters a proper environment, the living proto- plasmic contents excyst and the emerged organism once more return to its active trophic phase of existence. In Sporozoa, no encystment occurs. Here at the end of active schizogony, sexual reproduction usually initiates the production of large numbers of the spores (Fig. 68). Sexual reproduction and life-cycles Besides reproducing by the asexual method, numerous Proto- zoa reproduce themselves in a manner comparable with the 144 PROTOZOOLOGY sexual reproduction which occurs universally in the Metazoa. Various types of sexual reproduction have been reported in literature, of which a few will be considered here. The sexual fusion, which is a complete union of two gametes, has been re- ported from various groups, while the conjugation which is a Fig. 68. Diagram illustrating the life-cycle of Thelohania legeri (Kudo), a, extrusion of the polar filament in gut of anopheline larva; b, emerged amoebula; c-f, schizogony in fat body; g-m, sporont- formation; n-x, spore-formation. temporary union of two gametes for the purpose of exchanging the nuclear material, is found almost exclusively in the Ciliophora. Sexual fusion. If the two gametes which take part in this process, are morphologically alike, they are called isogametes and the act the isogamy; but if unlike, anisogametes, and the act, anisogamy. The isogamy is typically represented by the flagellate Copromonas suhtilis (Fig. 69), in which there occurs, according to Dobell, a complete nuclear and cytoplasmic fusion between two isogametes. Each nucleus, after casting off a portion REPRODUCTION 145 of its nuclear material, fuses with the other and the zygote thus formed, encysts. In Stephanosphaera pluvialis (Fig. 70), both asexual and sexual reproductions occur, according to Hieronymus, Each individual multiplies and develops into numerous biflagel- late gametes, all of which are alike. Isogamy between two gametes results in formation of numerous zygotes which later develop into trophozoites. Anisogamy has been observed in certain Foraminifera, Gregari- nida (Lankesterella, Fig. 174; Schizocystis, Fig. 185), etc. It per- Wm ^ Fig. 69. Sexual fusion in Copromonas subtilis, X1300 (Dobell). haps occurs in the Radiolaria also, although positive evidence has yet to be presented. Anisogamy seems to be more widely dis- tributed. On the whole, the differences between the micro- and macro-gametes are comparable with those which exist between the spermatozoa and ova of the Metazoa. The microgametes are motile, relatively small and usually numerous, while the macro- gametes are usually not motile, much more voluminous and fewer in number (Fig. 71). In Chlamydomonas monadina (Fig. 90), ac- cording to Goroschankin, the two gametes come in contact at the anterior end where the membranes become dissolved and the contents of the microgamete stream into the macrogamete. A new shell is then secreted around them. Later the shell becomes swollen and the organism multiplies into 2, 4, or 8 swarmers which in turn develop into the trophozoites. In Pandorina morum (Fig. 72), Pringsheim observed that each cell asexually develops into a young colony (a, h) or into anisogametes (c) which undergo sexual fusion {d-g) and encyst {h). The organism emerged from the cyst, develops into a young trophozoite {i-m). A similar life- cycle was found by Goebel in Eudorina elegans (Fig. 73). Among the Sporozoa, anisogamy is of common occurrence. In 14G PROTOZOOLOGY Fig. 70. The life-cycle of Stephanosphaera pluvialis (Hieronymus). a-e, asexual reproduction; f-m, sexual reproduction. Coccidia, the process was well studied in Eimeria schuhergi (Fig. 188), Aggregata eberthi {Fig. 190), Adelea ovata (Fig. 194), etc., and the resulting products are the oocyst (zygote) in which the spores or sporozoites develop. Similarly in Haemosporidia such as Plasmodium vivax (Fig. 197), anisogamy results in the forma- tion of the ookinete or motile zygote which gives rise to a large REPRODUCTION 147 Fig. 71. a, macrogamete, and b, microgamete of Volvox aureus, XlOOO (Klein). number of sporozoites. Among Myxosporidia, a complete infor- mation as to how the initiation of sporogony is associated with sexual reproduction, is still lacking. Na\dlle, however, states that Fig. 72. The life-cycle of Pandorina morum, X400 (Pringsheini). a, b, asexual reproduction; c-m, sexual reproduction. 148 PROTOZOOLOGY in the trophozoite of Sphaeromyxa sahrazesi (Fig. 210), micro- and macro-gametes develop, each with a haploid nucleus. Anisog- amy, however, is peculiar in that the two nuclei remain inde- pendent. The microgametic nucleus divides once and the two nuclei remain as the vegetative nuclei of the pansporoblast, while the macrogamete nucleus multiplies repeatedly and develop into two spores. Anisogamy^has been suggested to occur in some mem- bers of Amoebina, particularly in Endamoeba hlattae. Mercier (1909) believed that in this amoeba there occurs anisogamy soon Fig. 73. The life-cycle of Eudorina elegans (Goebel). a, asexual repro- duction; b, se.xual reproduction, a female colony with clustered and isolated microgametes. after excystment in the host's intestine, but this awaits confirma- tion. Cultural studies of various parasitic amoebae in recent years show no evidence of sexual reproduction in those forms. Among the Ciliophora, the sexual fusion occurs only in Proto- ciliata (Fig. 225) and the conjugation described below is the usual method of sexual reproduction. Conjugation. The conjugation is a temporary union of two individuals of one and the same species for the purpose of ex- changing part of the nuclear material and occurs almost ex- clusively in the Eucihata and Suctoria. The two individuals which participate in this process may be either isogamous or anisog- amous. In Paramecium caudatum (Fig. 74), two individuals come in contact on their oral surfaces. The micronucleus in each REPRODUCTION 149 Fig. 74. Diagram illustrating the conjugation of Paramecium caudatum. a-q, X about 130 (Calkins); r, X1200 (Dehorne). conjugant divides twice (6-e), forming four micronuclei, three of which degenerate and do not take active part during further 150 PROTOZOOLOGY changes (f-h). The remaining microniicleiis divides once more, l)rodiicing a wandering pronucleus and a stationary pronucleus (/, g). The wandering pronucleus in each of the conjugants enters the other individual and fuses with its stationary pronucleus {h, r). The two zygotes now separate from each other and become exconjugants. In each exconjugant, the synkaryon divides three times in succession (i-m) and produces eight nuclei (n), four of which remain as micronuclei, while the other four develop into new macronuclei (o). Cystosomic fission follows then, producing first, two individuals with four nuclei (p) and then, four small individuals, each containing a micronucleus and a macronucleus (a). According to Jennings, however, of the four smaller nuclei formed in the exconjugant indicated in Fig. 74, o, only one re- mains active, and the other three degenerate. This active nucleus divides prior to the cytosomic division so that in the next stage (p), there are two developing macronuclei and one micronucleus which divides once more before the second and last cytosomic division (q). During these changes the original macronucleus disintegrates, degenerates, and finally becomes absorbed in the cytoplasm. When the cihate possesses more than one micronucleus, the first division ordinarily occurs in all and the second may or may not take place in all, varying apparently even among individuals of the same species. In Paramecium aurelia, of the eight micro- nuclei formed by two fissions of the two original micronuclei, according to Woodruff, only one undergoes the third division to produce two pronuclei. This is the case with the majority, al- though more than one micronucleus may divide for the third time to produce several pronuclei, for example, two in Euplotes patella, Stylonychia pustulata; two to three in Oxytrichafallax and two to four in Uroleptus mobilis. This third division is always characterized by long extended nuclear membrane stretched be- tween the division products. Ordinarily the individuals which undergo conjugation appear to be morphologically similar to those that are engaged in the trophic activity, but in some species, the organism divides just prior to conjugation. According to Wichterman (1936), conjuga- tion in Nyctotherus cordiformis (Fig. 75) takes place only among those which live in the tadpoles undergoing metamorphosis (f-j). The conjugants are said to be much smaller than the ordinary REPRODUCTION 151 Fig. 75. The life-cycle of Nyctotherus cordiformis in Hijla versicolor (Wichterman). a, a cyst; b, excystment in tadpole; c, d, division is repeated until host metamorphoses; e, smaller preconjugant; f-j, con- jugation; k, exconjugant; 1, amphinucleus divides into 2 nuclei, one micronucleus and the other passes through the "spireme ball" stage before developing into a macronucleus; k-n, exconjugants found nearly exclusively in recently transformed host; o, mature trophozoite; p-s, binary fission stages; t, precystic stage. 152 PROTOZOOLOGY trophozoites, because of the preconjugation fission (d-e). The microiuiclear divisions are similar to those that have been de- scribed for Paramecium caudatum and finally two pronuclei are formed in each conjugant. Exchange and fusion of pronuclei follow. In each exconjugant, the synkaryon divides once to form the micronucleus and the macronuclear anlage (k-l) which de- velop into the "spireme ball" and finally into the macronucleus (m-o). A sexual process which is somewhat intermediate between the sexual fusion and conjugation, is noted in several instances. Ac- cording to Maupas' classical work on Vorticella riehulifera, the ordinary vegetative form divides twice, forming four small in- dividuals, which become detached from one another and swim about independently. Presently each becomes attached to one side of a stalked individual. In it, the micronucleus divides three times and produces eight nuclei, of which seven degenerate; and the remaining nucleus divides once more. In the stalked form the micronucleus divides twice, forming four nuclei, of which three degenerate, the other dividing into two. During these changes the cytoplasm of the two conjugants fuse completely. The wandering nucleus of the smaller conjugant unites with the stationary nu- cleus of the larger conjugant, the other two pronuclei degenerat- ing. The synkaryon divides several times to form a number of nuclei, from some of which macronuclei are differentiated and exconjugant undergoes multiplication. Another example of this type has been observed by Noland (1927) in Metopus es (Fig. 76). According to Noland, the con- jugants fuse at the anterior end (a), and the micronucleus in each individual divides in the same way as was observed in Para- mecium caudatum (b-e). But the cytoplasm and both pronuclei of one conjugant pass into the other (/), leaving the degenerating macronucleus and a small amount of cytoplasm behind in the shrunken pellicle of the smaller conjugant which then separates from the other (j). In the larger exconjugant, two pronuclei fuse, and the other two degenerate and disappear {g, h). The synkaryon divides into two nuclei, one of which condenses into the micro- nucleus and the other grows into the macronucleus {i-m). This is followed by the loss of cilia and encystment. What is the significance of conjugation? What are the condi- tions which bring about conjugation in the ciliates? These are REPRODUCTION 153 Fig. 76. Conjugation of Metopus es (Noland). a, early stage; b, first micronuclear division; c, d, second micronuclear division; e, third micronuclear division; f, migration of pronuclei from one conjugant into the other; g, large conjugant with two pronuclei ready to fuse; h, large conjugant with the synkaryon, degenerating pronuclei and macronucleus; i, large exconjugant with newly formed micronucleus and macronucleus, showing the degenerating old macronucleus; j, small exconjugant with degenerating macronucleus; k-m, develop- ment of two nuclei, a, X290; b-j, X 250; k-m, X590. but two of the many problems which numerous investigators at- tempted to solve since the appearance of the first comprehensive study of the phenomenon by Maupas in 1889. Woodruff's ob- servation (1932) among others which showed that 5071 genera- tions produced asexually from a single individual of Paramecium 154 PROTOZOOLOGY aurelia between May 1, 1907 and May 1, 1915, did not manifest any decrease in vitality after eight years of asexual r(>])roduction, demonstrates beyond doubt that the sexual reproduction in the form of conjugation is not necessary for the well-being of Para- mecium aurelia under favorable environmental conditions. On the other hand, there is a large body of evidence to sup])ort the view expressed first by Maupas to the effect that the conjugation cor- rects an inherent tendency toward senescence under unfavorable conditions. Recently Sonneborn and Lynch (1932) demonstrated by using different clones of P. aurelia that the effects of conjuga- tion are diverse and characteristic of different races: 1) the con- jugation increases fission rate in some clones, decreases the rate in others; 2) it increases variation in some clones, but not in others; and 3) it increases mortality in some clones but not in others. Sonneborn (1937) continuing controlled observations on this ciliate, discovered that in certain races there are two classes of individuals with respect to sexual differentiation and that the members of different classes conjugate, while the members of each class do not. He further found that the individuals produced by binary fission from a single individual belong all to the sex re- action type to which the original individual belonged, and that in conjugation in which two sex reaction types participate, the four sets of progeny consist of the two types in chance combination, the ratio being identical with those for inheritance in higher organisms. Jennings (1938) found further four sex raction types in P. bursaria, in which the type behavior toward conjugation was exactly like that of the two types found in P. aurelia. Automixis. In certain Protozoa, the fusion occurs between two nuclei which originate in a single nucleus of an individual. This process has been called automixis by Hartmann, in contrast to the amphimixis (Weismann) which is the complete fusion of two nuclei originating in two individuals, as was discussed in the preceding pages. If the two nuclei which undergo a complete fusion are present in a single cell, the process is called autogamy, but, if they are in two different cells, then paedogamy. The autogamy is of common occurrence in the myxosporidian spores. The young sporoplasm contains two nuclei which fuse together prior to or during the process of germination in the ahmentary canal of a specific host fish, as for example in Sphaeromyxa sahrazesi (Figs. 209; 210) and Myxosoma catostomi (Fig. 208). In REPRODUCTION 155 the Microsporidia, autogamy initiates the spore-formation at the end of schizogonie activity of individuals as in Thelohania legeri (Fig. 68). Recently Diller (1936) observed in solitary Paramecium aurelia (Fig. 77), certain micronuclear changes similar to those which occur in conjugating individuals. The two micronuclei divide twice, forming eight nuclei, some of which divide for the third time, producing two functional and several degenerating nuclei. The two functional nuclei then fuse in the "preoral cone" and Fig. 77. Diagram illustrating autogamy in Paramecium aurelia (Diller). a, normal animal; b, first micronuclear division; c, second micronuclear division; d, individual with 8 micronuclei and a macro- nucleus preparing for skein formation; e, some micronuclei dividing for the third time, with two functional nuclei near 'preoral cone'; f, two gamete-nuclei formed by the third division in the cone; g, fusion of the nuclei, producing synkaryon; h, i, first and second division of synkaryon; j, with 4 nuclei, 2 becoming macronuclei and the other 2 remaining as micronuclei; k, macronuclei developing, micronuclei dividing; 1, one of the daughter individuals produced by fission. form the synkaryon which divides twice into four. The original macronucleus undergoes fragmentation and becomes absorbed in the cytoplasm. Of the four micronuclei, two transform into the new macronuclei and two remain as micronuclei, each dividing into two after the body divides into two. Diller is "inclined 156 PROTOZOOLOGY to feel that if an animal does not happen to meet another indi- vidual in the same physiological condition as itself, its reorga- nizing 'urge' will be expressed by autogamy, as a substitute for conjugation." The paedogamy occurs in at least two species of Myxosporidia, namely, Leptotheca ohlmacheri (Fig. 212) and Unicapsula muscularis (Fig. 213). The spores of these Myxosporidia contain two uninucleate sporoplasms which are independent at first, but prior to emergence from the spore, they undergo a complete fusion to metamorphose into a uninucleate amoebula. Perhaps the classical example of the paedogamy is that which was found by Hertwig (1898) in Actinosphaeriiim eichhorni. The organism encysts and the body divides into numerous uninucleate second- ary cysts. Each secondary cyst divides into two and remains together within a common cyst-wall. In each the nucleus divides twice, and forms four nuclei, one of which remains functional, the remaining three degenerating. The paedogamy results in formation of a zygote in place of a secondary cyst. Belaf (1922) observed a similar process in Adinophrys sol (Fig. 78). The helio- zoan withdraws its axopodia and divides into two uninucleate bodies which become surrounded by a common gelatinous en- velope. Both nuclei divide twice and produce four nuclei, three of which degenerate. The two daughter cells, each with one haploid nucleus, undergo paedogamy and the resulting individual now contains a diploid nucleus. Endomixis. Woodruff and Erdmann (1914) observed that in Paramecium aurelia (Fig. 79) at regular intervals of about 30 days, the old macronucleus breaks down and disappears, while each of the two micronuclei divide twice, forming eight nuclei. Of these, six disintegrate. At this point the organism divides into two, each daughter individual receiving one micronucleus. This nucleus soon divides twice into four, two of which develop into macronuclei, and the other two divide again. Here the organisms divide once more by binary fission, each bearing one macronucleus and two micronuclei. This process which is "a com- plete periodic nuclear reorganization without cell fusion in a pedigreed race of Paramecium" was called by the two authors endomixis. In the case of P. caudatum, they found endomixis occurs at intervals of about 60 days. Sonneborn (1937) succeeded in inducing endomixis in certain stocks of P. aurelia by placing REPRODUCTION 157 small mass cultures containing surplus animals from isolation lines at 31°C. for 1-2 days. Endomixis has since been observed more often in encysted stage of Spathidium spathula, Uroleptus mobilis, Euplotes longipes, Didinium nasutum, etc. As to its sig- nificance, the statement made for conjugation appears also to hold true. In Paramecium aurelia, Diller (1936) found simple fragmenta- Fig. 78. Paedogamy in Actinophrys sol, X460 (Belaf). a, withdrawal of axopodia; b, c, division into two uninucleate bodies, surrounded by a common gelatinous envelope; d-f, the first reduction division; g-i, the second reduction division; j-1, synkaryon formation. tion of the macronucleus which was not correlated with any special micronuclear activity and which could not be stages in conjugation or autogamy. Diller suggests that if conjugation or autogamy is to create a new nuclear complex, as is generally held, it is conceivable that somewhat the same result might be achieved by 'purification act' (through fragmentation) on the part of the macronucleus itself, without involving micronuclei. He coined the term 'hemixis' to include these reorganizations. Meiosis. In the foregoing sections, references have been made 158 PROTOZOOLOGY to the divisions which the nuclei undergo prior to sexual fusion or conjugation. In all Metazoa, during the development of the gametes, the gametocytes undergo reduction division or meiosis, by which the number of chromosomes is halved; that is to say, each fully mature gamete possesses half number (haploid) of chromosomes typical to the species (diploid). In the zygote, the Fig. 79. Diagram showing the endomixis in Paramecium aurelia (Woodruff), a, normal individual; b, degeneration of macronucleus and first micronuclear division; c, second micronuclear division; d, degeneration of 6 micronuclei; e, cell division; f, g, first and second reconstruction micronuclear division; h, transformation of 2 micro- nuclei into macronuclei; i, micronuclear and cell division; j, typical nuclear condition is restored. diploid number is reestablished. In the Protozoa in which sexual reproduction occurs during their life-cycle, meiosis presumably takes place to maintain the constancy of chromosome-number, but the process is understood only in a small number of species. In conjugation, the meiosis seems to take place in the second micronuclear division, although in some, for example, Oxytricha fallax, according to Gregory, the actual reduction occurs during the first division. Prandtl (1906) was the first to note a reduction REPRODUCTION 159 in number of chromosomes in the Protozoa. In conjugating Didinium nasutum, he observed 16 chromosomes in each of the daughter micronuclei during the first division, but only 8 in the second division. Since that time, the fact that meiosis occurs during the second micronuclear division has been observed in Chilodonella uncinata (Enrique; MacDougall), Carchesium poly- piniim (Popoff), Uroleptiis halseyi (Calkins), etc. (see the ciliates in the list on p. 135). In various species of Paramecium and many- other forms, the number of chromosomes appears to be too great to allow a precise counting, but it is generally agreed that here probably reduction in the number also takes place. Information on the meiosis involved in the complete fusion of gametes is even more scanty and fragmentary. In Monocystis rostrata, a parasite of the earthworm, Mulsow, noticed that the nuclei of two gametocytes which encyst together, multiply by mitosis in which eight chromosomes are constantly present, but in the last division in gamete formation, each daughter nucleus receives only 4 chromosomes. In another species of Monocystis, Calkins and Bowling (1926) observed that the diploid number of chromosomes was 10 and that haploid condition is established in the last gametic division, thus confirming Mulsow's finding. In the paedogamy of Actinopkrys sol, Belaf found 44 chromo- somes in the first nuclear division, but after two meiotic divisions, the remaining functional nucleus contains only 22 chromosomes so that when paedogamy is completed the diploid number is re- stored. On the other hand, in the coccidian Aggregata eberthi (Fig. 190), according to Dobell and Jameson, Belaf, and Naville, and in the gregarine Diplocystis schneideri, according to Jameson, there is no reduction in the number of chromosomes during the gamete-formation, but the first zygotic division is meiotic, 12 to 6 and 6 to 3, respectively. A similar reduction in chromosome (12 to 6) takes place also in the gregarine Zygosoma glohosum, accord- ing to Noble's recent study (1938). Thus it appears in these cases that the zygote or oocyst is the only stage in which diploid nucleus occurs, while the nuclei in the stages in the remainder of the life- cycle are haploid. References Belar, K. 1926 Der Formwechsel der Protistenkerne. Ergebn. u. Fortschr. Zool., Vol. 6. 160 PROTOZOOLOGY Calkins, G. N. 1926 The biology of the Protozoa. Philadelphia. — and R. C. Bowling 1926 Gametic meiosis in Mono- cystis. Biol. Bull., Vol. 51. Chalkley, H. W. and G. E. Daniel 1933 The relation be- tween the form of the living cell and the nuclear phases of division in Amoeba proteus. Physiol. Zool., Vol. 6. Chen, T. T. 1936 Observations on mitosis in opalinids. I. Proc. Nat. Acad. Sci., Vol. 22. ^ Cleveland, L. R. 1938 Longitudinal and transverse division in two closely related flagellates. Biol. Bull., Vol. 74. 1938 Origin and development of the achromatic figure. Ibid. S. R. Hall, E. P. Sanders and J. Collier 1934 The wood-feeding roach Cryptocercus, its Protozoa, and the symbiosis between Protozoa and roach. Mem. Amer. Acad. Arts and Sci., Vol. 17. DiLLER, W. F. 1936 Nuclear reorganization processes in Para- mecium aurelia, with descriptions of autogamy and 'hcmixis'. Jour. Morph., Vol. 59. DoBELL, C. 1908 The structure and life history of Copromonas subtilis. Quart. Jour. Micr. Sci., Vol. 52. 1917 On Oxnerella maritima, no v. gen., nov, spec, a new heliozoan, and its method of division, with some remarks on the centroplast of the Heliozoa. Ibid., Vol. 62. 1925 The life-history and chromosome cycle of Ag- gregata eberthi. Parasitology, Vol. 17. and A. P. Jameson 1915 The chromosome cycle in Coc- cidia and Gregarines. Proc. Roy. Soc. (B), Vol. 89. Hall, R. P. 1923 Morphology and binary fission of Menoidium incurvum. Univ. Calif. Publ. Zool., Vol. 20. 1925 Binary fission in Oxijrrhis marina. Ibid., Vol. 26. Jameson, A. P. 1920 The chromosome cycle of gregarines with special reference to Diplocystis schneideri. Quart. Jour. Micr. Sci., Vol. 64. Jennings, H. S. 1929 Genetics of the Protozoa. Bibliogr. Gen., Vol. 5. 1938 Sex reaction types and their interrelations in Paramecium bursaria. I. II. Proc. Nat. Acad. Sci., Vol. 24. Kidder, G. W. 1933 Studies on Conchophthirius mytili de Mor- gan. I. Arch. f. Protistenk., Vol. 79. and W. F. Diller 1934 Observations on the binary fission of four species of common free-living ciliates, with special reference to the macronuclear chromatin. Biol. Bull., Vol. 67. and F. M. Summers 1935 Taxonomic and cytological studies on the ciliates associated with the amphipod family Orchestiidae from the Woods Hole district. Ibid., Vol. 68. Kofoid, C. a. and Olive Swezy 1919 On Streblomastix strix, a polymastigote flagellate with a linear plasmodial phase. Univ. Calif. Publ. Zool., Vol. 20. REPRODUCTION 161 1919 On Trichonympha campanula sp. nov. Ibid. Kudo, R. R. 1925 Observations on Endamoeha blattae. Amer. Jour. Hyg., Vol. 6. 1926 Observations on Lophomonas blattarum, a flagel- late inhabiting the colon of the cockroach, Blalta orientalis. Arch. f. Protistenk., Vol. 53. 1926 A cytological study of Lophomonas striata. Ibid., Vol. 55. 1936 Studies on Nydotherus oralis Leidy, with special reference to its nuclear structure. Ibid., Vol. 87. LiESCHE, W. 1938 Die Kern- und Fortpflanzungsverhaltnisse von Amoeba proteus. Ibid., Vol. 91. Lund, E. J. 1917 Reversibility of morphogenetic processes in Bursuria. Jour. Exp. Zool., Vol. 24. Noble, E. R. 1938 The life-cycle of Zygosoma globosum sp. nov., a gregarine parasite of Urechis caupo. Univ. Calif. Publ. Zool., Vol. 43. NoLAND, L. E. 1927 Conjugation in the ciliate Metopus sig- moides. Jour. Morph. Physiol., Vol. 44. Prandtl, H. 1906 Die Konjugation von Didinium nasutum. Arch. f. Protistenk., Vol. 7. Reichenow, E. 1928 Ergebnisse mit der Nuclealfarbung bei Protozoen. Ibid., Vol. 61. SoNNEBORN, T. M. 1936 Factors determining conjugation in Paramecium aurelia. I. Genetics, Vol. 21. 1937 Induction of endomixis in Paramecium aurelia. Biol. Bull., Vol. 72. 1937 Sex, sex inheritance and sex determination in Paramecium aurelia. Proc. Nat. Acad. Sci., Vol. 23. and B. M. Cohn 1936 Factors determining conjugation in Paramecium aurelia. II. Genetics, Vol, 21. and R. S. Lynch 1937 III. Ibid., Vol. 22. Summers, F. M. 1935 The division and reorganization of the macronuclei of Aspidisca lynceus, Diophrys appendiculata and Stylonychia pustulata. Arch. f. Protistenk., Vol. 85. Turner, J. P. 1930 Division and conjugation in Euplotes patella with special reference to the nuclear phenomena. Univ. Calif. Publ. Zool., Vol. 33. Wichterman, R. 1936 Division and conjugation in Nyctotherus cordiformis with special reference to the nuclear phenomena. Jour. Morph., Vol. 60. Woodruff, L. L. 1932 Paramecium aurelia in pedigree culture for twenty-five years. Trans. Amer. Micr. Soc, Vol. 51. and R. Erdmann 1914 A normal periodic reorganization process without cell fusion in Paramecium. Jour. Exp. Zool., Vol. 17. Chaptp:r 6 Variation and heredity IT is generally recognized that individuals of a species of organism show a greater or less morphological variation. Pro- tozoa are no exceptions. Various Protozoa manifest a wide variation in a limited or in widely separated localities so that different groups of the same species are spoken of as races, varieties, etc. It is well-known that dinoflagellates show a great morphological variation in different localities. Schroder (1914) showed that there were at least nine varieties of Ceratium hirundinella (Fig. 80) occurring in various waters of Europe, and List found that the organisms living in shallow ponds showed a marked morphological difference from those living in deep ponds. Cyphoderia ampulla is said to vary in size among those inhabiting the same deep lakes, namely, individuals from deep water may reach 200^ in length, while those from the surface water measure only about lOOju long. In Foraminifera, the shell varies in thickness even in one and the same species, depending upon the part of the ocean in which they live. Thus the forms which live floating in surface water have a much thinner shell than those which dwell on the bottom of the ocean. For example, according to Rhumbler, Orhulina universa inhabiting surface water has a very thin shell, 1.28- 18m thick, while individuals living on the bottom may show a thick shell, up to 24^ in thickness. According to Uyemura, Amoeba sp., occurring in the thermal waters of Japan, showed a distinct dimensional difference in different springs; namely, it varied from 10-40^t in diameter in sulphurous water, and from 45-80)u in ferrous water; in both types of water the amoebae were larger at 36-40°C. than at 51°C. Such differences in morpho- logical characteristics appear to be influenced by environmental conditions, and will continue to exist under those conditions, but when the organisms are subjected to a similar environment the differences disappear, as has been demonstrated by many observers. Evidences obtained by various investigators point to a general conclusion that when environmental influences are brought upon 162 VARIATION AND HEREDITY 163 a protozoan at the time of nuclear reorganization either by division, conjugation, or by endomixis, they may bring about long-lasting modifications (JoUos) or mutations. In Popoff's ex- periment with Stentor and in Chatton's with Glaucoma, both Fig. 80. Varieties of Ceratium hirundineUa from various European waters (Schroder), a, /?trcoiV/es-type (130-300/i by 30-45/x); b, brachy- ceroides-type (130-145)u by 30-45ju); c, silesiacurn-type (148-280/i by 28-34^i); d, carinthiacum-type (120-145/i by 45-60ju); e, gracile-tyTpe (140-200M by 60-75ju); f, aiistriacum-type (120-160/x by 45-60^); g, robustum-type (270-310/i by 45-55ju); h, scotticum-type (160-210ju by 50-60m); i, piburgense-type (180-260^ by 50-60^). conducted during the asexual division, long-lasting modifications have appeared in the experimental animals. Calkins (1924) ob- served a double-type Uroleptus mohilis which was formed by a complete fusion of two conjugants. This abnormal animal divided 367 times, living for 405 days, but reverted into normal forms 164 PROTOZOOLOGY without reversion to a double form. It is probable that the organ- ism showed a long-lasting modification, but there was no con- stitutional change in the organization of the animal. Jollos (1913-1934) observed that Paramecium, when subjected to various environmental influences, such as high temperature, arsenic acid, etc., showed variations which were gradually lost, although lasting through one or more periods of conjugation and endomixis, and that if the organisms were subjected to environ- mental changes during the late phase of conjugation, certain Fig. 81. Chilodonella uncinata (MacDougall). a, b, ventral and side view of normal individual; c, d, ventral and side view of the tailed mutant. individuals, if not all, become permanently changed. Possibly here one sees that the reorganizing nuclear material has been affected in such a way that the hereditary constitution or geno- type has become altered. MacDougall subjected Chilodonella uncinata to ultraviolet rays and produced many changes which were placed in three groups: 1) abnormalities which caused the death of the organism; 2) tem- porary variations which disappeared by the third generation; and 3) variations which were transferred unchanged through successive generations, hence considered as mutations. The mutants were triploid, tetraploid, and tailed diploid forms (Fig. 81), which bred true for a variable length of time in pure-line cultures, either being lost or dying off finally. The tailed form dif- fered from the normal form in the body shape, the number of VARIATION AND HEREDITY 165 ciliary rows, with three contractile vacuoles, and mode of move- ment, but during conjugation showed the diploid nimiber of chro- mosomes as in the normal form. The tailed form remained true and underwent 20 conjugations during ten months. The first comprehensive study dealing with the variation in size with respect to inheritance in the uniparental reproduction of Protozoa was done by Jennings (1909). From a "wild" lot of Paramecium, Jennings isolated eight races with the relative mean lengths of 206, 200, 194, 176, 142, 125, 100, and 45// which were inherited in each race. It was found further that within each clone derived from a single parent the size of different component individuals varies extremely, which is attributable to growth, amoimt of food and other environmental conditions, any one of which may give rise to progeny of the same mean size. Jennings thus showed that selection within the pure race has no effect on the size and that differences brought about merely by environ- ment are not inherited. Jennings (1916) also studied the inheritance of size and number of spines, dimensions of tests, diameter of mouth and size and number of teeth of the testacean Difflugia corona, and found that "a population consists of many hereditarily diverse stocks, and a single stock, derived from a single progenitor, gradually differen- tiates into such hereditarily diverse stocks, so that by selection marked results are produced." Root (1918) with Centropyxis aculeata, Hegner (1919) with Arcella dentata, and Reynolds (1923) with A. polypora, obtained similar results. Jennings (1937) carried on his study on the inheritance of teeth in Difflugia corona further in normal reproduction and by altering the mouth and teeth of the parent by operation, and observed that operated normal mouth or teeth were restored in three to four generations and that three factors appeared to determine the character and number of teeth: namely, the size of the mouth, the number and arrange- ment of the teeth in the parent, and "something in the constitu- tion of the clone (its genotype) which tends toward the produc- tion of a mouth of a certain size, with teeth of a certain form, arrangement and number." In the case of biparental inheritance, two nuclei of two different individuals participate to produce new combinations which would naturally bring about a greater variation among the off- spring. For example, if two individuals from a single clone of a 16G PROTOZOOLOGY ciliate, conjugate and the exconjugants are allowed to reproduce by fission, the descendants will show a greater variation among them with respect to the dimensions, fission-rate, etc. Thus several new biotypes may appear. If conjugation takes place between individuals of different clones and the descendants of Fig. 82. Hybridization in Chlamydomonas (Pascher). a, vegetative individual of Chlamydomonas I; b, that of II; c, sexual fusion of two gametes of I; d, that of two gametes of II; e, homozygote of I; f, homozygote of II; g, sexual fusion of a gamete of I with a gamete of II; h, i, heterozygotes between I and II; j-m, four types of individuals arising from a heterozygote in culture. this pair in turn conjugate and multiply by fission, the progeny will show conditions comparable to those which one sees in Mendehan inheritance in higher animals. In nature and in mass culture, it is supposed that this process is taking place con- tinuously. Since various species of Protozoa commonly co-inhabit small confines of water in nature, it is probable that hybridization be- tween varieties or species may occur. Information on hand on VARIATION AND HEREDITY 167 experimental hybridization of Protozoa is however very meager. Pascher (1916) succeeded in producing a small number of hybrid zygotes between two species of Chlamydomonas (Fig. 82). The two possessed the following characteristics. Species I: pyriform; without a membrane-papilla; with a delicate mem- brane; flagella about twice the body length; chromatophore and pyrenoid lateral; nucleus central; stigma a narrow streak in the anterior third; with 2 contractile vacuoles (a); division into 4 zoospores ; gametes up to 8, narrowed without membrane ; zygote deeply sculptured and without spreading envelope (e). Species II: spherical; with a distinct membrane and a membrane-papilla; chromatophore and pyrenoid posterior; nucleus central; stigma more anterior and fusiform; flagella short (6); division into 4 zoospores; gametes ellipsoid, ends rounded; zygote with a smooth but spreading envelope; with discarded gamete membrane (/). The hybrid-zygotes were morphologically intermediate {h, i) between the two parent zygotes. Thirteen zygotes were reared and in five cultures the offspring were either species I or II, two of each four zoospores being similar to those of I and the other two similar to those of II. In the eight cultures, each zygote de- veloped into four different zoospores. Pascher described these four zoospores (j-m), which tended to indicate that for each of several pairs of characters, two zoospores possessed that of I and the other two that of II and that hybridization brought to- gether two diverse sets of determiners in the heterozygote, which became segregated into four new sets of determiners, because of reduction during the formation of zoospores. These zoospores were however less active and abnormal so that they finally died in the culture without further development. Strehlow (1929) at- tempted to produce hybrids from three combinations of species of Chlamydomonas, succeeding in only one. Heterozygotes were obtained from the "positive" strain of C. paradoxa and the "negative" strain of C. hotnjodes (Fig. 83). Germination of the zygotes was however not observed. Hybridization between different varieties or different species of the same genus of ciliates, was either unsuccessful or not genetically studied until quite recently. By using different clones of Paramecium aurelia which differed in fission rate, viability, and body length, Sonneborn and Lynch succeeded in following through three or four sexual generations and observed: "Groups 168 PROTOZOOLOGY of hybrid clones obtained by crossing diverse clones manifested, on the average, characteristics intermediate between those of the l)arent clones or intermediate between those of the two groups of clones obtained by inbreeding the parent clones. Hybrid clones are of two types differing in the origin of their cytoplasm and Fig. 83. Hybridization of Chlamydomonas (Strehlow). a, C. paradoxa; h, C. botryodes; c-f, heterozygotes between them. macronuclear fragments; one type derives these from one parent clone, the other type from the other parent clone entering into the cross. One hybrid clone of each type arises from each pair of hybrid exconjugants. Sets of each of the two types of hybrid clones, as well as groups including both types of sets, were inter- mediate in characteristics. When hybrids of either type of cyto- plasmic descent were inbred, the resulting F2 generation included some clones resembling one parent, some clones resembling the other parent, and some clones with intermediate characteristics. When such F2 segregates were further inbred, the resulting F3 generation showed that some F2 segregates were pure and others still mixed in genetic constitution." Sonneborn and Lynch point out further that "there is no longer ground for doubting that the nucleus carries the determiners of hereditary characters, and there is considerable evidence that the nucleus carries these determiners arranged in separable pairs like the chromosomes or genes of higher organisms. If the cytology of the chromosomes in Paramecium were better known, the exact strength of the latter point could be more precisely estimated. For P. aurelia, Hertwig (1889) described a small number of chromosomes (8-10) undergoing conventional reduction during conjugation; but other investigators of this species have not hazarded chromosome counts and have given the impression that little progress in Paramecium chromosome cytology can be ex- VARIATION AND HEREDITY 169 pected with present methods. Unless further progress can be made in cytological studies, the burden of attack must fall all the more heavily on purely genetic methods. On the basis of genetic work alone, we are led to conclude that the usual Mendelian situation, modified by certain details pecuHar to the organism, probably exists in Paramecium. In agreement with Pascher, we find the fundamental patterns of protozoan and metazoan genetics to be very nearly the same." De Garis produced monsters in P. caudatum by exposing dividing individuals either to low temperature or cyanide vapor, which were L-shaped and one or both components divided usually on the second or third day, producing free individuals. The genet- ic constitution of progeny was not altered by the experience of monster formation. By bringing about conjugation between monsters and free individuals which differed in fission rate and body length, De Garis produced hereditary diverse races from the two lines. On the other hand, the conjugation between P. aurelia and double monster of P. caudatum was found to have lethal effects on both ciliates, as the former species degenerated ("cloudy swelling") and died on the second or third day after conjugation, while the latter species manifested hyaline degenera- tion and died on the second to twelfth day after conjugation. The discovery of sex reaction types in Paramecium aurelia and P. bursaria, as was stated in the last chapter, and further researches along this line, will, it is hoped, throw a clearer light on various genetical problems in Protozoa. References Calkins, G. N, 1924 Urole-ptus mohilis. V. Jour. Exp. Zool., Vol. 41. De Garis, C. F. 1934 Genetic results expressed by fission rates following conjugation between double monsters and free individuals of Paramecium caudatum. Amer. Nat., Vol. 68. 1935 Lethal effects of conjugation between Paramecium aurelia and double monsters of P. caudatum. Ibid., Vol.69. Jennings, H. S. 1909 Heredity and variation in the simplest organisms. Ibid., Vol. 43. 1916 Heredity, variation and the results of selection in the uniparental reproduction of Difflugia corona. Genetics, Vol. 1. 1929 Genetics of the Protozoa. Bibliographia Genetica, Vol. 5. 170 PROTOZOOLOGY 1937 Formation, inheritance and variation of the teeth in Difflugia corona. Jour. Exp. ZooL, Vol. 77. JoLLOS, V, 1934 Dauermodifikationen und Mutationen bei Protozoen. Arch. f. Protistenk., Vol. 83. Hegner, R. W. 1919 Heredity, variation, and the appearance of diversities during the vegetative reproduction of Arcella dentata. Genetics, Vol. 4. MacDougall, M. S. 1929 Modifications in Chilodon uncinatus produced by ultraviolet radiations. Jour. Exp. Zool.,Vol. 54. 1931 Another mutation of Chilodon uncinatus produced by ultra-violet radiation, with a description of its maturation process. Ibid., Vol. 58. Pascher, a. 1916 Ueber die Kreuzung einzelliger, haploider Organismenl Chalmydomonas. Ber. deutsch. Bot. Ges. Vol. 34. - — 1918 Ueber die Beziehung der Reduktionsteilung zur Mendelschen Spaltung. Ibid., Vol. 36. Reynolds, B. D. 1923 Inheritance of double characteristics in Arcella polypora Penard. Genetics, Vol. 8. — 1924 Interactions of protoplasmic masses in relation to the study of heredity and environment in Arcella polypora. Biol. Bull., Vol. 46. Root, F. M. 1918 Inheritance in the asexual reproduction in Centropyxis aculeata. Genetics, Vol. 3. SoNNEBORN, T. M. and R. S. Lynch 1934 Hybridization and segregation in Paramecium aurelia. Jour. Exp. Zool.,Vol. 67, Strehlow, K. 1929 Ueber die Sexualitat einiger Volvocales. Zeitschr. Botanik, Vol. 21. Taliaferro, W. H. 1926 Variability and inheritance of size in Trypanosoma lewisi. Jour. Exp. Zool., Vol. 43. Chapter 7 Phylum Protozoa Goldfuss rriHE Protozoa are divided into two subphyla as follows: Locomotor organellae, pseudopodia or flagella, or lacking (in Sporo- zoa); nucleus of one kind Subphylum 1 Plasmodroma Locomotor organellae, cilia or cirri; nuclei of two kinds Subphylum 2 Ciliophora (p. 481) Subphylum 1 Plasmodroma Doflein Class 1 Mastigophora Diesing The Mastigophora includes those Protozoa which possess one to several flagella. Aside from this common characteristic, this class makes a very heterogeneous assemblage and seems to pre- vent a sharp distinction between the Protozoa and the Proto- phyta, as it includes Phytomastigina which are often dealt with by botanists. In the majority of Mastigophora, each individual possesses 1-4 flagella during the vegetative stage, although species of Polymastigina may possess up to 8 or more flagella and of Hyper- mastigina a greater number of flagella. The palmella stage (Fig. 84) is common among the Phytomastigina and, unlike the encysted stage, the organism is capable in this stage not only of metabolic activity and growth, but also of reproduction. In this respect, this group shows also a close relationship to algae. All three types of nutrition, carried on separately or in com- bination, are to be found among the members of Mastigophora. In holophytic forms, the chlorophyll is contained in the chromato- phores which are of various forms among different species and which differ in colors, from green to red. The difference in color appears to be due to the pigments which envelop the chlorophyll body (p. 79). Many forms adapt their mode of nutrition to changed environmental conditions, for instance, from holophytic to saprozoic in the absence of the sunlight. Holozoic, saprozoic and holophytic nutrition are said to be combined in such a form as Ochromonas. In association with chromatophores, there occurs a refractile granule or body, the pyrenoid, which is connected 171 172 PROTOZOOLOGY with starch-formation. Reserve food substances are starch, oil, etc. (p. 94-95). In less complicated forms, the body is naked except for a slight cortical differentiation of the ectoplasm to delimit the body surface and is capable of forming pseudo])odia. In others, there occurs a thin plastic pellicle produced by the cytoplasm, which covers the body surface closely. In still others, the body form is constant, being encased in a shell, test, or lorica, which is composed of chitin, pseudochitin, or cellulose. Not infrequently a gelatinous secretion envelops the body. In three families of Protomonadina there is a collar-like structure located at the anterior end, through which the flagellum protrudes. The great majority of Mastigophora possess a single nucleus, and only a few are multinucleated. The nucleus is vesicular and contains a conspicuous endosome. Contractile vacuoles are always present in the forms inhabiting fresh water. In simple forms, the contents of the vacuoles are discharged directly through the body surface to the exterior; in others there are several contractile vacuoles arranged around a reservoir which opens to the exterior through the so-called cytopharynx. In the Dinoflagellata, there are apparently no contractile vacuoles, but non-contractile pusules (p. 217) occur in some forms. In chromatophore-bearing forms, there occurs usually a stigma which is located near the base of the flagellum and seems to be the center of phototactic activity of the organism which possesses it (p. 79). Asexual reproduction is, as a rule, by longitudinal fission, but in some forms multiple fission also takes place under certain circumstances, and in others budding may take place. Colony- formation (p. 140), due to incomplete separation of daughter in- dividuals, is widely found among this group. Sexual reproduction has been reported in a number of species. The Mastigophora are free-living or parasitic. The free-living forms are found in fresh and salt waters of every description; many are free-swimming, others creep over the surface of sub- merged objects, and still others are sessile. Together with algae, the Mastigophora compose a major portion of plankton hfe which makes the foundation for the existence of all higher aquatic organisms. The parasitic forms are ecto- or endo-parasitic, and the latter inhabit either the digestive tract or the circulatory system of the host animal. Trypanosoma, a representative genus MASTIGOPHORA, CHRYSOMONADINA 173 of the latter group, includes important disease-causing parasites of man and of domestic animals. The Mastigophora are divided into two subclasses as follows: With chromatophores Subclass 1 Phytomastigina Without chromatophores Subclass 2 Zoomastigina (p. 235) Subclass 1 Phytomastigina Doflein The Phytomastigina possess the chromatophores and their usual method of nutrition is holophytic, though some are holozoic, saprozoic or mixotrophic; the majority are conspicuously colored; some that lack chromatophores are included in this group, since their structure and development resemble closely those of typical Phytomastigina. 1-4 flagella, either directed anteriorly or trailing Chromatophores yellow, brown or orange Anabolic products fat, leucosin Order 1 Chrysomonadina Anabolic products starch or similar carbohydrates Order 2 Cryptomonadina (p. 184) Chromatophores green Simple contractile vacuole, anabolic products starch and oil. . Order 3 Phytomonadina (p. 188) Contractile vacuole complex Anabolic products paramylon. . Order 4 Euglenoidina (p. 203) Anabolic products oil Order 5 Chloromonadina (p. 213) 2 flagella, one of which transverse. . . .Order 6 Dinoflagellata (p. 216) Order 1 Chrysomonadina Stein The chrysomonads are minute organisms and are plastic, since the majority lack a definite cell-wall. Chromatophores are yellow to brown (rarely green or bluish) and usually discoid, though sometimes reticulated, in form. Metabolic products are refractile bodies, known collectively as leucosin (probably carbo- hydrates) and fats. Starches have not been found in them. 1-2 flagella are inserted at or near the anterior end of body where a stigma is present. Many chrysomonads are able to form pseudopodia for obtain- ing food materials which vary among different species. Nutrition, though chiefly holophytic, is sometimes holozoic or saprozoic. Contractile vacuoles are invariably found in freshwater forms, and are ordinarily of simple structure, although a complicated system seems to be found in some. 174 PROTOZOOLOGY Under conditions not fully understood, the Chrysomonadina lose their flagella and undergo division with development of mucilaginous envelope and thus transform themselves often into large bodies known as the palmella phase and undertake meta- bolic activities as well as multiplication (Fig. 84). Asexual re- production is, as a rule, by longitudinal division during either the motile or the palmella stage. Incomplete separation of the daughter individuals followed by repeated fission, results in numerous colonial forms mentioned elsewhere (p. 141). Some Fig. 84. The life-cycle of Chromulina, X about 200 (Kiihn). a, en- cystment; b, fission; c, colony-formation; d, palmella-formation. resemble higher algae very closely. Sexual reproduction is en- tirely unknown in this group. Encystment occurs commonly; in this the flagellum is lost and the cyst is enveloped by a sihcious wall possessing an opening with a plug. The chrysomonads inhabit both fresh and salt waters, often occurring abundantly in plankton. Motile stage dominant Suborder 1 Euchrysomonadina Palmella stage dominant Sarcodina-like; flagellate stage unknown Suborder 2 Rhizochrysidina (p. 181) Palmella phase dominant Suborder 3 Chrysocapsina (p. 182) Suborder 1 Euchrysomonadina Pascher With or without simple shell One flagellum Family 1 Chromulinidae (p. 175) 2 flagella Flagella equally long Family 2 Syncryptidae (p. 177) Flagella unequally long Family 3 Ochromonadidae (p. 179) MASTIGOPHORA, CHRYSOMONADINA 175 With calcareous or silicious shell Bearing calcareous discs and rods. .Family 4 Coccolithidae (p. 181) Bearing silicious skeleton Family 5 Silicoflagellidae (p. 181) Family 1 Chromulinidae Engler Minute forms, naked or with sculptured shell; with a single flagellum; often with rhizopodia; a few colonial; free-swimming or attached. Genus Chromulina Cienkowski. Oval; round in cross-section; amoeboid; 1-2 chromatophores; palmella stage often large; in fresh water. Numerous species. The presence of a large number of these organisms gives a golden-brown color to the surface of the water. C. pascheri Hofeneder (Fig. 85, a, h). 15-20/i in diameter. Genus Chrysapsis Pascher. Solitary; plastic or rigid; chromato- phore diffused or branching; with stigma; amoeboid movement; holophytic, holozoic; fresh water. C. sagene P. (Fig. 85, c). Anterior region actively plastic; stigma small; 8-14/i long; flagellum about 30/u long. Genus Chrysococcus Klebs. Shell spheroidal or ovoidal, smooth or sculptured and often brown-colored; through an opening a flagellum protrudes; 1-2 chromatophores; one of the daughter individuals formed by binary fission leaves the parent shell and forms a new one; fresh water. C. ornatus Pascher (Fig. 85, d). 14-16m by T-lO/x. Genus Mallomonas Perty {Pseudomallomonas Chodat). Body elongated; with silicious scales and often spines; 2 chromato- phores, rod-shaped; fresh water. Numerous species. M. litomosa Stokes (Fig. 85, e). Scales very dehcate, needle-like projections at both ends; flagellum as long as body; 24-3 2/i by 8m. Genus Pyramidochrysis Pascher. Body form constant; pyri- form with 3 longitudinal ridges; flagellate end drawn out; a single chromatophore; 2 contractile vacuoles; fresh water. P. modesta P. (Fig. 85,/). 11-13/x long. Genus Sphaleromantis Pascher. Triangular or heart-shaped; highly flattened; shghtly plastic; 2 chromatophores; 2 contractile vacuoles; stigma large; long flagellum; fresh water. S. ochracea P. (Fig. 85, g). 6-13/x long. Genus Kephyrion Pascher. With oval or fusiform lorica; body fills posterior half of lorica; one chromatophore; a single short flagellum; small; fresh water. 176 PROTOZOOLOGY Fig. 85. a, b, Chronmlina pascheri, X670 (Hofeneder) ; c, Chrysapsis sagene, XlOOO (Pascher); d, Chrysococcus ornatus, X600 (Pascher); e, Mallomonas litomosa, X400 (Stokes); f, Pyramidochrysis modesta, X670 (Pascher); g, Sphaleromantis ochracea, X600 (Pascher); h, Kephyrion ovum, X1600 (Pascher); i, Chrysopyxis cyathus, X600 (Pascher); j, Cyrtophora pedicellata, X400 (Pascher); k, Palatinella cyrtophora, X400 (Lauterborn); 1, Chrysosphaerella longispina, X600 (Lauterborn). MASTIGOPHORA, CHRYSOMONADINA 177 K. ovum P. (Fig. 85, h). Lorica up to 7n by 4/x. Genus Chrysopyxis Stein. With lorica of various forms, more or less flattened; 1-2 chromatophores; a flagellum; attached to algae in fresh water. C. cyathus Pascher (Fig. 85, i). One chromatophore; flagellum twice body length; lorica 20-25^ by 12-15/^. Genus Cyrtophora Pascher. Body inverted pyramid with 6-8 tentacles and a single flagellum; with a contractile stalk; a single chromatophore; a contractile vacuole; fresh water. C. pedicellata P. (Fig. 85, j). Body 18-22^ long; tentacles 40- 60)u long; stalk 50-80^ long. Genus Palatinella Lauterborn. Lorica tubular; body heart- shaped; anterior border with 16-20 tentacles; a single flagellum; a chromatophore; several contractile vacuoles; fresh water. P. cyrtopJiora L. (Fig. 85, k). Lorica 80-1 50m long; body 20-25iu by 18-25m; tentacles 50/x long. Genus Chrysosphaerella Lauterborn. In spherical colony, in- dividual cell, oval or pyriform, with 2 chromatophores; imbedded in gelatinous mass; fresh water. C. longispina L. (Fig. 85, I). Individuals up to 15/x by 9/x; colony up to 250/x in diameter; in standing water rich in vegeta- tion. Family 2 Syncryptidae Poche Solitary or colonial chrysomonads with 2 equal fiagella; with or without pellicle (when present, often sculptured) ; some possess stalk. Genus Syncrypta Ehrenberg. Spherical colonies; individuals with 2 lateral chromatophores, embedded in a gelatinous mass; 2 contractile vacuoles; without stigma; cysts unknown; fresh water. S. volvox E. (Fig. 86, a). 8-Ufx by 7-12ai; colony 20-70m in diameter; in standing water. Genus Synura Ehrenberg. Spherical or ellipsoidal colony com- posed of 2-50 ovoid individuals arranged radially; body usually covered by short bristles; 2 chromatophores lateral; no stigma; asexual reproduction of individuals is by longitudinal division; that of colony by bipartition; cysts spherical; fresh water. >S. uvella E. (Fig. 86, b). Cells oval; bristles conspicuous; 20- 40m by 8-1 7m; colony 100-400m in diameter; if present in large numbers, the organism is said to be responsible for an odor of the water resembhng that of ripe cucumber (Moore). 178 PKOTOZOOLOGY S. adamsi Smith (Fig. 86, c). Spherical colony with individuals radiating; individuals long spindle, 42-4 7)u by 6.5-7/x; 2 flagella up to 17ju long; in fresh water pond. Genus Hymenomonas Stein. Solitary; ellipsoid to cylindrical; membrane brownish, often sculptured; 2 chromatophores ; with- out stigma; a contractile vacuole anterior; fresh water. H. roseola S. (Fig. 86, d). 17-50^ by 10-20^. Genus Derepyxis Stokes. With cellulose lorica, with or without short stalk; body ellipsoid to spherical with 1-2 chromatophores; 2 equal flagella; fresh water. Fig. 86. a, Syncrypta volvox, X430 (Stein); b, Synura uvella, X500 (Stein); c, *S. adamsi, X280 (Smith); d, Hymenomonas roseola, X400 (Klebs); e, Derepyxis amphora, X540 (Stokes); f, D. ollula, X600 (Stokes); g, Stylochrysallis parasitica, X430 (Stein). D. amphora S. (Fig. 86, e). Lorica 25-30^ by 9-18/x; on algae in standing water. D. ollula S. (Fig. 86,/). Lorica 20-25^ by 15^. Genus Stylochrysallis Stein. Body fusiform; with a gelatinous stalk attached to Volvocidae; 2 equal flagella; 2 chromatophores; without stigma; fresh water. S. parasita S. (Fig. 86, g). Body 9-1 l/x long; stalk about 15//. long; on phytomonads. MASTIGOPHORA, CHRYSOMONADINA 179 Family 3 Ochromonadidae Pascher With 2 unequal flagella; body has no pellicle and is plastic; contractile vacuoles simple; with or without dehcate test; solitary or colonial; free-swimming or attached. Genus Ochromonas Wyssotzki. Solitary or colonial; body surface delicate; posterior end often drawn out for attachment; 1-2 chromatophores; usually with a stigma; encystment; fresh water. 0. mutdbilis Klebs (Fig. 87, a). Ovoid to spherical; plastic; 15-30m by 8-22/x. 0. ludihunda Pascher (Fig. 87, 6). Not plastic; 12-17ai by 6-1 2m. Genus Uroglena Ehrenberg. Spherical or ovoidal colony, com- posed of ovoid or ellipsoidal individuals arranged on periphery of a gelatinous mass; all individuals connected with one another by gelatinous processes running inward and meeting in a point; with a stigma and a plate-like chromatophore; asexual reproduc- tion of individuals by longitudinal fission, that of colony by bipartition; cysts spherical with spinous projections, and a long tubular process; fresh water. One species. U. volvox E. (Fig. 87, c). Cells 12-20^ by S-IBm; colony 40- 400/z in diameter; in standing water. Genus Uroglenopsis Lemmermann. Similar to Uroglena, but individuals without inner connecting processes. U. americana (Calkins) (Fig. 87, d). Each cell with one chro- matophore; 5-8jU long; flagellum up to 32/i long; colony up to 300/i in diameter; when present in abundance, the organism gives an offensive odor to the water (Calkins). U'. europaea Pascher. Similar to the last-named species; but chromatophores 2; cells up to 7^ long; colony 150-300/^ in diameter. Genus Cyclonexis Stokes. Wheel-like colony, composed of 10- 20 wedge-shaped individuals; young colony funnel-shaped; chro- matophores 2, lateral; no stigma; reproduction and encystment unknown; fresh water. C. annularis S. (Fig. 87, e). Cells ll-14;u long; colony 25-30/i in diameter; in marshy water with sphagnum. Genus Dinobryon Ehrenberg. Sohtary or colonial; individuals with vase-like, hyahne, but sometimes, yellowish cellulose test, drawn out at its base; elongated and attached to the base of test 180 PROTOZOOLOGY with its attenuated posterior ti]); 1-2 lateral chroniatophores; usually with a stigma; asexual r(>production by binary fission; one of the daughter individuals leaving test as a swarmer, to form a new one; in colonial forms daughter individuals remain attached Fig. 87. a, Ochromonas mutabilis, X670 (Senn); b, 0. ludibunda, X540 (Pascher); c, Uroglena volvox, x430 (Stein); d, Uroglenopsis americana, X470 (Lemmermann) ; e, Cyclonexis annularis, X540 (Stokes); f, ■Dinohryon sertularia, X670 (Scherffel) ; g, Hyalobryon ramosu7n, X540 (Lauterborn); h, Stylopyxis mucicola, X470 (Bol- ochonzew). to the inner margin of aperture of parent tests and there secrete new tests; encystment common; the spherical cysts possess a short process; Ahlstrom (1937) studied variability of North American species and found the organisms occur more com- monly in alkaline regions than elsewhere; fresh water. Numerous species. MASTIGOPHORA, CHRYSOMONADINA 181 D. sertularia E. (Fig. 87,/). 30-44^ by 10-14^. D. divergens Imhof. 31-53^ long; great variation in different localities (Ahlstrom). Genus Hyalobryon Laiiterborn. Solitary or colonial; individual body structure similar to that of Dinobryon; lorica in some cases tubular, and those of young individuals are attached to the ex- terior of parent tests; fresh water. H. ramosum L. (Fig. 87, g). Lorica 50-70/i long by 5-9/x in diameter; body up to 30^ by 5m; on vegetation in standing fresh water. Genus Stylopyxis Bolochonzew. Solitary; body located at bot- tom of a delicate stalked lorica with a wide aperture; 2 lateral chromatoi)hores; fresh water. S. mucicola B. (Fig. 87, h). Lorica 17-18/x long; stalk about 33m long; body 9-11m long; fresh water. Family 4 Coccolithidae Lohmann The members of this family, with a few exceptions, occur in salt water only; with perforate (tremahth) or imperforate (discohth) discs, composed of calcium carbonate; 1-2 flagella; 2 yellowish chromatophores; a single nucleus; oil drops and leuco- sin ; holophytic. Examples : Pontos'phaera haeckeli Lohmann (Fig. 88, a). Discosphaera tuhijer Murray et Blackman (Fig. 88, 6). Family 5 Silicoflagellidae Borgert Exclusively marine planktons; with siliceous skeleton which envelops the body. Example: Distephanus speculum (Mliller) (Fig. 88, c). Suborder 2 Rhizochrysidina Pascher No flagellate stage is knoMai to occur; the organism possesses pseudopodia; highly provisional group, based wholly upon the absence of flagella; naked or with test; various forms; in some species chromatophores are entirely lacking, so that the organisms resemble some members of the Sarcodina. Several genera. Genus Rhizochrysis Pascher. Body naked and amoeboid; with 1-2 chromatophores; fresh water. R. scherffeli P. (Fig. 88, d). 10-14^ in diameter; 1-2 chromato- phores; branching rhizopods; fresh water. Genus Chrysidiastrum Lauterborn. Naked; spherical; often 182 PROTOZOOLOGY Fig. 88. a, Pontosphaera haeckeli, X1070 (Kiihn); b, Discosphaera tubifer, X670 (Kiihn); c, Distephanus speculum, X530 (Kiihn); d, Rhizochrysis scherffeli, X670 (Doflein); e-g, Hydrurus foetidus (e, en- tire colony; f, portion; g, cyst), e (Bertholcl), f, X330, g, X800 (Klebs); h, i, Chrysocapsa paludosa, X530 (West); j, k, Phaeosphaera gelatinosa (j, part of a mass, X70; k, three cells, x330) (West). several in linear association by pseudopodia; one yellow-brown chromatophore; fresh water. C. catenatum L. Cells 12-14yu in diameter. Suborder 3 Chrysocapsina Pascher Palmella stage prominent; flagellate forms transient; colonial; individuals enclosed in a gelatinous mass; 1-2 flagella, one chro- matophore, and a contractile vacuole; one group of relatively minute forms and the other of large organisms. Genus Hydrurus Agardh. In a large (1-30 cm. long) branching gelatinous cylindrical mass; cells yellowish brown; spherical to eUipsoidal; with a chromatophore; individuals arranged loosely MASTIGOPHORA, CHRYSOMONADINA 183 in gelatinous matrix; apical growth resembles much higher algae; multiphcation of individuals results in formation of pyramidal forms with a flagellum, a chromatophore, and a leucosin mass; cyst may show a wing-like rim; cold freshwater streams. H. foetidus Kirschner (Figs. 31, d-f; 88, e-g). OHve-green, feathery tufts, 1-30 cm. long, develops an offensive odor; sticky to touch; occasionally encrusted with calcium carbonate; in running fresh water. Genus Chrysocapsa Pascher. In a spherical to ellipsoidal gelatinous mass; cells spherical to ellipsoid; 1-2 chromatophores; with or without stigma; freshwater. C. paludosa P. (Fig. 88, h, i). Spherical or elhpsoidal wdth cells distributed without order; \\\i\i a stigma; 2 chromatophores; swarmer pyriform with 2 flagella; cells l\^x long; colony up to 100/i in diameter. Genus Phaeosphaera West et West. In a simple or branching cylindrical gelatinous mass; cells spherical with a single chroma- tophore; fresh water. P. gelatinosa W. et W. (Fig. 88, j, k). Cells 14-17.5)u in diameter. References BtJTSCHLi, 0. 1883-1887 Mastigophora. In: 'Bromi' s Klassen und Ordnungen des Thierreichs. Vol. 1, part 2. Calkins, G. N. 1926 The biology of the Protozoa. Philadelphia. DoFLEiN, F. and E. Reichenow. 1929 Lehrbuch der Protozoen- kunde. Jena. Kent, S. 1880-1882 A Manual of Infusoria. London. Pascher, A. 1914 Flagellatae; Allgemeiner Teil. In: Die Silss- wasserfiora Deutschlands. Part 1, Stein, F. 1878, 1883 Der Organismus der Infusionsthiere. 3 Abt. Der Organismus der Flagellate oder Geisselinfusorien. Parts 1 and 2. Leipzig. Ahlstrom, E. H. 1937 Studies on variabiUty in the genus Dino- bryon (Mastigophora). Trans. Amer. Micr. Soc, Vol. 56. Fritsch, F. E. 1935 The structure and re-production of the algae. Cambridge. Pascher, A. 1913 Chrysomonadinae. In: Die Siisswasserflora Deutschlands. Part 2. Smith, G. M. 1933 The freshwater algae 'of the United States. New York. West, G. S. and F. E. Fritsch. 1927 A treatise on the British freshwater algae. Cambridge. Chapter 8 Order 2 Cryptomonadina Stein THE cryptomonads differ from the chrysomonads in having a constant body form. Pseudopodia are very rarely formed, as the body is covered by a pelhcle. The majority show dorso- ventral differentiation, with an oblique longitudinal furrow. 1-2 unequal flagella arise from the furrow or from the cytopharynx. In case 2 flagella are present, both may be directed anteriorly or one posteriorly. These organisms are free-swimming or creeping. 1-2 chromatophores are usually present. They are discoid or band-form. The color of chromatophores vary from common brown, red, olive-green up to blue-green. The nature of the pig- ment is not well understood, but it is said to be similar to that which is found in the Dinofiagellata (Pascher). One or more spherical pyrenoids which are enclosed within a starch envelope appear to occur outside the chromatophores. Nutrition is mostly holophytic; a few saprozoic or holozoic. Assimilation products are solid discoid carbohydrates which stain blue with iodine in Cryptomonas or which stain reddish violet by iodine as in Crypto- chrysis; fat and starch are produced in holozoic forms which feed upon bacteria and small Protozoa. The stigma is usually as- sociated with the insertion point of the flagella. Contractile vacuoles, one to several, are simple and are situated near the cytopharynx. A single vesicular nucleus is ordinarily located near the middle of the body. Asexual reproduction, by longitudinal fission, takes place in either the active or the non-motile stage. Sexual reproduction is unknown. Some cryptomonads form palmella stage and others gelatinous aggregates. In the suborder Phaeocapsina, the pal- mella stage is permanent. Cysts are spherical, and the cyst wall is composed of cellulose. The Cryptomonadina occur in fresh or sea water, living also often as symbionts in marine organisms. Flagellate forms predominant Suborder 1 Eucryptomonadina (p. 185) Palmella stage permanent Suborder 2 Phaeocapsina (p. 187) 184 CRYPTOMONADINA 185 Suborder 1 Eucryptomonadina Pascher Truncate anteriorly; 2 anterior flagella; with an oblique furrow near anterior end Familj^ 1 Cryptomonadidae Reniform; with 2 lateral flagella; furrow equatorial Family 2 Nephroselmidae (p. 186) Family 1 Cryptomonadidae Stein Genus Cryptomonas Ehrenberg. Body elliptical with a firm pellicle; anterior end truncate; dorsal side convex, ventral side slightly so or flat; nucleus posterior; longitudinal furrow; tubular cavity extending to the middle of body, through which equally long flagella arise; 2 lateral chromatophores vary in color from green to blue-green, brown or rarely red; holophytic; with small starch-like bodies which stain blue in iodine; 1-3 contractile vacuoles anterior; fresh water. Several species. C. ovata E. (Fig. 89, a). 20-30/i long; among vegetation. Genus Chilomonas Ehrenberg. Similar to Cryptomonas in general body form and structure, but colorless because of the absence of chromatophores; without pyrenoid; cytopharynx deep, lower half marked by "rudimentary trichocysts" ; 1-2 contractile vacuoles, anterior; nucleus in posterior half; endoplasm often filled with polygonal starch grains; fresh water. C. Paramecium E. (Fig. 89, h). Posterior end narrowed, slightly bent "dorsally"; 20-40^1 long; saprozoic; widely distributed in stagnant water and hay infusion. C. ohlonga Pascher. Oblong; posterior end broadly rounded; 20-50m long. Genus Chrysidella Pascher. Somewhat similar to Cryptomonas^ but much smaller; yellow chromatophores much shorter; those occurring in Foraminifera or Radiolaria as symbionts are known as Zooxanthellae. Several species. C. schaudinni (Winter) (Fig. 89, c, d). Body less than lO/i long; in the foraminiferan Peneroplis pertusus. Genus Cyathomonas Fromentel. Body small, somewhat oval; without chromatophores; much flattened; anterior end obliquely truncate; with 2 equal or subequal anterior flagella; colorless; nucleus central; anabolic products, stained red or reddish violet by iodine; contractile vacuole usually anterior; a row of refractile granules, protrichocysts (p. 65), close and parallel to anterior margin of body; asexual reproduction by longitudinal fission; holozoic; in stagnant water and infusion. One species. 186 PROTOZOOLOGY C. tnmcata Ehreiiborg (Fig. 89, e). 15-30/^ long. Genus Cryptochrysis Pascher. Furrow indistinctly granulated; 2 or more chromatoi)hores brownish, olive-green, or dark green, rarely red; pyrenoid central; 2 equal flagella; some lose flagella and may assume amoeboid form; fresh water. C. commutata P. (Fig. 89,/). Bean-shaped; 2 chromatophores; 19m by 10/1. Fig. 89. a, Cryptomonas ovata, XSOO (Pascher); b, Chilomonas Para- mecium., X1330 (Btitschli); c, d, Chrysidella schaudinni, X1330 (Win- ter); e, Cyathomonas truncata, X670 (Ulehla); f, Cryptochrysis com- ynutata, X670 (Pascher); g, RJiodomonas lens, X1330 (Ruttner); h, Nephroselmis olvacea, X670 (Pascher) ;i, Protochrysis phaeophycearum, XSOO (Pascher); j, k, Phaeothamnion confervicolum, X600 (Klihn). Genus Rhodomonas Karsten. Furrow granulated; chromato- phore one, red (upon degeneration the coloring matter becomes dissolved in water) ; pyrenoid central ; fresh water. R. lens Pascher et Ruttner (Fig. 89, g). Spindle-form; about IQn long; in fresh water. Family 2 Nephroselmidae Pascher Body reniform; with lateral equatorial furrow; 2 flagella arising from furrow, one directed anteriorly and the other posteriorly. Genus Nephroselmis Stein. Reniform; flattened; furrow and cytopharynx distinct; no stigma; 1-2 chromatophores, discoid. CRYPTOMONADINA 187 brownish green; nucleus dorsal; a central pyrenoid; 2 contractile vacuoles; with reddish globules; fresh water. N. olvacea S. (Fig. 89, h). 20-25// by 15^. Genus Protochrysis Pascher. Reniform; not flattened; with a distinct furrow, but without cytopharynx; a stigma at base of flagella; 1-2 chromatophores, brownish yellow; pyrenoid central; 2 contractile vacuoles; fission seems to take place during the rest- ing stage; fresh water. P. phaeophycearum P. (Fig. 89, i). 15-17/1 by 7-9iu. Suborder 2 Phaeocapsina Pascher Palmella stage predominant; perhaps border-line forms be- tween brown algae and cryptomonads. Example: Phaeothamnion confervicolum Lagerheim (Fig. 89, j, k) which is less than lOfx long. References Fritsch, F. E. 1935 The structure and reproduction of the algae. Cambridge. Pascher, A. 1913 Cryptomonadinae. Siisswasserflora Deutsch- lands, etc. part 2. Jena. West, G. S. and F. E. Fritsch. 1927 A treatise on the British freshwater algae. Cambridge. Chapter 9 Order 3 Phytomonadina Blochmann THE phytomonads are small, more or less rounded, green flagellates with a close resemblance to the algae. They show a definite body form, and most of them possess a cellulose mem- brane, which is thick in some and thin in others. There is a defi- nite opening in the membrane at the anterior end, through which 1-2 (or seldom 4 or more) flagella protrude. The majority possess numerous grass-green chromatophores, each of which contains one or more pyrenoids. The method of nutrition is mostly holo- phytic or mixotrophic; some colorless forms are, however, sapro- zoic. The metabolic products are usually starch and oils. Some phytomonads are stained red, owing to the presence of haemato- chrome. The contractile vacuoles may be located in the anterior part or scattered throughout the body. The nucleus is ordinarily centrally located, and its division seems to be mitotic, chromo- somes having been definitely noted in several species. Asexual reproduction is by longitudinal fission, and the daughter individuals remain within the parent membrane for some time. Sexual reproduction seems to occur widely. Colony formation also occurs, especially in the family Volvocidae. Encystment and formation of the palmella stage are common among many forms. The phytomonads have a much wider distribution in fresh than in salt water. Solitary Membrane a single piece; rarely indistinct 2 flagella Family 1 Chlamydomonadidae 3 flagella Family 2 Trichlorididae (p. 193) 4 flagella Family 3 Carteriidae (p. 194) 5 flagella Family 4 Chlorasteridae (p. 196) 6 or more flagella Family 5 Polyblepharididae (p. 196) Membrane bivalve Family 6 Phacotidae (p. 196) Colonial, of 4 or more individuals; 2 (1 or 4) flagella Family 7 Volvocidae (p. 197) Family 1 Chlamydomonadidae Biitschli Solitary; spheroid, oval, or ellipsoid; with a cellulose mem- brane; 2 flagella; chromatophores, stigma, and pyrenoids usually present. 188 PHYTOMONADINA 189 Genus Chlamydomonas Ehrenberg. Spherical, ovoid or elon- gated; sometimes flattened; 2 flagella; membrane often thickened at anterior end; a large chromatophore, containing one or more pyrenoids; stigma; a single nucleus; 2 contractile vacuoles an- terior; asexual reproduction and palmella formation known; sexual reproduction isogamy or anisogamy; fresh water. Numer- ous species. C. monadina Stein (Fig. 90, a-c). 15-30/i long; fresh water; Landacre noted that the organisms obstructed the sand filters used in connection with a septic tank, together with the diatom Navicula. C. angulosa Dill. About 20^ by 12-15/i; fresh water. C. epiphytica Smith (Fig. 90, d). 8-9 fj, by I-Sjjl; in freshwater lakes. C. glohosa Snow (Fig. 90, e). Spheroid or ellipsoid; 5-7/^ in diameter; in freshwater lakes. C. gracilis Snow (Fig. 90,/). 10-13^ by 5-7m; fresh water. Genus Haematococcus Agardh {Sphaerella Sommerfeldt). Spheroidal or ovoid with a gelatinous envelope; chromatophores peripheral and reticulate, with 2-8 scattered pyrenoids; several contractile vacuoles; haematochrome frequently abundant in both motile and encysted stages; asexual reproduction in motile form; sexual reproduction isogamy; fresh water. H. pluvialis (Flotow) (Figs. 38; 90, g). Oval or elhpsoid; wdth numerous radial cytoplasmic processes; chromatophores thick- walled; body up to 60ju by SO^u; stigma about 13yu long; fresh water; according to Reichenow (1909), the haematochrome dis- appears under experimental condition if the culture medium is rich in nitrogen and phosphorus. Genus Sphaerellopsis Korschikoff (Chlamydococcus Stein). With gelatinous envelope which is usually ellipsoid with rounded ends; body elongate fusiform or pyriform, no protoplasmic processes to envelope; 2 equally long flagella; chromatophore large; a pyrenoid; with or without stigma; nucleus in anterior half; 2 contractile vacuoles; fresh water. ,S. fluviatilis (Stein) (Fig. 90, h). 14-30^ by 10-20^; fresh water. Genus Brachiomonas Bohlin. Lobate; with horn-like processes, all directed posteriorly; contractile vacuoles; ill-defined chro- matophore; pyrenoids; with or without stigma; sexual and asexual reproduction; fresh, brackish or salt water. 190 PROTOZOOLOGY Fig. 90. a-c, Chlamijdomonas monadina, X470 (Goroschankin); d, C. epiphytica, X1030 (Smith); e, C. globosa, X2000 (Snow); f, C. gracilis, X770 (Snow); g, Haemalococcus pluvialis, X500 (Reichenow); h. Sphaerellopsis fluviatilis, X490 (Korschikoff) ; i, Brachivionas ivedi- ana X960 (West); j, Lohomonas rostrata, X1335 (Hazen); k, Diplo- stauron pentagonium, XlllO (Hazen); 1, Gigantochloris permaxima, X370 (Pascher); m, Gloeomonas ovalis, X330 (Pascher); n, Scourjieldia complanata, X1540 (West); o, Thorakomonas sabulosa, X670 (Kor- schikoff). B. westiana Pascher (Fig. 90, i). 15-24/i by 13-23^; brackish water. Genus Lobomonas Dangeard. Ovoid or irregularly angular; PHYTOMONADINA 191 chromatophore cup-shaped; pyrenoid; stigma; a contractile vacuole; fresh water. L. rostrata Hazen (Fig. 90, j). 5-12^1 by 4-8/x. Genus Diplostauron Korschikoff. Rectangular with raised corners; 2 equally long flagella; chromatophore; one pyrenoid; stigma; 2 contractile vacuoles anterior; fresh water. D. pentagonium (Hazen) (Fig. 90, k). 10-13/z by 9-10;u. Genus Gigantochloris Pascher. Unusually large form, equalling in size a colony of Eudorina; flattened; oval in front view; elongate ellipsoid in profile; membrane radially striated; 2 flagella widely apart, less than body length; chromatophore in network; numerous pyrenoids; often without stigma; in wood- land pools. G. permaxima P. (Fig. 90, 0- 70-150^ by 40-80^ by 25-50^. Genus Gloeomonas Klebs. Broadly ovoid, nearly subspherical; with a delicate membrane and a thin gelatinous envelope; 2 flagella widely apart; chromatophores numerous, circular or oval discs; pyrenoid (?); stigma; 2 contractile vacuoles, anterior; fresh water. G. ovalis K. (Fig. 90, m). 38-42iU by 23-33/x; gelatinous envelope over 2yu thick. Genus Scourfieldia West. Whole body flattened; ovoid in front view; membrane delicate; 2 flagella 2-5 times body length; a chromatophore; wdthout pyrenoid or stigma; contractile vacuole anterior; nucleus central; fresh water. S. complanata W. (Fig. 90, n). 5.2-5.7 /j. by 4.4-4. 6^; fresh water. Genus Thorakomonas Korschikoff. Flattened; somewhat ir- regularly shaped or ellipsoid in front view; membrane thick, enclustered with iron-bearing material, deep brown to black in color; protoplasmic body similar to that of Chlamydomonas; a chromatophore with a pyrenoid; 2 contractile vacuoles; standing fresh water. T. sahulosa K. (Fig. 90, o). Up to 16^ by 14/x. Genus Coccomonas Stein. Shell smooth; globular; body not filling intracapsular space; stigma; contractile vacuole; asexual reproduction into 4 individuals; fresh water. C. orbicularis S. (Fig. 91, a). 18-25/^ in diameter; fresh water. Genus Chlorogonium Ehrenberg. Fusiform; membrane thin and adheres closely to protoplasmic body; plate-like chromato- phores usually present, sometimes ill-contoured; one or more 192 PROTOZOOLOGY Fig. 91. a, Coccomonas orbicularis, x500 (Stein); b, Chlorogonium euchlorum, X430 (Jacobsen); c, Phyllomonas phacoides, X200 (Kor- schikoff); d, Sphaenochloris printzi, X600 (Printz); e, Korschikoffia guttula, X1670 (Pascher); f, Furcillalobosa, X670 (Stokes); g, Hyalo- gonium klebsi, X470 (Klebs); h, Polytoma iwella, X670 (Dangeard); i, Parapolytorna satura, Xl600 (Jameson); j, Trichloris paradoxa, X990 (Pascher). pyrenoids; numerous scattered contractile vacuoles; usually a stigma; a central nucleus; asexual reproduction by 2 successive transverse fissions during motile phase; isogamy reported; fresh water. C. euchlorum E. (Fig. 91, 6). 25-70yu by 4-15^1; in stagnant water. Genus Phyllomonas Korschikoff. Extremely flattened; mem- brane delicate; 2 flagella; chromatophore often faded or indistinct; numerous pyrenoids; with or without stigma; many contractile vacuoles; fresh water. P. phacoides K. (Fig. 91, c). Leaf-like; rotation movement; up to 100/x long; in standing fresh water. Genus Sphenochloris Pascher. Body truncate or concave at flagellate end in front view; sharply pointed in profile; 2 flagella widely apart; chromatophore large; pyrenoid; stigma; contractile vacuole anterior; fresh water. S. printzi P. (Fig. 91, d). Up to 18m by 9/^. PHYTOMONADINA 193 Genus Korschikoffia Pascher. Elongate pyriform with an undulating outline; anterior end narrow, posterior end more bluntly rounded; plastic; chromatophores in posterior half; stigma absent; contractile vacuole anterior; 2 equally long flagella; nucleus nearly central; salt water. K. guttula P. (Fig. 91, e). 6-10^ by 5^; brackish water. Genus Furcilla Stokes. U-shape, with 2 posterior processes; in side view somewhat flattened; anterior end with a papilla; 2 flagella equally long; 1-2 contractile vacuoles anterior; oil droplets; fresh water. F. lohosa S. (Fig. 91,/). ll-14/i long; fresh water. Genus Hyalogonium Pascher. Elongate spindle-form; anterior end bluntly rounded; posterior end more pointed; 2 flagella; protoplasm colorless; with starch granules; a stigma; asexual reproduction results in up to 8 daughter cells; fresh water. H. klebsi P. (Fig. 91, g). 30-80^ by up to lOfx; stagnant water. Genus Polytoma Ehrenberg (Chlamydohlepharis France; Tus- setia Pascher). Ovoid; no chromatophores; membrane yellowish to brown; pyrenoid unobserved; 2 contractile vacuoles; 2 flagella about body length; stigma if present, red or pale-colored; many starch bodies and oil droplets in posterior half of body; asexual reproduction in motile stage; isogamy; saprozoic; in stagnant fresh water. P. uvella E. (Figs. 8, e; 91, h). Oval to pyriform; stigma may be absent; 15-30^ by 9-20m. Genus Parapolytoma Jameson. Anterior margin obliquely truncate, resembling a cryj^tomonad, but without chromato- phores; without stigma and starch; division into 4 individuals within envelope; fresh water. P. satura J. (Fig. 91, i). About 15/i by lO/z; fresh water. Family 2 Trichlorididae With three flagella. Genus Trichloris Scherffel et Pascher. Bean-shape; flagellate side flattened or concave; opposite side convex; chromatophore large, covering convex side; 2 pyrenoids surrounded by starch granules; a stigma near posterior end of chromatophore; nucleus central; numerous contractile vacuoles scattered; 3 flagella near anterior end. T. paradoxa S. et P. (Fig. 91, j). 12-15/^ broad by 10-12^ high; flagella up to 30/^ long. 194 PROTOZOOLOGY Family 3 Carteriidae With four flagella arising from anterior pole. Genus Carteria Dicsing (Corhierea, Pithiscus, Dangeard; Teiramastix Korschikoff). Ovoid, chromatophore cup-shaped; pyrenoid; stigma; 2 contractile vacuoles; fresh water. Numerous species. C. cordiformis (Carter) (Fig. 92, a). Heart-shaped in front view; ovoid in profile; chromatophore large; 18-23^1 by 16-20;u. C. elUpsoidalis Bold. Ellipsoid; chromatophore; a small stigma; division into 2, 4, or 8 individuals in encysted stage; 6-24ju long; fresh water, Maryland (Bold, 1938). Genus Pyramimonas Schmarda (Pyramidomonas Stein). Small pyramidal or heart-shaped body; with bluntly drawn-out posterior end; usually 4 ridges in anterior region; 4 flagella; green chromatophores cup-shaped; with or without stigma; with a large pyrenoid in the posterior part; contractile vacuoles in the anterior portion; fresh water. Several species. P. tetrarhnnchus S. (Fig. 92, h). 20-28/^ by 12-18yu; fresh water; Wisconsin (Smith, 1933). P. montana Geitler. Bluntly conical; anterior end 4-lobed or truncate; posterior end narrowly rounded; plastic; pyriform nu- cleus anterior, closely associated with 4 flagella; stigma; 2 con- tractile vacuoles anterior; chromatophore cup-shaped, granular, with scattered starch grains and oil droplets; a pyrenoid with a ring of small starch grains; 17-22.5^ long (Geitler); 12-20/i by 8-16^1 (Bold), flagella about body length; fresh water, Maryland (Bold, 1938). Genus Polytomella Aragao. ElHpsoid, or oval, with a small papilla at anterior end, where 4 equally long flagella arise; with stigma; starch; fresh water. P. agilis A. (Fig. 92, c, d). Numerous starch grains; 8-18/1 by 5-9/i; flagella 12-17/* long; fresh water; hay infusion. Genus Medusochloris Pascher. Hollowed hemisphere with 4 processes, each bearing a flagellum at its lower edge; a lobed plate-shaped chromatophore; without pyrenoid below convex surface. One species. M. phiale P. In salt water pools with decaying algae in the Baltic. Genus Spirogonium Pascher. Body spindle-form; membrane delicate; flagella a little longer than body; chromatophore con- PHYTOMONADINA 195 Fig. 92. a, Carteria cordiformis, X600 (Dill); b, Pyramimonas tetra- rhynchus, X400 (Dill); c, d, Polytomella agilis, XlOOO (Doflein); e, Spirogonium chlorogonioides, X670 (Pascher); f, Tetrablepharis multifile, X670 (Pascher); g, Spermatozopsis exultans, X1630 (Pascher) ; h, Chloraster gyrans, X670 (Stein) ; i, Polyblepharides singu- laris, XS70 (Dangeard); j, k, Pocillomonas flos aquae, X920 (Stein- ecke);l, m, Phacotus lenticularis, X430 (Stein); n, Pteromonas angu- losa, X670 (West); o, p, Dysmorphococcus variabilis, XlOOO (Bold). spicuous; a pyrenoid; stigma anterior; 2 contractile vacuoles; fresh water. One species. *S. chlorogonioides (P.) (Fig. 92, e). Body up to 25^1 by 15ju. Genus Tetrablepharis Senn. Ellipsoid to ovoid; pyrenoid pres- ent; other characters are those of Polytoma; fresh water. T. multifilis (Klebs) (Fig. 92, /). 12-20^ by 8-1 5At; stagnant water. Genus Spermatozopsis Korschikoff. Sickle-form; bent easily, occasionally plastic; chromatophore mostly on convex side; a distinct stigma at more rounded anterior end; flagella equally long; 2 contractile vacuoles anterior; fresh water infusion. S. exultans K. (Fig. 92, g). 7-9/^ long; also biflagellate; in fresh water with algae, leaves, etc. 196 PROTOZOOLOGY Family 4 Chlorasteridae With 5 flajj;('lla arising from anterior pole. Genus Chloraster Ehrenbcrg. Similar to Pyramvnonas, but anterior half with a conical envelope drawn out at four corners; with 5 flagella; fresh or salt water. C. gyrans E. (Fig. 92, h). Up to 18At long; standing water; also reported from salt water. Family 5 Polyblepharididae Dangeard With 6 or more flagella arising from anterior end. Genus Polyblepharides Dangeard. Ellipsoid or ovoid; flagella 6-8, shorter than body length; chromatophore; a pyrenoid; a central nucleus; 2 contractile vacuoles anterior; cysts; a question- able genus ; fresh water. P. singularis D. (Fig. 92, i). 10-14^ by 8-9^. Genus Pocillomonas Steinecke. Ovoid with broadly concave anterior end; covered wdth gelatinous substance with numerous small projections; 6 flagella; chromatophores disc-shaped; 2 contractile vacuoles anterior; nucleus central; starch bodies; without pyrenoid. P. flos aquae S. (Fig. 92, j, k). 13/x by IO/jl; fresh water pools. Family 6 Phacotidae Poche The shell typically composed of 2 valves; 2 flagella protrude from anterior end; with stigma and chromatophores; asexual re- production within the shell; valves may become separated from each other owing to an increase in gelatinous contents. Genus Phacotus Perty. Oval to circular in front view; lentic- ular in profile; protoplasmic body does not fill dark-colored shell completely; flagella protrude through a foramina; asexual repro- duction into 2 to 8 individuals; fresh water. P. lenticularis (Ehrenberg) (Fig. 92, I, m). 13-20^ in diameter; in stagnant water. Genus Pteromonas Sehgo. Body broadly winged in plane of suture of 2 valves; protoplasmic body fills shell; chromatophore cup-shaped; one or more pyrenoids; stigma; 2 contractile vacuoles; asexual reproduction into 2-4 individuals; sexual re- production by isogamy; zygotes usually brown; fresh water. Several species. P. angulosa (Lemmermann) (Fig. 92, n). With a rounded wing PHYTOMONADINA 197 and 4 protoplasmic projections in profile; 13-17^1 by 9-20^1; fresh water. Genus Dysmorphococcus Takeda. Circular in front view; an- terior region narrowed; posterior end broad; shell distinctly flattened posteriorly, ornamented by numerous pores; sutural ridge without pores; 2 fiagella; 2 contractile vacuoles; stigma, pyrenoid, cup-shaped chromatophore; nucleus; multiplication by binary fission; fresh water. D. variahilis Takeda (Fig. 92, o, p). Shell 14-19^ by 13-17/z; older shells dark brown; fresh water; Maryland (Bold, 1938). Family 7 Volvo cidae Ehrenberg An interesting group of colonial flagellates; individual similar to Chlamydomonadidae, with 2 equally long flagella (one in Mastigophaera; 4 in Spondylomorum), green chromatophores, pyrenoids, stigma, and contractile vacuoles; body covered by a cellulose membrane and not plastic; colony or coenobium is dis- coid or spherical; exclusively freshwater inhabitants. Genus Volvox Linnaeus. Often large spherical or subspherical colonies, consisting of a large number of cells which are dif- ferentiated into somatic and reproductive cells; somatic cells numerous, embedded in gelatinous matrix, and contains a chro- matophore, one or more pyrenoids, a stigma and several contrac- tile vacuoles; in some species protoplasmic connections occur between adjacent cells; generative cells few and large. Both mono- and bi-sexual reproduction occurs; monosexual gametes usually fewer and larger in size than bisexual ones, each producing a young colony by repeated division; bisexual reproduction aniso- gamy; zygotes usually brownish red in color, with smooth, un- dulating, or spinous envelopes; fresh water. V. glohator L. (Fig. 93, a). Elhpsoid colony, composed of 5000- 20,000 cells which are 3-5yu high by up to 8/x wide; monoecious; up to SOOyu in diameter; in European waters. V. yerglohaior Powers. Colony up to 1.5 mm. in diameter; cells resemble those of V. glohator; in American waters. V. aureus Ehrenberg (Figs. 71; 93, h). Dioecious; cytoplasmic threads relatively thin and long; cells pyriform, 5-9/^ in diameter; colony 500-800/i in diameter. V. spermatosphaera Powers. Monoecious; cells number 1000- 3000; without any cytoplasmic connections; colony 150-1000/x in diameter. 198 PROTOZOOLOGY Fig. 93. a, Volvox globator, X200 (Janet); b, V. aureus, XllO (Klein); c, Gonium sociale, X270 (Chordat); d, G. pedorale, X670 (Hartmann); e, G. fortnosum, X600 (Pascher). PHYTOMONADINA 199 V. tertius Meyer. Dioecious; without cytoplasmic connections in mature state; individuals about 7-8ai in diameter. Genus Gonium M tiller. 4 or 16 individuals arranged in one plane; cell ovoid or slightly polygonal; with 2 flagella arranged in the plane of coenobium; with or without a gelatinous envelope; protoplasmic connections among individuals occur occasionally; asexual reproduction through simultaneous divisions of com- ponent cells; sexual reproduction isogamy; zygotes reddish; fresh water. G. sociale (Dujardin) (Fig. 93, c). 4 individuals form a discoid colony; cells 10-22/^ by 6-16ai wide; in open waters of ponds and lakes. G. pectorale M. (Fig. 93, d). 16 (rarely 4 or 8) individuals form a colony; 4 cells in center; 12 peripheral, closely arranged; cells 5-14^t by 10;u; colony up to 90/i in diameter; fresh water. G. formosiim Pascher (Fig. 93, e). 16 cells in a colony further apart; peripheral gelatinous envelope reduced; cells similar in size to those of G. sociale but colony somewhat larger: freshwater lakes. Genus Stephanoon Schewiakoff . Spherical or ellipsoidal colony, surrounded by gelatinous envelope, and composed of 8 or 16 biflagellate cells, arranged in 2 alternating rows on equatorial plane; fresh water. S. askenasii S. (Fig. 94, a). 16 individuals in ellipsoidal colony; cells dfx in diameter; flagella up to 30yu long; colony 78^ by 60/i. Genus Platydorina Kofoid. 32 cells arranged in a slightly twisted plane; flagella directed alternately to both sides; fresh water. P. caudata K. (Fig. 94, h). Individual cells lO-lSju long; colony up to 165^1 long, 145yu wide, and 25^ thick; rivers and lakes. Genus Spondylomorum Ehrenberg. 16 cells in a compact group in 4 transverse rings; each with 4 flagella; asexual reproduction by simultaneous division of component cells; fresh water. One species. S. quaternarium E. (Fig. 94, c). Cells 12-26^1 by 8-15At; colony up to 60/i long. Genus Chlamydobotrys Korschikoff. Colony composed of 8 or 16 individuals; cells with 2 flagella; chromatophore; stigma; no pyrenoid; fresh water. C. stellata K. (Fig. 94, d). Colony composed of 8 individuals 200 PROTOZOOLOGY Fig. 94. a, Stephanoon askenasii, X4'40 (Schewiakoff) ; b, Platij- dorina caudata, X280 (Kofoid); c, Sipondylomorum quaternnrium, X330 (Stein); d, Chlamydobotrys stellata, X430 (Korschikoff); e, Ste- phanosphaera pluvialis, x250 (Hieronymus); f, Pandorina morum, XBOO (Smith); g, Mastigosphaera gobii, X520 (Schewiakoff); h, Eu- dorina elegans, X310 (Goebel); i, Pleodorina illinoisensis, X200 (Ko- foid). arranged in 2 rings; individuals 14-15/i long; colony 30-40// in diameter; Maryland (Bold, 1933). Genus Stephanosphaera Cohn. Spherical or subspherical colony, with 8 (rarely 4 or 16) cells arranged in a ring; cells pyri- form, but with several processes; 2 flagella on one face; asexual reproduction and isogamy (p. 146); fresh water. S. pluvialis C. (Figs. 70; 94, e). Cells 7-13yu long; colony 30-60m in diameter. PHYTOMONADINA 201 Genus Pandorina Bory. Spherical or subspherical colony of usually 16 (sometimes 8 or 32) biflagellate individuals, closely packed within a gelatinous, but firm and thick matrix; individuals often angular; with stigma and chromatophores ; asexual repro- duction through simultaneous division of component indi\dduals; anisogamy preceded by division of each cell into 16 to 32 gametes; zygotes colored and covered by a smooth wall; fresh water. One species. P. morum (Mtiller) (Figs. 72; 94,/). Cells 8-17ju long; colony 20-40m, up to 250^1 in diameter; ponds and ditches. Genus Mastigosphaera Schewiakoff . Similar to Pandorina; but individual with a single flagellum which is 3.5 times the body length; fresh water. M. gobii S. (Fig. 94, g). Individual 9m long; colony 30-33m. Genus Eudorina Ehrenberg. Spherical or ellipsoidal colony of usually 32 or sometimes 16 spherical cells; asexual reproduction similar to that of Pandorina; isogamy with 32-64 spherical green macrogametes and numerous clustered microgametes ; reddish zygote with a smooth wall; fresh water. E. elegans E. (Figs. 73; 94, h). Cells 10-24/^ in diameter; colony 40-150ai in diameter; in ponds, ditches and lakes. Genus Pleodorina Shaw. Somewhat similar to Eudorina, being composed of 32, 64, or 128 ovoid or spherical cells of 2 types: small somatic and large generative, and are located within a gelatinous matrix; fresh water. P. illinoisensis Kofoid (Figs. 31, 6, c; 94, i). 32 cells in ellipsoid colony, 4 vegetative and 28 reproductive individuals; arranged in 5 circles, 4 in each polar circle, 8 at equator and 8 on either side of equator; 4 small vegetative cells at anterior pole; vegeta- tive cells 10-1 6m in diameter; reproductive cells 19-25m in diame- ter; colony up to 160yu by 130^. P. calif ornica S. Spherical colony with 64 or 128 cells, of which 1/2-2/3 are reproductive cells; vegetative cells 13-15/x; reproduc- tive cells up to 27/x; colony up to 450/x, both in diameter. References Bold, H. C. 1938 Notes on Maryland Algae. Bull. Torrey Bot. Club., Vol. 65. Crow, W. B. 1918 The classification of some colonial chlamy- domonads. New Phytologist, Vol. 17. Dangeard, p. 1900 Observations sur la structure et le develop- pement du Pandorina morum. Le Botaniste, Vol. 7. 202 PROTOZOOLOGY Entz, G. Jr. 1913 Cytologische Beobachtungen an Polytoma uvella. Verb. Dcutscb. Zool. Ges. Ver., Vol. 23. Fritsch, F. E. 1935 The structure and reproduction of the algae. Cambridge. Janet, C. 1912, 1922, 1923 Le Volvox. I, II, and III Memoires. Paris. KoFOiD, C. A. 1900 Plankton Studies, Nos. 2 and 3. Ann. Mag. Nat. Hist., Ser. 7, Vol. 6. Mast, S. O. 1928 Structure and function of the eye-spot in uni- cellular and colonial organisms. Arch. f. Protistenk., Vol. 60. Pascher, a. 1927 Vovocales — Phytomonadinae. In: Die Suss- wasserflora Deutschlands, Part 4. Shaw, W. R. 1894 Pleodorina, a new genus of the Volvocideae. Bot. Gaz., Vol. 19. Smith, G. M. 1933 The freshwater algae of the United States. New York. West, G. S. and F. E. Fritsch 1927 A treatise on the British freshwater algae. Cambridge. Chapter 10 Order 4 Euglenoidina Blochmann THE body is as a rule elongated; some are plastic, others have a definite body form with a well-developed, striated or variously sculptured pellicle. At the anterior end, there is an opening shrough which a flagellum protrudes. In holophytic forms the to-called cytostome and cytopharynx, if present, are apparently not concerned with the food-taking, but seem to give a passage- way for the flagellum and also to excrete the waste fluid matters which become collected in one or more contractile vacuoles located around the reservoir. In holozoic forms, a well-developed cytostome and cytopharynx are present. Ordinarily there is only one flagellum, but some possess two or three. Chromatophores are present only in the majority of the Euglenidae and absent in the other two families. They are green, vary in shape, such as spheroidal, band-form, cup-form, discoidal, or fusiform, and usually possess pyrenoids. Some forms may contain haemato- chrome. A small but conspicuous stigma is invariably present near the anterior end of the body in chromatophore-bearing forms. Reserve food material is the paramylon body, fat, and oil, the presence of which depends naturally on the metabolic condi- tion of the organism. The paramylon body assumes diverse forms in different species, but is, as a rule, constant in each species, and this facilitates specific identification to a certain extent. Nutrition is holophytic in chromatophore-possessing forms, which, however, may be saprozoic, depending on the amount of light and organic substances present in the water. The holozoic forms feed upon bacteria, algae, and smaller Protozoa. The nucleus, as a rule, is large and distinct and contains almost always a large endosome. Asexual reproduction is by longitudinal fission; sexual reproduction has been observed in a few species. Encystment is common. The majority inhabit fresh water, but some live in brackish or salt water, and a few are parasitic in animals. 203 204 I'ROTOZOOLOGY With stigma Family 1 Euglenidae Without stigma With 1 flageUum Family 2 Astasiidae (p. 209) With 2 flagella Family 3 Anisonemidae (p. 212) Family 1 Euglenidae Stein Body plastic ("euglonoid"), but, as a rule, more or less spindle- shaped during movement; the majority possess a single anterior flagellum (with the exception of Eutreptia and Euglenamorpha) ; green (sometimes red) chromatophores (except one genus) and stigma occur, though in some cases absent; metabolic products oil and paramylon; asexual reproduction by longitudinal fission in either active or resting stage; mostly freshwater inhabitants. Genus Euglena Ehrenberg. Short or elongated spindle, cylin- drical, or band-form; pelhcle usually marked by longitudinal or spiral striae; some highly plastic with a thin pellicle; others regu- larly spirally twisted; stigma usually anterior; chromatophores numerous and discoid, band-form, or fusiform; pyrenoids may or may not be surrounded by starch envelope; metabolic products paramylon bodies which may be two in number; one being located on either side of nucleus, and rod-like to ovoid in shape or numerous and scattered throughout; contractile vacuoles small, near reservoir; asexual reproduction by longitudinal fission; sexual reproduction reported in Euglena sanguinea; common in stagnant water, especially where algae occur; when present in large numbers, the active organisms may form a green film on the surface of water and resting or encysted stages may produce conspicuous green spots on the bottom of pond or pool; in fresh water. Numerous species. E. pisciformis Klebs (Fig. 95, a). 25-30^ by 7-1 0^; spindle- form, with bluntly pointed anterior and sharply attenuated posterior end; slightly plastic; highly active; paramylon indis- tinct; chromatophores lateral and discoidal; 2 pyrenoids; flagellum fairly long. E. viridis Ehrenberg (Fig. 95, 6). 50-60/i by 14-18/x; anterior end rounded, posterior end pointed; spindle-shaped during motion, highly plastic when stationary; pellicle obhquely striated; chromatophores more or less band-form, arranged in a stellate form; nucleus posterior; nutrition holophytic, but also able to carry on saprozoic nutrition, during which period chromato- phores degenerate. EUGLENOIDINA 205 E. acus E. (Figs. 24, h; 95, c). 100-200^ long; long spindle-form; posterior end sharply pointed; flagelliim short; spiral striation on pellicle very delicate; paramylon bodies rod-form; nucleus cen- tral; stigma distinct; numerous disc-like chromatophores; with- out pyrenoids; sluggish. Fig. 95. a, Euglena pisciformis, X270 (Klebs); b, E. viridis, X370 (Lemmermann); c, E. acus, X270 (Klebs); d, E. spirogyra, X430 (Stein); e, E. oxyuris, X430 (Stein); f, E. sanguinea, Xl30 (Klebs); g, E. deses, X230 (Lemmermann); h, E. gracilis, X270 (Klebs). E. spirogyra E. (Figs. 24, c; 95, d). 80-125^ by 10-20m; cylin- drical; with spiral striae, consisting of small knobs; numerous disc-like chromatophores; without pyrenoids; 2 ovoidal paramy- lon bodies, one on either side of centrally located nucleus; flagellum short; stigma prominent; sluggish. E. oxyuris Schmarda (Fig. 95, e), 375-500^ by 30-45^; almost 206 PROTOZOOLOGY always spirally twisted, somewhat flattened; pellicle with spirally arranged striae; numerous chromatophores; without pyrenoids; 2 ovoid paramylon bodies conspicuously observable, one on either side of nucleus; flagellum short. E. sanguinea E. (Figs. 37, e-h; 95, /). 55-120^ by 28-33^; with haematochrome; often found in crust on surface or half-dry bed of a pool; considered by some workers as a variety of E. viridis. E. deses E. (Figs. 24, a; 95, g). 85-155m by 15-22^; elongate, highly plastic; body striation faintly visible; stigma distinct; nucleus central, numerous chromatophores hemi-lenticular; several small rod-shaped paramylon bodies scattered; flagellum short. E. gracilis Klebs (Figs. 37, a-d; 95, h). 37-45/x by 6-23m; cylindrical to elongated oval; highly plastic; flagellum less than body length; chromatophores numerous, discoid; nucleus central; pyrenoids. Genus Khawkinea Jahn et McKibben. Similar to Genus Euglena, but without chromatophores and thus permanently colorless; fresh water. K. halli J. et Mc. 40-45^ (30-65^) by 12-14^; fusiform; pellicle spirally striated; plastic; flagellum slightly longer than body; stigma 2-3/i in diameter, yellow-orange to reddish-orange, com- posed of numerous granules; numerous (25-100) paramylon bodies elliptical or polyhedral; cysts 20-30ju in diameter; putrid leaf infusion; saprozoic. K. ocellata (Khawkine). Similar to above; flagellum 1.5-2 times body length; fresh water. Genus Phacus Nitzsch. Highly flattened; asymmetrical; body- form constant; pellicle often with prominent longitudinal or oblique striae; a flagellum and a stigma; nucleus posterior; a short "cytopharynx"; green chromatophores rounded discoid; with or without paramylon bodies around a pyrenoid; in fresh water. Numerous species. P. pleuronectes (Miiller) (Fig. 96, a). 4:5-50^i by 30-33/1 ; short posterior prolongation slightly curved ; a prominent fold on con- vex side, extending to middle of body; longitudinally striated; one or more circular paramylon bodies ; colorless forms sometimes appear; flagellum as long as body. P. longicaudus (Ehrenberg) (Fig. 96, 6). 85-115/1 by 45-70/t; EUGLENOIDINA 207 usually twisted with a long caudal prolongation; stigma promi- nent; discoidal paramylon body central; pellicle longitudinally striated. P. pyrum (E.) (Fig. 96, c). About 40^1 long; pyriform, with a straight caudal prolongation; pellicle obliquely striated. P. triqueter (E.) (Fig. 96, d). 50-55/x by 30-35^; ovate; with a longitudinal ridge; posterior end acuminate; oblique striation distinct; 1-2 paramylon bodies. P. anacoelus Stokes (Fig. 96, e). About 42/^ long; oval or round; with flagellum as long as body. P. acuminata S. (Fig. 96, /). About 25m long; nearly circular in outline; longitudinally striated; fold long; flagellum as long as body; 2 small paramylon bodies. Genus Crumenula Dujardin (LepocincUs Perty). Body more or less ovo-cylindrical; rigid with spirally striated pellicle; often with a short posterior spinous projection; stigma sometimes present; numerous discoidal chromatophores marginal; paramy- lon bodies usually large and ring-shaped, laterally disposed; without pyrenoids; fresh water. Several species. C. ova (Ehrenberg) (Fig. 96, g). 20-40^ long; in fresh water with Euglena. Genus Trachelomonas Ehrenberg. With a lorica which often possesses numerous spinous projections; sometimes yellowish to dark brown; a single flagellum protrudes from anterior aperture, the rim of which is frequently thickened to form a collar; chroma- tophores either 2 curved plates or numerous discs; paramylon bodies small grains; stigma and pyrenoids; multiplication by longitudinal fission; one daughter individual retains lorica and flagellum, while the other escapes through flagellar aperture, forms a new flagellum and secretes a lorica; cysts common; specific differentiation is based upon the lorica; fresh water. Numerous species. T. hispida (Perty) (Figs. 31, a; 96, h). Lorica oval, with numer- ous minute spines; brownish; 8-10 chromatophores; 20-42/i by 15-26/x; many varieties. T. urceolata Stokes (Fig. 96, i). Lorica vasiform, smooth with a short neck; about 45^ long. T. piscatoris (Fisher) (Fig. 96, j). Lorica cylindrical with a short neck and with numerous short, conical spines; 25-40/z long; flagellum 1-2 times body length. 208 PROTOZOOLOGY Fig. 96. a, Phacus pleuronectes, X670 (Lemmermann); b, P. longi- caudus, X430 (Stein); c, P. pyrum, X400 (Lemmermann); d, P. triqueter, x430 (Stein); e, P. anacoelus, X330 (Stokes); f, P. acuminata X560 (Stokes); g, Crumenula ova, X430 (Stein); h, Trachelomonas hispida, X430 (Stein); i, T. urceolata, x430 (Stokes); j, T. piscatoris, X520 (Fischer); k, T. verrucosa, X550 (Stokes); 1, T. vermiculosa, X800 (Palmer); m, Cryptoglena pigra, X430 (Stein); n, Ascoglena vaginicola, X390 (Stein); o, Colacmm vesiculosuvi, X390 (Stein); p, Eutreptia viridis, X270 (Klebs); q, E. marina, X670 (da Cunha); r, Euglenamorpha hegneri, X730 (Wenrich). T. verrucosa Stokes (Fig. 96, h). Lorica spherical, with numer- ous knob-like attachments; no neck; 24-25ai in diameter. T. vermiculosa Palmer (Fig. 96, I). Lorica spherical; with sausage-form markings; 23^t in diameter. Genus Cryptoglena Ehrenberg. Body rigid, flattened; 2 band- EUGLENOIDINA 209 form chromatophores lateral; a single flagelliim; nucleus pos- terior; among freshwater algae. One species. C. pigra E. (Fig. 96, ?n). Ovoid, pointed posteriorly; fiagelUim short; stigma prominent; 10-15/^ by 6-10^; standing water. Genus Ascoglena Stein. Encased in a flexible, colorless to brown lorica, attached with its base to foreign object; solitary, without stalk; body ovoidal, plastic; attached to test with its posterior end; a single fiagellum; a stigma; numerous chromato- phores discoid; with or without pyrenoids; reproduction as in Trachelomonas (p. 207); fresh water. A. vaginicola S. (Fig. 96, n). Lorica about ^2>^x by 15^. Genus Colacium Ehrenberg. Stalked individuals form colony; frequently attached to animals such as copepods, rotifers, etc.; stalk mucilaginous; individual cells pyriform, ellipsoidal or cylindrical; without fiagellum; a single fiagellum only in free- swimming stage; discoidal chromatophores numerous; with pyrenoids; multiplication by longitudinal fission; also by swarmers, possessing a fiagellum and a stigma; fresh water. Several species. C. vesiculosum E. (Fig. 96, o). Colony of 2-8 cells; also solitary; 20-30/i by 9-18^; attached to freshwater copepods. Genus Eutreptia Perty (Eutreptiella Cunha). With 2 flagella at anterior end; pellicle distinctly striated; plastic; spindle- shaped during movement; stigma; numerous discoid chromato- phores; pyrenoids absent; paramylon bodies spherical or sub- cylindrical; multiplication as in Euglena; cyst with a thick stratified wall; fresh or salt water. E. viridis P. (Fig. 96, p). 50-70^ by 5-13/x; in fresh water; a variety was reported from brackish water ponds. E. marina (da Cunha) (Fig. 96, q). Flagella unequal in length; longer one as long as body, shorter one 1/3; body 40-50At by 8-1 0/x; salt water. Genus Euglenamorpha Wenrich. Body form and structure similar to those of Euglena, but with 3 flagella; in gut of frog tadpoles. One species. E. hegneri W. (Fig. 96, r). 40-50/x long. Family 2 Astasiidae Biitschli Similar to Euglenidae in body form and general structure, but without chromatophores; body is plastic, although it assumes 210 PROTOZOOLOGY I FiG. 97. a, Astasia klebsi, X500 (Klebs); b, Urceolus cyclostomus, X430 (Stein); c, U. sabulosiis, X430 (Stokes); d, Peranema triclio- 'phorum, X530 (Kudo); e, Petalmonas mediocanellata, XlOOO (Klebs); f, Menoidium incurvum, X1400 (Hall); g, Scytomonas pusilla, x430 (Stein); h, Anisonema acinus, X400 (Klebs); i, A. truncatum, X430 (Stein); j, ^. emerginalum, X530 (Stokes); k, Heteronema acus, X430 (Stein); 1, H. mutabile, Xl20 (Stokes); m, TropidoscAjphus odocostatus, X290 (Lemmermann); n, Distigma proteus, x430 (Stein); o, Enlosi- phon sulcatum, x430 (Stein); p, Notosolenus apocamptus, X1200 (Stokes); q, N. sinatus, x600(Stokes); r, Marsupiogaster striata, X590 (Schewiakoff) ; s, M. picta (Faria, da Cunha and Pinto). EUGLENOIDINA 211 usually an elongated form; there is a cytopharynx and cytostome, the former being connected with the reservoir of contractile vacuoles; without stigma; flagellum usually straight and its free end vibrates in a characteristic manner; asexual reproduction by longitudinal fission. Genus Astasia Dujardin. Body plastic, although ordinarily elongate; fresh water or endoparasitic (?) in Cyclops, etc. Several species. A. klehsi Lemmermann (Fig. 97, a). Spindle-form; posterior portion drawn out; flagellum as long as body; plastic; paramylon bodies oval; 50-60ai by 13-20^; stagnant water. Genus Urceolus Mereschkowsky {Phialonema Stein). Body colorless; plastic; flask-shaped; striated; a funnel-like neck; posterior region stout; a single flagellum protrudes from funnel and reaches inward the posterior third of body; fresh or salt water. U. cyclostomus (Stein) (Figs. 8, /; 97, h). 25-50yu long; fresh water. U. sahulosus (Stokes) (Fig. 97, c). Spindle-form ; surf ace covered with minute sand-grains; about 58^ long; fresh water. Genus Peranema Dujardin. Elongate with a broad, rounded or truncate posterior end during locomotion; highly plastic when stationary; delicate pellicle shows a fine striation; flagellum long, tapers toward free end and vibrates; nucleus central; con- tractile vacuoles; saprozoic and holozoic; in stagnant water; often in hay infusion. P. trichophorum (Ehrenberg) (Figs. 26; 97, d). 20-70/i long; very common. P. granulijera Penard. Much smaller, 8-15/x long; spherical or elongate; pellicle granulated; standing water. Genus Petalomonas Stein. Colorless; constant in form; pellicle often with longitudinal keels on one side; a single flagellum; holozoic or saprozoic; cytostome at anterior end; cytopharynx fairly deep; in fresh water, rich in vegetable matter. Many species. P. mediocanellata S. (Fig. 97, e). Ovoid with longitudinal fur- row; flagellum about as long as body; 22-23ai long. Genus Menoidium Perty. Rigid body, more or less curved; peUicle striated; a single flagellum; fresh water. M. incurvum (Fresenius) (Figs. 24, d; 64; 97,/). Crescentic cyl- 212 • PHOTOZOOLOCY indcr; flagellum as long as body; nuclous central or terminal; 15- 25m by 7-8m; in standing fresh water. Hall (1923) made a careful cytological study of the organism. M. tortuosum Stokes. S-form; posterior end drawn out to a sharp point; elongate paramylon bodies; 42-78^ long; in infusion. Genus Scytomonas Stein. Oval or pyriform, with a delicate pel- licle; a single flagellum; a contractile vacuole with a reservoir; holozoic on bacteria; longitudinal fission in motile stage; stag- nant water and coprozoic. S. pusilla S. (Fig. 97, g). About 15m long. Genus Copromonas Dobell. Elongate ovoid; with a single fla- gellum; a small cytostome at anterior end; holozoic on bacteria; permanent fusion followed by encystment (p. 145); coprozoic in faecal matters of frog, toad, and man; several authors hold that this genus is probably identical with Scytomonas which was in- completely described by Stein. C. siibtilis D. (Fig. 69). 7-20^ long. Family 3 Anisonemidae Schewiakofif Colorless body plastic or rigid with a variously marked pellicle; 2 flagella, one directed anteriorly and the other usually posteri- orly; contractile vacuoles and reservoir; stigma absent; paramy- lon bodies as a rule present; free-swimming or creeping. Genus Anisonema Dujardin. Generally ovoid; more or less flattened; asymmetrical; plastic or rigid; a slit-like ventral fur- row; flagella at anterior end; cytopharynx long; contractile vacu- ole anterior; nucleus posterior; in fresh water. Several species. A. acinus D. (Fig. 97, h). Rigid; oval; somewhat flattened; pel- licle slightly striated; 25-40/x by 16-22^. A. truncatum Stein (Fig. 97, i). Rigid; ovoid; 60/i by 20/^. A. emarginatum Stokes (Fig. 97, j). Rigid; 14/x long; flagella long. Genus Heteronema Dujardin. Plastic; rounded or elongate; flagella arise from anterior end, one directed forward and the other trailing; cytostome near base of flagella; holozoic; fresh water. Several species. H. acus (Ehrenberg) (Fig. 97, k). Extended body tapers to- wards both ends ; anterior flagellum as long as body, trailing one about 1/2; contractile vacuole anterior; nucleus central; 45-50^ long; freshwater. EUGLENOIDINA 213 H. mutabile (Stokes) (Fig. 97, I). Elongate; highly ])Iastic; longitudinally striated; about 254/i long; in cypress swamp. Genus Tropidoscyphus Stein. Slightly plastic; pellicle with 8 longitudinal ridges; 2 unequal flagella at anterior pole; holozoic or saprozoic; fresh or salt water. T. octocostatus S. (Fig. 97, m). 35-63/^ long; fresh water, rich in vegetation. Genus Distigma Ehrenberg. Plastic; elongate when extended; body surface without any marking; 2 flagella unequal in length, directed forward; cytostome and cytopharynx located at anterior end; endoplasm transparent; holozoic. One species. D. proteus E. (Fig. 97, n). 50-1 10/z long when extended; nu- cleus central; stagnant water; infusion. Genus Entosiphon Stein. Oval, flattened; more or less rigid; flagella arise from a cytostome, one flagellum trailing; protrusible cytopharynx a long conical tubule almost reaching posterior end ; nucleus centro-lateral; fre>sh water. E. sulcatum (Dujardin) (Fig. 97, o). About 20// long. E. ovatum Stokes. Anterior end rounded; 10-12 longitudinal striae; about 25-28/z long. Genus Notosolenus Stokes. Free-swimming; rigid oval; ventral surface convex, dorsal surface with a broad longitudinal groove; flagella anterior; one long, directed anteriorly and vibratile; the other shorter and traihng; fresh water with vegetation. N. apocamptus S. (Fig. 97, p). Oval with broad posterior end; 6-1 1m long. N. sinuatus S. (Fig. 97, q). Posterior end truncate or concave; about 22/x long. Genus Marsupiogaster Schewiakoff. Oval; flattened; asym- metrical; cytostome occupies entire anterior end; cytopharynx conspicuous, 1/2 body length; body longitudinally striated; 2 flagella, one directed anteriorly, the other posteriorly; spherical nucleus; contractile vacuole anterior; fresh or salt water. M. striata Schewiakoff (Fig. 97, r). About 27 fi by IS/x; fresh water; Hawaii. M. picta Faria, da Cunha et Pinto (Fig. 97, s). In salt water; Rio de Janeiro. Order 5 Chloromonadina Klebs The chloromonads are of rare occurrence and consequently not 214 rilOTOZOOLOGY b c Fig. 98. a, Gonyostomum semen, X540 (Stein); b, Vacuolaria vires- cens, X460 (Senn); c, Trentonia flagellata, X330 (Stokes); d, Thau- matomastrix setifera, X830 (Lauterborn), well known. The majority possess small discoidal grass-green chromatophores with a large amount of xanthophyll which on addition of an acid become blue-green. No pyrenoids occur. The metabolic products are fatty oil. Starch or allied carbohydrates are absent. Stigma is also not present. Genus Gonyostomum Diesing (Rhaphidomonas Stein). With grass-green chromatophores; highly refractile trichocyst-like structures in cytoplasm; in fresh water. A few species. G. semen D. (Fig. 98, a). Sluggish animal; about 45-60ju long; in marshy water among decaying vegetation. Genus Vacuolaria Cienkowski. Highly plastic; without tricho- cyst-like structures; anterior end narrow; with 2 flagella; cysts with a gelatinous envelope. One species. V. virescens C. (Fig. 98, h). About 50-150m long; fresh water. Genus Trentonia Stokes. Bi-flagellate as in the last genus; but flattened; anterior margin slightly bilobed. One species. T. flagellata S. (Fig. 98, c). Slow-moving organism; encystment followed by binary fission; about 60^1 long; fresh water. Genus Thaumatomastix Lauterborn. Colorless; pseudopodia formed; 2 flagella, one extended anteriorly, the other trailing; holozoic; perhaps a transitional form between the Mastigophora and the Sarcodina. One species. T. setifera L. (Fig. 98, d). About 20-35^ by 15-28m; fresh water. EUGLENOIDINA, CHLOROMONADINA 215 References Dangeard, p. 1901 Recherches sur les Eugleniens. Le Bota- niste. P. 97. Fritsch, F. E. 1935 The structure and reproduction of the algae. Vol. 1. Cambridge. Hall, R. P. 1923 Morphology and binary fission of Menoidium incurvuni (Fres.) Klebs. Uni. Cal. Publ. Zool., Vol. 20. Lemmermann, E. 1913 Eugleninae. In: Susswasserfl. Deutsch- lands, Part 2. Pascher, a. 1913 Chlorojnonadinae. Ibid. Part 2. Smith, G. M. 1933 The freshwater algae of the United States. New York, Wenrich, D. H. 1924 Studies on Euglenamorpha hegneri n. g., n. sp., a euglenoid flagellate found in tadpoles, Biol. Bull,, Vol. 47. West, G. S. and F. E. Fritsch. 1927 A treatise on the British freshwater algae. Cambridge. '''' k: Chapter 11 Order 6 Dinoflagellata Butschli THE dinoflagellates make one of the most distinct groups of the Mastigophora, inhabiting mostly marine water, and to a lesser extent fresh water. In the general appearance, the arrangement of the two flagella, the characteristic furrows, and the possession of brown chromatophores, they are closely related to the Crypto- monadina. The body is covered by an envelope composed of cellulose which may be a simple smooth piece, or may be composed of two valves or of numerous plates, that are variously sculptured and possess manifold projections. Differences in the position and course of the furrows and in the projections of the envelope pro- duce numerous asymmetrical forms. The furrows, or grooves, are a transverse annulus and a longitudinal sulcus. The annulus is a girdle around the middle or toward one end of the body. It may be a complete or incomplete ring or sometimes spiral. While the ma- jority show a single transverse furrow, a few may possess several. The part of the shell anterior to the annulus is called the epitheca and that posterior to the annulus the hypotheca. In case the en- velope is not developed, the terms epicene and hypocone are used (Fig. 99). The sulcus may run from end to end or from one end to the annulus. The two flagella arise ty]jically from the annulus, one being transverse and the other longitudinal. -Anterior flagellar pore x,^ y — "n. Epicene , Transverse flagelluni Annulus or girdle _ -Sulcus Hypocone Longitudinal flagellum [ "^Posterior flagellar pore Fig. 99. Diagram of a typical naked dinoflagellate (Lebour). The transverse flagellum which is often band-form, encircles the body and undergoes undulating movements, which in former 216 DINOFLAGELLATA 217 years were looked upon as ciliary movements (hence the name CiHoflagellata). In the suborder Adinida, this fiagellum vibrates freely in a circle near the anterior end. The longitudinal fiagellum often projects beyond the body and vibrates. Combination of the movements of these flagella produces whirling movements char- acteristic of the organisms. The majority of dinoflagellates possess a single somewhat mas- sive nucleus with evenly scattered chromatin, and usually several endosomes. There are two kinds of vacuoles. One is often sur- rounded by a ring of smaller vacuoles, while the other is large contains pink-colored fluid and connected with the exterior by a canal opening in a flagellar pore. The latter is known as the pusule which functions as a digestive organella (Kofoid and Swezy). In many freshwater forms a stigma is present, and in Pouchetiidae there is an ocellus composed of an amyloid lens and a dark pig- ment-ball. The majority of planktonic forms possess a large num- ber of small chromatophores which are usually dark yellow, brown or sometimes slightly greenish and are located in the pe- riphery of the body, while bottom-dwelling and parasitic forms are, as a rule, colorless, because of the absence of chromatophores. A few forms contain haematochrome. The method of nutrition is holophytic, holozoic, saprozoic, or mixotrophic. In holophytic forms, anabolic products are starch, oil, or fats. Asexual reproduction is by binary or multiple fission or bud- ding in either the active or the resting stage and differs among different goups. Encystment is of common occurrence. In some forms the cyst wall is formed within the test. The cysts remain alive for many years ; for example, Ceratium cysts were found to retain their vitahty in one instance for six and one-half years. Conjugation and sexual fusion have been reported in certain forms, but definite knowledge on sexual reproduction awaits further investigation. The dinoflagellates are abundant in the plankton of the sea and play an important part in the economy of marine life as a whole. A number of parasitic forms are also known. Their hosts include various diatoms, copepods and several pelagic animals. Bivalve shell without furrows Suborder 1 Prorocentrinea (p. 218) Nakes or with shell showing furrows Suborder 2 Peridiniinea (p. 219) Naked; without furrows; no transverse fiagellum Suborder 3 Cystoflagellata (p. 233) 218 a PROTOZOOLOGY c d Fig. 100. a, Prorocentnim micans, X420 (Schiitt); b, c, Exuviaella marina, X420 (Schiitt); d, e, Cystodinium steini, X370 (Klebs); f, Glenodinium cinctuni, X590 (Schilling); g, G. j)ulvisculum, x420 (Schilling); h, G. uliginosum, X590 (Schilling); i, G. edax, X490 (Schilling); j, G. negleduni, X650 (Schilling). Suborder 1 Prorocentrinea Poche Test bivalve; without any groove; with yellow chromato- phores; 2 flagella anterior, one directed anteriorly, the other vi- brates in a circle; fresh or salt water. Family Prorocentridae Kofoid Genus Prorocentrum Ehrenberg. Elongate oval; anterior one bluntly pointed, with a spinous projection at pole; chromato- phores small, yellowish brown; salt water. P. micans E. (Fig. 100, a). 36-52/x long; a cause of "red water." P. triangulatum Martin. Triangular with rounded posterior end; shell-valves flattened; one valve with a delicate tooth; sur- face covered with minute poroids; margin striated; chromato- phores yellow-brown, irregular, broken up in small masses; 17- 22/i (excluding tooth); Martin found it extremely abundant in brackish water in New Jersey. DINOFLAGELLATA 219 Genus Exuviaella Cienkowski. Subspherical or oval; no anterior projection, except 2 flagella; 2 lateral chromatophores, large, brown, each with a pyrenoid and a starch body; nucleus posterior; salt water. Several species. E. marina C. (Fig. 100, h, c). 36-50/i long. E. apora Schiller. Compressed, oval; striae on margin of valves; chromatophores numerous yellow-brown irregular in form; 30- 32m by 21-26m (Schiller); 17-22/z by 14-19; (Lebour; Martin); common in brackish water. New Jersey. Suborder 2 Peridiniinea Poche Typical dinofiagellates with one to many transverse annuli and a sulcus; 2 flagella, one of which undergoes a typical undulating movement, while the other usually directed posteriorly. Accord- ing to Kofoid and Swezy, this suborder is divided into two tribes. Body naked or covered by a thin shell . . . Tribe 1 Gymnodinioidae Body covered by a thick shell Tribe 2 Peridinioidae (p. 229) Tribe 1 Gymnodinioidae Poche Naked or covered by a single piece cellulose membrane with annulus and sulcus, and 2 flagella; chromatophores abundant, yellow or greenish platelets or bands; stigma sometimes present; asexual reproduction binary or multiple division; holophytic, holozoic, or saprozoic; the majority are deep-sea forms; a few coastal or fresh water forms also occur. With a cellulose membrane Family 1 Cystodiniidae Without shell Furrows rudimentary Family 2 Pronoctilucidae (p. 220) Annulus and sulcus distinct Solitary With ocellus Family 3 Pouchetiidae (p. 220) Without ocellus With tentacles Family 4 Noctilucidae (p. 222) Without tentacles Free-living Family 5 Gymnodiniidae (p. 223) Parasitic Family 6 Blastodiniidae (p. 227) Permanently colonial Family 7 Polykrikidae (p. 228) Family 1 Cystodiniidae Kofoid et Swezy Genus Cystodinium Klebs. In swimming phase, oval, with ex- 220 PROTOZOOLOGY tremely delicate envelope; annulus somewhat acyclic; cyst-mem- brane drawn out into 2 horns. C. steini K. (Fig. 100, d, e). Stigma beneath sulcus; chromato- phores brown; swarmer about 45ju long; freshwater ponds. Genus Glenodinium Ehrenberg. (Glenodiniopsis, Stasziecella, Woloszynska). Spherical; ellipsoidal or reniform in end-view; an- nulus a circle; several discoidal, yellow to brown chromatophores; horseshoe- or rod-shaped stigma in some; often with gelatinous envelope; fresh water. Many species. G. cinctum E. (Fig. 100, /). Spherical to ovoid; annulus equa- torial; stigma horseshoe-shaped; 43/x by 40/i. G. pulvisad'um Stein (Fig. 100, g). No stigma; 38At by 30^:. G. uliginosum Schilling (Fig. 100, h). 36-48/z by 30/i. G. edax S. (Fig. 100, i). Mix by 33^^. G. neglectum S. (Fig. 100, j). 30-32^ by 29/x. Family 2 Pronoctilucidae Lebour Genus Pronoctiluca Fabre-Domergue. Body with an antero- ventral tentacle and sulcus; annulus poorly marked; salt water. P. tentaculatum (Kofoid et Swezy) (Fig. 101, a). About 54/i long; off California. Genus Oxyrrhis Dujardin. Subovoidal, asymmetrical posterior- ly; annulus incomplete; salt water. 0. marina D. (Fig. 101, 6). 10-37^ long. Family 3 Pouchetiidae Kofoid et Swezy Ocellus consists of lens and melanosome (pigment mass) ; sulcus and annulus somewhat twisted; pusules usually present; cyto- plasm colored; salt water (pelagic). Genus Pouchetia Schiitt. Nucleus anterior to ocellus; ocellus with red or black pigment mass with a red, brown, yellow, or colorless central core; lens hyahne; body surface usually smooth; holozoic; encystment common; salt water. Many species. P.fusus S. (Fig. 101, c). About 94ju by 41^; ocellus 27m long. P. maxima Kofoid et Swezy (Fig. 101, d). 145^ by 92/x; ocellus 20iu; off California. Genus Protopsis Kofoid et Swezy. Annulus and sulcus similar to those of Gymnodinium or Gyrodinium ; with a simple or com- pound ocellus, no tentacles; body not twisted; salt water. A few species. DINOFLAGELLATA 221 Fig. 101. a, Pronodiluca tenia culat inn, x730 (Kofoid and Swezy); b, Oxyrrhis marina, XSIO (Senn); c, Pouchetia fusus, X340 (Schiitt); d, P. maxima, X330 (Kofoid and Swezy); e, Protopsis ochrea, X340 (Wright); f, Nematodinium partitum, X560 (Kofoid and Swezy); g, Proterythropsis crassicaudata, x740 (Kofoid and Swezy); h, Ery- thropsis cornuta, X340 (Kofoid and Swezy); i, j, Noctihica scintillans (i. side view; j, budding process), Xl40 (Robin). 222 PROTOZOOLOGY P. ochrea (Wright) (Fig. 101, e). 55/x by 45)u; ocellus 22/i long; Nova Scotia. Genus Nematodinium Kofoid et Swezy. With nematocysts; girdle more than 1 turn; ocellus distributed or concentrated, pos- terior; holozoic; salt water. N. partitum K. et S. (Fig. 101,/). Ol^i long; off CaHfornia. Genus Proterythropsis Kofoid et Swezy. Annulus median; ocel- lus posterior; a stout rudimentary tentacle or prod-like antapical process; salt water. One species. P. crassicaudata K. et S. (Fig. 101, g). 70/u long; off California. Genus Erythropsis Hertwig. Epicone flattened, less than 1/4 hypocone; ocellus very large, composed of one or several hyaline lenses attached to or imbedded in a red, brownish or black pig- ment body with a red, brown or yellow core, located at left of sulcus; sulcus expands posteriorly into ventro-posterior tentacle; salt water. Several species. E. cornuta (Schlitt) (Fig. 101, h). 104^ long; off California (Ko- foid and Swezy). Family 4 Noctilucidae Kent Tentacle somewhat contractile, arises from sulcal area and ex- tends posteriorly; this group had formerly been included in the Cystoflagellata; studies by recent investigators, particularly by Kofoid, show their affinities with the present suborder; holozoic; salt water. Genus Noctiluca Suriray. Spherical, bilaterally symmetrical; peristome marks median line of body; a cytostome at bottom of peristome; with a conspicuous tentacle; cytoplasm much vacuo- lated, and cytoplasmic strands connect central mass with periph- ery; peripheral granules phosphorescent (p. 95); cytoplasm colorless or blue-green; sometimes tinged with yellow coloration in center; swarmers formed by budding, and each possesses one flagellum, annulus, and tentacle; widely distributed in salt water; holozoic. One species. N. scintillans (Macartney) {N. miliaris S.) (Fig. 101, i, j). Usually 500-1000;u in diameter, with extremes of 200/i and 2 mm. Gross (1934) observed that complete fusion of two swarmers (isogametes) results in cyst formation from which trophozoites develop. Acid contents of the body fluid is said to be about pH 3. Genus Pavillardia Kofoid et Swezy. Annulus and sulcus similar to those of Gymnodinium; longitudinal flagellum absent; stout DINOFLAGELLATA 223 finger-like mobile tentacle directed posteriorly; salt water. One species. P. tentacuUfera K. et S. 58// by 27m; pale yellow; off California. Family 5 Gymnodiniidae Kofoid Naked forms with simple but distinct 1/2-4 turns of annulus; with or without chromatophores; fresh or salt water. Genus Gymnodinium Stein. Pellicle delicate; subcircular; bi- laterally symmetrical; numerous discoid chromatophores vari- colored (yellow to deep brown, green, or blue) or sometimes ab- sent; stigma present in few; many with mucilaginous envelope; salt, brackish, or fresh water. Numerous species. G. aeruginosum S. (Fig. 102, a). Chromatophores green; 33-35/x by 22m ; ponds and lakes. G. rotundatum Klebs (Fig. 102, 6). 32-35m by 22-25^; fresh wa- ter. G. palustre Schilling (Fig. 102, c). 45m by 38m; fresh water. G. agile Kofoid et Swezy (Fig. 102, d). About 28m long; in sandy beaches. Genus Hemidinium Stein. Asymmetrical; oval; annulus about half a turn, only on left half. One species. H. nasutu7n S. (Fig. 102, e). Sulcus on hjrpocone; chromato- phores yellow to brown; with a reddish brown oil drop; nucleus posterior; transverse fission; 24-28m by 16-1 7m; fresh water. Genus Amphidinium Claparede et Lachmann. Form variable; epicone small; annulus anterior; sulcus straight on hypocone or also on part of epicone; with or without chromatophores; mainly holophytic, some holozoic; coastal or fresh water. Numerous spe- cies. A. lacustre Stein (Fig. 102, /). 30m by 18m; in fresh and salt (?) water. A. scissum Kofoid et Swezy (Fig. 102, g). 50-60m long; in sandy beaches. A.fusiforme Martin. Fusiform, twice as long as broad; circular in cross-section; epicone rounded conical; annulus anterior; hypo- cone 2-2.5 times as long as epicone; sulcus obscure; body filled with yellowish green chromatophores except at posterior end; stigma dull orange, below girdle; nucleus ellipsoid, posterior to annulus; pellicle delicate; 17-22m by 8-1 1m in diameter. Martin (1929) found that it was extremely abundant in parts of Delaware 224 PROTOZOOLOGY Fig. 102. a, Gymnodinium aeruginosum, X500 (Schilling); b, G. ro- timdatum, X360 (Klebs); c, G. palustre, X360 (Schilling); d, G. agile, X740 (Kofoid and Swezy); e, Hemidinium nasutum, X670 (Stein); f, Amphidinium lacustre, X440 (Stein); g, A. scissum, X8S0 (Kofoid and Swezy); h, Gyrodiniwn hiconicum, X340 (Kofoid and Swezy); i, G. hyalinum, X670 (Kofoid and Swezy); j, Cochlodinimn atromacu- latum, X340 (Kofoid and Swezy); k, Torodinium robustum, X670 (Kofoid and Swezy); 1, Massartia nie^tportensis, X670 (Conrad); m, Chilodinium cruciatum, X900 (Conrad); n, o, Trochodiniitm pris- maticurn, X1270 (Conrad); p, Ceratodinium asymetricuvi, X670 (Con- rad). DINOFLAGELLATA 225 Bay and gave rise to red coloration of the water ("Red water"). Genus Gyrodinium Kofoid et Swezy. Annuliis descending left spiral; sulcus extending from end to end; nucleus central; pusules; surface smooth or striated; chromatophores rarely present; cyto- plasm colored; holozoic; salt or fresh water. Many species. G. hiconicum K. et S. (Fig. 102, h). 68m long; salt water; off Cali- fornia. G. hyalinum (Schilling) (Fig. 102, i). About 24^ long; fresh- water. Genus Cochlodinium Schiitt. Twisted at least 1.5 turns; annu- lus descending left spiral; pusules; cytoplasm colorless to highly colored; chromatophores rarely present; holozoic; surface smooth or striate; salt water. Numerous species. C. atromaculatum Kofoid et Swezy (Fig. 102, j). 183-185m by 72m; longitudinal flagellum 45ju long; ofif California. Genus Torodinium Kofoid et Swezy. Elongate; epicone several times longer than hypocone; annulus and hypocone form augur- shaped cone; sulcus long; nucleus greatly elongate; salt water. 2 species. T. robustum K. et S. (Fig. 102, h). Ql-7^ti long; off California. Genus Massartia Conrad. Cylindrical; epicone larger (9-10 times longer and 3 times wider) than hypocone; no sulcus; with or without yellowish discoid chromatophore. M. nieu'portensis C. (Fig. 102, I). 28-37m long; brackish water. Genus Chilodinium Conrad. Ellipsoid; posterior end broadly rounded, anterior end narrowed and drawn out into a digitform process closely adhering to body; sulcus, apex to 1/5 from pos- terior end; annulus oblique, in anterior 1/3. C. crvciatum C. (Fig. 103, m). 40-50/x by 30-40^; with trich- ocysts; brackish water. Genus Trochodinium Conrad. Somewhat similar to Amphidin- ium; epicone small, button-hke; hypocone with 4 longitudinal rounded ridges; stigma; without chromatophores. T. prismaticum C. (Fig. 102, n, o). 18-22^ by 9-12^; epicone 5-7m in diameter; brackish water. Genus Ceratodinium Conrad. Cuneiform; asymmetrical, color- less, more or less flattened; annulus complete, oblique; sulcus on half of epicone and full length of hypocone; stigma. C. asymetricum C. (Fig. 102, p). 68-80^ by about 10^; brackish water. 226 PROTOZOOLOGY Fig. 103. a, Blastodinium spinulosum, X240 (Chatton); b, c, Oodi- nium poucheti (c, a swarmer) (Chatton); d, e, Apodinium mycetoides (d, swarmer-formation, X450; e, a younger stage, X640) (Chatton); f, Chytriodinium parasilicum in a copepod egg (Dogiel); g, Trypano- dinium ovicola, X1070 (Chatton); h, Duboscquella tintinnicola (Du- boscq and Collin); i, j, Haplozoon clymenellae (i, mature colony, X300; j, a swarmer, Xl340) (Shumway); k, Syndinium turbo, X1340 (Chat- ton); 1, Paradinium poucheti, XSOO (Chatton); m, Ellobiopsis chattoni on Calanus finmarchicus (Caullery); n, Paraellobiopsis coutieri (Collin). DINOFLAGELLATA 227 Family 6 Blastodiniidae Kofoid et Swezy All parasitic in or on plants and animals; in colony forming genera, there occur trophoc5rte (Chatton) by which organism is attached to host and more or less numerous gonocytes (Chatton). Genus Blastodinium Chatton. In gut of copepods; spindle- shaped, arched, ends attenuate)!; envelope (not cellulose) often with 2 spiral rows of bristles; young forms binucleate; when pres- ent, chromatophores in yellowdsh brown network; swarmers sim- ilar to those of Gymnodinium; in salt water. Many species. B. spinulosum C. (Fig. 103, a). About 235^ by 33-39/^; swarm- ers 5-lOyu; in Palacalanus parvus, Clausocalanus arcuicornis and C. furcatus. Genus Oodinium Chatton. Spherical or pyriform ; with a short stalk; nucleus large; often with yellowish pigment; on Salpa, An- nelida, Siphonophora, etc. 0. poucheti (Lemmermann) (Fig. 103, 6, c). Fully grown indi- viduals up to 170 fji long; bright yellow ochre; mature forms be- come detached and float, dividing into numerous gymnodinium- like swarmers; on the tunicate, Oikopleura dioica. Genus Apodinium Chatton. Young individuals elongate, spher- ical or pyriform; binucleate; adult colorless; formation of numer- ous swarmers in adult stage is peculiar in that lower of the 2 individuals formed at each division secretes a new envelope, and delays its further division until the upper divides for the second time, leaving several open cups; on tunicates. A. mycetoides C. (Fig. 103, d, e). On gill-slits of Fritillaria pel- lucida. Genus Chytriodinium Chatton. In eggs of planktonic copepods; young individuals grow at the expense of host egg and when fully formed, body divides into many parts, each producing 4 swarm- ers. Several species. C. parasiticum (Dogiel) (Fig. 103,/). In copepod eggs; Naples. Genus Trypanodinium Chatton. In copepod eggs; swarmer- stage only known. T. ovicola C. (Fig. 103, g). Swarmers biflagellate ; about 15)u long. Genus Duboscquella Chatton. Rounded cell with a large nu- cleus; parasitic in Tintinnidiidae. One species. D. tintinnicola (Lohmann) (Fig. 103, h). Intracellular stage oval, about lOO^t in diameter with a large nucleus; swarmers bi- flagellate. 228 PROTOZOOLOGY Genus Haplozoon Dogiel. In gut of polychaetes; mature forms composed of variable number of cells arranged in line or in pyra- mid; salt water. Many species. H. clymenellae (Calkins) (Fig. 103, i, j). In Clymenella tor- quata; colonial forms consist of 250 or more cells; Woods Hole. Genus Syndinium Chatton. In gut and body cavity of marine copepods; multinucleate round cysts in gut considered as young forms; multinucleate body in host body cavity with numerous needle-like inclusions. S. turho C. (Fig. 103, h). In Paracalanus parvus, Corycaeus venustus, Calanus finmarchicus ; swarmers about 15m long. Genus Paradinium Chatton. In body-cavity of copepods; mul- tinucleate body without inclusions; swarmers formed outside the host body. P. poucheti C. (Fig. 103, I). In the copepod, Acartia clausi; swarmers about 25^1 long, amoeboid. Genus Ellobiopsis Caullery. Pyriform ; with stalk ; often a sep- tum near stalked end; attached to anterior appendages of marine copepods. E. chattoni C. (Fig. 103, m). Up to TOO^i long; on antennae and oral appendages of Calanus finmarchicus, Pseudocalanus elongatus and Acartia clausi. Genus Paraellobiopsis Collin. Young forms stalkless; spherical; mature individuals in chain-form; on Malacostraca. P. coutieri C. (Fig. 103, n). On appendages of Nebalia hipes. Family 7 Polykrikidae Kofoid et Swezy 2, 4, 8, or 16 individuals permanently joined in chain; individu- als similar to Gymnodinium; sulcus however extending entire body length; with nematocysts (Fig. 104, 6); greenish to pink; nuclei about 1/2 the number of individuals; holozoic; salt water. Genus Polykrikos Biitschli. With the above-mentioned char- acters; salt or brackish water. P. kofoidi (Chatton) (Fig. 104, a, h). Greenish grey to rose; composed of 2, 4, 8, or IG individuals; with nematocysts; each nematocyst possesses presumably a hollow thread, and discharged under suitable stimulation; a binucleate colony composed of 4 in- dividuals about llO/i long; off California. P. harnegatensis Martin. Ovate, nearly circular in cross-section, slightly concave ventrally; composed of 2 individuals; constric- DINOFLAGELLATA 229 tion slight; beaded nucleus in center; annuli descending left spiral, displaced twice their width; sulcus ends near anterior end; cyto- plasm colorless, with numerous oval, yellow-brown chromato- phores; nematocysts absent; 46ju by 31.5ju; in brackish water of Barnegat Bay. Tribe 2 Peridinioidae Poche The shell composed of epitheca, annulus and hypotheca, which may be divided into numerous plates; body form variable. With annulus and sulcus Shell composed of plates; but no suture Family 1 Peridiniidae Breast plate divided by sagittal suture Family 2 Dinophysidae (p. 233) Without annulus or sulcus Family 3 Phj^todiniidae (p. 233) Family 1 Peridiniidae Kent Shell composed of numerous plates; annulus usually at equator, covered by a plate known as cingulum ; variously sculptured and finely perforated plates vary in shape and number among differ- ent species; in many species certain plates drawn out into various processes, varying greatly in different seasons and localities even among one and the same species; these processes seem to retard descending movement of organisms from upper to lower level in water when flagellar activity ceases; chromatophores numerous, small platelets, yellow or green; some deep-sea forms without chromatophores; chain formation in some forms; mostly surface and pelagic inhabitants in fresh or salt water. Genus Peridinium Ehrenberg. Subspherical to ovoid; reniform in cross-section; annulus slightly spiral with projecting rims; hy- potheca often with short horns and epitheca drawn out ; colorless, green, or brown; stigma usually present; cysts spherical; salt or fresh water. Numerous species. P. tahulatum Claparede et Lachmann (Fig. 104, c). 48m by 44^; fresh water. P. divergens (E.) (Fig. 104, d). About 45m in diameter; yellow- ish, salt water. Genus Ceratium Schrank. Body flattened; with one anterior and 1-4 posterior horn-like processes; often large; chromato- phores yellow, brown, or greenish; color variation conspicuous; fission is said to take place at night and in the early morning; 230 PROTOZOOLOGY Fig. 104. a, b, Polykrikos kofoidi (a, colony of four individuals, X340; b, a nematocyst, X1040) (Kofoid and Swezy); c, Peridinium tabulatum, X460 (Schilling); d, P. diver gens, X340 (Calkins); e, Cera- tium hirundinella, x540 (Stein); f, C. longipes, XlOO (Wailes); g, C. tripos, Xl40 (Wailes); h, C. fiisus, XlOO (Wailes); i, Heterodinium scrippsi, X570 (Kofoid and Adamson). fresh or salt water. Numerous species; specific identification is difficult due to a great variation (p. 162). DINOFLAGELLATA 231 C. hirundineUa (Muller) (Figs. 80; 104, e). 1 apical and 2-3 antapical horns; seasonal and geographical variations; chain-for- mation frequent; 95-700yu long; fresh and salt water. Numerous varieties. C. longpipes (Bailey) (Fig. 104,/). About 210^ by 51-57^; salt water. C. tripos (Miiller) (Fig. 104, g). About 225)U by 75/x; salt water. Wailes (1928) observed var. atlantica in British Columbia; Mar- tin (1929) in Barnegat Inlet, New Jersey. C. fusus (Ehrenberg) (Fig. 104, h). 300-600^ by 15-30^; salt water; widely distributed; British Columbia (Wailes), New Jer- sey (Martin), etc. Genus Heterodinium Kofoid. Flattened or spheroidal; 2 large antapical horns; annulus submedian; with post-cingular ridge; sulcus short, narrow; shell hyahne, reticulate, porulate; salt wa- ter. Numerous species. H. scippsi K. (Fig. 104, i). 130-155/x long; Pacific and Atlantic (tropical). Genus Dolichodinium Kofoid et Adamson. Subcorneal, elon- gate; wdthout apical or antapical horns; sulcus not indenting epi- theca; plate porulate; salt water. D. lineatum (Kofoid et Michener) (Fig. 105, a). 58/x long; east- ern tropical Pacific. Genus Goniodoma Stein. Polyhedral with a deep annulus; epi- theca and hypotheca slightly unequal in size, composed of regu- larly arranged armored plates; chromatophores small brown platelets ; fresh or salt water. G. acuminata (Ehrenberg) (Fig. 105, h). About 50^ long; S'alt water. Genus Gonyaulax Diesing. Spherical, polyhedral, fusiform, or elongated with stout apical and antapical prolongations, or dorso- ventrally flattened; apex never sharply attenuated; annulus equa- torial; sulcus from apex to antapex, broadened posteriorly; plates 1-6 apical, 0-3 anterior intercalaries, 6 precingulars, 6 annular plates, 6 postincingulars, 1 posterior intercalary and 1 antapical; porulate; chromatophores yellow to dark brown, often dense; without stigma; fresh, brackish or salt water. Numerous species. G. polyedra Stein (Fig. 105, c). Angular, polyhedral; ridges along sutures, annulus displaced 1-2 annulus widths, regularly pitted; salt water. "Very abundant in the San Diego region in the 232 PROTOZOOLOGY Fig. 105. a, Dolichodinium lineatum, X670 (Kofoid and Adamson); b, Goniodoma acuminata, x340 (Stein); c, Gorumlax polyedra, X670 (Kofoid); d, G. apiculata, x670 (Lindemann); e, Spiraulax jolliffei, right side of theca, X340 (Kofoid) ; f, Dinophysis aciita, X580 (Schiitt); g, h, Oxyphysis oxytoxoides, X780 (Kofoid); i, Phytodinium simplex, X340 (Klebs); j, k, Dissodinium lunula: j, primary cyst (Dogiel); k, secondary cyst with 4 s warmers (Wailes), X220. summer plankton, July-September, when it causes local out- breaks of 'red water,' which extend along the coast of southern and lower California" (Kofoid, 1911). G. apiculata (Penard) (Fig. 105, d). Ovate, chromatophores yellowish brown; 30-60^ long; fresh water. Genus Spiraulax Kofoid. Bi conical; apices pointed; sulcus not reaching apex; no ventral pore; surface heavily pitted; salt water. DINOFLAGELLATA 233 S. jolliffei (Murray et Whitting) (Fig. 105, e). 132^ by 92m; California. Family 2 Dinophysidae Kofoid Genus Dinophysis Ehrenberg. Highly compressed; annulus widened, funnel-like, surrounding small epitheca; chromato- phores yellow; salt water. Several species. D. acuta E. (Fig. 105,/). Oval; attenuated posteriorly; 54-94/i long; widely distributed; British Columbia (Wailes). Genus Oxyphysis Kofoid. Epitheca developed; sulcus short; sulcal lists feebly developed; sagittal suture conspicuous; annulus impressed; salt water. 0. oxytoxoides K. (Fig. 105, g, h). 63-68ai by 15/^; off Alaska. Family 3 Phytodiniidae Klebs Genus Phytodinium Klebs. Spherical or ellipsoidal; without furrows; chromatophores discoidal, yellowish brown. P. simplex K. (Fig. 105, i). Spherical or oval; 42-50/i by 30- 45m; fresh water. Genus Dissodinium Klebs (Pyrocystis Paulsen). Primary cyst, spherical, uninucleate; contents divide into 8-16 crescentic sec- ondary cysts which become set free; in them are formed 2, 4, 6, or 8 Gymnodinium-like swarmers ; salt water. D. lunula (Schlitt) (Fig. 105, j, k). Primary cysts 80-155m in diameter; secondary cysts 104-130/1 long; swarmers 22^ long; widely distributed; British Columbia (Wailes). Fig. 106. a, Leptodiscus medusoides, X50 (Hertwig); b, Craspedotella pileolus, XllO (Kofoid). Suborder 3 Cystoflagellata Haeckel Since Noctiluca which had for many years been placed in this suborder has been removed, according to Kofoid, to the second suborder, the Cystoflagellata becomes a highly ill-defined group and includes two peculiar marine forms: Leptodiscus medusoides Hertwig (Fig. 106, a), and Craspedotella pileolus Kofoid (Fig. 106, b), both of which are medusoid in general body form. 234 PROTOZOOLOGY References Chatton, E. 1920 Les Peridieniens parasites; morphologie, reproduction, ethologie, Arch. zool. exp. et gen. Vol. 59. Fritsch, F, E. 1935 The structure and reproduction of the algae. Vol. 1. Cambridge. Gross, F. 1934 Zur Biologic und Entwicklungsgeschichte von Noctiluca miliaris. Archiv. f. Protistenk., Vol. 83. KoFOiD, C. A. 1906 On the significance of the symmetry of the Dinoflagellata. Uni. Calif. Piibl. Zool., Vol. 3. 1920 A new morphological interpretation of Noctiluca and its bearing on the status of Cystoflagellata. Ibid., Vol. 19. and A. M. Adamson 1933 The Dinoflagellata: The family Heterodiniidae of the Peridinioidae. Mem. Mus. Comp. Zool., Harvard, Vol. 54. and Olive Swezy. 1921 The free-living unarmored Dinoflagellata. Mem. Uni. Calif., Vol. 5. Lebour, Marie V. 1925 The dinoflagellates of northern seas. London. Martin, G. W. 1929 Dinoflagellates from marine and brackish waters of New Jersey. Uni. Iowa Studies in Nat. Hist., Vol. 12. Reichenow, E. 1930 Parasitische Peridinea. Grimpe's Die Tier- welt der Nord- und Ostsee. Part 19. Schilling, A. 1913 Dinoflagellatae (Peridineae). Siisswasser- fiora Deutschlands, etc. H. 3. Wailes, G. H. 1928 Dinoflagellates and Protozoa from British Columbia. Vancouver Mus. Notes. Vol. 3. Chapter 12 Subclass 2 Zoomastigina Doflein THE Zoomastigina lack chromatophores and their body or- ganizations vary greatly from a single to a very complex type. The majority possess a single nucleus which is, as a rule, vesicular in structure. A characteristic organella, the parabasal body (p. 66) is present in numerous forms and myonemes are found in some species. Nutrition is holozoic or saprozoic (parasitic). Asex- ual reproduction is by longitudinal fission; sexual reproduction is unknown. Encystment occurs commonly. The Zoomastigina are free-living or parasitic in various animals. With pseudopodia besides flagella Order 1 Rhizomastigina With flagella only With 1-2 flagella Order 2 Protomonadina (p. 239) With 3-8 flagella Order 3 Polyraastigina (p. 260) With more than 8 flagella Order 4 Hypermastigina (p. 277) Order 1 Rhizomastigina Biitschli A number of borderline forms between the Sarcodina and the Mastigophora are placed here. Flagella vary in number from one to several and pseudopods also vary greatly in number and in ap- pearance. With many flagella Family 1 Multiciliidae With 1-3 rarely 4 flagella Family 2 Mastigamoebidae (p. 236) Family 1 Multiciliidae Poche Genus Multicilia Cienkowski. Generally spheroidal, but amoe- boid; with 40-50 flagella, long and evenly distributed; one or more nuclei; holozoic; food obtained by means of pseudopodia; contractile vacuoles numerous ; multiplication by fission ; fresh or salt water. M. marina C. (Fig. 107, a). 20-30/x in diameter; uninucleate; salt water. M. lacustris Lauterborn (Fig. 107, h). Multinucleate; 30-40m in diameter ; fresh water. 235 236 PROTOZOOLOGY Fig. 107. a, Multicilia marina, x400 (Cienkowski) ; b, M. lacustris, X400 (Lauterborn); c, Mastigamoeba aspera, X200 (Schulze); d, M. longifilum, X340 (Stokes); e, M. setosa, x370 (Goldschmidt) ; f, Masti- gella vitrea, x370 (Goldschmidt). Family 2 Mastigamoebidae With 1-3 or rarely 4 flagella and axopodia or lobopodia; uni- nucleate; flagellum arises from a basal granule which is often con- nected with the nucleus by a rhizoplast; binary fission in both trophic and encysted stages; sexual reproduction has been re- ported in one species; holozoic or saprozoic; the majority are free-living, though a few parasitic. Genus Mastigamoeba Schulze (Mastigina Frenzel). Mono- mastigote, uninucleate, with finger-like pseudopodia; flagellum long and connected with nucleus; fresh water, soil or endocom- mensal. ZOOMASTIGINA, RHIZOMASTIGINA 237 M. aspera S. (Fig. 107, c). Subspherical or oval; during locomo- tion elongate and narrowed anteriorly, while posterior end rounded or lobed; numerous pseudopods slender, straight; nu- cleus near flagellate end; 2 contractile vacuoles; 150-200^1 by about 50/x; in ooze of pond. M. longifilum Stokes (Fig. 107, d). Elongate, transparent flagel- lum twice body length; pseudopods few, short; contractile vacu- ole anterior; body 28^^ long when extended, contracted about 10/x stagnant water. M. setosa (Goldschmidt) (Fig. 107, e). Up to 140/x long. Fig. 108. a, Mastigamoeba hylae, X690 (Becker); b, Adinomonas mirabilis, X1140 (Griessmann); c, Dimoryha mutans, X940 (Bloch- mann); d, Pteridomonas pulex, X540 (Penard); e, Histomonas melea- gris, X940 (Tyzzer); f, Rhizomastix gracilis, X1340 (Mackinnon). M. hylae (Frenzel) (Fig. 108, a). In hind gut of frogs and tad- poles; 80-100/x by 20ju; flagellum about IOjjl long. Genus Mastigella Frenzl. Flagellum apparently not connected with nucleus; pseudopods numerous, digitate; body form changes actively and continuously; contractile vacuole. M. vitrea Goldschmidt (Fig. 107,/). I50fx long; sexual reproduc- tion (Goldschmidt). Genus Actinomonas Kent. Generally spheroidal, with a single 238 PHUTOZUOl.OC.Y flagellum and radiating pseudopods; ordinarily attached to for- eign object with a cytoplasmic process, but swims freely by with- drawing it; nucleus central; several contractile vacuoles; holo- zoic. A. mirabilis K. (Fig. 108, h). Numerous simple filopodia; about lO^i in diameter; flagellum 20yu long; fresh water. Genus Dimorpha Gruber. Ovoid or subspherical ; with 2 flagella and radiating axopodia, all arising from an eccentric centriole ; nucleus eccentric; pseudopods sometimes withdrawn; fresh water. D. mutans G. (Fig. 108, c). 15-20yu in diameter; flagella about 20-30m long. Genus Pteridomonas Penard. Small, heart-shaped; usually at- tached with a long cytoplasmic process ; from opposite pole there arises a single flagellum, around which occurs a ring of extremely fine filopods; nucleus central; a contractile vacuole; holozoic; fresh water. P. pulex P. (Fig. 108, d). 6-12^ broad. Genus Histomonas Tyzzer. Parasitic in domestic fowls; body amoeboid with a blepharoplast; indication of flagellum (?); with- out cytostome. H. meleagris (Smith) (Fig. 108, e). 12-21/i long; rounded re- sistant phase up to ll^t by 9;u; the cause of the "blackhead" dis- ease of young turkeys, chicken, grouse, and quail (Tyzzer) in which the intestinal mucosa as well as liver tissues become in- fected by this organism. Genus Rhizomastix Alexeieff. Body amoeboid; nucleus central: blepharoplast located between nucleus and posterior end; a long fiber (rhizostyle) runs from it to anterior end and continues into the flagellum; without contractile vacuole; division in spherical cyst. R. gracilis A. (Fig. 108, /). 8-14/i long; flagellum l^ifx long; in intestine of axolotles and tipulid larvae. References Becker, E. R. 1925 The morphology of Mastigina hylae (Fren- zel) from the intestine of the tadpole. Jour. Paras., Vol. 11. Lemmermann, E. 1914 Pantostomatinae. Siisswasser flora Deutschlands, etc. H. 1. Tyzzer, E. E. 1919 Developmental phases of the Protozoon of "blackhead" in Turkeys. Jour. Med. Res., Vol. 40. Chapter 13 Order 2 Protomonadina Blochmann THE protomonads possess one or two flagella and are com- posed of a heterogeneous lot of Protozoa, mostly parasitic, whose affinities to one another are very incompletely known. The body is in many cases plastic, having no definite pelhcle, and in some cases amoeboid. The method of nutrition is holozoic, or saprozoic (parasitic). Reproduction is, as a rule, by longitudinal fission, although budding or multiple fission has also been known to occur, while sexual reproduction, though reported in some forms, has not been confirmed. With 1 flagellum With cytoplasmic collar Collar enclosed in jelly Family 1 Phalansteriidae Collar not enlosed in jelly Without lorica Family 2 Codosigidae With lorica Family 3 Bicosoecidae (p. 241) Without cytoplasmic collar Free-living Family 4 Oikomonadidae (p. 243) Parasitic Family 5 Trypanosomatidae (p. 244) With 2 flagella With undulating membrane Family 6 Cryptobiidae (p. 252) Without undulating membrane Flagella equally long Family 7 Amphimonadidae (p. 253) Flagella unequallj' long no traiUng flagellum Family 8 Monadidae (p. 255) one flagellum trailing Family 9 Bodonidae (p. 256) Family 1 Phalansteriidae Kent Genus Phalansterium Cienkowski. Small, ovoid; one flagellum and a narrow collar; numerous individuals are embedded in gelat- inous substance which presents a dendritic form, with protruding flagella; fresh water. P. digitatum Stein (Fig. 109, a). Cells about 17/i long; oval; colony dendritic; fresh water among vegetation. Family 2 Codosigidae Kent Small flagellates, sometimes with second flagellum which serves for fixation of body; delicate collar surrounds flagellum; ordina- 239 240 PROTOZOOLOGY rily sedentary forms; if temporarily freed, organisms swim with fiagellum directed backward; holozoic on bacteria or saprozoic; often colonial; free-living in fresh water. Genus Codosiga Kent (Codonocladium Stein; Astrosiga Kent). Individuals clustered at end of a simple or branching stalk; fresh water. C. utriculus Stokes (Fig. 109, b). About ll/j. long; attached to freshwater plants. C. disjuncta (Fromentel) (Fig. 109, c). In stellate clusters; cells about 15/x long; fresh water. Genus Monosiga Kent. Solitary; with or without stalk; occa- sionally with short pseudopodia; attached to freshwater plants. Several species. Fig. 109. a, Phalansterium digitatum, X540 (Stein); b, Codosiga utriculus, X1340 (Stokes); c, C. disjuncta, X400 (Kent); d, Monosiga ovata, X800 (Kent); e, M. rohusta, x770 (Stokes); f, Desmarella nioniliformis, X800 (Kent) ; g, Proiospon^ia haeckeli, X400 (Lemmer- mann); h, Sphaeroeca volvox, X890 (Lenimermann) ; i, Diplosiga francei, X400 (Lemmermann) ; j, D. socialis, X670 (Franc6). PROTOMONADINA 241 M. ovata K. (Fig. 109, d). 5-1 5m long; with a short stalk. M. robusta Stokes (Fig. 109, e). 13/i long; stalk very long. Genus Desmarella Kent. Cells united laterally to one another; fresh water. D. moniliformis K. (Fig. 109, /). Cells about 6/u long; cluster composed of 2-12 individuals; standing fresh water. D. irregularis Stokes. Cluster of individuals irregularly branch- ing, composed of more than 50 cells; cells 7-1 l/x long; pond water. Genus Protospongia Kent. Stalkless individuals embedded ir- regularly in a jelly mass, collars protruding; fresh water. P. haeckeli K. (Fig. 109, g). Body oval; 8^ long; flagellum 24- 32/i long; 6-60 cells in a colony. Genus Sphaeroeca Lauterborn. Somewhat similar to the last genus; but individuals with stalks and radiating; gelatinous mass spheroidal; fresh water. S. volvox L. (Fig. 109, h). Cells ovoid, 8-12^ long; stalk about twice as long; flagellum long; contractile vacuole posterior; colony 82-200m in diameter; fresh water. Genus Diplosiga Frenzel (Codonosigopsis Senn). With 2 collars; without lorica; a contractile vacuole; solitary or clustered (up to 4) ; fresh water. D. francei Lemmermann (Fig. 109, i). With a short pedicle; 12m long; flagellum as long as body. D. socialis F. (Fig. 109, j). Body about 15yu long; usually 4 ■ clustered at one end of stalk (15^ long). Family 3 Bicosoecidae Poche Small monomastigote; with lorica; solitary or colonial, collar may be rudimentary; holozoic; fresh water. Genus Bicosoeca James-Clark. With vase-Hke lorica; body small, ovoid with rudimentary collar, a flagellum extending through it ; protoplasmic body anchored to base by a cytoplasmic filament (flagellum?); a nucleus and a contractile vacuole; at- tached or free-swimming. B. socialis Lauterborn (Fig. 110, a). Lorica cylindrical, 23m by 12m; body about 10m long; often in groups; free-swimming in fresh water. Genus Salpingoeca James-Clark. With a vase-like chitinous lorica to which stalked or stalkless organism is attached; fresh or salt water. Numerous species. 242 PROTOZOOLOGY S. fusiforynis Kent (Fig. 110, b). Lorica short vase-like, about 15-16m long; body filling lorica; flagellum as long as body; fresh water. Fig. 110. a, Bicosoeca socialis, X560 (Lauterborn); b, Salpingoeca Jusijormis, X400 (Lemmermann); c, Diplosigopsis affinis, X590 (Franc6); d, Histiona zachariasi, x440 (Lemmermann); e, Poterioden- dron petiolatum, X440 (Stein); f, Codonoeca inclinata, X540 (Kent); g, Lagenoeca ovata, x400 (Lemmermann). Genus Diplosigopsis France. Similar to Diplosiga (p. 241), but with lorica; solitary; fresh water on algae. D. affinis Lemmermann (Fig. 110, c). Chitinous lorica, spindle- form, about \bn long; body not filling lorica; fresh water. Genus Histiona Voigt. With lorica; but body without attaching filament; anterior end with lips and sail-like projection; fresh water. H. zachariasi V. (Fig. 110, d). Lorica cup-like; without stalk; about ISyu long; oval body 13/i long; flagellum long; standing fresh water. Genus Poteriodendron Stein. Similar to Bicosoeca; but colo- nial; lorica vase-shaped; with a prolonged stalk; fresh water. P. petiolatum (S.) (Fig. 110, e). Lorica 17-50/x high; body 21- 35m long; flagellum twice as long as body; contractile vacuole terminal ; standing fresh water. Genus Codonoeca James-Clark. With a stalked lorica; a single flagellum; 1-2 contractile vacuoles; fresh or salt water. C. inclinata Kent (Fig. 110,/). Lorica oval; aperture truncate; about 23ju long; stalk twice as long; body oval, about 17/x long; PROTOMONADINA 243 flagellum 1.5 times as long as body; contractile vacuole posterior; standing fresh water. Genus Lagenoeca Kent. Resembles somewhat Salpingoeca; with lorica; but without any pedicle between body and lorica; solitary; free-swimming; fresh water. L. ovata Lemmermann (Fig. 110, g). Lorica oval, IS/z long; body loosely filling lorica; flagellum 1.5 times body length; fresh water. Family 4 Oikomonadidae Hartog Genus Oikomonas Kent. A rounded monomastigote; uninu- cleate; encystment common; stagnant water, soil and exposed faecal matter. Fig. 111. a, Oikomonas termo, X1330 (Lemmermann); b, Thylaco- monas compressa, X640 (Lemmermann); c, Ancijromonas contorta, X2000 (Lemmermann); d, Platytheca microspora, X650 (Stein). 0. termo (Ehrenberg) (Fig. Ill, a). Spherical or oval; anterior end hp-like; flagellum about twice body length; a contractile vacuole; 5-9/i in diameter; stagnant water. Genus Thylacomonas Schewiakoff. Pellicle distinct; cytostome anterior; one flagellum; contractile vacuole anterior; rare. T. compressa S. (Fig. Ill, fe). 22^t by IS/x; flagellum body length; fresh water. Genus Ancyromonas Kent. Ovate to triangular; free-swimming or adherent ; flagellum trailing, adhesive or anchorate at its distal end, vibratile throughout remainder of its length; nucleus central; a contractile vacuole; fresh or salt water. A. contorta (Klebs) (Fig. Ill, c). Triangular, flattened, poste- rior end pointed; 6-7/x by 5-6^; flagellum short; a contractile vac- uole ; standing fresh water. Genus Platytheca Stein. With a flattened pyriform lorica, with a small aperture; 1 or more contractile vacuoles; fresh water. 244 PKOTOZOOLOCY P. microspora S. (Fig. Ill, d). Lorica yellowish brown, with a small aperture; 12-18// long; flagcllum short; among roots of Lemna. Family 5 Trypanosomatidae Doflein Body characteristically leaf-like, although changeable to a cer- tain extent; a single nucleus and a blepharoplast; a flagellum originates in a basal granule w^hich may be independent from, or united with, the blepharoplast (Figs. 9, 112); basal portion of flagellum forms outer margin of undulating membrane which ex- tends along one side of body; exclusively parasitic; a number of important parasitic Protozoa which are responsible for serious diseases of man and domestic animals in various parts of the world are included in it. In vertebrate host In invertebrate host In vertebrate host Trypanosoma Trypanosoma Crithidia Leptomonas Leishmania Leishmania Leptomonas and Phytomonas (in plant) Leishmania Crithidia Herpetomonas Trypanosoma Fig. 112. Diagram illustrating the structural differences among the genera of Trypanosomatidae (Wenyon). Genus Trypanosoma Gruby. Parasitic in the circulatory system of vertebrates; highly flattened, pointed at flagellate end, and bluntly rounded, or pointed, at other; polymorphism due to dif- ferences in development common; nucleus central; near bluntly rounded end, there is a blepharoplast and usually a basal granule from which the flagellum arises and runs toward^opposite end, marking the outer boundary of the undulating membrane; in PROTOMONADINA 245 most cases flagelliim extends freely beyond body; many with myonemes; multiplication by binary or multiple fission. The or- ganism is carried from host to host by blood-sucking invertebrates and undergoes a series of changes in the digestive system of the latter (Fig. 113). A number of forms are pathogenic to their hosts and the diseased condition is termed trypanosomiasis in general. T. gambiense Button (Fig. 114, a). Parasitic in blood and lymph of man in certain regions of Africa; transmitted by the tsetse fly, Glossi7ia palpalis; reservoir hosts are domestic and wild animals. Body 15-30m long; mature forms slender and long, w^th a long flagellum; individuals formed by longitudinal fission short and broad with no projecting flagellum; half-grown forms intermediate in size and structure; the cause of the "sleeping sickness" of man in Africa. T. (Schizotrypanum) cruzi (Chagas) (Fig. 114, h). Parasitic in children in South America (Brazil, Peru, Venezuela, etc.). A small curved form about 20/i long; nucleus central; blepharoplast large, located close to sharply pointed non-flagellate end; multi- plication takes place in the cells of nearly every organ of the host body; upon entering a host cell, the trypanosome loses its flagel- lum and undulating membrane, and assumes a leishmania form which measures 2 to 5yu in diameter; this form undergoes repeated binary fission, and a large number of daughter individuals are produced; they develop sooner or later into trypanosomes which, through rupture of host cell, become liberated into blood stream ; transmitted by the reduviid bug, Triatoma megista and allied species; the diseased condition is known as "Chagas' disease." Apparently the organism occurs in wood rats (Neotoma) and meadow mice (Microtus) in south-western United States, trans- mitted from host to host by the cone-nose or kissing bug, Triatoma protracta (Kofoid and others). T. hrucei PHmmer et Bradford (Figs. 9, a; 114 c). Polymorphic; 15-30/i long (average 20^); transmitted by various species of tsetse flies, Glossina; the most virulent of all trypanosomes; the cause of the fatal disease known as "nagana" among mules, don- keys, horses, camels, cattle, swine, dogs, etc., which terminates in the death of the host animal in from two weeks to a few months ; wild animals are equally susceptible; the disease occurs, of course, only in the region in Africa where the tsetse flies live. 246 PROTOZOOJ.OGY Fig. 113. The life-cycle of Trypanosoma lewisi in the flea, Cera- tophyllus fasciattis (Minchin and Thomson, modified), a, trypanosome from rat's blood; b. individual after being in flea's stomach for a few hours; c-1, stages in intracellular schizogony in stomach epithelium; m-r, two ways in which rectal phase may arise from stomach forms in rectum; s, rectal phase, showing various types; t, secondary infection of pylorus of hind-gut, showing forms similar to those of rectum. PROTOMONADINA 247 Fig. 114. a, Trypanosoma gambiense (5 individuals) and a human erythrocyte; b, T. cruzi; c, T. hrucei; d, T. theileri; e, T. vielophagimn ; f, T. evansi; g, T. equinum; h, T. equiperdum, all X 1000 (various in- vestigators) . T. theileri Layeran (Fig. 114, d). Non-pathogenic large tryp- anosome which occurs in blood of cattle; sharply pointed at both ends; 60-70/x long; myonemes are well developed. T. americanum Crawley. In American cattle; probably iden- tical with T. theileri; transmitted from cattle to cattle by tabanid flies. T. melophagium (Flu) (Fig. 114, e). Non-pathogenic trypano- some of the sheep; 50-60yu long with attenuated ends ; transmitted by Melophagus ovinus. T. evansi (Steel) (Fig. 114,/). In horses, mules, donkeys, cattle, dogs, camels, elephants, etc.; infection in horses seems to be usu- ally fatal and known as "surra"; about 25/ilong; monomorphic; transmitted by tabanid flies; widely distributed. T. equinum Vages (Fig. 114, g). In horses in South America, causing an acute disease known as "mal de Caderas"; other do- mestic animals do not suffer as much as do horses; 2()-25fx long; without blepharoplast. T. equiperdum Doflein (Fig. 114, h). In horses and donkeys; causes "dourine," a chronic disease; widely distributed; 25-30)u long; no intermediate host; transmission takes place directly from host to host during sexual act. T. lewisi (Kent) (Figs. 113; 114, i). In blood of various species of rat; widely distributed; non-pathogenic under ordinary condi- tions; about 25/x long; very active; slender; with a long flagellum; 248 PROTOZOOLOGY transmitted by the flea, Ceratophyllus fasciatus, in which the or- ganism undergoes changes (Fig. 113); when, a rat swallows freshly voided faecal matter containing the organisms, it becomes in- fected. T. duttoni Thiroux. In the mouse; similar to T. lewisi, but rats are not susceptible,, hence considered as a distinct species; trans- mission by fleas. T. peromysci Watson. Similar to T. lewisi; in Canadian deer mice, Peromyscus maniculatus and others. T. nahiasi Railliet. Similar to T. lewisi; in rabbits, Lepus domesticus and L. cuniculus. T. paddae Laveran et Mesnil. In Java sparrow, Munia oryzi- vora. T. noctuae (Schaudinn). In the little owl, Athene noctua. Several other species are known. Crocodiles, snakes, and turtles are hosts for Trypanosoma. Transmission by blood-sucking arthropods or leeches. T. rotatorium (Meyer) (Fig. 115, a). In tadpoles and adults of various species of frog ; between a slender form with a long pro- jecting flagellum measuring about 35m long and a very broad one without free portion of flagellum, various intermediate forms are to be noted in a single host; blood vessels of internal organs, such as kidneys, contain more individuals than the peripheral vessels; nucleus central, hard to stain; blepharoplast small; undulating membrane highly developed; myonemes prominent; multiplica- tion by longitudinal fission; the leech, Placohdella marginata, has been found to be the transmitter in some localities. T. inopinatum Sergent et Sergent (Fig. 115, b). In blood of various frogs; slender; 12-20^ long; larger forms 30-35/i long; blepharoplast comparatively large; transmitted by leeches. Numerous species of Trypanosoma have been reported from the frog, but specific identificsPtion is indistinct; it is better and safer to hold that they belong to one of the 2 species mentioned above until their development and transmission become known. T. diemyctyli Tobey (Fig. 115, c). In blood of the newt, Tri- turus viridescens ; a comparatively large form; slender; about 50^ by 2-5^; flagellum 20-25;u long; with well developed undulating membrane. Both fresh and salt water fish are hosts to different species of trypanosomes; what effects these parasites exercise upon the host PROTOMONADINA 249 Fig. 115. a, Tnj-panosovia rolatoriuvi, X750 (Kudo); b, T. ino'pina- tum, X1180 (Kudo); c, T. diemyctyli, X800 (Hegner); d, T. giganteum, X500 (Neumann); e, T. granulosum, XlOOO (Minchin); f, T. reniaki, X1650 (Kudo); g, T. percae, XlOOO (Minchin); h, T. danilewskyi, XlOOO (Laveran and Mesnil); i, T. rajae, X1600 (Kudo), fish are not understood; as a rule, only a few individuals are ob- served in the peripheral blood of the host. T. granulosum Laveran et Mesnil (Fig. 115, e). In the eel, An- guilla vulgaris; 70-80/^ long. T. giganteum Neumann (Fig. 115, d). In Raja oxyrhynchus; 125-130Mlong. T. remaki Laveran et Mesnil (Fig. 115,/). In Esox lucius, E. reticulatus and probably other species; dimorphic; 24-33/i long. T. percae Brumpt (Fig. 115, g). In Perca fluviatilis; 45-50)U long. T. danilewskyi Laveran et Mesnil (Fig. 115, h). In carp and goldfish; widely distributed; 40/x long. T. rajae Laveran et Mesnil (Fig. 115, i). In various species of Raja; 30-35/x long. Genus Crithidia Leger. Parasitic in arthropods and other in- vertebrates; blepharoplast located between central nucleus and fiagellum-bearing end (Fig. 112); undulating membrane not so well developed as in Trypanosoma; it may lose the flagellum and form a leptomonas or rounded leishmania stage which leaves host 250 PKOTOZOOLOGY intestine with faecal matter and becomes the source of infection in other host animals. C. gerridis Patton (Fig. 116, d). In intestine of water bugs, Ger- ris and Micro veha; 22-45)U long. C. hyalommae O'Farrell (Fig. 116, e, /). In body cavity of the cattle tick, Hyalomma aegyptmm in Egypt; the flagellate through its invasion of ova is said to be capable of infecting the offspring while it is still in the body of the parent tick. C. euryophthalmi McCulloch (Fig. 116, a-c). In gut of Eury- ophthalmus convivus; California coast. Fig. 116. a-c, Crithidia euryophthalmi (a, b, in mid-gut; c, in rec- tum), X880 (McCulloch); d, C. gerridis, X1070 (Becker); e, f, C. hyalommae, XlOOO (O'Farrell); g, h, Leptomonas denocephali, XlOOO (Wenyon); i, j, Phytomonas elmassiani (i, in milkweed, Asclepias sp.; j, in gut of a suspected transmitter, Oncopeltus fasciatus), X1500 (Holmes); k, Herpetomonas muscarum, X1070 (Becker); 1-n, H. drosophilae, XlOOO (Chatton and L^ger). Genus Leptomonas Kent. Exclusively parasitic in inverte- brates; blepharoplast very close to flagellate end; without un- dulating membrane (Fig. 112); non-flagellate phase resembles Leishmania. L. ctenocephali Fantham (Fig. 116, g, h). In hindgut of the dog flea, Ctenocephalus cants; widely distributed. Genus Phytomonas Donovan. Morphologically similar to Lep- tomonas (Fig. 112); in the latex of plants belonging to the fami- Hes: Euphorbiaceae, Asclepiadaceae, Apocynaceae, Sapotaceae and Utricaceae; transmitted by hemipterous insects; often found in enormous numbers in localized areas in host plant; infection PROTOMOXADINA 251 spreads from part to part; infected latex is a clear fluid, owing to the absence of starch grains and other particles, and this results in degeneration of the infected part of the plant. Several species. P. davidi (Lafront). 15-20/z by about 1.5)u; posterior portion of body often twisted two or three times; multiplication by longi- tudinal fission; widely distributed; in various species of Euphor- bia. P. elmassiani (Migone) (Fig. 116, i, j). In various species of milk- weeds; 9-20;u long; suspected transmitter, Oncopeltus fas- ciatus (Holmes) ; in South and North America. Genus Herpetomonas Kent. Ill-defined genus (Fig. 112); ex- clusively invertebrate parasites; Trypanosoma-, Crithidia-, Lep- tomonas-, and Leishmania-forms occur during development. Several species. H. muscaruyn (Leidy) {H. muscae-domesticae (Burnett)) (Fig. 116, k). In gut of flies, belonging to the genera Musca, CalHphora, Sarcophaga, Lucilia, Phormia, etc.; up to 30a£ by 2-3//. H. drosophilae (Chatton et Alilaire) (Fig. 116, l-n). In intestine of Drosophila confusa; large leptomonad forms 21-25^ long, flagellum body-length; forms attached to rectum 4-5^ long. Genus Leishmania Ross. Parasitic in vertebrate and inverte- brate hosts, the latter not having been actually demonstrated, but suspected; non-flagellate and flagellate forms occur (Fig. 112); very minute; in vertebrate host the organism not flagellated; spherical or ovoid, with a definite pellicle; nucleus eccentric; a blepharoplast ; 2-5;u in diameter; organism enters endothelial cells of blood capillaries and mucosae; spleen becomes highly en- larged; transmitting agent believed to be blood-sucking arthro- pods; in culture, the organism develops into leptomonad forms; 4 "species" in man, all of which are practically indistinguishable morphologically from one another, and 2 of which are considered as identical. L. donovani (Laveran et Mesnil) (L. infantum Nicolle) (Fig. 117, a-f). The organism attacks endothelial cells and macrophage of man, causing the disease known as "kala azar"; it occurs in India, China, west to southern Russia, and regions bordering the Mediterranean Sea. L. tropica (Wright) (Fig. 117, g, h). The organism invades ex- posed skin and sometimes mucous lining of mouth, pharynx, and nose of man; the disease is known as "Oriental sore"; distribution is similar to the above-mentioned species. 252 PROTOZOOLOGY ^ Q Q a Fig. 117. a-f, Leishmania donovani (a, three individuals from lymph smear of a kala azar patient; b, from a spleen smear; c-f, cultural forms), X2000 (Wenyon; Thomson and Robertson); g, h, L. tropica (g, from an Oriental sore; h, the organisms in a polymorphonuclear cell from a sore), X2000 (Wenyon; Thomson and Robertson); i, Cryptobia helicis, X2530 (Belaf); j, C. borreli, X870 (Mavor); k, C. cyprini, X890 (Plehn). L. hrasiliensis Vianna. The organism occurs in South and Cen- tral America; some authors consider this species as identical with L. tropica. Although morphologically identical, these species show specific serum reactions. Family 6 Cryptobiidae Poche Biflagellate trypanosome-like protomonads; 1 flagellum free, the other marks outer margin of undulating membrane; bleph- aroplast an elongated rod-like structure, often referred to as the parabasal body; all parasitic. Genus Cryptobia Leidy (Trypanoplasma Laveran et Mesnil). Parasitic in reproductive organs of molluscs and other inverte- brates and in blood and gut of fish. PROTOMONADINA 253 C. helicis L. (Fig. 117, i). In reproductive organs of various species of Helix in America and Europe; 6-20)U long; asexual re- production through binary fission. C. horreli (Laveran et Mesnil) (Fig. 117, j). In blood of various freshwater fish such as Catostomus, Cyprinus, etc. ; 20-25m long. C. cyprini (Plehn) (Fig. 117, k). In blood of carp and goldfish; lO-SOfx long; rare. C. grohbeni (Keysselitz). In coelenteric cavity of Siphonophora; about 65ju by 4/x. Family 7 Amphimonadidae Kent Body naked or with a gelatinous envelope; 2 equally long an- terior flagella; often colonial; 1-2 contractile vacuoles; free- swimming or attached; mainly fresh water. Genus Amphimonas Dujardin. Small oval or rounded amoe- boid; flagella at anterior end; free-swimming or attached by an elongated stalk-like posterior process; fresh or salt water. A. glohosa Kent (Fig. 118, a). Spherical; about 13yu in diameter; stalk long, delicate; fresh water. Genus Spongomonas Stein. Individuals in granulated gelati- nous masses; flagella with 2 basal granules; one contractile vacuole; colony often several centimeters high; with pointed pseudopodia in motile stage; fresh water. S. uvella S. (Fig. 118, h). Oval; 8-12yu long; flagella 2-3 times as long; colony about 50ju high; fresh water. Genus Cladomonas Stein. Individuals are embedded in dichot- omous dendritic gelatinous tubes which are united laterally; fresh water. C . fruticulosa S. (Fig. 118, c). Oval; about 8^ long; colony up to 85/i high. Genus Rhipidodendron Stein. Similar to Cladomonas, but tubes are fused lengthwise; fresh water. R. splendidurn S. (Fig. 118, d, e). Oval; about 13yu long; flagella about 2-3 times body length; fully grown colony 350^ high. Genus Spiromonas Perty. Elongate; without gelatinous cover- ing ; spirally twisted ; 2 flagella anterior ; solitary ; fresh water. S. augusta (Dujardin) (Fig. 118, /). Spindle-form; about lOfx long; stagnant water. Genus Diplomita Kent. With transparent lorica; body at- tached to bottom of lorica by a retractile filamentous process; a rudimentary stigma (?); fresh water. 254 PROTOZOOLOGY Fig. 118. a, AmpJmnonas globosa, X540 (Kent); b, Spongomonas uvella, X440 (Stein); c, Cladomonas fruticulosa, X440 (Stein); d, e, Rhipidodendron splendidum (d, a young colony, X440; e, a free- swimming individual, X770) (Stein); f, Spiromonas augusta, XlOOO (Kent); g, Diplomita socialis, XlOOO (Kent); h, Streptomonas cordata, X890 (Lemmermann); i, Dinomonas vorax, X800 (Kent). D. socialis K. (Fig. 118, g). Oval; flagellum about 2-3 times the body length; lorica yellowish or pale brown; broadly spindle in form; about 15/x long; pond water. Genus Streptomonas Klebs. Free-swimming; naked; distinctly keeled; fresh water. S. cordata (Perty) (Fig. 118, h). Heart-shaped; IS^t by 13/^; rota- tion movement. Genus Dinomonas Kent. Ovate or pyriform, plastic, free-swim- ming; 2 flagella, equal or sub-equal, inserted at anterior extrem- ity, where large oral aperture visible only at time of food inges- tion, is also located, feeding on other flagellates; vegetative infusions. D. vorax K. (Fig. 118, i). Ovoid, anterior end pointed; 15-16ju long; flagella longer than body; hay infusion and stagnant water. PROTOMONADINA Family 8 Monadidae Stein 255 2 unequal flagella; one primary and the other secondary; motile or attached; 1-2 contractile vacuoles; colony formation frequent; free-living. Genus Monas M tiller {Physomonas Kent). Plastic and actively motile ("dancing movement"); often attached to foreign objects; not longer than 20/^; known for a long time, but still very in- completely. Krijgsman (1925) studied the flagellar movements (p. 107). M. guttula Ehrenberg (Fig. 119, a). Spherical to ovoid; 14-16m long; free-swimming or attached; longer fiagellum about 1-2 times body length; cysts 12/x in diameter; stagnant water. M. elongata (Stokes) (Fig. 119, h). Elongate; about 11/x long; Fig. 119. a, Mo7ias guttula, X620 (Fisch); b, M. elongata, X670 (Stokes); c, M. socialis, X670 (Kent); d, M. vestita, X570 (Stokes); e, Stokesiella dissimilis, X500 (Stokes); f, S. leptostonia, x840 (Stokes); g, Stylohryon abbotti, X480 (Stokes); h, Dendromonas virgaria, a young colony of, X670 (Stein); i, Ce-phalothamniuni cyclopicm, X440 (Stein); j, k, Anthophysa vegetans (j, part of a colonv, X230; k, an individual, X770) (Stein). 256 PROTOZOOLOGY free-swimming or attached; anterior end obliquely truncate; fresh water. M. socialis (Kent) (Figs. 8, g; 119, c). Spherical; 5-10^ long; among decaying vegetation in fresh water. M. vestita (Stokes) (Fig. 119, d). Spherical; about 13.5/x in diameter; stalk about 40;u long; pond water. Reynolds (1934) made a careful study of the organism. Genus Stokesiella Lemmermann. Body attached by a fine cytoplasmic thread to a delicate and stalked vase-Hke lorica; 2 contractile vacuoles ; fresh water. S. dissimilis (Stokes) (Fig. 119, e). Solitary; lorica about 28yu long. S. leptostoma (S.) (Fig. 119,/). Lorica about 17yu long; often in groups; on vegetation. Genus Stylobryon Fromentel. Similar to Stokesiella; but colonial; on algae in fresh water. S. ahbotti Stokes (Fig. 119, g). Lorica campanulate; about 17^ long; main stalk about 100 fj. high; body oval or spheroidal; flagella short. Genus Dendromonas Stein. Colonial; individuals without lorica, located at end of branched stalks; fresh water among vegetation. D. virgaria (Weisse) (Fig. 119, h). About S/j, long; colony 200ijl high; pond water. Genus Cephalothamnium Stein. Colonial; without lorica, but individuals clustered at end of a stalk which is colorless and rigid; fresh water. C. cyclopum S. (Fig. 119, i). Ovoid; 5-10^ long; attached to body of Cyclops and also among plankton. Genus Anthophysa Bory. Colonial forms, somewhat similar to Cephalothamnium; stalks yellow or brownish and usually bent; detached individuals amoeboid with pointed pseudopodia. A. vegetans (Mliller) (Fig. 119, j, k). About 5-6/z long; common in stagnant water and infusion. Family 9 Bodonidae Btitschh With 2 flagella; one directed anteriorly and the other pos- teriorly and trailing; flagella arise from anterior end which is drawn out to a varying degree; one to several contractile vacuoles; asexual reproduction by binary fission; holozoic or saprozoic (parasitic). PROTOMONADINA 257 Genus Bodo Ehrenberg {Prowazekia Hartmann et Chagas). Small, ovoid, but plastic; cytostome anterior; nucleus central or anterior; flagella connected \^^th 2 blepharoplasts in some species; encystment common; in stagnant water and coprozoic. Numerous species. B. caudatus (Dujardin) (Fig. 120, a, 6). Highly flattened, usually tapering posteriorly; ll-22ju by 5-10)u; anterior flagellum about body length, trailing flagellum longer; blepharoplast ; cysts spherical; stagnant water. B. edax Klebs (Fig. 120, c). Oval with pointed anterior end; 11-15^1 by 5-7/x; stagnant water. Genus Pleuromonas Perty. Naked, somewhat amoeboid; usually attached with trailing flagellum; active cytoplasmic movement; fresh water. P. jaculans P. (Fig. 120, d). Body G-lO^t by about 5ai; flagellum 2-3 times body length; 4-8 young individuals are said to emerge from a spherical cyst ; stagnant water. Genus Rhynchomonas Klebs (Cruzella Faria, da Cunha et Pinto). Similar to Bodo, but there is an anterior extension of body, in which one of the flagella is embedded, while the other flagellum trails; a single nucleus; minute forms; fresh or salt water; also sometimes coprozoic. R. nasuta (Stokes) (Fig. 120, e). Oval, flattened; 5-6yLt by 2-3 fx; fresh water and coprozoic. R. marina (F., C. et P.). In salt water. Genus Proteromonas Kunstler (Prowazekella Alexeieff). Elon- gated pyriform; 2 flagella from anterior end, one directed an- teriorly and the other, posteriorly; nucleus anterior; encysted stage is remarkable in that it is capable of increasing in size to a marked degree; exclusively parasitic; in gut of various species of lizards. P. lacertae (Grassi) (Figs. 9, h; 120, /). Elongate, pyriform; 10-30/z long; gut of lizards belonging to the genera Lacerta, Tarentola, etc. Genus Retortamonas Grassi (Emhadomonas Mackinnon). Spindle-form or pyriform, drawn out posteriorly; ventral side usually more convex than dorsal side; large oval pouch on ventral side, about 1/3 as long as body; nucleus anterior; 2 flagella longer than body, anterior flagellum shorter than the posterior one which usually shows 2 or 3 undulations; cysts ovoid; parasitic in gut of various animals. PROTOZOOLOGY Fig. 120. a, b, Bodo caudatus, X1500 (Sinton); c, B. edax, X1400 (Kiihn); d, Pleuromonas jaculans, X650 (Lemmermann); e, Rhin- chomonas nasuta, X1800 (Parisi); f, Proteromonas lacertae, X2500 (Kiihn); g, Retortamonas gryllotalpae, X2000 (Wenrich); h, R. blattae, X2000 (Wenrich); i, R. intestinalis, X2000 (Wenrich); j, PhyUomitus undidans, XlOOO (Stein); k, Colj)onema loxodes, X650 (Stein); 1, Cer- comonas longicauda, X2000 (Wenyon); m, C. crassicauda, x2000 (Dobell). R. gnjllotalpae (G.) (Fig. 120, g). About 7-14/x (average lOyu) long; in intestine of the mole cricket, Gryllotalpa gryllotalpa. R. hlattae (Bishop) (Fig. 120, h). About Q-Q/j. long; in colon of cockroaches. R. intestinalis (Wenyon et O'Connor) (Fig. 120, i). 6-1 4/^ long; in human intestine. Genus PhyUomitus Stein. Oval; highly plastic; cytostome large and conspicuous; 2 unequal flagella, each originates in a basal granule; apparently no blepharoplast; fresh water or coprozoic. PROTOMONADINA 259 P. undulans S. (Fig. 120, j)- Ovoid; 21-27yu long; trailing flagel- lum much longer than anterior one; stagnant water. Genus Colponema Stein. Body small; rigid; ventral furrow conspicuous, wide at anterior end; one flagellum arises from anterior end and the other from middle of body; fresh water. C. loxodes S. (Fig. 120, A;). 18-30^1 by 14/^; cytoplasm with re- fractile globules. Genus Cercomonas Dujardin. Biflagellate, both flagella arising from anterior end of body; one directed anteriorly and the other runs backward over body surface, becoming a traihng flagellum; plastic; pyriform nucleus connected with the basal granules of flagella; spherical cysts uninucleate; fresh water or coprozoic. C. longicauda D. (Fig. 120, I). Pyriform or ovoid; posterior end drawn out; 18-36/x by 9-14/^; flagella as long as body; pseudo- podia; fresh water and coprozoic. C. crassicauda D. (Fig. 120, m). IO-ICai by 7-10/u; fresh water and coprozoic. References Holmes, F. O. 1925 The relation of Herpetomonas elmassiani (Migone) to its plant and insect hosts. Biol. Bull., Vol. 49. Laveran, a. and F. Mesnil. 1912 Trypanosomes et Trypano- somiases. Second edition. Paris. Lemmermann, E. 1914 Protomastiginae. Susswasserjl. Deutsch- lands, etc., H. 1. MiNCHiN, E. A. and J. D. Thomson. 1915 The rat trypanosome, Trypanosoma lewisi, in its relation to the rat flea, Cerato- phyllus fasciatus. Quart. Jour. Micr. Sci., Vol. 60. Nelson, R. 1922 The occurrence of Protozoa in plants affected with mosaic and related diseases. Michigan Agr. Coll. Bot. Stat., Tech. Bull. No. 58. Reynolds, B. D. 1934 Studies on monad flagellates. I, II. Arch. f. Protistenk., Vol. 81. Wenyon, C. M. 1926 Protozoology, Vol. 1. London. Chapter 14 Order 3 Polymastigina Blochmann THE Zoomastigina placed in this group possess 3-8 (in one family up to a dozen or more) flagella and generally speak- ing, are minute forms with varied characters and structures. Many possess a cytosome and one to many nuclei and the body is covered by a thin pellicle which allows the organism to change form, although each species shows a typical form. The cyto- plasm does not show any special cortical differentiation; in many, there is an axial structure known as axostyle or axostylar fila- ments (p. 61). In forms with an undulating membrane, there is usually a rod-like structure beneath the membrane which is known as costa (Kunstler). Parabasal body of various forms occur in many species. The majority of Polymastigina inhabit the di- gestive tract of animals and nutrition is holozoic or saprozoic (parasitic). Asexual reproduction is by longitudinal fission, some- times multiple. Encystment is common, and the cyst is responsi- ble for infection of new hosts through mouth. Sexual reproduction has not been definitely established. With 1 nucleus Suborder 1 Monomonadina With 2 nuclei Suborder 2 Diplomonadina (p. 272) With more than 2 nuclei Suborder 3 Polymonadina (p. 274) Suborder 1 Monomonadina Without axial organella With 3 flagella Family 1 Trimastigidae With 4 flagella None undulates on body surface. . T Family 2 Tetramitidae (p. 263) One undulates on body surface Family 3 Chilomastigidae (p. 264) With more than 4 flagella Family 4 Callimastigidae (p. 265) With axial organella Without undulating membrane. .Family 5 Polymastigidae (p. 265) With undulating membrane. .Family 6 Trichomonadidae (p. 269) Family 1 Trimastigidae Kent Free-swimming or attached; with 3 flagella; no cytostome; free- living in fresh or salt water, coprozoic or parasitic. 260 POLYMASTIGINA 261 Genus Trimastix Kent. Ovate or pyriform; naked; free- swimming; with a laterally produced membranous border; 3 flagella, 1 anterior flagellum vibrating, 2 trailing; salt water. 'M Fig. 121. a, Trimastix marina, X1250 (Kent); b, DaUingeria drys- dali, X2000 (Kent); c, Macromastix lapsa, XloOO (Stokes); d, En- teromonas hominis, X2000 (da Fonseca). T. marina K. (Fig. 121, a). About 18)U long; salt water. Genus DaUingeria Kent. Free-swimming or attached; with trailing flagella; body small; with drawn-out anterior end; fresh water with decomposed organic matter. D. drysdali K. (Fig. 121, b). Small; elongate oval; less than 6/x long; stagnant water. Genus Macromastix Stokes. Free-swimming, somewhat like DaUingeria, but anterior region not constricted; 3 flagella from anterior end; one contractile vacuole; fresh water. M. lapsa S. (Fig. 121, c). Ovoid; 5. 5m long; anterior flagellum 1/2 and trailing flagella 2-3 times body length; pond water. Genus Enteromonas da Fonseca. Body globular; 2 anterior flagella and one traihng flagellum. E. hominis d. F. (Fig. 121, d). Small, 5-6^ in diameter; in human faeces. Genus Mixotricha Sutherland. Large; elongate; anterior tip spirally twisted and motile; posterior end probably eversible; 262 PROTOZOOLOGY body surface with a coat of cilia in closely packed transverse bands (insertion and movement entirely different from those of Trichonytnpha) exce})t })()st(n'i()r end; 3 short flagella at anterior end; nucleus, 20// by 2/x, conn(^cted with blepharoplasts by pro- FiG. 122. Diagram illustrating the life-cycle of Tetramitus rostratus (Bunting), a, cyst; b, vegetative amoeba; c, division; d, after division; e, f, stages in transformation to flagellate form; g, fully formed flagel- late; h, flagellate prior to division; i, flagellate after division; j-1, trans- formation stages to amoeba. longed tube which encloses nucleus itself; cytoplasm with scat- tered wood chips; in termite gut. One species. Taxonomic position undetermined. M. paradoxa S. About 340)u long, 200/^ broad and 25/x thick; in gut of Mastotermes darwiniensis ; Australia. POLYMASTIGINA 263 Family 2 Tetramitidae Biitschli With 4 flagella, no one of which undulates on body surface. Genus Tetramitus Perty. Ellipsoidal or pyriform; free-swim- ming; cytostome at anterior end; 4 flagella unequal in length; a contractile vacuole; holozoic; fresh or salt water. T. rostratus P. (Fig. 123, a). Form variable; usually ovoid with narrow posterior region; 18-30/x by 8-1 1/z; stagnant water. Bunt- ing (1922, 1926) observed a very interesting life-cycle of an organism which she found in culture of caecal contents of rat and which she identified as T. rostratus (Fig. 122). Fig. 123. a, Tetramitus rostratus, X620 (Lemmermann); b, T. pyri- f or mis, X670 (Klebs); c, T. salinus, X1630 (Kirby); d, Collodictyon triciliatimi , X400 (Carter): e-j, Costia necatrix (e, f, X800 (Weltner); g-i, X1400 (Moroff); j, two individuals attached to host integument X500 (Kudo)); k, Tricercomonas intestinalis, X1730 (Wenyon and O'Connor); 1, Coproviastix prowazeki, X1070 (Aragao). T. pyriformis Klebs (Fig. 123, h). Pyriform, with pointed pos- terior end; 11-13^ by 10-12^i; stagnant water. T. salinus (Entz) (Fig. 123, c). 2 anterior flagella, 2 long trailing flagella; nucleus anterior; cytostome anterior to nucleus; a 264 PROTOZOOLOGY groove to posterior end; cytopharynx temporary and length variable; 20-30/x long (Entz); 15-19// long (Kirby). Kirby ob- served it in a pool with salinity of about 15 per cent at Marina, California. Genus Collodictyon Carter. Body highly plastic; with longi- tudinal furrows; posterior end bluntly narrowed or lobed; no apparent cytostome; 4 flagella; a contractile vacuole anterior; fresh water. C. triciliatum C. (Fig. 123, d). Spherical, ovoid or heart-shaped; 27-60/1 long; flagella as long as the body; pond water. Rhodes (1919) made a comprehensive cytological study of the organism. Genus Costia Leclerque. Ovoid in front view; pyriform in pro- file; toward right side, a funnel-like depression, at the posterior end of which are located cytostome (?) and 2 long and 2 short flagella; contractile vacuole in posterior half; longitudinal divi- sion; encystment; ectoparasitic in various freshwater fishes. C. necatrix (Henneguy) (Fig. 123, e-j). 10-20^ by 5-10//; compact nucleus central; a contractile vacuole; cyst uninucleate, spherical, 7-10/z in diameter; when present in large numbers, the epidermis of fish appears to be covered by a whitish coat. Genus Tricercomonas Wenyon et O'Connor. Body similar to that of Cercomonas (p. 259), but with 3 anterior flagella and a posterior flagellum; oblong cyst with 4 nuclei when mature; parasitic. T. intestinalis W. et O'C. (Fig. 123, k). 4-8/1 long; in human intestine. Genus Copromastix Aragao. 4 anterior flagella equally long; body triangular or pyramidal; coprozoic. C. prowazeki A. (Fig. 123, /). About I6-I8/1 long; in human and rate faeces. Family 3 Chilomastigidae Wenyon 4 flagella, one of which undulates on body surface. Genus Chilomastix Alexeieff . Pyriform ; with a large cytostomal cleft at anterior end; nucleus anterior; 3 anteriorly directed flagella; short fourth flagellum undulates within cleft; cysts common; in intestine of vertebrates. Several species. C. mesnili (Wenyon) (Fig. 124, a-c). 10-15/t long; cyst 5-10/t long; in human intestine; commensal, although often found in diarrhoeic stools. C. intestinalis Kuczynski. In guinea pigs. POLYMASTIGINA 265 C. hettencourti da Fonseca. In rats and mice. C. cuniculi da Fonseca. In rabbits. C. caprae da Fonseca. In goat. C. gallinarum Martin et Robertson. 11-20/i by S-Qfj.; in domes- tic fowls. Family 4 Callimastigidae da Fonseca Flagella 12 or more; in stomach of ruminants or in caecum and colon of horse. Genus Callimastix Weissenberg. Ovoid; compact nucleus central or anterior; 12-15 long flagella near anterior end, vibrate in unison. Weissenberg (1912) considered this genus to be related to Lophomonas (p. 280), but organism lacks axial organellae; in Cyclops and alimentary canal of ruminants and horse. C. cyclopis W. In body-cavity of Cyclops sp. C. frontalis Braune (Fig. 124, d). 12 flagella; about 12ju long; flagella 30// long; in cattle, sheep and goats. C. equi Hsiung (Fig. 124, e). 12-15 flagella; 12-18/z by 7-10^; nucleus central; in caecum and colon of horse. Family 5 Polymastigidae Biitschli With axial structures; without undulating membrane; flagella variable in number. Genus Polymastix BiitschH. Pyriform; 4 flagella arise from 2 blepharoplasts located at anterior end; cytostome and axostyle inconspicuously present; ectoplasm covered by longitudinal ridges; endocommensal in insects. P. melolonthae (Grassi) (Fig. 124,/). 5-22ju long; in hindgut of Melolontha, Oryctes, Cetonia, Rhizotrogus, Tipula, etc. Genus Eutrichomastix Kofoid et Swezy (Trichomastix Bloch- mann). Pyriform; anterior end rounded; cytostome and nucleus anterior; 3 flagella of equal length arise from anterior end, the fourth traihng; axostyle projects beyond posterior end of body; all endocommensal. E. serpentis (Dobell) (Fig. 124, g). About 10-25/^ long; in in- testine of snakes; Pituophis, Eutaenia, and Python. E. batrachorum (Dobell) (Fig. 124, h). Ovoid; 6-20// long; in intestine of Rana fusca. E. axostylis Kirby (Fig. 124, i). Elongate, ellipsoid, or pyri- form; axostyle projecting; 5-10. 5ju by 2-3. 5^; 3 anterior flagella 5-10m long; in gut of Nasutitermes kirhyi. 266 PKOTOZOOLOGY Fig. 124. a-c, Chilomastix mesnili, X1350 (Kudo); d, Callimastix frontalis, XlSOO (Braune); e, C. equi, XHOO (Hsiung); f, Polymastix melolonthae, X540 (Hamburger); g, Eutrichomastix serpentis, X1450 (Kofoid and Swezy) ; h, E. hatrachorum, X 1350 (Dobell) ; i, E. axostylis, X2000 (Kirby); j, Hexamastix termopsidis, X2670 (Kirby) ; k, H. hatrachorum, XlOOO (Alexeieff); 1, Protrichomonas legeri, XlOOO (Alexeieff); m, Parajoenia grassii, X890 (Kirby); n, Oxynionas pro- jector, X1260 (Kofoid and Swezv); o, Streblomastix strix, XlOBO (Kidder). Genus Hexamastix Alexeieff. Body similar to Eutrichomastix, but with 6 flagella, of which one trails; axostyle conspicuous; parabasal body prominent. H. termopsidis Kirby (Fig. 124, j). Ovoidal or pyriform; S-ll/i long; flagella 15-25ju long; in gut of Zootermopsis angusticollis and Z. nevadensis ; California. POLYMASTIGINA 267 H. hatrachorum Alexeieff (Fig. 124, k). Oval or spindle form; 8-14/i by 4-8/z; flagella about body length; in gut of Triton taeniatus. Genus Protrichomonas Alexeieff. 3 anterior flagella of equal length, arising from a blepharoplast located at anterior end; parasitic. P. legeri A. (Fig. 124, I). In oesophagus of the marine fish, Box boops. Genus Parajoenia Janicki. Medium large; ends rounded; 3 anterior flagella; 1 long trailing flagellum; axostyle stout; para- basal body in 2 parts; Kirby (1937) showed that this genus belongs to Polymastigina; in termite gut. P. grassii J. (Fig. 124, m). 29-59^ by 12-33/x; numerous spiro- chaetes, about 15-20/1 long, adherent to anterior and posterior parts of body; in Neotermes connexus; Hawaii. Genus Oxymonas Janicki. Oval or pyriform; extensible and retractile rostellum (proboscis) at anterior end; at its base 2 groups of 3 flagella; nucleus anterior; bundle of axial filaments; in termite gut. 0. projector Kofoid et Swezy (Fig. 124, n). 12-40^ long; in Kalotermes perparvus. 0. dimorpha Connell. Subovoid; delicate pellicle; axostyle pro- truding; a pair of long anterior flagella from 2 blepharoplasts connected by rhizoplast; nucleus anterior, Feulgen negative; when attached to intestine, rostellum elongate, flagella disappear; xylophilous; 165-195/x by 14-17^; in Neotermes simplicicornis ; California and Arizona. Genus Streblomastix Kofoid et Swezy. Elongate, spindle; 4 anterior flagella; nucleus elongate spindle; with spiral ridges; in termite gut. S. strix K. et S. (Fig. 124, o). 200-530m by 20-80m; in Zooter- mopsis angusticollis. Genus Devescovina Foa. Oblong; axostyle rigid, extends to posterior end; 3 anterior flagella and one long trailing flagellum; parabasal body; in termite gut. D. lemniscata Kirby (Fig. 125, a). 12-41ju by 7-15ju; in Crypto- termes hermsi. Genus Pseudodevescovina Sutherland. Relatively large and stout; a single anterior flagellum; without (Sutherland) or with one comparatively short trailing flagellum (Kirby); axostyle 268 PROTOZOOLOGY stout; parabasal body large; investment of short spirochaetes; in termite gut. P. unijlagdlata S. About 65/i by 40-45^ (Sutherland); 52-95^ by 26-60^1 (Kirby); in Kalotermes insularis. Genus Monocercomonas Grassi. Small; 4 flagella inserted in pairs in 2 places; 2 directed anteriorly and the other 2, posteriorly; axostyle filamentous; parasitic. Fig. 125. a, Devescovina lemniscata, XlOOO (Kirby); b, Monocer- comonas bufonis, X1670 (Alexeieff); c, Pyrsonympha vertens, X260 (Comes); d, Dinenyni'pha finihriala, X830 (Kirby); e, Metadevescovina debilis, X1130 (Light); i, Foaina nana, X1670 (Kirby); g, Saccino- bac'ulus ambloaxostylus, XSOO (Cleveland et al.). M. bufonis Dobell (Fig. 125, h). Spindle-form; 12-15// long; cysts spherical; in Axolotle, Triton, frogs and toads. Genus Pyrsonympha Leidy. Ovoid or ellipsoid; axostyle divided into 2 parts along its posterior portion and the whole POLYMASTIGINA 269 vibrates in life; 4-8 flagella adhering to the body; in termite gut. P. vertens L. (Fig. 125, c). 100-1 60ju long; in Reticulitermes flavipes. Genus Dinenympha Leidy. Elongate; 4-8 flagella spirally ad- hering to the body; axostyle conspicuous; in termite gut. D. gracilis L. In Reticulitermes flavipes and R. lucifugus; Duboscq and Grasse hold that this is an immature stage of Pyrsonympha vertens. D. fimbriata Kirby (Fig. 125, d). 52-78m by about 18^; in Reticulitermes hesperus. Genus Metadevescovina Light. Spindle to elongate oval; circular in cross-section; body surface smooth, but often with attached bacteria; nucleus anterior; axostyle not extending be- yond the posterior end of body; parabasal body a spiral rod around axostyle; one primary flagellum and 3 long secondary flagella; spirochaetes adhering to body surface (Ivirby) ; in termite gut. M. debilis L. (Figs. 23; 125, e). 30-70^ by 15-30/x; in Kalo- termes hubhardi. Genus Foaina Janicki (Paradevescovina Kirby). Ellipsoidal; rigid axostyle protrudes a little; flagella similar to those of Devescovina in number and appearance; parabasal body a long curved rod; in termite gut. F. nana Kirby (Fig. 125, /). 10/x by 7/^; in Cryptoterynes hermsi. Genus Saccinobaculus Cleveland. Elongate to spherical; 4 (8 or 12) flagella; axostyle large, paddle-like, deeply stained with Heidenhain, undulates, and serves for locomotion; parasitic. S. amhloaxostylus C. (Fig. 125, ^f). 65-1 10/x by 18-26^; in Cryptocercus punctulatus. Family 6 Trichomonadidae With both axial organellae and an undulating membrane. Genus Trichomonas Donne {Ditricho?7ionas Cutler). Pyriform; 4 anterior flagella; another flagellum along the margin of undu- lating membrane; costa along the base of the membrane; axostyle projects beyond the posterior end of body; cysts observed in forms inhabiting the animal intestines, but not in those living in man; parasitic in gut of vertebrates and invertebrates. Numerous species. T. hominis (Davaine) (Fig. 126, a). 5-18/i long; in human intestine. 270 PROTOZOOLOGY T. elongata Steinberg (T. hiiccalis Goodey et Wellings) (Fig. 126, h). About 10-20yLt long; in hunuin mouth. T. vaginalis Donne (Fig. 126, c). 10-25)U long; in human vagina. T. batrachonim (Perty). Ovoid; 14-18ai by 6-10/x; in frog gut. T. auguda Alexeieff. Spindle-form; 18-22yu by 8-14/x; in frog gut. T. linearis Kirby (Fig. 126, d). Elongate, spindle-form; 9-24/i by 3-8/jl; in gut of Orthognathotermes wheeleri; Panama. T. termitis (Cutler) (Fig. 126, e). 30-88m by 13-57^ (Imms); in gut of Archotermopsis wroughioni ; India. Genus Gigantomonas Dogiel (Myxomonas D.). Somewhat similar to Trichomonas, but much larger; 3 short flagella and a very long flagellum; axostyle large; undulating membrane well developed; parasitic. G. herculea D. (Fig. 126, /). 60-75ac by 30-35yu; in gut of Hodotermes mossambicus. Myxomonas polymorpha D. (g) reported from the same host appears to be a degenerating specimen. Genus Tritrichomonas Kofoid. Similar to Trichomonas in ap- pearance and structure; but 3 anterior flagella; parasitic. T. hrevicollis Kirby (Fig. 126, h). Ovoid; undulating membrane curved around end; 10-17yu by 4-8ai; in gut of Kalotermes hrevicollis; Panama. T. foetus (Riedmiiller). Pathogenic; in genitalia of cattle; simi- lar to Trichomonas vaginalis; but 3 anterior flagella; body about 15m by 5fx; transmission by sexual act, from cow to bull or bull to cow ; in infected cow conception temporarily or permanently sus- pended or death of foetus occurs. T.fecalis Cleveland. 5/i by 4^ to 12^ by 6m; average dimensions 8.5m by 5.7m; axostyle long, protruding 1/3-1/2 the body length from the posterior end; of 3 flagella, one is longer and less active than the other two; in the faeces of man. Its remarkable adapta- bihty observed by Cleveland was noted elsewhere (p. 28"). Genus Tricercomitus Kirby. Small; 3 anterior flagella; a long trailing flagellum, adhering to body; nucleus anterior, without endosome; blepharoplast large, with a parabasal body and an axial filament; parasitic. T. termopsidis K. (Fig. 126, i, j). 4-12m by 2-3m; anterior flagella 6-20m long; trailing flagellum 19-65m long; in gut of Zootermopsis angusticollis, Z. nevadensis and Z. laticeps; Cali- fornia and Arizona. POLYMASTIGINA 271 Fig. 126. a, Trichomonas hominis, X1070 (Kudo); b, T. elongata, X1070 (Kudo); c, T. vaginalis, X870 (Wenyon); d, T. linearis, X2000 (Kirby); e, T. termitis, X630 (Cutler); f, Gigantomonas herculea, X530 (Dogiel); g, a degenerating form, X400 (Dogiel); h, Tritrichomonas brevicollis, x2000 (Kirby); i, j, Tricercomitus termopsidis, X890 (Kirby); k, Pentatrichomonas scroa, X2000 (Kirby); 1, Pseudotryp- anosoma giganteum, X580 (Kirby). Genus Pentatrichomonas Chatterjee. 5 anterior flagella; axo- style very slightly developed; parabasal body fusiform; nucleus at some distance from anterior end; parasitic. 272 PROTOZOOLOGY P. scroa Kirby (Fig. 126, k). 18-45m by 6-1 5/x; in Kalotermes dudleyi and K. longicollis ; Panama. Gonus Pseudotrypanosoma Grassi. Large, elongate; 3 anterior flagella; undulating membrane; slender axostyle; costa conspicu- ous; band-like structure between blepharoplast and nucleus; striae near body surface; parabasal body long; parasitic. P. giganteum G. (Fig. 126, I). 55-1 ll/x long (Grassi); 145-205^ by 20-40/i; anterior flagella about 30)U long (Kirby); cytostome not observed; in gut of Porotermes adamsoni and P. grandis; Australia. Suborder 2 Diplomonadina The suborder consists of a number of binucleate flagellates possessing bilateral symmetry. Family Hexamitidae Kent Genus Hexamita Dujardin {Octomitus Prowazek). Pyriform; 2 nuclei at anterior pole, 6 anterior and 2 posterior flagella; 2 axostyles; 1-2 contractile vacuoles; cytostome obscure; endo- plasm with refractile granules; encystment; in stagnant water or parasitic. H. inflata D. (Fig. 127, a). Broadly oval; posterior end trun- cate; 13-25m by 9-15^; in stagnant water. H. iiitestinalis D. (Fig. 127, h, c). 10-16m long; in intestine of frogs, also in midgut of Trutta fario and in rectum of Motella tricirrata and M. mustela in European waters. H. salmonis (Moore) (Fig. 127, d). 10-12/i by 6-8/^; in intestine of various species of trout and salmon; schizogony in epithelium of pyloric caeca and intestine; cysts; pathogenic to young host fish (Davis, 1925). H. periplanetae (Belaf) In gut of cockroaches. H. cryptocerci Cleveland (Fig. 127, e). 8-13/i by 4-5. 5m; in Cryptocercus puntulatus. Genus Giardia Kunstler {Lamhlia Blanchard). Pyriform; bi- laterally symmetrical; dorsal side convex; ventral side with sucking disc at anterior region; 8 flagella; 4 from margin of suck- ing disc; 2 from middle part and 2 from posterior end of body; parasites in intestine of various vertebrates. Several species. G. intestinalis (Lambl) (Fig. 127, f-h). 10-20m by 6-10/x; com- mensal in human intestine. G. muris (Grassi). 7-13^ by 5-10ai; in intestine of mice and rats. POLYMASTIGINA 273 Fig. 127. a, Hexamita inflata, X690 (Klebs); b, c, H. intestinalis, X1600 (Alexeieff); d, H. salmonis, X2100 (Davis); e, H. cryptocerci, X1600 (Cleveland); f-h, Giardia inlestinalis, X1070 (Kofoid and Swezy); i, Treipomonas agilis, X1070 (Klebs); j, T. rotans, X710 (Lemmermann); k, Gyromonas amhulans, X530 (Seligo); 1, Trigo- noynonas compressa, X490 (Klebs); m, Urophagus rostratus, X800 (Klebs). Genus Trepomonas Dujardin. Free-swimming; flattened; more or less rounded; cytosomal grooves on posterior half, one on each side; 8 flagella (one long and 3 short flagella on each side) arise from anterior margin of groove; at anterior end there is a horse- 274 PROTOZOOLOGY shoe-like structure, in which two nuclei are located; fresh water, parasitic, or coprozoic. T. agilis D. (Fig. 127, i). More or less ovoid; 7-30^ long; 1 long and 3 short flagella on each side; rotation movement; stagnant water; also reported from intestine of Amphibians. T. rolans Klebs (Fig. 127, j). Broadly oval; posterior half highly flattened; 2 long and 2 short flagella on each of 2 cytostomes; stagnant water. Genus Gyromonas Seligo. Free-swimming; small; form con- stant, flattened; slightly spirally coiled; 4 flagella at anterior end; cytostome not observed; fresh water. G. ambulans S. (Fig. 127, k). Rounded; 8-15yu long; standing water. Genus Trigonomonas Klebs. Free-swimming; pyriform; plastic; cytostome on either side, from anterior margin of which arise 3 flagella; flagella 6 in all; 2 nuclei situated near anterior end; move- ment rotation; holozoic; fresh water. T. compressa K. (Fig. 127, I). 24-33^ by 10-16m; flagella of different length; standing water. Genus Urophagus Klebs. Somewhat similar to Hexamita; but a single cytostome; 2 moveable posterior processes; holozoic; stagnant water. U. rostratus (Stein) (Fig. 127, m). Spindle-form; 16-25iu by 6- 1 2m. Suborder 3 Polymonadina This group includes forms which inhabit the intestine of various species of termites, most probably as symbionts. The majority are multinucleate. Each nucleus gives rise to a basal body (from which flagella extend), a parabasal body, and an axial filament. Janicki called this complex a karyomastigont, and the other type of complex which does not contain a nucleus akaryomastigont. Genus Calonympha Foa. Body rounded; large; numerous long flagella arise from anterior region; nuclei arranged near insertion points of flagella; with karyomastigonts or akaryomastigonts; axial filaments form a bundle; in termite gut. C. grassi F. (Fig. 128, a). In Cryptotermes grassii; Q9-90fjL long. Genus Stephanonympha Janicki. Oval, but plastic; pellicle sculptured with foreign bodies ; numerous nuclei spirally arranged around anterior end; in termite gut. POLYMASTIGINA 275 S. nelumhium Kirby (Fig. 128, b). 45/i by 27^; in Cryptotermes hermsi. Genus Microrhopalodina Grassi et Foa (Prohoscidiella Kofoid et Swezy). One to many nuclei, each in a karyomastigont com- FiG. 128. a, Calonympha grassii, X900 (Janicki); b, Stephaiionympha nelumhium, X400 (Kirby); c, Microrhopalodina multinudeata, x440 (Kofoid and Swezy); d, Coronympha clevelandi, XlOOO (Kirby); e, Snyderella tabogae, X350 (Kirby). plex; a single extensible and retractile rostellum; binary fission; in termite gut. M. multinudeata (Kofoid et Swezy) (Fig. 128, c). 25-160a£ long; in Kalotermes nocens. M. occidentis (Lewis). 26-133^ by 11-80/^; average number of 276 PROTOZOOLOGY nucloi 5.5, about 23 per cent uninucleate; in Kalotermes Oc- cident if^. Geiuis Coronympha Kirby. Pyriform with 16 nuclei, arranged in a single circle in anterior region; each nucleus center of a karyo- mastigont; in termite gut. C. clevelandi K. (Fig. 128, d). 25-53^ by 18-46yu, in Kalotermes clevelandi; Panama. Genus Snyderella Kirby. Numerous nuclei scattered through cytoplasm; akaryomastigonts close together and extend through greater part of peripheral region; axial filaments in bundle; in termite gut. S. tahogae K. (Fig. 128, e). Pyriform; rounded posteriorly; bluntly conical anteriorly; 77-1 72ju by 53-97yu; in Kalotermes longicollis; Panama. References Cleveland, L. R. et al. 1934 The wood-feeding roach, Crypto- cercus, its Protozoa, and the symbiosis between Protozoa and roach. Mem. Amer. Acad. Arts and Sci., Vol. 17. DoBELL, C. and F. W. O'Connor 1921 The intestinal Protozoa of man. London. Grasse, p. p. 1926 Contribution a I'etude des Flagelles para- sites. Arch. zool. exp., et gen.. Vol. 65. Kirby, H. 1930, 1931 Trichomonad flagellates from termites. I, IL Uni. Cal. Pub. Zool., Vols. 33, 36. KoFOiD, C. A. and Olive Swezy 1915 Mitosis and multiple fis- sion in trichomonad flagellates. Proc. Amer. Acad. Arts and Sci., Vol. 51. 1920 On the morphology and mitosis of Chilo- mastix mesnili (Wenyon), a common flagellate of the human intestine. Uni. Cal. Pub. Zool., Vol. 20. 1922 Mitosis and fission in the active and en- cysted phases of Giardia enterica etc. Ibid., Vol. 20. Rees, C. W. 1938 Observations on bovine venereal trichomoni- asis. Veterin. Med., Vol. 33. Sutherland, J. L. 1933 Protozoa from Australian termites. Quart. Jour. Micr. Sci., Vol. 76. Wenyon, C. M. 1926 Protozoology, Vol. 1. London. Chapter 15 Order 4 Hypermastigina Grassi ALL members of this order are inhabitants of the alimentary ,. canal of the termite or other insects. The cytoplasmic or- ganization is of high complexity, although there is only a single nucleus. Flagella are numerous and have their origin in blepharo- plasts located at the anterior region of the body. In some species, it has been established by Cleveland that there exists a true symbiotic relationship between the host insects and the proto- zoans (p. 24). Method of nutrition is either holozoic or saprozoic (parasitic). No cytostome has been detected and bits of wood, starch grains, and other food materials, are taken in by means of pseudopodia. Asexual reproduction is by longitudinal fission; multiple divi- sion has also been noted in some species under certain conditions, while sexual reproduction has not been observed. Encystment occurs in some genera of Lophomonadidae and certain species in- habiting wood-roaches, in which moulting of the host insect leads to encystment. Because of the peculiarity and complexity of their structures and also of their common occurrence in termites, the Hypermastigina have in recent years been frequently studied. Body without segmented appearance Flagella in spiral rows Family 1 Holomastigotidae Flagella not arranged in spiral rows Flagella in one or more anterior tufts 1 tuft of flagella Family 2 Lophomonadidae (p. 280) 2 tufts of flagella Family 3 Hoplonymphidae (p. 282) 4 tufts of flagella Family 4 Staurojoeninidae (p. 284) Several tufts (loriculae) Family 5 Kofoidiidae (p. 284) Flagella not arranged in tufts Posterior part without flagella Family 6 Trichonymphidae (p. 284) Flagella over entire body . Family 7 Eucomonymphidae (p. 286) Body with segmented appearance. Family 8 Teratonymphidae (p. 287) Family 1 Holomastigotidae Janicki Flagella are arranged in spiral rows; posterior region may be without flagella; the "anterior body" surrounds, or occurs near, 277 278 PROTOZOOLOGY the nucleus; reproduction by longitudinal division; inhabitants of termito gut. Genus Holomastigotes Grassi. Body small; spindle-shajjed; few spiral rows reach from anterior to i)osterior end; nucleus anterior, surrounded by a mass of dense cytoplasm; nutrition by absorp- tion of fluid material; in termite gut. H. elongatum G. (Fig. 129, a). In gut of Reticulitermes lucifugus, R. speratus, R. flaviceps, and Macrohodotermes mossambicus; up to 70ai by 24m (Grassi). Genus Holomastigotoides Grassi et Foa. Large; spindle-shaped; spiral rows of flagella as in the last genus, but more numerous (12-40 rows); a mass of dense cytoplasm surrounds ovoid nucleus; in termite gut. H. hartmanni Koidzumi (Fig. 129, 6). 50-140yu long; in Copto- termes formosanus. Genus Spirotrichonympha Grassi. Moderately large; elongate pyriform; flagella deeply embedded in cytoplasm in anterior region, arising from 1-several spiral bands; mass of dense cyto- plasm conical and its base indistinct; nucleus spherical ; in termite gut. S. leidyi Koidzumi (Fig. 129, c). In Coptotennes formosanus; 15-50m by 8-30^. ,S. pulchella Brown (Fig. 129, d). 36 42/x by 14-16^; in Reticu- litermes hageni. S. polygyira Cupp. (Fig. 58). In Kalotermes simplicicornis ; 63-1 12/x by 25-60/x; four flagellar bands. Genus Spirotrichonymphella Grassi. Small; without spiral ridges; flagella longer; not wood-feeding; in termite gut. S. pudihunda G. In Porotermes adamsoni; Australia. Multiple fusion (Sutherland). Genus Microspirotrichonympha Koidzumi {Spironympha Koid- zumi). Small, surface not ridged; spiral rows of flagella only on anterior half; a tubular structure between nucleus and anterior extremity; a mass of dense cytoplasm surrounds nucleus; with or without axial rod; in termite gut. M. porteri K. (Fig. 129, e). In Leucotermes flaviceps; 20-55^ by 20-40m. M. ovalis (Brown) (Fig. 129,/). 36-48^ by about 40^; in Reticu- litermes hesperus. Genus Spire tricho soma Sutherland. Pyriform or elongate; be- HYPERMASTIGINA 279 low operculum, two deeply staining rods from which flagella arise and which extends posteriorly into 2 spiral flagellar bands; with- out axostyle; nucleus anterior, median; wood chips ahvays present, but method of feeding unknown; in Stolotermes victoriensis ; Australia. 'f'f'il'll t-fM \ ^^^ vMJ 'H Fig. 129. a, Holomastigotes elongatum, x700 (Koidzumi); b, Holo- mastigotoides hartmanni, X250 (Koidzumi); c, Spirotrichonyinpha leidyi, X400 (Koidzumi); d, S. pidchella, X900 (Brown); e, Micro- spirotrichonympha porteri, X250 (Koidzumi); f, M. ovalis, X600 (Brown); g, Macrospironympha xylopletha, X300 (Cleveland et al.); h, Leptospironympha eupora, X1050 (Cleveland et al.). S. capitata S. 97/x by 38/i; flagellar bands closely spiral, reach posterior end. Genus Macrospironympha Cleveland. Broadly conical; flagella on 2 broad flagellar bands which make 10-12 spiral turns, 2 inner bands; axostyles 36-50 or more; during mitosis nucleus migrates posteriorly; encystment, in which only nucleus and centrioles are 280 PROTOZOOLOGY retained, takes place at each ecdysis of host; in Cryptocercus punctulatus. M. xijlopletha C. (Fig. 129, g). 112-154m by 72-127ax. Genus Leptospironympha Cleveland. Cylindrical; small; flagella on 2 bands winding spirally along body axis; axostyle single, hya- line; nucleus does not migrate posteriorly during division; en- cystment unknown; in Cryptocercus punctulatus. L. eupora C. (Fig. 129, h). 30-38^ by 18-21m. Family 2 Lophomonadidae Kent Numerous flagella arise from anterior end in a tuft; each flagellum originates in a blepharoplast from which extends in- ward an axostylar filament; nucleus anterior, surrounded by a funnel-shaped space formed by filaments; no cytostome; para- basal body; nutrition holozoic or parasitic; reproduction by bi- nary or multiple fission; encystment common; sexual reproduc- tion unknown; in cockroaches and termite guts. Genus Lophomonas Stein. Ovoid or elongate; small; a vesicular nucleus anterior; cysts common; in colon of cockroaches. L. hlattarum S. (Figs. 23; 59; 66; 130, a-e). Small, pyriform, but plastic; bundle of axostylar filaments may project beyond pos- terior margin; active swimming movements; binary or multiple fission; 25-30^ long; holozoic in colon of cockroaches; widely distributed. L. striata Biitschli (Fig. 130, f-h). Elongate spindle; surface with obliquely arranged needle-like structures which some in- vestigators believe to be a protophytan (to which Grasse gave the name, Fusiformis lopho7nonadis) ; bundle of axial filaments short, never protruding; movement sluggish; cyst spherical with needle-like structures; in same habitat as the last species. Genus Eulophomonas Grassi et Foa. Similar to Lophomonas, but flagella vary from 5-15 or a little more in number; in termite gut. E. kalotermitis Grassi. In Kalotermes flavicollis; this flagellate has not been observed by other workers. Genus Prolophomonas Cleveland. Similar to Eulophomonas; established since Eulophomonas had not been seen by recent workers; would become synonym "if Eulophomonas can be found in K. flavicollis" (Cleveland). P. tocopola C. (Fig. 130, i). 14-19m by 12-15^; in Cnjptocercus punctulatus. HYPERMASTIGINA 281 Genus Joenia Grassi. Ellipsoidal; anterior portion capable of forming pseudopodia; flagellar tufts in part directed posteriorly; surface covered by numerous immobile short filamentous process- es, which some hold to be symbiotic bacteria; nucleus spherical Fig. 130. a-e, Lopho7nonas blattarum (a, b, in life, X320; c, d, stained specimens; e, cyst, X1150) (Kudo); f-h, L. striata (f, in life, X320; g, h, stained individuals, X1150) (Kudo); i, Prolophomonas tocopola, X1200 (Cleveland et al.); j, Joenia annectens (Grassi and Foa) ; k, Mi- crojoenia pyriformis, X 920 (Brown); 1, Torquenympha octoplus, x920 (Brown). anterior; posterior to it a conspicuous axostyle composed of numerous axial filaments, a parabasal apparatus surrounding it; bits of wood used as food; in termite gut. J. annectens G. (Fig. 130, j)- Ii^ Kalotermes flavicollis. Genus Joenina Grassi. More complex in structure than that of 282 PROTOZOOl.OCJY Joenia; flagclla inserted at anterior end in a semi-circle; j^ara- basal bodies 2 elongated curved rods; feeding on wood fragments. J. pidchcUa G. In Porotermes adam„som. Genus Joenopsis Cutler. Oval; large; a horseshoe-shaped pillar at anterior end, flagella arising from it; some directed an- teriorly, others posteriorly; parabasal bodies long rods; a strong axostyle; feeding on bits of wood; in termite gut. J. polytricha C. In Archotermopsis wroughtoni ; 95-129)u long. Genus Microjoenia Grassi. Small, pyriform; anterior end flat- tened; flagella arranged in longitudinal rows; axostyle; parabasal body simple; in termite gut. M. pyriformis Brown (Fig. 130, k). 44-52/x by 24-30)li; in Reticulitermes hageni. Genus Mesojoenia Grassi. Large; flagellar tuft spread over a wide area; distinct axostyle, bent at posterior end; 2 parabasal bodies; in termite gut. M. decipiens G. In Kalotermes flavicollis. Genus Torquenympha Brown. Small; pyriform or top-form; axostyle; radially symmetrical; 8 radially arranged parabasal bodies; nucleus anterior; in termite gut. T. octoplus B. (Fig. 130, I). 15-26/x by 9-13^; in Reticulitermes hesperus. Family 3 Hoplonymphidae Light 2 flagellar tufts; each arises from a plate near anterior end of slender body which is protected by a highly developed pellicular armor. Genus Hoplonympha Light. Slender fusiform, covered with thick, rigid pelUcular armor; each tuft of flagella arises from a plate connected with blepharoplasts at anterior end; nucleus near anterior extremity, more or less triangular in form; in termite gut. H. natator L. (Fig. 131, a, 6). 60-1 20m by 5-12//; in Kalotermes sirnplicicornis. Genus Barbulanympha Cleveland. Acorn-shaped; small, nar- row, nuclear sleeve between centrioles; number of rows of flagella greater at base; large chromatin granules; numerous (80-350) parabasals; axostylar filaments 80 350; flagella 1500-13,000; different species show different number of chromosomes during mitosis; in gut of Cryptocercus punctulatus. Four species. B. ufalula C. (Figs. 57; 131, c). 250-340// by 175-275/x; 50 HYPERMASTIGINA 283 ^T>i ^;., > ''*M Fig. 131. a, b, Hoplonympha natator, X450 (Light); c, Barbula- iiympha ufalula, X210 (Cleveland et al.); d, Urinympha talea, X350 (Cleveland et al.); e, Staurojoenina assimilis, X200 (Kirby); f, Idio- nympha perissa, X250 (Cleveland et al.);g, Teratonympha viirabilis, X200 (Dogiel). chromosomes; flagellated area 36-4 l^u long; centriole 28-35/i long. B. laurabuda C. 180-240// by 135-170^; 40 chromosomes; flagellated area 29-33// long; 24-28/x long. Genus Rhynchonympha Cleveland. Elongate; number of flagel- lar rows same throughout; axial filaments somewhat larger and 284 PROTOZOOLOGY longer, about 30; 30 parabasals; 2400 flagella; in Cryptocercus punctulatus. R. tarda C. (Fig. 132,/). 130-215/x by 30 70m. Genus Urinympha Cleveland. Narrow, slender; flagellated area, smaller than that of the two genera mentioned above; flagella move as a unit; about 24 axial filaments; 24 parabasals; 600 flagella ; in gut of Cryptocercus punctulatus. U. talea C. (Fig. 131, d). 75-300m by 15-50^. Family 4 Staurojoeninidae Grassi 4 flagellar tufts arise from the anterior end. Genus Staurojoenina Grassi. Pyriform to cylindrical; anterior region conical; nucleus spherical, central; 4 flagellar tufts from anterior end; ingest wood fragments; in termite gut. S. assimilis Kirby (Fig. 131, e). 105-190^ long; in Kaloter^nes minor. Genus Idionympha Cleveland. Acorn-shaped; axostyles 8-18; fine parabasals grouped in 4 areas; pellicle non-striated; nucleus nearer anterior end than that of Staurojoenina; flagellated areas smaller; in gut of Cryptocercus punctulatus. I. perissa C. (Fig. 131,/). 160-275^ by 98-155m. Family 5 Kofoidiidae Light Flagellar tufts composed of 8-16 loriculae (permanently fused bundles of flagella); without either axostyle or parabasal body. Genus Kofoidia Light. Spherical; between oval nucleus and bases of flagellar tufts, there occurs a chromatin collar; wood fragments as food; in termite gut. K. loriculata L. (Fig. 132, a, h). 60-140^ in diameter; in Kalotermes simplicicornis. Family 6 Trichonymphidae Kent The body is divisible into three regions; rostellum with caps, flagellated region behind rostellum and non-flagellated area at posterior end; flagellated area 1/3-2/3 of body length; surface of anterior portion differentiated into 1-2 thick ectoplasmic layers, densely traversed by numerous flagella; an "axial core" or "head organ" at anterior tip; no cytostome; a single nucleus; flagella numerous and long, arranged in longitudinal rows ; multiplication by simple longitudinal fission; inhabitants of termites and wood- roach. HYPERMASTIGINA 285 Fig. 132. a, b, Kofoidia loriculata, Xl75, X300 (Light); c, Tricho- nympha campanula, Xl50 (Kofoid and Swezy); d, T. agilis, X410 (Kirby); e, Eiicomonymphaimla, X350 (Cleveland etal.); f, Rhyncho- nympha tarda, X350 (Cleveland et al.). Genus Trichonympha Leidy (Leidyonella Frenzel; Gymno- nympha Dobell; Leidyopsis Kofoid et Swezy). Anterior portion consists of nipple and bell, both of which are composed of 2 layers; a distinct axial core; nucleus central; flagella located in longi- 286 PROTOZOOLOGY tudinal rows on bell; in termite gut. Many species. Cleveland and his associates (1934) observed that encystment takes place in species inhabiting the wood-roach, Cryptocercus 'punctulatus and that it occurs only at the time of moulting of the host roach, namely once a year. T. campanula Kofoid et Swezy (Figs. 56; 132, c). 144-313^4 by 57-144;u; wood particles are taken in by posterior region by a method of Rumbler's "import" (Cleveland). In Zootcrmopsis angusticollis, Z. nevadensis and Z. laticeps. T. agilis Leidy (Fig. 132, d). 55-1 15m by 22-45yu; in Reticuli- termes flavipes, R. lucifugus, R. speratus, R. flaviceps, R. hesperus, R. tibialis. T. grandis Cleveland. 190-205iu by 79-88m; in Cryptocercus punctualatus. Genus Pseudotrichonympha Grassi. 2 parts in anterior end as in Trichonympha; head organ with a spherical body at its tip and surrounded by a single layer of ectoplasm; bell covered by 2 layers of ectoplasm; nucleus lies freely; body covered by slightly oblique rows of short fiagella; in termite gut. P. ^rassu Koidzumi. In Coptotermes formosanus; spindle-form; 200-300/x by 50-120m. Genus Deltotrichonympha Sutherland. Triangular; with a small dome-shaped "head"; composed of 2 layers; head and neck with long active fiagella; body fiagella short, arranged in 5 longitudinal rows; fiagella absent along posterior margin; nucleus large oval, located in anterior third; cytoplasm with wood chips; in termite gut. One species. D. operculata S. Up to 230^ long, 164/x wide, and about 50^ thick; in gut of Mastotermes darwiniensis; Australia. Family 7 Eucomonymphidae Cleveland All or most of body covered with fiagella that arise from basal granules arranged in nearly longitudinal rows; fiagella in 2 dif- ferent groups, and never in 3 groups as in Trichonymphidae; with- out peri-nuclear arrangement of parabasals. Genus Eucomonympha Cleveland. Body covered with fiagella arranged in 2 (longer rostral and shorter post-rostral) zones; rostral tube very broad, filled with hyaline material; nucleus at base of rostrum; in gut of Cryptocercus punctulatus. E. imla C. (Fig. 132, e). 100-165^ by 48-160^; attached forms more elongate than free individuals. HYPERMASTIGINA 287 Family 8 Teratonymphidae Koidzumi Genus Teratonympha Koidzumi {Cyclonympha Dogiel). Large and elongate; transversely ridged, and presents a metameric ap- pearance; each ridge with a single row of flagella; no cytostome; anterior end complex, containing a nucleus; reproduction by longitudinal fission; in termite gut. T. mirahilis K. (Fig. 131, g). 200-300^ or longer by 40-50ai; in Reticulitermes speratus of Japan. References Cleveland, L. R. 1925 The effects of oxygenation and starva- tion on the symbiosis between the termite, Termopsis, and its intestinal flagellates. Biol. Bull., Vol. 48. and others 1934 The wood-feeding roach, Cryptocercus, its Protozoa, and the symbiosis between Protozoa and roach. Mem. Amer. Acad. Arts and Sci., Vol. 17. Dogiel, V. 1922 Untersuchungen an parasitischen Protozoen aus dem Darmkanal der Termiten. III. Trichonymphidae. Arch. soc. Russe Protist., Vol. 1. Janicki, D. v. 1910, 1915 Untersuchungen an parasitischen Flagellaten. I, II. Zeitschr. wiss. Zool., Vols. 95, 112. KiRBY, H. 1926 On Staurojoenina assimilis sp. nov., an intestinal flagellate from the termite, Kalotermes minor Hagen. Uni. Calif. Publ. Zool., Vol. 29. 1932 flagellates of the genus Trichonympha in termites. Ibid., Vol. 37. KoFoiD, C. A. and Olive Sw^ezy 1919, 1926 Studies on the parasites of termites. Ibid. Vols. 20, 28. Koidzumi, M. 1921 Studies on the intestinal Protozoa found in the termites of Japan. Parasit., Vol. 13. Kudo, R. 1926 Observations on Lophomonas hlattarum, a flagel- late inhabiting the colon of the cockroach, Blatta orienialis. Arch. f. Protistenk., Vol. 53. Sutherland, J. L. 1933 Protozoa from Australian termites Quart. Jour. Micr. Sci., Vol. 76. Chapter 16 Class 2 Sarcodina Butschli THE members of this class do not possess any definite pellicle and, therefore, are capable of forming pseudopodia (p. 40). The term 'amoeboid' is often used to describe their appearance. The pseudopodia serve for both locomotion and food-capturing. The peripheral portion of the body shows no structural dif- ferentiation in Amoebina, Proteomyxa, and Mycetozoa. Internal and external skeletal structures are variously developed in other orders. Thus, in Testacea and Foraminifera, there is a well- developed test or shell that usually has an aperature, through which the pseudopodia are extruded; in Heliozoa and Radiolaria, skeletons of various forms and materials are developed. The cytoplasm is, as a rule, differentiated into the ectoplasm and the endoplasm, but this differentiation is not constant. In Radiolaria, there is a perforated membranous 'central capsule' which marks the border line between the two cytoplasmic layers. The endoplasm contains the nuclei, food vacuoles, various granules, and contractile vacuoles. The majority of Sarcodina are uninucleate, but numerous species of Foraminifera and Mycetozoa are multinucleate. In the family Paramoebidae, there occurs a peculiar 'secondary nucleus.' The Sarcodina are typically holozic, but in a few cases holo- phytic. Their food organisms are Protozoa, small Metazoa and Protophyta, which present themselves conspicuously in the cytoplasm. One or more contractile vacuoles are invariably pres- ent in forms inhabiting the fresh water, but absent in parasitic forms or in those which live in the salt water. Asexual reproduction is usually by binary (or rarely multiple) fission, budding, or plasmotomy. Definite proof of sexual re- production has been given in a comparatively small number of species. Encystment is common in the majority of Sarcodina, but is unknown in a few species. The life-cycle has been worked out in some forms and seems to vary among different groups. The young stages are either amoeboid or flagellate, and on this account, it is sometimes very difficult to distinguish the Sarcodina and the Mastigophora. In some forms the mature trophic stage 288 SARCODINA, PROTEOMYXA 289 may show an amoeboid or flagellate phase owing to differences in environmental conditions. The Sarcodina are divided into two subclasses as follows: With lobopodia, rhizopodia, or filopodia Subclass 1 Rhizopoda With axopodia Subclass 2 Actinopoda (p. 356) Subclass 1 Rhizopoda Siebold The name Rhizopoda has often been used to designate the entire class, but it is used here for one of the subclasses, which is further subdivided into five orders, as follows : Without test or shell With radiating pseudopodia Order 1 Proteomyxa With rhizopodia; forming Plasmodium Order 2 Mycetozoa (p. 296) With lobopodia Order 3 Amoebina (p. 304) With test or shell Test single-chambered; chitinous Order 4 Testacea (p. 323) Test 1- to many -chambered; calcareous Order 5 Foraminifera (p. 344) Order 1 Proteomyxa Lankester A number of incompletely known Rhizopods are placed in this group. The pseudopodia are filopodia which often branch or anastomose with one another. In this respect the Proteomyxa show affinity to the Mycetozoa. Flagellate swarmers and encyst- ment occur commonly. The majority of Proteomyxa lead para- sitic life in algae or higher plants in fresh or salt water. Pseudoplasmodium-formation Family 1 Labyrinthulidae Solitary and Heliozoa-like With flagellate swarmers . . . Family 2 Pseudosporidae (p. 290) Without flagellate swarmers . Family 3 Vampyrelhdae (p. 290) Family 1 Labyrinthulidae Haeckel Small fusiform protoplasmic masses are grouped in network of sparingly branched and anastomosing filopodia; individuals encyst independently; with or without flagellate stages. Genus Labyrinthula Cienkowski. Minute forms feeding on various species of algae in fresh or salt water; often brightly colored due to the chlorophyll bodies taken in as food. 290 PROTOZOOLOGY L. cienkowshii Zopf (Fig. 133, a). Attacks Vaucheria in frosli water. L. sp. Renn. Renn (1934, 1936) found in the diseased leaf tissue of the eel-grass, Zostera marina, whose leaves showed 'spotting and darkening,' a species of Labyrinthula; fusiform with termi- nal, often branching, filopods; frequently in network by associa- tion of many individuals; infected host cell is completely destroyed; Atlantic coast. Genus Labyrinthomyxa Duboscq. Body fusiform; amoeboid and flagellate phases, variable in size; flagellate stage penetrates the host cell membrane; in plants. L. sauvageaui D. (Fig. 133, b-e). Fusiform body 7-1 l/z long; pseudoplasmodium-formation; amoeboid stage 2.5-14/i long; flagellate stage 7-18^ long; parasitic in Laminaria lejolisii at Roscoff, France. Family 2 Pseudosporidae Berlese Genus Pseudospora Cienkowski. Body minute; parasitic in algae and Mastigophora (including Volvocidae); organism nourishes itself on host protoplasm, grows and multiplies into a number of smaller individuals, by repeated division; the latter bifiagellate, seek a new host, and transform themselves into amoeboid stage; encystment common. P. volvocis C. (Fig. 133, /, g). Heliozoan form about 12-30^ in diameter; pseudopodia radiating; cysts about 25/x in diameter; in species of Volvox. P. parasitica C. Attacks Spirogyra and allied algae. P. eudorini Roskin. Heliozoan forms 10-12^ in diameter; radiating pseudopodia 2-3 times longer; amoeboid within host colony; cysts 15/x in diameter; in Eudorina elegans. Genus Protomonas Cienkowski. Body irregularly rounded with radiating filopodia; food consists of starch grains; division into bifiagellate swarmers which become amoeboid and unite to form pseudoplasmodium; fresh or salt water. P. aniyli C. (Fig. 133, h-j). In fresh water. Family 3 Vampyrellidae Doflein Filopodia radiate from all sides or formed from a limited area; flagellate swarmers do not occur; the organism is able to bore through the cellulose membrane of various algae and feeds on SARCODINA, PROTEOMYXA 291 protoplasmic contents; body often reddish because of the forma- tion of carotin; multinucleate; multiplication in encysted stage into uni- or multi-nucleate bodies; cysts often also reddish. Genus Vampyrella Cienkowski. Heliozoa-like; endoplasm Fig. 133. a, Labyrinthula cienkoivskii, X200 (Doflein); b-e, Laby- rinthomyxa sauvageaui (b, c, flagellate forms, XlOO; d, e, amoeboid forms, X500) (Duboscq); f, g, Pseudospora volvocis, X670 (Robert- son); h-j, Protomonas amyli (Zopf); k, 1, Vampyrella lateritia, X530 (k (Leidy), 1 (Doflein)); m, n, Nuclearia delicatula, X300 (Cash). vacuolated or granulated, with carotin granules; numerous vesic- ular nuclei and contractile vacuoles; midtinucleate cysts, some- times with stalk; 50-700/1 in diameter. Several species. V. lateritia (Fresenius) (Fig. 133, k, I). Spherical; orange-red 292 PROTOZOOLOGY except hyaline ectoplasm; feeds on Spirogyra and other algae in fresh water. On coming in contact with an alga, it often travels along it and sometimes breaks it at joints, or pierces individual cell and extracts chlorophyll bodies by means of pseudopodia; multiplication in encysted condition; 30-40^ in diameter. Genus Nuclearia Cienkowski. Subspherical, with sharply pointed fine radiating pseudopodia; actively moving forms vary in shape; with or without a mucous envelope; with one or many nuclei; fresh water. A^. delicatula C. (Fig. 133, m, n). Multinucleate; bacteria often adhering to gelatinous envelope ; up to 60ju in diameter. N . simplex C. Uninucleate; 30;u in diameter. Genus Arachnula Cienkowski. Body irregularly chain-form with filopodia extending from ends of branches; numerous nuclei and contractile vacuoles; feeds on diatoms and other micro- organisms. A. impatiens C. (Fig. 134, a). 40-350/i in diameter. Genus Chlamydomyxa Archer. Body spheroidal ; ectoplasm and endoplasm well differentiated ; endoplasm often green-colored due to the presence of green spherules; numerous vesicular nuclei; 1-2 contractile vacuoles; secretion of an envelope around the body is followed by multiplication into numerous secondary cysts; cyst wall cellulose; in sphagnum swamp. C. montana Lankester (Fig. 134, 6, c). Rounded or ovoid; cyto- plasm colored; about 50/x in diameter; when moving, elongate with extremely fine pseudopodia which are straight or slightly curved and which are capable of movement from side to side; non-contractile vacuoles at bases of grouped pseudopods; in active individual there is a constant movement of minute fusi- form bodies (function?); when extended 100-150/x long; total length 300)U or more; fresh water among vegetation. Genus Rhizoplasma Verworn. Spherical or sausage-shaped; with anastomosing filopodia; orange-red; with a few nuclei. R. haiseri V. (Fig. 134, d). Contracted form 0.5-1 mm. in diameter; with 1-3 nuclei; pseudopodia up to 3 cm. long; ex- tended body up to 10 mm. long; originally described from Red Sea. Genus Chondropus Greeff. Spherical to oval; peripheral portion transparent but often yellowish; endoplasm filled with green, yellow, brown bodies; neither nucleus nor contractile vacuoles SARCODINA, PROTEOMYXA 293 Fig 134. a, Arachnula impatiens, X670 (Dobell); b, c, Chlamy- domyxa moniana: b, X270 (Cash); c, X530 (Penard); d, Rhizoplasrna kaiseri, X30? (Verworn); e, Bionnjxa vagans, X200 (Cash); f, Penardia mutabilis, X200 (Cash); g, Hyalodiscus rubicundus, X370 (Penard). 294 PROTOZOOLOGY observed; pseudopods straight, fine, often branched; small pearl- like bodies on body surface and pseudopodia. C. viridis G. Average diameter 35-45ju; fresh water among algae. Genus Biomyxa Leidy {Gymno'phrys Cienkowski). Body form inconstant; initial form spherical; cytoplasm colorless, finely granulated, capable of expanding and extending in any direction, and of projecting filopodia which freely branch and anastomose; cytoplasmic movement active throughout; numerous small con- tractile vacuoles in body and pseudopodia; with one or more nuclei. B. vagans L. (Fig. 134, e). Main part, of various forms; size varies greatly; in sphagnous swamps, bog-water, etc. B. cometa (C.). Subspherical or irregularly elHpsoidal; pseudo- podia small in number, formed from 2 or more points; body 35- 40m, or up to 80m or more; pseudopodia 400m long or longer. Cienkowski maintained that this was a 'moneran.' Genus Penardia Cash. When inactive rounded or ovoid; at other times expanded; exceedingly mobile during progression; endoplasm chlorophyll-green with a pale marginal zone; filopodia, branching and anastomosing, colorless; nucleus inconspicuous; one or more contractile vacuoles, small; fresh water. P. mutabilis C. (Fig. 134,/). Resting form 90-100m in diameter; extended forms (including Pseudopodia) 300-400m long. Genus Hyalodiscus Hertwig et Lesser. Discoid, though outhne varies; endoplasm reddish, often vacuolated and sometimes shows filamentous projections reaching body surface; a single nucleus; ectoplasmic band of varying width surrounds the body com- pletely; closely allied to Vampyrella; fresh w^ater. H. ruhicundus H. et L. (Fig. 134, g). 50-80m by about 30m; polymorphic; when its progress during movement is interrupted by an object, the body doubles back upon itself, and will move on in some other direction; freshwater ponds among surface vegetation. References Calkins, G. N. 1926; 1933 The biologij of the Protozoa. Phila- delphia. DoFLEiN, F. and E. Reichenow 1929 Lehrhuch der Protozoen- kunde. Jena. KtJHN, A. 1926 Morphologie der Tiere in Bildern. H. 2; T. 2. Rhizopoden. SARCODINA 295 Cash, J. 1905 The British freshwater Rhizopoda and Heliozoa, Vol. 1. London. DoBELL, C. 1913 Observations on the life-history of Cienkow- ski's Arachnula. Arch. f. Protistenk., Vol. 31. DuBOSCQ, 0. 1921 Labyrinthomyxa sauvageaui n. g., n. sp., pro- teomyxee parasite de Laminaria lejolisii Sauvageau. C. r. soc. biol., Paris. Vol. 84. Leidy, J. 1879 Freshwater Rhiozpods of North America. Re- port U. S. Geol. Survey. Vol. 12. RosKiN, G. 1927 Zur Kenntnis der Gattung Pseudospora Cien- kowski. Arch. f. Protistenk., Vol. 59. ZoPF, W. 1887 Handhuch der Botanik (A. Schenk). Vol. 3. Chapter 17 Order 2 Mycetozoa de Bary THE Mycetozoa had been considered to be closely related to fungi, being known as Myxomycetes, or Myxogasteres, the 'slime molds.' Through extended studies of their development, de Bary showed that they are more closely related to the Protozoa than to the Protophyta, although they stand undoubtedly on the border-line between these two groups of microorganisms. The Mycetozoa occur on dead wood or decaying vegetable matter of various kinds. The most conspicuous part of a mycetozoan is its Plasmodium which is formed by fusion of several myxamoebae, thus producing a large multinucleate body (Fig. 135, a). The greater part of the cytoplasm is granulated, although there is a thin layer of hyaline and homogeneous cytoplasm surrounding the whole body. The numerous vesicular nuclei are distributed throughout the granu- lar cytoplasm. Many small contractile vacuoles are present in the peripheral portion of the Plasmodium. The nuclei increase in number by division as the body grows; the division seems to be amitotic during the growth period of the plasmodium, but is mitotic prior to the spore-formation. The granulation of the cytoplasm is due to the presence of enormous numbers of granules which in Calcarinea are made up of carbonate of lime. The Plas- modium is usually colorless, but sometimes yellow, green, or reddish, because of the numerous droplets of fluid pigment present in the cytoplasm. The food of Mycetozoa varies among different species. The great majority feed on decaying vegetable matter, but some, such as Badhamia, devour living fungi. Thus the Mycetozoa are holozoic or saprozoic in their mode of nutrition. Pepsin has been found in the plasmodium of Fuligo and is perhaps secreted into the food vacuoles, into which proteins are taken. The plasmodium of Badhamia is said to possess the power of cellulose digestion. When exposed to unfavorable conditions, such as desiccation, the protoplasmic movement ceases gradually, foreign bodies are extruded, and the whole plasmodium becomes divided into numerous sclerotia or cysts, each containing 10-20 nuclei and 296 MYCETOZOA 297 being surrounded by a resistant wall (b). These cysts may live as long as three years. Upon return of favorable conditions, the contents of the sclerotia germinate, fuse together, and thus again produce plasmodia (c-e). Fig. 135. The life-cycle of the endosporous mycetozoan (de Bary, Lister, and others), a, plasmodium-formation by fusion of numerous myxamoebae; b, c, formation of sclerotium; d, e, germination of sclero- tium and formation of Plasmodium; f, portion of a Plasmodium show- ing streaming protoplasmic thickenings; g, h, formation of sporangia; i, a sporangium opened, showing capillitium; j, a spore; k, germination of spore; 1, myxamoeba; m, n, myxoflagellates; o-q, multiplication of myxoflagellate; r, microcyst; s, myxamoeba. Variously magnified. When lack of food material occurs, the Plasmodium undergoes changes and develops sporangia. The first indication of this process is the appearance of lobular masses of protoplasm in various parts of the body (/, g). These masses are at first con- nected with the streaming protoplasmic thickenings, but later become completely segregated into young sporangia. During the 298 PROTOZOOLOGY course of sporangium-formation, foreign bodies are thrown out of the body, and around each sporangium there is secreted a wall which, when mature, possesses a wrinkled appearance (h). The wall continued down to the substratum as a slender stalk of varying length, and in many genera the end of a stalk spreads into a network over the substratum, which forms the base, hypothal- lus, for the stalk. With these changes the interior of the spo- rangium becomes penetrated by an anastomosing network, capillitium, of flat bands which are continuous with the outer covering (i). Soon after the differentiation of these protective and supporting structures, the nuclei divide simultaneously by mitosis and the cytoplasm breaks up into as many small bodies as are nuclei. These uninucleate bodies are the spores which measure 3-20yu in diameter and which soon become covered by a more or less thick cellulose membrane (j), variously colored in dilTerent species. The mature sporangium breaks open sooner or later and the spores are carried, and scattered, by the wind. When a spore falls in water, its membrane ruptures, and the protoplasmic con- tents emerge as an amoebula (k, I). The amoebula possesses a single vesicular nucleus and contractile vacuoles, and undergoes a typical amoeboid movement. It presently assumes an elongate form and protrudes a flagellum from the nucleated end, thus developing into a myxoflagellate (zoospore or swarmer) (m, n) which undergoes a peculiar dancing movement and is able to form short, pointed pseudopodia from the posterior end. It feeds on bacteria, grows and multiplies by binary fission (o-g). After a series of division, the myxoflagellate may encyst and be- comes a microcyst (r). When the microcyst germinates, the con- tent develops into a myxamoeba (s) which, through fusion with many others, produces the Plasmodium mentioned before. This is the life-cycle of a typical endosporous mycetozoan. In the genus Ceratiomyxa in which spores are formed on the surface of sporophores, the development is briefly as follows : the Plasmodium lives on or in decayed wood and presents a horn-like appearance. The body is covered by a gelatinous hyaline sub- stance, within which the protoplasmic movements may be noted. The protoplasm soon leaves the interior and accumulates at the surface of the mass; at first as a close-set reticulum and then into a mosaic of polygonal cells, each containing a single nucleus. MYCETOZOA 299 Each of these cells moves outward at right angles to the surface, still enveloped by the thin hyaline layer, which forms a stalk below. These cells are spores, which become ellipsoid and covered by a membrane when fully formed. The spore is uninucleate at first, but soon becomes tetranucleate. When a spore reaches the water, its contents emerge as an amoebula which divides three times, forming 8 small bodies, each of which develops a flagellum and becomes a myxofiagellate. The remaining part of the de- velopment is presumably similar to that of the endosporous form. An enormous number of mycetozoan genera are known. The order is divided here into two suborders according to Lister. Spore develops into myxoflag^ellate; myxamoebae fuse completely and form Plasmodium Suborder 1 Euplasmodia No flagellate stage; myxamoebae grouped prior to spore-formation, but do not fuse to form a true Plasmodium Suborder 2 Sorophora (p. 302) Suborder 1 Euplasmodia Lister Spores develop within sporangia Tribe 1 Endosporeae Spores violet or violet-brown Legion 1 Amaurosporales Sporangia with lime Sublegion 1 Calcarinea Lime in small granular form Family 1 Physaridae Genus Badhamia Berkeley (Fig. 136, a, b) Capillitium, a coarse network with lime throughout. Genus Fuligo Haller (Fig. 136, c, d) Capillitium, a delicate network of threads with vesicular ex- pansions filled with granules of lime. Lime in crystalline form Family 2 Didymiidae Genus Didymium Schrader (Fig. 136, e, f) Lime crystals stellate, distributed over the wall of sporangium. Sporangia without lime Sublegion 2 Amaurochaetinea Sporangia stalked Family 1 Stemonitidae Genus Stemonitis Gleditsch (Fig. 136, g, h) Sporangium-wall evanescent; capillitium arising from all parts of columella to form a network. Sporangium combined into aethalium Familv 2 Amaurochaetidae 300 PROTOZOOLOGY Fig, 136. a, b, Badhamia utricularis Berkeley (a, cluster of sporangia, X4; b, part of capillitium and spore-cluster, X 140) (Lister) ; c, d, Fuligo septica Gmelin (c, a group of sporangia, X^; d, part of capillitium and two spores, Xl20) (Lister); e, f, Didymiwm effusutn Link (e, sporan- gium, Xl2; f, portion of capillitium and wall of sporangium showing the crystals of calcium carbonate and two spores, X200) (Lister); g, h, Stemonitis s-plendens Rostafinski (g, three sporangia, X2; h, col- umella and capillitium, X42) (Lister). Genus Amaurochaete Rostafinski (Fig. 137, a, h) With irregularly branching thread-like capillitium. Spores variously colored, except violet. . . . Legion 2 Lamprosporales Capillitium absent or not forming a system of uniform threads. . Sublegion 1 Aneminea Sporangium-wall membranous; with minute round granules. . . . Family 1 Cribrariidae Genus Cribraria Persoon (Fig. 137, c) Sporangia stalked; wall thickened and forms a delicate persist- ent network expanded at the nodes. Sporangia solitary; stalked Family 2 Liceidae Genus Orcadella Wingate (Fig. 137, d) Sporangia stalked, furnished with a lid of thinner substance. Sporangium-wall membranous -without granular deposits Family 3 Tubulinidae MYCETOZOA c .^^..^ d 301 g ssa: )W Fig. 137. a, b, Amaurochaete fuliginosa MacBride (a, group of spo- rangia, X|; b, capillitium, XlO) (Lister); c, Empty sporangium of Cribraria aurantiaca Schrader, x20 (Lister); d, sporangium of Orca- della operculata Wingate, X80 (Lister); e, Cluster of sporangia of Tuhulina Jragijormis Persoon, x3 (Lister); f, Aethalium of Reticularia lycoperdon Bull., Xl (Lister); g, Aethalium of Lycogala miniatum Persoon, Xl (Lister); h-j, Trichia affinis de Bary (h, group of sporan- gia, X2; i, elater, X250; j, spore, X-iOO) (Lister); k,\, Arcyriapunicea Persoon (k, four sporangia, X2; 1, part of capillitium, X250 and a spore, X560) (Lister); m, n, Ceratiomyxa fruticulosa MacBride (m, sporophore, X40; n, part of mature sporophore, showing two spores, X480) (Lister). Genus Tubulina Persoon (Fig. 137, e) Sporangia without tubular extensions. Many sporangia more or less closely fused to form large bodies (aethalia); sporangium-wall incomplete and perforated Family 4 Reticulariidae Genus Reticularia Bulliard (Fig. 137, /) Walls of convoluted sporangia incomplete, forming tubes and folds with numerous anastomosing threads. Sporangia forming aethalium Family 5 Lycogalidae 302 PROTOZOOLOGY Genus Lycogala Adan.son (Fig. 137, (j) Capillitium a system of uniform threads. .Sublegion 2 Caloneminea Capillitium Threads with spiral or annular thickenings Family 1 Trichiidae Genus Trichia Haller (Fig. 137, h-j) Capillitium abundant, consisting of free elasters with spiral thickenings. Capillitium combined into an elastic network with thickenings in forms of cogs, half-rings, spines, or warts Family 2 Arcyriidae Genus Arcyria Wiggers (Fig. 137, k, I) Sporangia stalked; sporangium-wall evanescent above, persist- ent and membranous in the lower third. Capillitium abundant; sporangia normally sessile Family 3 Margaritidae Genus Margarita Lister Capillitium profuse, long, coiled hair-Hke. Spores develop on the surface of sporophores . . Tribe 2 Exosporeae Spores white; borne singly on filiform stalk Family Ceratiomyxidae Genus Ceratiomyxa Schroter (Fig. 137 m, n) Suborder 2 Sorophora Lister Pseudoplasmodium incomplete; myxamoeba of limax-form Family 1 Guttuliniidae Pseudoplasmodium complete; myxamoeba with short pointed pseudopodia Family 2 Dictyosteliidae The Proteomyxa and the Mycetozoa as outlined above, are not distinctly defined groups. Li reality, there are a number of forms which stand on the border line between them. Phytomyxinae Schroter These organisms which possess a large multinucleate amoeboid body, are parasitic in various plants and also in a few animals. They do not form any sporangium and their methods of spore- formation are simple. Genus Plasmodiophora Woronin. Parasitic in the root of the MYCETOZOA 303 h ^ c e f Fig. IBS. Plasinodiophora brassicae. a, root-hernia of cabbage; b, a spore, X620; c-e, stages in germination of spore, X620; f, myxamoeba, X620 (Woronin); g, a host cell with several young parasites, X400; h, an older parasite, X400 (Nawaschin). cabbage and other Cruciferae. The organism produces knotty enlargements, sometimes known as 'root-hernia,' or 'fingers and toes' (Fig. 138, a). The small spore (h) gives rise to a myxo- flagellate (c-f) which penetrates into the host cell. The organism grows in size and the nucleus divides (g). Several myxamoebae fuse into a plasmodium, thus destroying the host cells. The nuclei undergo mitotic division and finally the plasmodium divides into a large number of simple spores. P. hrassicae W. (Fig. 138). In the species of Brassica. Other genera are Sorosphaera Schroter, parasitic in Veronica; Tetramyxa Goebel, forming gall in Ruppia, etc. References DE Bary. 1864 Die Mycetozoa. Leipzig. Jahn, E. 1901-1920 Myxomycetenstudien. I to X. Ber. Deutsch. Bot. Ges., Vols. 19, 20, 22-26, 29, 36 and 37. Jones, P. M. 1928 Morphology and cultural study of Plas- modiophora hrassicae. Arch. f. Protistenk., Vol. 62. Lister, A. 1924 A monograph on the Mycetozoa. 3rd ed. London. MacBride, T. H. 1922 North American slime molds. 2nd ed. New York. Palm, B. T. and Myrle Burk 1933 The taxonomy of the Plasmodiophoraceae. Arch. f. Protistenk., Vol. 79. Chapter 18 Order 3 Amoebina Ehrenberg THE Amoebina show a very little cortical differentiation. There is no pellicle or test, surrounding the body, although in some there are indications that a very thin and delicate pellicle exists. The cytoplasm is more or less distinctly differentiated into the ectoplasm and the endoplasm. The ectoplasm is hyaHne and homogeneous, and appears tougher than the endoplasm. In the endoplasm which is granulated or vacuolated, are found one or more nuclei, various food vacuoles, crystals, and other inclusions. In the freshwater forms, there is at least one distinctly visible contractile vacuole. The pseudopodia are lobopodia, and ordinarily both the ectoplasm and endoplasm are found in them. They are formed by streaming or fountain movements of the cytoplasm. In some members of this order, the formation of pseudopodia is described as eruptive or explosive, since the granules present in the endoplasm break through the border line between the two cytoplasmic layers and suddenly flow into the pseudopodia. The life-history is not completely known, even among the species of the genus Amoeba. Asexual reproduction is ordinarily by binary fission, although multiple fission may occasionally take place. Encystment is of common occurrence. Sexual reproduction, which has been reported in a few species, has not been confirmed. The Amoebina inhabit all sorts of fresh, brackish and salt waters. They are also found in moist soil and on ground covered with decaying leaves. Many are inhabitants of the digestive tract of various animals, and some are pathogenic to the hosts. The taxonomic status of the group is highly uncertain and con- fusing, since their life-histories are mostly unknown and since numerous protozoans other than the members of this group often possess amoeboid stages. Forms such as Rhizomastigina (p. 235) may be considered as belonging to either the Sarcodina or the Mastigophora. The order is subdivided into three families as follows : With amoeboid and flagellate stages Family 1 Dimastigamoebidae (p. 305) 304 AMOEBINA 305 Amoeboid stage only With one or more nuclei of one kind Free-living Family 2 Amoebidae (p. 306) Parasitic Family 3 Endamoebidae (p. 312) With a 'secondary nucleus' Family 4 Paramoebidae (p. 321) Family 1 Dimastigamoebidae Wenyon The members of the two genera placed in this family possess both amoeboid and flagellate phases {diphasic). In the former, the organism undergoes amoeboid movement by means of lobo- podia and in the latter the body is more or less elongated. Binary fission seems to take place during the amoeboid phase only. Thus these are diphasic protozoans, in which the amoeboid stage pre- dominates over the flagellate. The amoeboid phase resembles a 'limax' amoeba; under natural circumstances, it is often exceed- ingly difficult by observing the amoeboid stage only, to deter- mine whether they belong to this family or the family Amoebidae. Genus Dimastigamoeba Blochmann {Naegleria Alexeieff). Minute; flagellate stage with 2 flagella; amoeboid stage resembles Vahlkampfia (p. 310), with lobopodia; cytoplasm differentiated; vesicular nucleus with a large endosome; contractile vacuole con- spicuous; food vacuoles contain bacteria; cysts uninucleate; free-living in stagnant water and often coprozoic. Fig. 139. a-c, trophozoite, flagellate phase and cyst (all stained) of Dimastigamoeba gruberi, X750 (Alexeieff); d-f, similar stages of D. bistadialis, X750 (Kiihn); g-j, trophozoite, flagellate phase, cyst and excj'station of Trimastig amoeba philippinensis, X950 (Whitmore). D. gruberi (Schardinger) (Fig. 139, a-c). Amoeboid stage 10- 50 fjL long; cyst wall with several openings; flagellate stage 10-30/x long. 306 PROTOZOOLOGY D. histadialis (Puschkarew) (Fig. 139, d-J). Similar in size; but cyst with a smooth wall. Genus Trimastigamoeba Whitmore. Flagellate stage bears 3 flagella of nearly equal length; vesicular nucleus with a large endosome; amoeboid stage small, less than 20;u in diameter; uni- nucleate cysts with smooth wall; coprozoic. One species. T. pMUppinensis W. (Fig. 139. g-j). Amoeboid stage 16-18ai in diameter; oval cysts 13-14^ by 8-12//; flagellate stage 16-22^ by e-S/x. Family 2 Amoebidae Bronn These amoebae do not have flagellate stage and are exclusively amoeboid (monophasic). They are free-living in fresh or salt wa- ter, in damp soil, moss, etc., and a few parasitic; 1, 2, or many nuclei; contractile vacuoles in freshwater forms; multiplication by binary or multiple fission; encystment common. Genus Amoeba Ehrenberg (Chaos Linnaeus; Proteus M tiller; Amiba Bory). Amoeboid; naked, in a few species there are indi- cations that a delicate pellicle occurs; usually with a nucleus, vesicular or somewhat compact; contractile vacuoles; pesudopo- dia mainly lobopodia, never anastomosing with one another; some students have used the nuclear structure for specific dif- ferentiation, but unfortunately not always clear; holozoic; fresh, brackish or salt water. Numerous species. A. proteus (Pallas) (Figs. 25; 32, b, c; 39,/; 41-43; 140, a, b). Up to 600 fx or longer in largest diameter; creeping with a few large lobopodia, showing longitudinal ridges; ectoplasm and en- doplasm usually distinctly differentiated; typically uninucleate; nucleus discoidal, but polymorphic; endoplasmic crystals trun- cate bipyramid, up to 4.5^ long (Schaeffer); nuclear and cytoso- mic divisions show a distinct correlation (p. 137); fresh water. A. discoides Schaeffer (Figs. 39, g; 140, c). About 400m long dur- ing locomotion; a few blunt, smooth pseudopodia; crystals abundant, truncate bipyramidal, about 2.5m long (Schaeffer); en- doplasm with numerous coarse granules; fresh water. A. dubia S. (Figs. 39, h-l; 140, d). About 400/i long; numerous pseudopodia flattened and with smooth surface; crystals, few, large, up to 30ju long and of various forms among which at least 4 types are said to be distinct; contractile vacuole one or more; fresh water. A. verrucosa Ehrenberg (Figs. 32, a, d-h; 40, a; 140, e). Ovoid AMOEBINA 307 Fig. 140. a, b, Amoeba proteus (a, Xl30 (Schaeffer), b (Doflein)); c, A. discoides, XlBO (Schaeffer); d, A. dubia, XlBO (Schaeffer); e, A. verrucosa, X200 (Cash); f, A. striata, X400 (Penard); g, A. gut- tula, X800 (Penard); h, A. limicola, X530 (Penard). in general outline with wart-like expansions; body surface usually wrinkled, with a definite pellicle; pseudopodia short, broad and blunt; nucleus ovoid; contractile vacuole; up to 200/^ in diameter; fresh water among algae. A. striata Penard (Fig. 140, /). Somewhat similar to A. verru- cosa, but small; body flattened; ovoid, narrowed and rounded posteriorly; contractile vacuole comparatively large and often 308 PROTOZOOLOGY not s])lH'rical; extrcmoly delicate pellicle shows 3 or 4 fine longi- tudinal lines which appear and disappear with the movement of the body; 25-45iu by 20-35//; fresh water among vegetation. .4. guttula Diijardin (Fig. 140, g). Ovoid during locomotion, narrowed behind; often with a few minute, nipple-like dentations at the temporary posterior end; movement by wave-like expan- sions of ectoplasm; endoplasm granulated, with crystals; a single contractile vacuole; 30-35m by 20-25^; fresh water in vegetation. A. limicola Rhumbler (Fig. 140, h). Somewhat similar to A. guttula; body more rounded; locomotion by eruption of cyto- plasm through the body surface; 45-55/^ by 35/^; fresh water among vegetation. A. spumosa Gruber (Fig. 141, a). Somewhat fan-shaped; flat- tened; during locomotion broad pseudopodia with pointed end at temporary anterior region; posterior region with nipple-like projections; a small number of striae become visible during movement, showing there is a very thin pellicle; endoplasm al- ways vacuolated, the vacuoles varying in size (up to SO/j. in di- ameter) ; vesicular nucleus with an endosome; 50 125^1 long during locomotion; fresh water. A. vespertilio Penard (Fig. 141, h, c). Pseudopodia conical, com- paratively short, connected at base by web-like expansions of ectoplasm ; endoplasm colorless, with numerous granules and food particles ; a single nucleus with a large endosome ; contractile vac- uoles; 60-100^1 long; fresh water. A. gorgonia P. (Fig. 141, d-f). Body globular when inactive with a variable number of radiating 'arms,' formed on all sides; locomotion by forming elongate pseudopodia, composed of both ectoplasm and endoplasm; 40-50/i in diameter; extended forms about 100// long; fresh water among vegetation. A. radiosa Ehrenberg (Fig. 141, g). Small, usually inactive; globular or oval in outline; with 3-10 radiating slender pseudo- podia which vary in length and degree of rigidity; when pseudo- pods are withdrawn, the organism may be similar to A. proteus in general appearance; pseudopods straight, curved or spirally coiled; size varies, usually about 30/i in diameter, up to 120/x or more; fresh water. Genus Dinamoeba Leidy. Essentially Amoeba, but the tempo- rary posterior region of body with retractile papillae; body sur- face including pseudopods and papillae, bristling with minute AMOEBINA 309 Fig. 141. a, Amoeba spumosa, x400 (Penard); b, c, A. vespertilio, X300 (Penard); d-f, A. gorgonia, X400 (Penard); g, A. radiosa, X500 (Penard); li, Dinamoeha mirabilis, X250 (Leidy). spicules or motionless cils; often surrounded by a thick layer of delicate hyaline jelly, even during locomotion; fresh water. Z>. mirabilis L. (Fig. 141, h). Oval to limaciform; spheroid when 310 PROTOZOOLOGY floating; pseudopodia numerous, conical; ectoplasm clear, usually with cils; endoplasm with food vacuoles, oil (?) spherules and large clear globules; nucleus and contractile vacuole obscure; spherical forms 64-160^1 in diameter; creeping forms 152-340/1 by 60-220/x; in sphagnous swamp. Genus Pelomyxa Greeff. Large sluggish amoebae; with a few to numerous nuclei; cytoplasm poorly differentiated; pseudopodia few, short, and broad; animal undergoes rolHng movement; with diatoms, bacteria, water vacuoles, sand grains and refractile bodies which are thought to be either reserve food material simi- lar to glycogen or metabohc products used by symbiotic bac- teria; contractile vacuole has not been noticed with certainty, multiphcation by binary fission; gamete formation has been re- ported; it is presumed that uninucleate bodies undergo fusion to form zygotes which develop into multinucleate forms; fresh wa- ter. Several species. P. palustris G. (Fig. 142, a). Large; 150^-2 mm. or larger in diameter; sluggish with one broad pseudopodium by which the organism undergoes rolling movement; cytoplasm undifferen- tiated; numerous vacuoles and nuclei; various inclusions often color the body brown to black and make it appear opaque; sym- biotic protophytan, Cladothrix pelomyxae Veley, occurs regularly; cysts with 2-3 envelopes ; cyst contents divide into several multi- nucleate bodies; in stagnant water, creeping on the muddy bot- tom. P. villosa (Leidy) (Fig. 142, h). Similar to the last-named spe- cies, but somewhat smaller; with numerous short and papillary villi at posterior extremity; during locomotion, about 250/^ long; in the ooze of freshwater bodies. Genus Vahlkampfia Chatton et Lalung-Bonnaire. Small amoe- bae; vesicular nucleus with a large endosome and peripheral chromatin; with polar caps during nuclear division; snail-hke movement, with one broad pseudopodium; cysts with a perfo- rated wall ; fresh water or parasitic. V. Umax (Dujardin) (Fig. 142, c). 30-40// long; fresh water. V. patuxent Hogue (Fig. 142, d). In the alimentary canal of the oyster; about 20/i long during the first few days of artificial culti- vation, but later reaching as long as 140/i in diameter; ordinarily one large broad fan-shaped pseudopodium composed of the ecto- plasm; in culture, pseudopodium-formation eruptive; holozoic on AMOEBINA Fig. 142. a, Pelomyxa palustris, Xl30 (Kiihn); b, P. villosa, X420 (Leidy); c, Vahlkampfia Umax, XS30 (Kudo); d, V. patuxent, X830 (Hogue); e, f, Hartmamiella hyalina, X1170 (Dobell); g, h, H. castel- lanii, X1590 (Hewitt). bacteria; multiplication by fission or budding; encystment rare; cysts uninucleate. Genus Hartmannella Alexeieff. Small amoebae with the follow- ing nuclear characteristics: vesicular; large endosome central and chromatin granules scattered along the periphery; at the time of division endosome disintegrates and chromosomes and spindle fibers appear; there are no so-called polar caps during division as are found in Vahlkampfia, from which differentiation is difficult. H. hyalina (Dangeard) (Fig. 142, e, f). Body more or less rounded; less than 20/i in diameter; a contractile vacuole; binary fission; spherical cyst, 10-15/x in diameter, covered with a smooth inner and a much wrinkled outer wall ; easily cultivated from old faeces of man and animals; also in soil and fresh water. H. castellanii Douglas (Fig. 142, g, h). In association with fungi 312 PROTOZOOLOGY and certain bacteria; Hewitt obtained it from agar cultures of a sample soil taken from among the roots of white clover; co-exist- ing with yeast-like fungi, Flavohacterium trifolium and Rhizohium sp. ; 12-30/i in diameter; cyst membrane without pore; some cysts viable at 37°C. for 6 days. Genus Sappinia Dangeard. With two closely associated nuclei. S. diploidea (Hartmann et Nagler). Coprozoic in the faeces of different animals; pseudopodia short, broad, and few; highly vacuolated endoplasm with 2 nuclei, food vacuoles, and a con- tractile vacuole; surface sometimes wrinkled; the nuclei divide simultaneously; during encystment, two individuals come to- gether and secrete a common cyst wall; 2 nuclei fuse so that each individual possesses a single nucleus; finally cytoplasmic masses unite into one; each nucleus gives off reduction bodies (?) which degenerate; 2 nuclei now come in contact without fusion, thus producing a binucleate cyst (Hartmann and Nagler). Family 3 Endamoebidae Calkins Exclusively endoparasitic amoebae; the vegetative form is rela- tively small and occurs mostly in the alimentary canal of the host; contractile vacuoles absent, except in Hydramoeba; multi- plication by binary fission; encystment common. The generic dif- ferentiation is based upon morphological characteristics of the nucleus. Summary No. 99 of 'Opinions Rendered' by the Inter- national Commission of Zoological Nomenclature (1928) holds that Entamoeba is a synonym of Endamoeba; in the present work, however, Endamoeba and Entamoeba are separated, since the two groups of species placed under them possess different nu- clear characteristics and since it is not advisable to establish an- other generic name in place of Entamoeba which has been so fre- quently and widely used throughout the world. Genus Endamoeba Leidy. Nucleus spheroidal to ovoid; mem- brane thick; in life, filled with numerous granules of uniform di- mensions along its peripheral region; upon fixation, a fine chro- matic network becomes noticeable in their stead; central portion coarsely reticulated; with several endosomes between the two zones; in some, cytoplasm becomes prominently striated during locomotion; in the intestine of invertebrates. E. hlattae (Biitschh) (Figs. 49; 143). In the colon of cock- roaches; 10-150m in diameter; rounded individuals with broad AMOEBINA 313 pseudopodia, show a distinct differentiation of cytoplasm; elon- gated forms with a few pseudopodia, show ectoplasm only at the extremities of the pseudopods; endoplasm of actively motile troph- ozoites shows a distinct striation, a condition not often seen in other amoebae; fluid-filled vacuoles occur in large numbers; amoebae feed on starch grains, yeast cells, bacteria and proto- zoans, all of which coexist in the host organ; cysts commonly Fig. 143. Endamoeha blattae. a-c, X530; d-f, X700 (Kudo). seen in the colon contents, with often more than 60 nuclei. The life-cycle of this amoeba is still unknown. Mercier (1909) held that when the multinucleate cysts gain entrance to the host in- testine through its mouth, each of the cyst-nuclei becomes the center of a gamete; when the cyst-membrane ruptures, the gam- etes are set free and anisogamy takes place, resulting in forma- tion of numerous zygotes which develop into the habitual tropho- zoites. Among the more recent investigators, Morris (1936) is 314 PROTOZOOLOGY inclined to think that sexual reproduction brings about 'zygotic adults.' The nucleus has been studied by Meglitsch (1939). E. thomsoni Lucas. In colon of the cockroaches; 7-30// in diameter; very adhesive; 1-3 chromatin blocks on the nuclear membrane; cysts 8-16// in diameter, with 1-4 nuclei. E. disparata Kirby. In colon of Microterines hispaniolae; 20- 40/i long; active; xylophilous. E. majestas K. (Fig. 144, a). In the same habitat; 65-165/t in diameter; many short pseudopodia; cytoplasm filled with food particles. E. simulans K. (Fig. 144, h). In the gut of Microiermes pana- maensis; 50-1 50/i in diameter. Fig. 144. a, Endamoeha majestus, X420 (Kirby); b, E. simnlans, X420 (Kirby); c, Entamoeba brasiliensis in Zelleriella, X290 (Stabler and Chen). E. sahulosa K. In the same habitat; small, 19-35/i in diameter Genus Entamoeba Casagrandi et Barbagallo. Nucleus vesic- ular, with a comparatively small endosome, located in or near the center and with varying number of peripheral chromatin granules attached to the nuclear membrane. It was established by the two Italian authors who were unaware of the existence of the genus Endamoeba (p. 312). Numerous species in vertebrates or invertebrates. E. histolytica Schaudinn (Fig. 145, a-f). 20-30/i in diameter; cytoplasm usually differentiated distinctly; eruptive formation of large lobopodia, composed exclusively of ectoplasm; the vesicular nucleus appears in life as a ring, difficult to recognize; food vacu- AMOEBINA 315 oles contain erythrocytes, tissue cells, leucocytes, etc.; stained nucleus shows a membrane, peripheral chromatin granules, a centrally located small endosome, and indistinct network with a few scattered chromatin granules. The trophozoites invade the tissues of the gut-wall of man and multiply by binary fission. Under certain circumstances not well understood, the amoeba extrudes its food material and becomes smaller in size, possibly by division also. Such a form is sluggish and shows frequently glycogen bodies and elongated refractile bodies which stain deep- ly with a nuclear stain (hence called chromatoid bodies). This stage is known as the precystic stage. The cyst is formed when the precystic form ceases to move about and becomes surrounded by a definite cyst-membrane which it secretes. The cysts measure 5-20;u in diameter. At first it contains a single nucleus which divides twice and tetranucleate cyst is thus formed. The glycogen and chromatoid bodies become absorbed, as the cyst grows older. The change between the cyst and the young trophozoite is not definitely known, although in recent years several investigators such as Dobell, Cleveland and Sanders and others, have been able to cultivate the amoeba in vitro and noted the excystment fol- lowed by division into up to 8 uninucleate amoebulae, each of which grows into a mature trophozoite. There is no evidence that sexual reproduction occurs in its development. This amoeba was first definitely recognized by Losch in Russia in 1875. It is now known to have a wide geographical distribution. The incidence of infection in man depends mainly upon the sanitary conditions of the community, since the amoeba is car- ried from man to man in the encysted stage. Faecal examinations which have been carried on by numerous investigators in different parts of the world, reveal that the incidence of the infection runs as high as 50 per cent. In the United States 49,336 examinations conducted in various localities show infection rate varied from 0.2 -53 per cent, averaging 11.6 per cent, which justifies Craig's (1926) early estimate that ten per cent of the general population harbor this organism. An acute infection by Entamoeba histolyt- ica is accompanied by dysentery, while in chronic cases, the host may void a number of infective cysts without suffering himself. Such a person is known as a 'carrier.' The amoeba invades the liver also and produces in it various abscesses of a serious nature. Numerous varieties are known. Cats and dogs are easily infected 316 PROTOZOOLOGY especially per anum by this amoeba and show typical symptoms. Spontaneous dysentery among cats due to this organism has also been noticed. Fig. 145. a-f, Entamoeha histolytica (a, trophozoite; b, precj^stic stage; c, cyst, X1330; d-f, excystment, X930) (a-c (Kudo); d-f (Yorke and Adams)); g, h, E. coli, X1330 (Kudo); i-k, E. gingivalis, X670 (Kudo). E. coli (Losch) (Fig. 145, g, h). Trophozoites 15-40jU in diame- ter; cytoplasm indistinctly differentiated; lobopodia slowly formed and movement sluggish; food vacuoles contain var3dng number of bacteria, also erythrocytes in a few cases (Tyzzer and Geiman); nucleus observable in vivo; compared with E. histolyt- ica, the endosome is somewhat larger and located eccentrically and peripheral chromatin granules more conspicuous; multiplica- tion by binary fission; precystic stage very similar in appearance to that of E. histolytica; mature cyst contains normally 8 nuclei and measures lO-SO^u in diameter; in young cysts there are gly- cogen bodies which are comparatively larger than those found in the last-named species; chromatoid bodies splinter-like and often grouped. This amoeba seems to have been observed first by Lewis in 1870 in India. It is a commensal in the human intestine and widely distributed throughout the world. AMOEBINA 317 E. gingivalis (Gros) {E. huccalis Prowazek) (Fig. 145, i-k). Fairly active amoeba; a few lobopodia are formed and retracted rapidly; 10-40ju long, the majority measuring 10-20^1 in diame- ter; cytoplasm distinctly differentiated; endoplasm with host tis- sue cells, bacteria, etc.; nucleus similar to that of E. histolytica, but endosome not always central; multiplication by binary fis- sion; cyst is unknown, and therefore transmission of the amoeba from man to man is considered to be direct. This amoeba is the first endoparasitic amoeba known to man and was observed by Gros in 1849 in human tartar. As to the ef- fect of the amoeba upon the host, some workers believe that it is the probable cause of pyorrhoea alveolaris, while the majority of investigators are inclined to think that it is a commensal of the human mouth. E. gedoelsti Hsiung (E. intestinalis (Gedoelst)). In colon and caecum of horse; 6-13^ by 6-11^; endomsome eccentric; bacteria- feeder. E. equi Fantham. 40-50/u by 23-29ju; nucleus oval; cysts tetra- nucleate, 15-24/x in diameter; seen in the faeces of horse; Fan- tham reports that the endoplasm contained erythrocytes. E. hovis Liebetanz. 5-20^ in diameter; in stomach of cattle. E. ovis Swellengrebel. Cyst uninucleate; in intestine of sheep. E. caprae Fantham. In goat intestine. E. polecki (Prowazek). In colon of pigs; 10-12yu in diameter; cyst uninucleate. E. debliecki Nieschulz. In intestine of pig; S-lOju in diameter; cyst uninucleate. E. venaticum Darling. In colon of dog; similar to E. histolytica; since the dog is experimentally infected with the latter, this amoeba discovered from spontaneous amoebic dysentery cases of dogs, in one of which was noted abscesses of liver, is probably E. histolytica. E. cuniculi Brug. Similar to E. coli in both trophic and en- cysted stages; in intestine of rabbits. E. cohayae Walker (E. caviae Chatton). Similar to E. coli; in intestine of guinea-pigs. E. muris (Grassi). Similar to E. coli; in intestine of rats and mice. E. gallinarum Tyzzer. In fowls intestine; cysts octonucleate. E. testudinis Hartmann. In intestine of turtles, Testudo graeca, T. argentina, T. calcarata and Terrapene Carolina. 318 PROTOZOOLOGY E. barreti Taliaferro et Holmes. In colon of snapping turtle, Chelydra serpentina. E. terrapinae Sanders et Cleveland. Trophozoites 10-15ju long; cysts 8-14ju in diameter, tetranucleate when mature; in colon of Chrysemys elegans. E. serpentis da Cunha et da Fonseca. In intestine of the snake, Driniohius bifossatus in South America. E. ranarum (Grassi) (Fig. 146, a, b). In colon of various species of frogs; resembles E. histolytica; 10-50^ in diameter; cysts are usually tetranucleate, but some contain as many as 16 nuclei; amoebic abscess of the liver was reported in one frog. E. minchini Mackinnon. In gut of tipulid larvae; 5-30^1 in diameter; cyst nuclei up to 10 in number. E. mesnili Keilin. In gut of dipterous insects, Trichocera hie- malis and T. annulata (larvae); 6-24;u long and multinucleate; plasmotomy; cysts 8-1 1m in diameter, with 2 or 4 nuclei. E. apis Fantham et Porter. In Apis mellifica; similar to E. coli. E. brasiliensis (Carini) (Fig. 144, c). In the cytoplasm of many species of Protociliata; trophozoites 5.3-14.3ju in diameter; cysts about 9.4^ in diameter, uninucleate; no effect upon host ciliates even in case of heavy infection (Stabler and Chen). Genus Endolimax Kuenen et Swellengrebel. Small; vesicular nucleus with a comparatively large irregularly shaped endosome, composed of chromatin granules embedded in an achromatic ground mass and several achromatic threads seen connecting the endosome with membrane; commensal in hindgut in man or ani- mals. Several species. E. nana (Wenyon et O'Connor) (Fig. 146, c, d). In colon of man; lobopodia formed quite actively, but sluggish; 6-1 2yu in diameter; cytoplasm fairly well differentiated into 2 zones; nu- cleus difficult to make out in life; food vacuoles contain bacteria; cyst ovoid, 8-10^ in diameter, tetranucleate when mature; widely distributed. E. gregariniformis (Tyzzer). In caecum of fowls; 4-1 2/i in diameter; cysts uninucleate. E. ranarum Epstein et Ilovaisky (Fig. 146, e, /). In colon of frogs; cyst octonucleate, up to 25ij. in diameter. E. blattae Lucas. In colon of cockroaches; 3-15^ long; cyst with more than one nucleus. Genus lodamoeba Dobell. Vesicular nucleus, with a large en- AMOEBINA 319 dosome rich in chromatin, a layer of globules which surrounds the endosome and which do not stain deeply, and achromatic strands between the endosome and membrane; cysts ordinarily uninu- cleate, contain a large glycogenous vacuole which stains con- spicuously with iodine; in intestine of man or mammals. /. butschlii (Prowazek) (/. williamsi (P.)) (Fig. 146, g, h). In colon of man; sluggish; 9-18m in diameter; cytoplasm with bac- teria in food vacuoles; cysts mostly irregular in shape, 6-15ai in diameter. Fig. 146. a, b, Entamoeba ranarum, X1090 (Mercier and Mathis); c, d, Endolimax nana, X1670 (Kudo); e, f, E. ranarum., XS40 (Ep- stein and Ilovaisky); g, h, lodanioeba butschlii, X1670 (Kudo); i-k, Di- entamoeba fragilis, X1840 (Kudo). 7. suis O'Connor. In colon of pig; widely distributed; indis- tinguishable from I. butschlii; it is considered by some that pigs are probably reservoir host of I. butschlii. Genus Dientamoeba Jepps et Dobell. Small amoeba; number of binucleate trophozoites often greater than that of uninucleate forms; nuclear membrane delicate; endosome consists of several chromatin granules embedded in plasmosomic substances and connected with the membrane by delicate strands; in colon of man. D. fragilis J. et D. (Fig. 146, i-k). 4-12/i long; cysts unknown. Genus Schizamoeba Davis. Nucleus vesicular, without endo- 320 PROTOZOOLOGY some, but with chromatin granules arranged along nuclear mem- brane; 1 to many nuclei; cyst-nuclei formed by fragmentation of those of the trophozoite and possess a large rounded chromatic endosome, connected at one side with the nuclear membrane by achromatic strands, to which chromatin granules are attached; in stomach of salmonoid fish. One species. S. salmonis D. (Fig. 147, a, h). Sluggish amoeba; 10-25m in diameter; 1 to several nuclei; multiplication by binary fission; nu- clear division amitotic. Cysts are said to be more abundant than trophozoites and their appearance seems to be correlated with the amount of available food; cysts spherical, 15-35)U in diameter; Fig. 147. a, b, Schizamoeba salmonis, xSOO (Davis); c, d, Hydra- moeba hydroxena (c, a heavily infected Hydra oligactis which lost its tentacles, X70; d, section of an infected hydra showing a trophozoite feeding on ectodermal cells, X350) (Reynolds and Looper); e, Para- moeba pigmentifera with its nucleus in the center, X600 (Janicki). • cyst-membrane thin and nuclei vary from 3 to many; during en- cystment, chromatin bodies of trophozoite become collected in several masses which then disintegrate and each chromatin grain becomes the endosome of newly formed nucleus; cyst contents divide sooner or later into 4-11 multinucleate bodies and the whole increases in size; finally cyst-membrane disintegrates and the multinucleate bodies become set free. Trophozoites are said to occur in the mucous covering of stomach of host fish; cysts occur in both stomach and intestine. Aside from the loss of certain amount of available food, no pathogenic effect of the amoeba up- on the host fish was noticed by Davis. Genus Hydramoeba Reynolds et Looper. Nucleus vesicular with a large central endosome composed of a centriole (?) and chromatin granules embedded in an achromatic mass, achromatic AMOEBINA 321 strands radiating from endosome to membrane; a ring made up of numerous rod-shaped chromatin bodies in the nuclear-sap zone; 1 or more contractile vacuoles; apparently the most primi- tive parasitic amoeba; parasitic on Hydra. H. hydroxena (Entz) (Fig. 147, c, d). Parasitic in various species of Hydra; first observed by Entz; Wermel found 90 per cent of Hydra he studied in Russia were infected by the amoeba; Rey- nolds and Looper stated that infected Hydra die on an average in 6.8 days and that the amoebae disappear in 4-10 days if removed from a host Hydra. More or less spheroidal, with blunt pseudo- pods; 60-380^1 in diameter; nucleus shows some 20 refractile pe- ripheral granules in hfe; contractile vacuoles; food vacuoles con- tain host cells; multiplication by binary fission; encystment has not been observed. Family 4 Paramoebidae Poche Genus Paramoeba Schaudinn. The amoeba possesses a nucleus and nucleus-like secondary cytoplasmic structure, both of which multiply by division simultaneously; free-living or parasitic. P. pigmentifera (Grassi) (Fig. 147, e). About SO/i long; slug- gish; cytoplasm distinctly differentiated; secondary body larger than the nucleus; flagellated swarmers are said to occur; parasitic in coelom of Chaetognatha such as Sagitta claparedei, Spadella hipunctata, S. inflata, and S. serratodentata. P. schaudinni Faria, da Cunha et Pinto. About 7-22// in diame- ter; in salt water; Rio de Janeiro, Brazil. References BoECK, W. C. and C. W. Stiles 1923 Studies on various intesti- nal parasites (especially amoebae) of man. U. S. Public Health Service, Hyg. Lab. Bull., No. 133. Cash, J. 1905 The British freshwater Rhizopoda and Heliozoa. Vol. 1. Chalkley, H. W. and G. E. Daniel 1933 The relation between the form of the living cell and the nuclear phases of division in Amoeba proteus (Leidy). Physiol. Zool., Vol. 6. Craig, C. F. 1934 Amebiasis and amebic dysentery. Springfield. DoBELL, C. and F. W. O'Connor 1921 The intestinal Protozoa of man. KiRBY, H., Jr. 1927 Studies on some amoebae from the termite Microtermes, with notes on some other Protozoa from the Termitidae. Quart. Jour. Micr. Sci., Vol. 71. 322 PROTOZOOLOGY Kudo, R. R. 1926 Observations on Endamoeba hlattae. Amer. Jour. Hyg., Vol. 6. Leidy, J. 1879 Freshwater Rhizopods of North America. Report U. S. Geol. Siirv. Terr., Vol. 12. Morris, S. 1935 Studies of Endamoeba hlattae (Biitsehli). Jour. Morph., Vol. 59. Penard, E. 1890 Etudes sur les rhizopodes d'eau douce. Mem. soc. phys. et I'hist. nat. Geneve, Vol. 31. 1902 Faune rhizopodique du Bassin du Leman. Geneva. ScHAEFFER, A. A. 1917 Notcs on the specific and other char- acteristics of Amoeha proteus Pallas (Leidy), A. discoides spec, nov., and A. dubia spec. nov. Arch. f. Protistenk., Vol. 37. Wenyon, C. M. 1926 Protozoology. Vol. 1. Chapter 19 Order 4 Testacea Schultze THE Testacea or Thecamoeba comprise those amoeboid or- ganisms which are enveloped by a simple shell or test, within which the body can completely be withdrawn. The shell has usu- ally a single aperture through which pseudopodia protrude, and varies in shape and structure, although a chitinous or pseudo- chitinous membrane forms the basis of all. It may be thickened, as in Arcella and others, or composed of foreign bodies cemented together as in Diflflugia, while in Euglypha siliceous platelets or scales are formed in the endoplasm and deposited on the mem- brane. The cytoplasm is ordinarily differentiated into the ectoplasm and endoplasm. The ectoplasm is conspicuously observable at the aperture of the shell where filopodia or slender ectoplasmic lobo- podia are produced. The endoplasm is granulated or vacuolated and contains food vacuoles, contractile vacuoles and nuclei. In some forms there are present regularly in the cytoplasm numerous basophilic granules which are known as 'chromidia' (p. 35). Asexual reproduction is either by longitudinal fission in the forms with soft tests, or by transverse division or budding, while in others multiple division occurs. Encystment is common. Sexual reproduction by amoeboid or flagellate gametes has been re- ported in some species. The testaceans are mostly inhabitants of fresh water, but some live in salt water and others are semi-terrestrial, being found in moss or moist soil, especially peaty soil. Shell simple and membranous Filopodia, often anastomosing Family 1 Gromiidae Pseudopodia filose, simply branched. . .Family 2 Arcellidae (p. 327) Shell with foreign bodies, platelets, or scales With foreign bodies Family 3 Difflugiidae (p. 334). With platelets or scales Family 4 Euglyphidae (p. 339). Family 1 Gromiidae Eimer et Fickert These forms are frequently included in the Foraminifera by other authors. Genus Gromia Dujardin (Allogromia, Rhynchogromia, Diplo- 323 324 PROTOZOOLOGY An ^ Fig. 148. a, Gromia fluvialis, Xl20 (Dujardin); b, G. ovoidea, X50 (Schultze); c, G. nigricmis, x200 (Cash and Wailes); d, Microgromia socialis, Xl70 (Cash); e, Microcoinetes paludosa, X670? (Penard); f, Artodiscus salta7is, X670 (Penard); g, Schultzella diffluens, Xl20 (Rhumbler). TESTACEA 325 gromia, Rhumbler). Thin test rigid or flexible, smooth or shghtly coated with foreign bodies; spherical to elongate ellipsoid; aper- ture terminal; 1 or more nuclei; contractile vacuoles; many filo- podia, branching and anastomosing; cytoplasm with numerous motile granules; fresh or salt water. Many species. G. fluvialis D. (Fig. 148, a). Test spherical to subspherical; smooth or sparsely covered with siliceous particles; yellowish cy- toplasm fills the test; aperture not seen; a large nucleus and nu- merous contractile vacuoles; filopodia long, often enveloping test; 90-250yu long; on aquatic plants, in moss or soil, G. ovoidea (Rhumbler) (Fig. 148, 6). In salt water. G. nigricans (Penard) (Fig. 148, c). Test large, circular in cross- section; a single nucleus; 220-400/x long; in pond water among vegetation. Genus Microgromia Hertwig et Lesser. Test small, hyaline, spherical or pyriform, not compressed; aperture terminal, circu- lar; filopodia long straight or anastomosing, arising from a pe- duncle; a single nucleus and contractile vacuole; solitary or grouped. M. socialis (Archer) (Fig. 148, d). Cytoplasm bluish; contrac- tile vacuole near aperture; filopodia arise from a peduncle, at- tenuate, branching, anastomosing; often numerous individuals are grouped; multiplication by fission and also by swarmers; 25-35jU in diameter; among vegetation in fresh water. Genus Microcometes Cienkowski. Body globular, enclosed within a transparent, delicate, light yellowish and pliable en- velope with 3-5 apertures, through which long branching filo- podia extend; body protoplasm occupies about 1/2 the space of envelope; 1-2 contractile vacuoles; fresh water. M. paludosa C. (Fig. 148, e). About 16-17^ in diameter; fresh water among algae. Genus Artodiscus Penard. Body globular, plastic; covered by envelope containing small grains of various kinds; nucleus eccen- tric; a few pseudopodia extend through pores of the envelope; movement very rapid; fresh water. A. saltans P. (Fig. 148,/). 18-23)U in diameter; fresh water. Genus Lieberkuhnia Claparede et Lachmann. Test ovoidal or spherical, with or without attached foreign particles; aperture usually single, lateral or subterminal; one or more nuclei; many contractile vacuoles; pseudopodia formed from a long peduncle, reticulate, often enveloping test; fresh or salt water. 326 PROTOZOOLOGY L. wagneri C. et L. (Fig. 149, a). Spheroidal; aperture subtermi- nal, oblique, flexible; cytoplasm slightly yellowish, fills the test; 80-150 vesicular nuclei; many contractile vacuoles; pseudopodia long, anastomosing; 60-1 60/i long; nuclei 6m in diameter; among algae in fresh and salt water. Fig. 149. a, Lieherkuhnia wagneri, Xl60 (Verworn); b, Diplophrys archeri, X930 (Hertwig and Lesser); c, Lecythiurn hyalinuni, X330 (Cash and Wailes); d, Myxotheca arenilega, x70 (Schaudinn); e, Dac- tylosaccus vermiforvufi, Xl5 (Rhumbler); f, Boderia turneri (Wright). Genus Diplophrys Barker. Test thin, spherical; 2 apertures, one at each pole; cytoplasm colorless; a single nucleus; several con- tractile vacuoles; filopodia radiating. One species. D. archeri B. (Fig. 149, b). With 1-3 colored oil droplets; pseu- dopodia highly attenuate, radiating, straight or branched; multi- plication into 2 or 4 daughter individuals; solitary or in groups; diameter 8-20^1; on submerged plants in fresh water. Genus Lecythiurn Hertwig et Lesser. Test thin, flexible, color- TESTACEA 327 less; aperture elastic, terminal; colorless cytoplasm fills the test; large nucleus posterior; numerous filopodia long, branching, not anastomosing; fresh water. L. hyalinum (Ehrenberg) (Fig. 149, c). Spheroidal; aperture circular with a short flexible neck; a single contractile vacuole; diameter 20-45yu; in submerged vegetation. Genus Schultzella Rhumbler. Test thin, delicate, difficult to recognize in life, easily broken at any point for formation of pseu- dopodia which branch and anastomose; irregularly rounded; without foreign material; salt water. S. diffluens (Grubler) (Fig. 148, g). Cytoplasm finely granu- lated; opaque colorless; with oil droplets, vacuoles and numerous small nuclei; up to 220/^ in diameter. Genus Myxotheca Schaudinn. Amoeboid; spherical or hemi- spherical, being flattened on the attached surface; a thin pseudo- chitinous test with foreign bodies, especially sand grains; pseu- dopodia anastomosing; salt water. M. arenilega S. (Fig. 149, d). Test yellow, with loosely attached foreign bodies; cytoplasm bright red due to the presence of highly refractile granules; 1-2 nuclei, 39-75^ in diameter; body diame- ter 160-560iu. Genus Dactylosaccus Rhumbler. Test sausage-shape and vari- ously twisted; pseudopodia filiform, anastomosing; salt water. D. vermiformis R. (Fig. 149, e). Test smooth; pseudopodia arise from small finger-like projections; 1-2 nuclei; body 4 mm. by 340ju; salt water. Genus Boderia Wright. Body form changeable; often spherical, but usually flattened and angular; filopodia long; test extremely delicate, colorless; salt water. B. turneri W. (Fig. 149,/). Body brown to orange; active cyto- plasmic movement; 1-10 nuclei; multiple division (?); 1.56-6.25 mm. in diameter; in shallow water. Family 2 Arcellidae Schultze Genus Arcella Ehrenberg. Test transparent, chitinous, densely punctated; colorless to brown (when old); in front view circular, angular, or stellate; in profile plano-convex or hemispherical; variously ornamented; aperture circular, central, inverted like a funnel; protoplasmic body does not fill the test and connected with the latter by many ectoplasmic strands; slender lobopodia, 328 PROTOZOOLOGY few, digitate, simple or branched; 2 nuclei; several contractile vacuoles; fresh water. Numerous species. A. vulgaris E. (Fig. 150, a, h). Height of test about 1/2 the diameter; dome of hemispherical test evenly convex; aperture circular, central; colorless, yellow, or brown; protoplasmic body conforms with the shape of, but does not fill, the test; lobopodia hyaline; 2 vesicular nuclei; several contractile vacuoles; test 30- lOO/i in diameter; in the ooze and vegetation in stagnant water Fig. 150. a, b, Arcella vulgaris, Xl70; X230 (Leidy); c, A. discoides, X170 (Leidy); d, A. mitrata, Xl40 (Leidy); e, f, A. catinus. Xl70 (Cash); g-i, .4. dentata, Xl70 (Leidy); j, k, ^4. artocrea, Xl70 (Leidy). and also in soil. Of several varieties, two may here be mentioned : var. angulosa (Perty), test smaller, 30-40At in diameter, faceted, forming a 5- to 8-sided figure, with obtuse angles; var. gihhosa (Penard), test gibbous, surface pitted with circular depressions of vmiform dimensions; 45-50yu up to lOO^i in diameter. A. discoides E. (Fig. 150, c). Test circular in front view, plano- convex in profile; diameter about 3-4 times the height; test color- ation and body structure similar to those of A. vulgaris; test 70- 260 fj, in diameter; in fresh water. A. mitrata Leidy (Fig. 150, d). Test balloon-shaped or poly- hedral; height exceeds diameter of base; aperture circular, crenu- TESTACEA 329 lated and usually evarted within inverted funnel; protoplasmic body spheroidal, with 'neck' to aperture and cytoplasmic strands to test; 6 or more slender lobopodia; test 100-145)U high, 100- 152/i in diameter; in fresh water among vegetation. A. catinus Penard (Fig. 150, e, /). Test oval or quadrate, not circular, in front view; aperture oval; dome compressed; lateral margins with 6 or 8 facets; test 100-120/i in diameter and about 45^1 high; fresh water among vegetation. A. dentata Ehrenberg (Fig. 150, g-4). Test circular and dentate in front view, crown-like in profile; diameter more than twice the height; aperture circular, large; colorless to brown; about 95/i in diameter, aperture 30/x in diameter; 15-17 spines; in the ooze of freshwater ponds. A. artocrea Leidy (Fig. 150, j, k). Height of test 1/4-1/2 the diameter; dome convex; surface mamillated or pitted; border of test everted and rising 1/4-1/2 the height of test; about 175/x in diameter; fresh water. Genus Pyxidicula Ehrenberg. Test patelliform; rigid, transpar- ent, punctate; aperture circular, almost the entire diameter of test; cytoplasm similar to that of Arcella; a single nucleus; 1 or more contractile vacuoles; fresh water. P. operculata (Agardh) (Fig. 151, a, h). Test smooth, colorless to brown; a single vesicular nucleus; pseudopodia short, lobose or digitate; 20^ in diameter; on vegetation. Genus Pseudochlamys Claparede et Lachmann. Test discoid, flexible when young; body with a central nucleus and several contractile vacuoles. P. patella C. et L. (Fig. 151, c). Young test hyahne, older one rigid and brown; often rolled up like a scroll; a short finger-like pseudopodium between folds; 40-45)U in diameter; in fresh water among vegetation, in moss and soil. Genus Difflugiella Cash. Test ovoid, not compressed, flexible and transparent membrane; colorless cytoplasm fills the test, usually with chlorophyllous food material; median pseudopodia lobate or digitate with aciculate ends, while lateral pseudopods long, straight, and fine, tapering to a point; fresh water. One species. D. apiculata C. (Fig. 151, d, e). About 40^ by 28/^; among vege- tation. Genus Cryptodifflugia Penard. Small test yellowish to brown- 330 PROTOZOOLOGY Fig. 151. a, b, Pyxidicula operculata, XSOO (Penard); c, Pseudo- chlamys patella, X330 (Cash); d, e, Difflugiella apiculata, X270 (Cash); f, Cryptodifflxigia ovijormis, X320 (Cash); g, Lesquereusia spiralis, X270 (West); h, Hyalosphenia papilio, X330 (Leidy); i, Corycia coro- nata, Xl70 (Penard); j, Pamphagus rmUabilis, X330 (Leidy); k, Plagi- ophrys parvipunctata, X330 (Penard). ish; Diffliigia-like in general appearance, compressed; with or without foreign bodies; pseudopodia long, acutely pointed; fresh water. C. oviformis P. (Fig. 151,/). Test ovoid; without foreign bodies; crown hemispherical; aperture truncate; cytoplasm with chloro- phyllous food particles; 16-20/i by 12-15/i; in marshy soil. Genus Lesquereusia Schlumberger. Test compressed, oval or globular in profile, narrowed at bent back; semispiral in appear- ance; with curved or comma-shaped rods or with sand-grains (in one species); body does not fill up the test; pseudopodia simple or branched; fresh water. L. spiralis (Ehrenberg) (Fig. 151, g). Aperture circular; border TESTACEA 331 distinct; cytoplasm appears pale yellow; a single nucleus; 96- 188/i by 68-1 14/x; in marsh water. Genus Hyalosphenia Stein. Test ovoid or pyriform; aperture end convex; homogeneous and hyaline, mostly compressed; crown uniformly arched; protoplasm partly filling the test; sev- eral blunt pseudopodia simple or digitate. Several species. H. papilio Leidy (Fig. 151, h). Test yellowish; transparent; pyriform or oblong in front view; a minute pore on each side of crown and sometimes one also in center; aperture convex; in nar- row lateral view, elongate pyriform, aperture a shallow notch; with chlorophyllous particles and oil globules; 110-140/1 long; in fresh water among vegetation. Genus Corycia Dujardin. Envelope extremely pliable, open at base, but when closed, sack-like; envelope changes its shape with movement and contraction of body; with or w^ithout spinous pro- jections. C. coronata Penard (Fig. 151, i). 6-12 spines; 140/1 in diameter; in moss. Genus Pamphagus Bailey. Test hyaline membranous, flexible; aperture small; body fills the envelope completely; spherical nu- cleus large; contractile vacuoles; filopodia long, delicate, branch- ing, but not anastomosing; fresh water. P. mutaUlis B. (Fig. 151, j). Envelope 40-100^ by 28-68^. Genus Plagiophrys Claparede et Lachmann. Envelope thin, hyaline, changeable with body form; usually elongate-oval with rounded posterior end; narrowed at other half; envelope shows fine punctuation with a few small plates; aperture round; cyto- plasm clear; nucleus large; pseudopods straight filopodia, some- times branching; fresh water. P. parvipunctata Penard (Fig. 151, k). Envelope 50/1 long. Genus Leptochlamys West. Test ovoid, thin transparent chitin- ous membrane, circular in optical section; aperture end slightly expanded with a short neck; aperture circular, often obHque; body fills test; without vacuoles; pseudopodium short, broadly expand- ed and sometimes cordate; fresh water. L. ampullacea W. (Fig. 152, a). Nucleus large, posterior; with green or brown food particles; test 45-55/t by 36-40ju in diame- ter; aperture 15-17/i; among algae. Genus Chlamydophrys Cienkowski. Test rigid, circular in sec- tion; aperture often on drawn-out neck; body fills the test; zonal 332 PROTOZOOLOGY differentiation of cytoplasm distinct, nucleus vesicular; refractile waste granules; pseudopodia branching; fresh water or coprozoic. C. stercorea C. (Fig. 152, k). Test 18-20^ by 12-15/x; mature cysts yellowish brown, 12-1 5m in diameter; multiplication by budding ; coprozoic and fresh water. Genus Cochliopodium Hertwig et Lesser. Test thin, flexible expansible and contractile; with or without extremely finehair- Hke processes; pseudopodia blunt or pointed, but not acicular. Several species. C. hilimbosum (Auerbach) (Fig. 152, h). Test hemispherical; pseudopodia conical with pointed ends; test 24-56/^ in diameter; fresh water among algae. Genus Amphizonella Greeff. Test membranous with a double marginal contour; inner membrane smooth, well-defined; outer serrulate; aperture inverted; a single nucleus; pseudopodia blunt, digitate, and divergent. A. violacea G. (Fig. 152, c). Test patelliform, violet-tinted; with chlorophyllous corpuscles and grains; sluggish; average diameter 160m; fresh water. Genus Zonomyxa Miisslin. Test rounded pyriform, flexible, chitinous, violet-colored; endoplasm vacuolated, with chloro- phyllous particles; several nuclei; pseudopodia simple, not digi- tate; fresh water. Z. violacea N. (Fig. 152, d). A single lobular pseudopodium with acuminate end; 4 nuclei; diameter 140-160//; actively motile forms 250/1 or longer; among sphagnum. Genus Microcorycia Cockerell. Test discoidal or hemispherical, flexible, with a diaphanous continuation or fringe around periph- ery, being folded together or completely closed; crown of test with circular or radial ridges; body does not fill the test; 1-2 nuclei; pseudopodia lobular or digitate; fresh water. A few spe- cies. M. flava (Greeff) (Fig. 152, e, /). Test yellowish brown; crown with few small foreign bodies; endoplasm with yellowish brown granules; 2 nuclei; contractile vacuoles; diameter SO-lOO/i; young individuals as small as 20/1; in moss. Genus Parmulina Penard. Test ovoid, chitinoid with foreign bodies; aperture capable of being closed, a single nucleus, 1 or more contractile vacuoles; fresh water. A few species. P. cyathus P. (Fig. 152, g, h). Test small, flexible; ovoid in aper- TESTACEA 333 Fig. 152. a, Leptochlamys ampullacea, x330 (West); b, Cochlio- podium bilimbosum, X670 (Leidy); c, Amphizonella violacea, X270 (Greeff); d, Zonomtjxa violacea, X200 (Penard); e, f, Microcorycia flava, X240 (Wailes); g, h, Parviidina cyathus, X500 (Penard); i, Capsellina timida, X270 (Brown); j, Diplochlamys leidyi, X270 (Wailes); k, Chlamydophrys stercorea, X670 (Wenyon). ture view, semicircular in profile; aperture a long, narrow slit when test is closed, but circular or elliptical when opened; 40-55^ long; in moss. Genus Capsellina Penard. Test hyaline, ovoid, membranous; with or without a second outer covering; aperture long slit; a single nucleus; 1 or more contractile vacuoles; filose pseudopodia; fresh water. C. timida Brown (Fig. 152, i). Small, ovoid; elhptical in cross- 334 PROTOZOOLOGY section; with many oil (?) globules; filopodium; 34yu by 25m; in moss. Genus Diplochlamys Greeff. Test hemispherical or cup-shaped, flexible with a double envelope; inner envelope a membranous sack with an elastic aperture, outer envelope with loosely at- tached foreign bodies; aperture large; nuclei up to 100; pesudo- podia few, short, digitate or pointed; fresh water. Several species. D. leidyi G (Fig. 152, j). Test dark gray; inner envelope pro- jecting beyond outer aperture; nuclei up to 20 in number; diame- ter 80-100m. Family 3 Difflugiidae Taranek Genus Difflugia Leclerc. Test variable in shape, but generally circular in cross-section; composed of cemented quartz-sand; diatoms, and other foreign bodies; aperture terminal; often with zoochlorellae; cytoplasmic body almost fills the test; a single nu- cleus; many contractile vacuoles; pseudopodia cylindrical, simple or branching; end rounded or pointed; fresh water, woodland soil, etc. D. oblonga Ehrenberg {D. 'pyriformis Perty) (Fig. 153, a). Test pyriform, flask-shaped, or ovoid; neck variable in length, fundus rounded, with occasionally 1-3 conical processes; aperture ter- minal, typically circular; test composed of angular sand-grains, diatoms; bright green with chlorophyllous bodies; 60-580^1 by 40-240m; in the ooze of freshwater ponds, ditches and bogs; also in moist soil. Several varieties. D. urceolata Carter (Fig. 153, h). A large ovoid, rotund test, with a short neck and a rim around aperture; 200-230;u by 150- 200ju; in ditches, ponds, sphagnous swamps, etc. D. arcula Leidy (Fig. 153, c, d). Test hemispherical, base sHght- ly concave, but not invaginated ; aperture triangular, central, tri- lobed; test yellowish with scattered sand-grains or diatoms, diameter 100-140^*, in sphagnous swamp, moss, soil, etc. D. lohostoma Leidy (Fig. 153, e). Test ovoid to subspherical; aperture terminal; with 3-6 lobes; test usually composed of sand- grains, rarely with diatoms; endoplasm colorless or greenish; diameter 80-1 20^; in fresh water. D. constrida (Ehrenberg) (Fig. 153, /). Test laterally ovoid, fundus more or less prolonged obliquely upward, rounded, and simple or provided with spines; soil forms generally spineless; aperture antero-inferior, large, circular or oval and its edge in- 335 Fig. 153. a, Difflugia oblonga, Xl30 (Cash); b, D. urceolata, Xl30 (Leidy); c, d, D. arcula, Xl70 (Leidy); e, D. lohostoma, Xl30 (Leidy); f, D. constricta, X200 (Cash); g, Centropyxis aculeata, X200 (Cash); h, Campuscus cornutus, Xl70 (Leidy); i, Cucurhitella mespiliformis, X200 (Wailes). verted; test composed of quartz grains; colorless to brown; cyto- plasm colorless; 80-340// long; in the ooze of ponds and in soil. D. corona Wallich. Test ovoid to spheroid, circular in cross- section; crown broadly rounded, with a variable number of spines, aperture more or less convex in profile, central and its border multidentate or multilobate; test with fine sand-grains, opaque; cytoplasm colorless; pseudopodia numerous, long, branching or bifurcating; 180-230^ by about ISO^t; in fresh water. Genus Centropyxis Stein. Test circular, ovoid, or discoid; aper- ture eccentric, circular or ovoidal, often with a lobate border; with or without spines; cytoplasm colorless; pseudopodia digi- tate; fresh water. C. aculeata S. (Fig. 153, g). Test variable in contour and size; with 4-6 spines; opaque or semitransparent; with fine sand-grains or diatom shells; pseudopodia sometimes knotted or branching; when encysted, the body assumes a spherical form in wider part of test; granulated, colorless or with green globules; diameter 100 -150/i; aperture 50-60ju in diameter. Genus Campascus Leidy. Test retort-shaped with curved neck, 336 PROTOZOOLOGY rounded triangular in cross-section; aperture circular, oblique, with a thin transparent discoid collar; nucleus large; 1 or more contractile vacuoles; body does not fill the test; fresh water. C. cornutus L. (Fig. 153, h). Test pale-yellow, retort-form; with a covering of small sand particles; triangular in cross-section; a single nucleus and contractile vacuole; filopodia straight; 110- 140m long; aperture 24-28m in diameter; in the ooze of mountain lakes. Genus Cucurbitella Penard. Test ovoid with sand grains, not compressed; aperture terminal, circular, surrounded by a 4-lobed annular collar; cytoplasm grayish, with zoochlorellae; nucleus large; 1 to many contractile vacuoles; pseudopodia numerous, digitate; fresh water. C. mespiliformis P. (Fig. 153, i). 115-140/1 long; diameter 80- 105yu; in the ooze or on vegetation in ponds and ditches. Genus Plagiopyxis Penard. Test subcircular in front view; ovoid in profile; aperture linear or lunate; cytoplasm gray, with a single nucleus and a contractile vacuole; fresh water. P. callida P. (Fig. 154, a). Test gray, yellowish, or brown; large nucleus vesicular; pseudopodia numerous, radiating, short, pointed or palmate; diameter 55-135/z; in vegetation. Genus Pontigulasia Rhumbler. Test similar to that of Difflugia, but with a constriction of neck and internally a diaphragm made of the same substances as those of the test. P. vas (Leidy) (Fig. 154, b). Round or ovoid test; constriction deep and well-marked; with sand-grains and other particles; aperture terminal; 125-170/i long; fresh water ponds. Genus Phryganella Penard. Test spheroidal or ovoid, with sand-grains and minute diatom shells; aperture terminal, round; pseudopodia drawn out to a point; fresh water. P. acropodia (Hertwig et Lesser) (Fig. 154, c). Test circular in aperture view; hemispherical in profile; yellowish or brownish, semi-transparent, and covered with sand-grains and scales; in front view sharply pointed pseudopodia radiating; colorless en- doplasm usually with chlorophyllous bodies; 30-50/i in diameter. Genus BuUinula Penard. Test ellipsoidal, flattened on one face, with silicious plates; on the flattened surface, co -shaped aperture; a single nucleus; pseudopodia digitate or spatulate, simple or branched; fresh water. BandicaF. (Fig. 154, d). Test dark brown; 120-250/t in diameter. Fig. 154. a, Plagiopyxis callida, X200 (Wailes);^b, Pontigulasia vas, X200 (Cash); c, Phryganella acropodia, Xl90 (Cash); d, Bullinula indica, Xl30 (Wailes); e, f, Heleopera petricola, Xl90 (Cash); g, Nadi- nella tenella, X400 (Penard) ; h, Frenzelina reniformis, X600 (Penard) ; i, Amphitrema flavum, X360 (Cash and Wailes); j, Pseudodifflugia gracilis, X330 (Cash); k, Diaphoropodon mobile, X270 (Cash and Wailes); 1, m, Clypeolina marginaia, X330 (Cash and Wailes). Genus Heleopera Leidy. Test variously colored; fundus hemi- spherical, with sand-grains; surface covered with amorphous scales, often overlapping; aperture truncate, narrow, elliptic notched in narrow lateral view; a single nucleus; pseudopodia variable in number, thin, digitate or branching; fresh water. Sev- eral species. H. 'petricola L. (Fig. 154, e, /). Test variable in size and color, strongly compressed; fundus rough with sand-grains of various 338 PROTOZOOLOGY sizes; aperture linear or elliptic, convex in front view; pseudopo- dia slender, branching; 80-100/i long; in boggy places. Genus Averintzia Schouteden. Test similar to that of Heleopera, but small aperture elliptical; test thickened around aperture; fresh water. A. cyclostoma (Penard). Test dark violet, with sand-grains of different sizes; elliptical in cross-section; pseudopodia unob- served; 135-180/x long; in sphagnum and other aquatic plants. Genus Nadinella Penard. Test chitinous, thin, hyaline, with foreign bodies and collar around aperture; filopodia; fresh water. N. tenella P. (Fig. 154, g). 50-55^1 long; fresh water lakes. Genus Frenzelina Penard. Two envelopes, outer envelope hemispherical, thin, rigid, covered with siliceous particles; inner envelope round or ovoid, drawn out at aperture, thin, hyaline and covering the body closely; aperture round, through which a part of body with its often branching straight filopods, extends; cyto- plasm with diatoms, etc.; a nucleus and a contractile vacuole; fresh water. F. reniformis P. (Fig. 154, h). Outer envelope 26-30/x in diame- ter; fresh water lakes. Genus Amphitrema Archer. Test ovoid, symmetrical, com- pressed; composed of a transparent membrane, with or without adherent foreign bodies; 2 apertures at opposite poles; with zoochlorellae; nucleus central; 1-several contractile vacuoles; straight filopodia, sparsely branched, radiating; fresh water. Sev- eral species. A.flavum A. (Fig. 154, i). Test brown, cyhndrical with equally rounded ends in front view; elliptical in profile; ovoid with a small central oval aperture in end-view; 45-77/x by 23-4 5m; in sphag- num. Genus Pseudodifflugia Schlumberger. Test ovoid, usually rigid, with foreign bodies; circular or elliptical in cross-section; aper- ture terminal; granulated cytoplasm colorless or greyish; nucleus posterior; a contractile vacuole; filopodia long, straight or branch- ing; fresh water. Several species. P. gracilis S. (Fig. 154, j). Test yellowish or brownish; sub- spherical, with sand-grains; aperture without neck; 20-65^ long. Genus Diaphoropodon Archer. Test ovoid, flexible, with mi- nute foreign bodies and a thick covering of hyaline hair-like pro- jections; pseudopodia long, filose, branching; fresh water. TESTACEA 339 D. mobile A. (Fig. 154, k). Test brown; of various shapes; aper- ture terminal; body does not fill the test; nucleus large; 1-2 con- tractile vacuoles; 60-120)u long; projections 8-10/x long; in vege- tation. Genus Clypeolina Penard. Test ovoid, compressed, formed of a double envelope; outer envelope composed of 2 valves with scales and particles; inner envelope a membranous sack; long filopodia, often branching; fresh water. C. marginata P. (Fig. 154, I, m). Outer test-valves yellow to dark brown; lenticular in cross-section; wide terminal aperture; endoplasm with many small globules; a single nucleus and con- tractile vacuole; 80-150ju long. Family 4 Euglyphidae Wallich Genus Euglypha Dujardin (Pareuglypha Penard). Test hya- line, ovoid, composed of circular, oval, or scutiform siliceous im- bricated scales, arranged in longitudinal rows; aperture bordered with regularly arranged denticulate scales; usually with spines; 1-2 nuclei large, placed centrally; filopodia dichotomously branched; contractile vacuoles; fresh w^ater. Numerous species. E. acanthophora (Ehrenberg) {E. alveolata D.) (Fig. 67). Test ovoid, or slightly elongate; 3-7 scales protruding around the cir- cular aperture; scales elliptical; body almost fills the test; 50-100/i long. E. cristata Leidy (Fig. 155, a). Test small, elongate with a long neck, fundus with 3-8 spines; scales oval; aperture circular, bor- dered by a single row of 5-6 denticulate scales; cytoplasm color- less; nucleus posterior; reserve scales are said to be collected around the exterior of aperture, unlike other species in which they are kept wathin the cytoplasm; 30-70^ long; 12-23iu in diameter; aperture 6-12;u; scales 4.5-9.5yu by 2.5-6.5//; spines 10- 15ju long. E. mucronata L. (Fig. 155, 6). Test large; fundus conical, with 1-2 terminal spines (12-44/i long); aperture circular, bordered by a single row of 6-8 denticulate scales; 100-150/x long, diameter 30-60ju; aperture 15-20^ in diameter. Genus Paulinella Lauterborn. Test small ovoid, not com- pressed; with siliceous scales in alternating transverse rows; aper- ture terminal; body does not fill the test completely; nucleus pos- terior; among vegetation in fresh or brackish water. 340 PROTOZOOLOGY P. chromatophora L. (Fig. 155, c). Scales arranged in 11-12 rows, 5 scales in each row; with 1-2 curved chromatophores; no food particles; a single contractile vacuole; 20-32// long; 14-23^1 in diameter. / Xl% Fig. 155. a, Euglypha cristata, X330 (Wailes); b, E. mucronata, X330 (Wailes); c, Paidinella chromatophora, XlOOO (Wailes); d, Cy- phoderia ampulla, X200 (Cash); e, f, Corythion pulchellum, X350 (Wailes). Genus Cyphoderia Schlumberger. Test retort-shaped; colorless to yellow; made up of a thin chitinous membrane, covered with discs or scales; aperture terminal, oblique, circular; body does not fill the test completely; nucleus large, posterior, pseudopodia, few, long filose, simple or branched; fresh water. C. ampulla (Ehrenherg) (Fig. 155, rf). Test usually yellow, trans- lucent, composed of. discs, arranged in diagonal rows; circular in cross-section; aperture circular; cytoplasm gray, with many gran- ules and food particles; 2 contractile vacuoles; 60-200/i long; diameter 30-70/x. Several varieties. Genus Trinema Dujardin. Test small, hyaline, ovoid, com- pressed anteriorly, with circular siliceous scales; aperture circular, TESTACEA 341 oblique, invaginate; nucleus posterior; filopodia not branched; fresh water in vegetation. T. enchelys (Ehrenberg) (Fig. 156, a). 1-2 contractile vacuoles; pseudopodia attenuate, radiating; 30-1 00/x long; 15-60/i wide; scales 4-12^1 in diameter. Genus Corythion Taranek. Test small, hyaline, composed of small oval siliceous plates; compressed; elliptical in cross-section; aperture subterminal, ventral or oblique, and circular or oval; numerous filopodia; fresh water. C. pulchellum Penard (Fig. 155, e,f). Aperture lenticular; cyto- plasm colorless; 2-3 contractile vacuoles; 25-35/^ by 15-20^i; aperture 7-10^1 by 3-4/x. Genus Placocista Leidy. Test ovoid, hyaline, compressed; len- ticular in cross-section; with oval or subcircular siliceous scales; aperture wide, linear, with flexible undulate borders; nucleus large, posterior; often with zoochlorellae; filopodia branching and many, generally arising from a protruded portion of cytoplasm; fresh water. P. spinosa (Carter) (Fig. 156, 6). Margin of test with spines, either singly or in pairs; 116-174^t by 70-100ai; in sphagnum. Genus Assulina Ehrenberg. Test colorless or brown; ovoid; with elliptical scales, arranged in diagonal rows; aperture oval, terminal, bordered by a thin chitinous dentate membrane; nu- cleus posterior; contractile vacuoles; filopodia divergent, some- times branching; fresh water. A. seminulum (E.) (Fig. 156, c). Body does not fill the test; with numerous food particles; pseudopodia few, straight, di- vergent, slender, seldom branched; 60-1 50/x by 50-75ju; in sphag- num. Genus Nebela Leidy. Test thin, ovate or pyriform; with cir- cular or oval platelets of uniform or various sizes; highly irregu- lar; endoplasm with oil-globules; nucleus posterior; body does not fill the test, and is connected with the latter by many ecto- plasmic strands at fundus end; pseudopodia blunt, rarely branched; fresh water. Numerous species. N. collaris (Ehrenberg) (Fig. 156, d). Test pyriform, fundus obtuse in profile; aperture without any notch; endoplasm wdth chlorophyllous food particles; pseudopodia digitate, short, usu- ally 3-6 in number; about 130^1 by 85-90/i; in marshes among sphagnum. PROTOZOOLOGY Fig. 156. a, Trinema enchelys, X330 (Wailes); b, Placocista spinosa, X200 (Wailes); c, AssuUna seminulum, X400 (Wailes); d, Nebela collaris, x200 (Cash); e, Quadrula symmetrica, X200 (Cash); f, Sphe- noderia tenia, X330 (Leidy). Genus Quadrula Schulze. Test pyriform, hemispherical, or dis- eoidal; with quadrangular siliceous or calcareous platelets, ar- ranged generally in obhque series, not overlapping; a single nu- cleus; body and pseudopodia similar to those of Difflugia; fresh water. Q. symmetrica (Wallich) (Fig. 156, e). Compressed, smaller platelets near aperture; cytoplasm very clear, with chlorophyllous granules; 3-5 pseudopodia digitate; nucleus posterior; 80-140ju by 40-96ai; in sphagnum. Genus Sphenoderia Schlumberger. Test globular or oval, some- times slightly compressed; hyaline, membranous, with a short broad neck, and a wide elliptical aperture; scales circular, oval, or hexagonal, arranged in alternating series; cytoplasm colorless; 1-2 contractile vacuoles; filopodia, fine, branching; fresh water. S. lenta S. (Fig. 156, /). Hyahne test ovoid or globular; scales circular or broadly oval; aperture terminal, surrounded by a thin chitinous collar, one side inclined inwards; nucleus large; cyto- plasm colorless; 2 contractile vacuoles; 30-64/^ by 20-46m; aper- ture 10-22/z in diameter. Cash, J. 1905, 1909 ozoa. Vols. 1, 2. References The British freshwater Rhizopoda and Heli- TESTACEA 343 and G. H. Wailes 1915, 1918 The British freshwater Rhizopoda and Heliozoa. Vols. 3, 4. Deflandre, G. 1928 Le genre Arcella Ehrenberg. Arch. f. Protistenk., Vol. 64. Hegner, R. W. 1920 The relation between nuclear number, chromatin mass, cytoplasmic mass, and shell characteristics in four species of the genus Arcella. Jour. Exp. Zool., Vol. 30. Leidy, J. 1879 Freshwater rhizopods of North America. Rep. U. S. Geol. Surv., Vol. 12. Penard, E. 1890 Etudes sur les rhizopodes d'eau douce. Mem. soc. phys. et d'hist. nat. Geneva, Vol. 31. 1902 Faune rhizcpodique du bassin du Leman. Geneva. Chapter 20 Order 5 Foraminifera d'Orbigny THE Foraminifera are comparatively large Protozoa, living almost exclusively in the sea. They were very abundant in geologic times and the fossil forms are important in applied geology (p. 9). The majority live on ocean bottom, moving about sluggishly over the mud and ooze by means of their pseu- dopodia. Some are attached to various objects on the ocean floor, while others are pelagic. The cytoplasm is ordinarily not differentiated into the two zones and streams out through the apertures, and in perforated forms through the numerous pores, of the shell, forming rhizo- podia which are fine and often very long and which anastomose with one another to present a characteristic appearance (Fig. 5). The streaming movement of the cytoplasm in the pseudopodia are quite striking; the granules move toward the end of a pseu- dopodium and stream back along its periphery. The body cyto- plasm is often loaded with brown granules which are apparently waste matter and in some forms such as Peneroplis pertusus (Fig. 160), these masses are extruded from the body from time to time, especially prior to the formation of a new chamber. Con- tractile vacuoles are usually not found in the Foraminifera. The test of the Foraminifera varies greatly in form and struc- ture. When alive, it may show various colorations — orange, red, or brown. The majority measure less than one milhmeter, al- though larger forms may frequently reach several millimeters. The test may be siliceous or calcareous and in some forms, vari- ous foreign materials, such as sand-grains, sponge-spicules, etc. which are more or less abundantly found where these organisms live, are loosely or compactly cemented together by pseudochiti- nous or gelatinous substances. Certain forms show a specific tendency in the selection of foreign materials for the test (p. 38-39). Siliceous tests are comparatively rare, being found in some spe- cies of Miholidae inhabiting either the brackish water or deep sea. Calcareous tests are sometimes imperforated, but even in such cases those of the young are always perforated. By far the ma- jority of the Foraminifera possess perforated calcareous tests. The 344 FORAMINIFERA 345 J ^"^ <:M \.:> .■r^»;i;i "".■■i ' ..-V-uv- Fig. 157. Diagram illustrating the life-cycle of Foraminifera (Kiihn). a-c, microspheric generation; d, uninucleate phase; e-g, megalospheric generation; h, isogametes; i-j, isogamy. thickness of shell varies considerably, as do also the size and number of apertures, among different species. Frequently the perforations are very small in the young and later become large and coarse, while in others the reverse may be the case. The form of shell varies greatly. In some there is only one chamber, composed of a central body and radiating arms which represent the material collected around the pseudopodia, as in Rhabdammina (Fig. 158, a), or of a tubular body alone, as in Hyperammina (Fig. 158, d). The polythalamous forms possess shells of various spirals. The first chamber is called the prolocu- lum which may be formed either by the union of two swarmers or 346 PR()T0Z()0L0(;Y by asexual reproduction (Fig. 157). The former is ordinarily small and known as the microspheric proloculum (a), while the latter, which is usually large, is called the megalo spheric pro- loculum (e). To the proloculum are added many chambers which may be closely or loosely coiled or not coiled at all. These cham- bers are ordinarily undivided, but in many higher forms they are divided into chamberlets. The chambers are deHmited by the suture on the exterior of the shell. The septa which divide the chambers are perforated by one or more foramina known as stolon canals, through which the protoplasm extends throughout the chambers. The last chamber has one or more apertures of variable sizes, through which the cytoplasm extends to the ex- terior as pseudopodia. The food of Foraminifera consists mostly of diatoms and algae, though pelagic forms are known to capture other Protozoa and microcrustaceans. All species of Foraminifera manifest a more or less distinct tendency toward a dimorphism: the megalospheric form with a large proloculum and the microspheric form with a small proloc- ulum (Fig. 157). The former is said to be much more numerous than the latter. The microspheric form is multinulceate, in which the nuclei are scattered without apparent order, and vary in size proportionately with the size of the chambers. As the animal grows the nuclei increase in number; around each of them a small island of cytoplasm becomes condensed (c); uninucleate bodies thus formed leave the parent body, and each secretes around itself a shell which is much larger than the proloculum of the parent in- dividual (d, e). To this proloculum, are added new chambers one by one, as the organism grows (/) and at the same time the single nucleus shifts its position, so that the latter is almost always in the middle chamber. As the animal grows further, endosomes ap- pear in increasing numbers in the nucleus which divides finally into many nuclei (g). Each of these nuclei becomes the center of swarmer. The swarmers leave the parent shell and undergo fusion in pairs to produce zygotes (h-j). The zygote secretes a shell around itself (a) and forms first a small proloculum, to which are added many chambers (6). This is the microspheric form which in some species appears to be unknown. More than 300 genera of extinct and living Foraminifera are now known. Cushman distinguished 45 families. The present work follows Cushman in recognizing and differentiating 44 fami- FORAMINIFERA 347 lies, and lists one genus as an example for each, but places Gromia and allied genera in the order Testacea (p. 323). Fig. 158. a, Rhahdammina abyssomm, X5 (Ktihn); b, Rhizammina algaeforniis, fragment of, Xl4 (Cushman); c, Saccavimina sphaerica, X8 (Rhumbler); d, Hijperammina subnodosa, X4 (Brady); e, Ammo- discus incertus, X20 (Kiihn); f, Silicina liynitata, Xl3 (Cushman); g, Reophax nodulostis, X3 (Brady). Test entirely or in part arenaceous Test single-chambered or rarely an irregular group of similar chambers loosely attached Test with a central chamber, 2 or more arms; fossil and recent Family 1 Astrorhizidae Genus Rhabdammina Sars (Fig. 158, a) Test without a central chamber, elongate, open at both ends; fossil and recent Family 2 Rhizamminidae Genus Rhizammina Brady (Fig. 158, b) Test a chamber or rarely series of similar chambers loosely at- tached, with normally a single opening; fossil and recent. . . Family 3 Saccamminidae Genus Saccammina Sars (Fig. 158, c) Test 2-chambered, a proloculum and long undivided tubular second chamber Test with the second chamber, simple or branching, not coiled; mostly recent and also fossil .... Family 4 Hyperamminidae 348 PIK)T(JZ()OJ.OGY Genus Hyperammina Brady (Fig. 158, d) Test with the second chamber usually coiled at least in young Test of arenaceous material with much cement, usually yellow- ish or reddish brown; fossil and recent Family 5 Ammodiscidae Genus Ammodiscus Reuss (Fig. 158, e) Test of siliceous material, second chamber partially divided; fossils only Family 6 Silicinidae Genus Silicina Bornemann (Fig. 158, /) Test typically many-chambered Test with all chambers in a rectilinear series; fossil and recent. . Family 7 Reophacidae Genus Reophax Montfort (Fig. 158, g) Test planispirally coiled at least in young Axis of coil, short; many uncoiled forms; fossil and recent. . . . Family 8 Lituolidae Genus Lituola Lamarck (Fig. 159, a) Axis of coil usually long, all close-coiled Interior not labyrinthic; fossil only. . . .Family 9 Fusulinidae Genus Fusulina Fisher (Fig. 159, h) Interior labyrinthic; fossil only Family 10 Loftusiidae Genus Loftusia Brady Test typically biserial at least in young of microspheric form; fossil and recent Family 11 Textulariidae Genus Textularia Def ranee (Fig. 159, c) Test typically triserial at least in young of microspheric form Aperture usually without a tooth, test becoming simpler in higher forms; fossil and recent. .Family 12 Verneuilinidae Genus Verneuilina d'Orbigny (Fig. 159, d) Aperture typically with a tooth, test becoming conical in higher forms; fossil and recent Family 13 Valvulinidae Genus Valvulina d'Orbigny (Fig. 159, e) Test with whole body labyrinthic, large, flattened, or cylindrical; recent Family 14 Neusinidae FORAMINIFERA 349 Fig. 159. a, Lituola nautiloidea (Cushman); b, section through a Fusulina (Carpenter); c, Textularia agglutinans, X90 (Rhumbler); d, Verneuilina propijiqua, X8 (Brady); e, Valvulina triangularis, (d'Orbigny); f, Trocharmnina inflata, X32 (Brady); g, Placopsilina cenomana (Reuss); h, Tetrataxis palaeotrochus, Xl5 (Brady); i, Spiro- loculina limhata, X20 (Brady); j, Triloculina trigonula, Xl5 (Brady); k, Fischerina helix, X32 (Heron-Allen and Earland); 1, Vertebralina striata, X40 (Kiihn); m, Alveolinella mello, X35 (Brady). Genus Neusina Goes Test trochoid at least while young Mostly free; typically trochoid throughout, fossil and recent. . Family 15 Trochamminidae Genus Trochammina Parker et Jones (Fig. 159, /) Attached; young trochoid, later stages variously formed; fossil and recent Family 16 Placopsilinidae Genus Placopsilina d'Orbigny (Fig. 159, g) Free; conical, mostly of large size; fossil only Family 17 Orbitolinidae Genus Tetrataxis Ehrenberg (Fig. 159, h) Test coiled in varying planes, wall imperforate, with arenaceous portion only on the exterior; fossil and recent Family 18 Miliolidae (in part) 350 PROTOZOOLOGY Genus Spiroloculina d'Orbigny (Fig. 159, i) Test calcareous, imperforate, porcellanous Test with chambers coiled in varyinjr planes, at least in young; aperture large, toothed; fossil and recent Family 18 Miliolidae (in part) Genus Triloculina d'Orbigny (Fig. 159, j) Test trochoid; fossil and recent Family 19 Fischerinidae Genus Fischerina Terquem (Fig. 159, k) Test planispiral at least in young Axis very short, chambers usually simple; fossil and recent Family 20 Ophthalmidiidae Genus Vertebralina d'Orbigny (Fig. 159, 1) Axis short, test typically compressed and often discoid, chambers mostly with many chamberlets; fossil and recent Family 21 Peneroplidae Genus Peneroplis Montfort (Figs. 4; 160) Axis typically elongate, chamberlets developed; mainly fossil. . . Family 22 Alveolinellidae Genus Alveolinella Douville (Fig. 159, m) Test globular, aperture small, not toothed; recent only Family 23 Keramosphaeridae Genus Keramosphaera Brady Test calcareous, perforate Test vitreous with a glassy lustre, aperture typically radiate, not trochoid Test planispirally coiled or becoming straight, or single-cham- bered; fossil and recent Family 24 Lagenidae Genus Lagena Walker et Jacob (Fig. 161, a) Test biserial or elongate spiral; fossil and recent Family 25 Polymorphinidae Genus Polymorphina d'Orbigny Test not vitreous; aperture not radiating Test planispiral, occasionally trochoid, then usually with proc- esses along the suture lines, septa single, no canal system ; fossil and recent Family 26 Nonionidae FORAMINIFERA 351 %.'^ 5?3^ 11 @ k J Fig. 160. Diagram illustrating the life-cycle of Peneroplis pertusiis (Winter), a-f, megalospheric generation; g, gamete formation; h-k, isogamy; 1-n, microspheric generation; o, multiple division. Genus Elphidium Montfort (Figs. 5; 161, h) (Polystomella Lamarck) Test planispiral, at least in young, generally lenticular, septa double, canal system in higher forms; fossil and recent Family 27 Camerinidae 352 PROTOZOOLOGY Fig. 161. a, Lagena striata, X50 (Rhumbler) ; b, Elphiduim strigilata, X40 (Klihn); c, Operculina ammonoides, X50 (Kiihn); d, Pavonina flaheUiJormis, X30 (Brady); e, Hantkenina alabamensis, X40 (Cush- man); f, Bolivina 'punctata, XlOO (Ktihn); g, Rotalia beccarii, X40 (Kiihn); h, Asterigerina carinata, X30 (d'Orbigny from Kiihn). Genus Operculina d'Orbigny (Fig. 161, c) Test generally biserial in at least microspheric form, aperture usually large, without teeth; fossil and recent Family 28 Heterohelicidae Genus Pavonina d'Orbigny (Fig. 161, d) Test planispiral, bi- or tri-serial with elongate spines and lobed aperture; fossil and recent Family 29 Hantkeninidae Genus Hantkenina Cushman (Fig. 161, e) Test typically with an internal tube, elongate Aperture generally loop-shaped or cribrate; fossil and recent. . Family 30 Buliminidae Genus Bolivina d'Orbigny (Fig. 161, /) Aperture narrow, curved, with an overhanging portion; mostly fossil, also recent Family 31 Ellipsoidinidae Genus Ellipsoidina Seguenza Test trochoid, at least in young of microspheric form, usually coarsely perforate; when lenticular, with equatorial and lateral chambers FORAMINIFERA 353 Test trochoid throughout, simple; aperture ventral No alternating supplementary chambers on ventral side; fossil and recent Family 32 Rotaliidae Genus Rotalia Lamarck (Fig. 161, g) Alternating supplementary chambers on ventral side; fossil and recent Family 33 Amphisteginidae Genus Asterigerina d'Orbigny (Fig. 161, h) Test trochoid and aperture ventral in young With supplementary material and large spines, independent of chambers; fossil and recent. . .Family 34 Calcarinidae Genus Calcarina d'Orbigny (Fig. 162, a) AVith later chambers in annular series or globose with multiple apertures, but not covering earlier ones; fossil and recent Family 35 Halkyardiidae Genus Halkyardia Heron-Allen et Earland (Fig. 162, 6) With later chambers somewhat biserial; aperture elongate in the. axis of coil; fossil and recent Family 36 Cassidulinidae Genus Cassidulina d'Orbigny (Fig. 162, c) With later chambers becoming involute, very few making up the exterior in adult; aperture tj^pically elongate, semi- circular; in a few species circular; fossil and recent Family 37 Chilostomellidae Genus AUomorphina Reuss (Fig. 162, d) With chambers mostly finely spinose and wall cancellated, adapted for pelagic life, globular forms with the last chamber completely involute; aperture umbilicate or along the suture; fossil and recent. . . .Family 38 Globigerinidae Genus Globigerina d'Orbigny (Fig. 162, e) Early chambers globigerine, later ones spreading and com- pressed; fossil and recent. .. .Family 39 Globorotallidae Genus Globorotalia Cushman Test trochoid at least in young, aperture peripheral or becoming dorsal 354 PROTOZOOLOGY Fig/162. a, Calcarina defrancei, X25 (Brady) ; b, Halkyardia radiata Xl5 (Cushman); c, Cassidulina laevigata, X25 (Brady); d, Allo- morphina trigona, X40 (Brady); e, Globigerina bulloides, X30 (Kiihn); f, Anomalina punctulata (d'Orbigny); g, Rupertia stabilis, x50 (Brady). Mostly attached, dorsal side usually flattened; fossil and recent Family 40 Anomalinidae Genus Anomalina d'Orbigny (Fig. 162, /) Later chambers in annular series; fossil and recent Family 41 Planorbulinidae Genus Planorbulina d'Orbigny Test trochoid in very young, later growing upward Later chambers in a loose spiral; fossil and recent Family 42 Rupertiidae Genus Rupertia Wallich (Fig. 162, g) Later chambers in masses or branching, highly colored ; mostly recent, also fossil Family 43 Homotremidae Genus Homotrema Hickson Test trochoid in the very young of microspheric form, chambers becoming annular later, with definite equatorial and lateral chambers, often with pillars; fossil only Family 44 Orbitoididae Genus Orbitoides d'Orbigny FORAMINIFERA 355 References Brady, B. H. 1884 Report on the Foraminifera dredged by H.M.S. Challenger, during the years 1873 to 1876. Rep. Voy Challenger., Vol. 9. CusHMAN, J. A. 1933 Foraminijera: their classification and eco- nomic use. Second edition. Sharon, Mass. 1933 An illustrated key to the genera of the Foraminijera. Sharon, Mass. Rhumbler, L. 1904 Systematische Zusammenstellung der rez- enten Reticulosa (Nuda u. Foraminifera). Arch. f. Proti- stenk., Vol. 3. Chapter 21 Subclass 2 Actinopoda Calkins THE Actinopoda are divided into two orders as follows: Without central capsule Order 1 Heliozoa With central capsule Order 2 Radiolaria (p. 367) Order 1 Heliozoa Haeckel The Heliozoa are, as a rule, spherical in form with many radi- ating axopodia. The cytoplasm is differentiated, distinctly in Actinosphaerium, or indistinctly in other species, into the coarse- ly vacuolated ectoplasm and the less transparent and vacuolated endoplasm. The food of Heliozoa consists of living Protozoa or Protophyta; thus their mode of obtaining nourishment is holo- zoic. A large organism may sometimes be captured by a group of Heliozoa which gather around the prey. When an active ciliate or a small rotifer comes in contact with an axopodium, it seems to become suddenly paralyzed and, therefore, it has been suggested that the pseudopodia contain some poisonous substances. The axial filaments of the axopodia disappear and the pseudopodia become enlarged and surround the food completely. Then the food matter is carried into the main part of the body and is di- gested. The ectoplasm contains several contractile vacuoles and numerous refractile granules which are scattered throughout. The endoplasm is denser and usually devoid of granules. In the axopodium, the cytoplasm undergoes streaming movements. The hyaline and homogeneous axial filament runs straight through both the ectoplasm and the endoplasm, and terminates in a point just outside the nuclear membrane. When the pseudopodium is withdrawn, its axial filament disappears completely, though the latter sometimes disappears without the withdrawal of the pseu- dopodium itself. In Acanthocystis the nucleus is eccentric (Fig. 165, 6), but there is a central granule, or centroplast, in the cen- ter of the body from which radiate the axial filaments of the axopodia. In multinucleate Actinosphaerium, the axilia filaments terminate at the periphery of the endoplasm. In Camptonema, an axial filament arises from each of the numerous nuclei (Fig. 163, d). 356 ACTINOPODA, HELIOZOA 357 b Fig. 163. a, Actinocoma ramosa, X630 (Penard); b, Adinophrys sol, X400 (Kudo); c, Actinosphaeruim eichhorni, X45 (Kudo); d, Camp- tone tna nutans, X350 (Schaudinn). The skeletal structure of the Heliozoa varies among different species. The body may be naked, covered by a gelatinous mantle, or provided with a lattice-test with or without spicules. The spic- ules are variable in form and location and may be used for specific differentiation. In some forms there occur colored bodies bearing chromatophores, which are considered as holophytic Mastigo- phora (p. 24) living in the heliozoans as symbionts. The Heliozoa multiply by binary fission or budding. Incom- plete division may result in the formation of colonies, as in Rhaphidiophrys. In Actinosphaerium, nuclear phenomena have been studied by several investigators (p. 156). In Acanthocystis 358 PROTOZOOLOGY and Oxncrella (Fig. 55), tho central granule behaves somewhat like the centriole in a metazoan mitosis. Budding has been known in numerous species. In Acanthocystis the nucleus under- goes amitosis several times, thus forming several nuclei, one of which remains in place while the other migrates toward the body surface. Each peripheral nucleus becomes surrounded by a pro- truding cytoplasmic body which becomes covered by spicules and which is set free in the water as a bud. These small individuals are supposed to grow into larger forms, the central granules being produced from the nucleus during the growth. Formation of swarmers is known in a few genera and sexual reproduction occurs in some forms. The Heliozoa live chiefly in fresh water, although some inhabit the sea. Without gelatinous envelope Without flagella Ps'eudopodia arise from thick basal parts, branching Family 1 Actinocomidae Pseudopodia not branching; cytoplasm highly vacuolated Family 2 Actinophryidae With 1-2 flagella Family 3 Ciliophryidae (p. 359) With gelatinous envelope; with or without skeleton Without flagella Without chitinous capsule Without definite skeleton .... Family 4 Lithocollidae (p. 360) With chitinous or siliceous spicules or scales With chitinous spicules. . .Family 5 Heterophryidae (p. 362) With siliceous skeleton Cup-like plates over body; 2-3 pseudopodia often grouped Family 6 Clathrellidae (p. 362) Scales flattened, not cup-like Family 7 Acanthocystidae (p. 362) With chitinous retiform capsule. Family 8 Clathulinidae (p. 364) With numerous flagella, among axopodia; siliceous scales Family 9 Myriophryidae (p. 366) Family 1 Actinocomidae Poche Genus Actinocoma Penard. Body spherical; one or more con- tractile vacuoles; nucleus with a thick membrane, central; filo- podia, not axopodia, simple or in brush-hke groups; fresh water. A. ramosa P. (Fig. 163, a). Average diameter 14-26^1. Family 2 Actinophyridae Glaus Genus Actinophrys Ehrenberg. Spheroidal; cytoplasm highly vacuolated, especially ectoplasm; with often symbiotic zoochlorel- ACTINOPODA, HELIOZOA 359 lae; nucleus central; 1- many contractile vacuoles; axopodia straight, numerous, axial filaments terminate at surface of the nucleus; "sun animalcules"; fresh water. A. sol E. (Figs. 78; 163, b). Spherical; ectoplasm vacuolated; endoplasm granulated with numerous small vacuoles; a large central nucleus; soHtary but may be colonial when young; diame- ter variable, average being 40-50ai; among plants in still fresh water. Reproduction studied by Belaf (p. 156); Looper (1928) studied its food reactions. A. vesiculata Penard. Ectoplasm with saccate secondary vesi- cles, extending out of body surface between axopodia; nucleus central, with many endosomes; 25-30^ in average diameter; fresh water. Genus Actinosphaerium Stein. Spherical; ectoplasm consists almost entirely of large vacuoles in one or several layers; endo- plasm with numerous small vacuoles; numerous nuclei; axial filaments end in the inner zone of ectoplasm. 2 species. A. eichhorni Ehrenberg (Figs. 6; 163, c). Numerous nuclei scattered in the periphery of endoplasm; 2 or more contractile vacuoles, large; axial filaments arise from a narrow zone of dense cytoplasm at the border line between endoplasm and ectoplasm; body large, diameter 200-300^, sometimes up to 1 mm.; nuclei 12-20/x in diameter; among vegetation in freshwater bodies. A. arachnoideum Penard. Ectoplasm irregularly vacuolated; no distinct endoplasmic differentiation; nuclei smaller in number; pseudopodia of 2 kinds; one straight, very long and the other fihform, and anastomosing; 70-80/^ in diameter. Genus Camptonema Schaudinn. Spheroidal; axial filaments of axopodia end in nuclei about 50 in number; (contractile?) vacu- oles numerous and small in size; salt water. C. nutans S. (Fig. 163, d). About 150^* in diameter. Genus Oxnerella Dobell. Spherical; cytoplasm indistinctly differentiated; eccentric nucleus with a large endosome; axial filaments take their origin in the central granule; no contractile vacuole; nuclear division typical mitosis (Fig. 55). 0. maritima D. (Fig. 55). Small, 10-22iu in diameter; solitary, floating or creeping; salt water. Family 3 Ciliophryidae Poche Genus Ciliophrys Cienkowski. Spherical with extremely fine 360 PROTOZOOLOGY radiating filopodia, giving the appearance of a typical heliozoan, with a single flagellum which is difficult to distinguish from the numerous filopodia, but which becomes conspicuous when the pseudopodia are withdrawn; fresh or salt water. C. infusionum C (Fig. 164, a). 25-30/1 long; freshwater in- fusion. C. marina Caullery. About lO/i in diameter; salt water. Family 4 Lithocollidae Poche Genus LithocoUa Schulze. Spherical body; outer envelope with usually one layer of sand-grains, diatoms, etc.; nucleus eccentric. L. glohosa S. (Fig. 164, h). Body reddish with numerous small colored granules; nucleus large; central granule unknown; envelope 35-50// in diameter; in lakes, ponds, and rivers; also in brackish water. Genus Astrodisculus Greeff . Spherical with gelatinous envelope, free from inclusions, sometimes absent; no demarcation between 2 regions of the cytoplasm; pseudopodia fine without granules; fresh water. A. radians G. (Fig. 164, c). Outer surface usually with adherent foreign bodies and bacteria; cytoplasm often loaded with green, yellow, or brown granules; nucleus eccentric; a contractile vacuole; diameter 25-30/i including envelope; in pools and ditches. Genus Actinolophus Schulze. Body pyriform, enveloped in a gelatinous mantle; stalked; stalk apparently hollow; axopodia long, numerous; nucleus eccentric; salt water. A. pedunculatus S. (Fig. 164, d). Diameter about 30/t; stalk about lOO/i long. Genus Elaeorhanis Greeff. Spherical; mucilaginous envelope with sand-grains and diatoms; cytoplasm with a large oil globule; nucleus eccentric; 1 or more contractile vacuoles; pseudopodia not granulated, sometimes forked; fresh water. E. cincta G. (Fig. 164, e). Bluish with a large yellow oil globule; without any food particles; no central granule; pseudopodia rigid, but apparently without axial filaments, sometimes forked; young forms colonial; soHtary when mature; outer diameter 50- 60/1 ; body itself 25-30/t; in lakes and pools. Genus Sphaerastrum Greeff. Somewhat flattened; greater part of axopodia and body covered by a thick gelatinous mantle; a central granule and an eccentric nucleus; fresh water. ACTINOPODA, HELIOZOA 361 Fig. 164. a, Ciliophrys infusionum, X400 (Biitschli); b, Lithocolla globosa, X250 (Penard); c, Astrodisculus radians, X600 (Penard); d, Actinolophus pedunculatus, X400 (Schultze); e, Elaeorhanis cincta, X300 (Penard); f, Sphaerastriim fockei, X300 (Stubenrauch) ; g, He- terophrys myriopoda, X270 (Penard). 362 PROTOZOOLOGY S. fockei G. (Fig. 164, /). Diameter about 30ju; often colonial; in swamps. Family 5 Heterophryidae Poche Genus Heterophrys Archer. Spherical; mucilaginous envelope thick, with numerous radial, chitinous spicules which project beyond periphery; nucleus eccentric; axial filaments originate in a central granule; fresh or salt water. H. myriopoda A. (Fig. 164, g). Nucleus eccentric; cytoplasm loaded with spherical algae, living probably as symbionts; con- tractile vacuoles indistinct; 50-80^ in diameter; in pools and marshes; and also among marine algae. H. glahrescens Penard. Spherical; gelatinous envelope poorly developed; chitinous needles indistinct; pseudopodia very long; 11-15m in diameter; fresh water. Family 6 Clathrellidae Poche Genus Clathrella Penard. Envelope distinct, polygonal; surface with uniform alveoli with interalveolar portion extending out; envelope appears to be continuous, but in reality formed by a series of cup-like bodies; contractile vacuole large; voluminous nucleus eccentric; filopodia straight, rarely bifurcated, arising between "cups." C. foreli P. (Fig. 165, a). Envelope about 40-55/x in diameter; fresh water. Family 7 Acanthocystidae Glaus Genus Acanthocystis Carter. Spherical; siliceous scales, ar- ranged tangentially and radiating siliceous spines with pointed or bifurcated ends; nucleus and endoplasm eccentric; a distinct central granule in which the axial filaments originate. Several species. A. aculeata Hertwig et Lesser (Fig. 165, b). Tangential scales stout and pointed; spines curved and nail-headed; cytoplasm greyish; a single contractile vacuole; diameter 35-40^; spines about 1/3 the body diameter; in fresh water. Genus Pompholyxophrys Archer. Spherical; outer mucilaginous envelope with minute colorless spherical granules arranged in concentric layers; nucleus eccentric; contractile vacuoles; pseudo- podia long, straight, acicular; fresh water. P. punicea A. (Fig. 165, c). Body colorless or reddish, with ACTINOPODA, HELIOZOA 363 Fig. 165. a, Clathrellaforeli, X250 (Penard); b, Acanthocystis acule- ala, X300 (Stern); c, Pompholyxophnjs punicea, X260 (West); d, Raphidiophrys pallida, X300 (Penard); e, Raphidocystis tubifera, X500 (Penard); f, Wagnerella borealis, x75 (Kiihn); g, Pinaciophora fluviatilis, X250 (Penard). usually many colored granules and green or brown food particles; nucleus large, eccentric; solitary, active; diameter 25-35/x; outer envelope 5-10/1 larger; in pools. 364 PROTOZOOLOGY Genus Raphidiophrys Archer. Spherical; mucilaginous envelope with spindle-shaped or discoidal spicules which extend normally outwards along pseudo})odia; nucleus and endoplasm eccentric; solitary or colonial; fresh water. Several species. R. pallida Schulze (Fig. 165, d). Outer gelatinous envelope crowded with curved lenticular spicules, forming accumulations around pseudopodia; ectoplasm granulated; nucleus eccentric; contractile vacuoles; axial filaments arise from the central granule; solitary; diameter 50-60/i; nucleus 12-15/u in diameter; spicules 20yu long; among vegetation in still fresh water. Genus Raphidocystis Penard. Spicules of various forms, but unlike those found in the last genus. R. tuhifera P. (Fig. 165, e). Spicules tubular with enlarged extremity; diameter about 18/x; envelope 25//; fresh water. Genus Wagnerella Mereschkowsky. Spherical, supported by a cylindrical stalk with an enlarged base; small siliceous spicules; nucleus in the base of stalk; multiplication by budding. W. borealis M. (Fig. 165, /). About ISO/t in diameter; stalk often up to 1.1 mm. long; salt water. Genus Pinaciophora Greeff. Spherical; outer envelope com- posed of circular discs, each being perforated with 19 minute pores; cytoplasm reddish; fresh water. P. fluviatilis G. (Fig. 165, g). Diameter 45-50jU, but somewhat variable; in freshwater ponds. Family 8 Clathrulinidae Glaus Genus Clathrulina Cienkowski. Envelope spherical, homo- geneous, with numerous regularly arranged openings; with a stalk; protoplasm central, not filling the capsule; nucleus central; pseudopodia numerous, straight or forked, granulated; fresh water. C. elegans C. (Fig. 166, a). Envelope colorless to brown, per- forated by numerous comparatively large circular or polygonal openings; 1 or more contractile vacuoles; nucleus central; diame- ter 60-90/i; openings 6-10/jl; stalk 2-4 times the diameter of envelope by 3-4/t wide; solitary or colonial; among vegetation in ponds. Genus Hedriocystis Hertwig et Lesser. Envelope spherical, openings minute, surrounded by polyhedral facets or ridges; with stalk; solitary or colonial; fresh water. ACTINOPODA, HELIOZOA 365 Fig. 166. a, ClathrulincTelegans, X250 (Leidy); b, Hedriocystis reticulata, X500 (Brown); c * Blaster greejfi, X680 (Penard); d, Choano- cystis lepidula, X690 (Penard); e, Myriophrys paradoza, X300 (Penard). 366 PROTOZOOLOGY //. reticulata Penard (Fig. 166, b). Envelope colorless or pale yellow, proliferations regularly polygonal with raised borders; stalk solid, straight; nucleus central; 1 contractile vacuole; each pseudopodium arises from a pore located in the center of a facet; solitary; capsule about 25^ in diameter; body about 12^1 in diame- er; stalk about TO^i by l.Sju; in marshy pools. Genus Blaster Grimm. Envelope spherical, delicate, penetrated by numerous more or less large pores; without stalk; pseudopodia many, straight filopodia. E. greeffi G. (Fig. 166, c). Diameter of envelope 20^1; envelope delicate, colorless; many pseudopodia; in peaty soil. Genus Choanocystis Penard. Spherical envelope with perfora- tions which possess conical borders; openings of cones provided with funnel-like expansions, edges of which nearly touch one another; fresh water. C. lepidula P. (Fig. 166, d). Diameter 10-13/x; envelope delicate; 1 or more contractile vacuoles; pseudopodia very long. Family 9 Myriophryidae Poche Genus Myriophrys Penard. Spherical or ovoid, covered with a protoplasmic envelope containing scales(?), surrounded by nu- merous fine processes; endoplasm vesicular; a large nucleus eccentric; a large contractile Vacuole; long pseudopodia granu- lated and attenuated toward ends. M. paradoxa P. (Fig. 166, e). Average diameter 40)u; in fresh- water swamps. References Belar, K. 1922 Untersuchungen an Actinophyrs sol Ehrenberg. I, II. Arch. f. Protistenk., Vols. 46, 48. Cash, J. and G. H. Wailes 1921 The British freshwater Rhizo- poda and Heliozoa. Vol. 5. Leidy, J. 1879 Freshwater Rhizopods of North America. Rep. U. S. Geol. Survey. Vol. 12. Penard, E. 1904 Les H eliozoaires d'eau douce. Geneva. 1905 Les Sarcodines des Grands Lacs. Geneva. Chapter 22 Order 2 Radiolaria MUller THE Radiolaria are pelagic in various oceans. A vast area of the ocean floor is known to be covered with the ooze made up chiefly of radiolarian skeletons. They seem to have been equally abundant during former geologic ages, since rocks composed of their skeletons occur in various geological formations. Thus this group is the second group of Protozoa important to geologists. The body is generally spherical, although radially or bilaterally symmetrical forms are also encountered. The cytoplasm is divided distinctly into two regions which are sharply delimited by a membranous structure known as the central capsule. This is a single or double perforated membrane of pseudochitinous or mucinoid nature. Although its thickness varies a great deal, the capsule is ordinarily very thin and only made visible after addi- tion of reagents. Its shape varies according to the form of the organism; thus in spherical forms it is spherical, in discoidal or lenticular forms it is more or less ellipsoidal, while in a few cases it shows a number of protruding processes. The capsule is capable of extension as the organism grows and of dissolution at the time of multiplication. The cytoplasm on either side of the capsule communicates with the other side through pores which may be large and few or small and numerous. The intracapsular portion of the body is the seat of reproduction, while the extracapsular region is nutritive and hydrostatic in function. The intracapsular cytoplasm is granulated, often greatly vacuolated, and is strati- fied either radially or concentrically. It contains one or more nuclei, pigments, oil droplets, fat globules, and crystals. The nucleus is usually of vesicular type, but its form, size, and struc- ture, vary among different species and also at different stages of development even in one and the same species. A thin assimilative layer, or matrix, surrounds the central capsule. In Tripylea, waste material forms a brownish mass known as phaeodium, around the chief aperture (astropyle) of the capsule. Then there is a highly alveolated region, termed calymma, in which the alveoli are apparently filled with a mucilaginous secretion of the cytoplasm. Brandt showed that the 367 368 PROTOZOOLOGY vertical movement of some Radiolaria is due to the formation and expulsion of a fluid which consists of water saturated with carbon dioxide. Under ordinary weather and temperature condi- tions, the interchange between the alveoli and the exterior is gradual and there is a balance of loss and gain of the fluid, so that the organisms float on the surface of the sea. Under rough weather conditions or at extraordinary high temperatures, the pseudo- podia are withdrawn, the alveoli burst, and the organisms descend into deeper water, where the alveoli are reformed. The Radiolaria feed on microplankton such as copepods, dia- toms, and various Protozoa. The food is taken in through pseudo- podia and passed down into the deeper region of calymma where it is digested in food vacuoles. The Radiolaria can, however, live under experimental conditions without solid food if kept under light. This is ordinarily attributed to the action of the yellow corpuscles which are present in various parts of the body, al- though they are, as a rule, located in the calymma. In Actipylea they are found only in intracapsular cytoplasm, and in Tripylea they are absent altogether. They are spherical bodies, about 15/z in diameter, with a cellulose wall, 2 chromatophores, a pyrenoid, starch, and a single nucleus. They appear to multiply by fission. These bodies are considered as zooxanthellae (p. 23-24). In the absence of organic food material, the Radiolaria live probably by utilizing the products of holophytic nutrition of these sym- biotic organisms. The axopodia arise from either the extracapsular or the intra- capsular portion and radiate in spherical forms in all directions, as in Heliozoa. In Actipylea, myonemes are present in certain pseudopodia and produce circular groups of short, rod-like bodies, clustered around each of the radial spines (Fig. 168, c). They connect the peripheral portion of the body with the pseudopodial covering of the spicule and possess a great contractile power, supposedly with hydrostatic function (p. 52-53). The skeletal structure of Radiolaria varies considerably from simple to complex and has a taxonomic value. The chemical nature of the skeleton is used in distinguishing the major sub- divisions of the order. In the Actipylea it seems to be made up of strontium sulphate, while in the three other groups, Peripylea, Monopylea, and Tripylea, it consists fundamentally of sihceous substances. The skeleton of the Actipylea is sharply marked RADIOLARIA 369 from others in form and structure. The majority of this group possess 20 rods radiating from the center. The rod-shaped skele- tons emerge from the body in most cases along five circles, which are comparable to the equatorial, two tropical and two circum- polar circles of the globe, which arrangement is known as M tiller's law, since J. M tiller first noticed it in 1858. The life-cycle of the Radiolaria is very incompletely known (Fig. 167). Binary or multiple fission or budding has been seen in some Peripylea, Actipylea, and Tripylea. Multiple division is Fig. 167. Diagram illustrating the life-cycle of Actipylea (Kiihn). a, mature individual; b, c, binary fission; d, e, multiplication by bud- ding; f, mature individual similar to a; g, formation of swarmers; h-j, supposed, but not observed, gametogony of two swarmers pro- ducing a zygote; k, 1, young individuals. 370 PROTOZOOLOGY also known to occur in Thalassophysidae in which it is the sole known means of reproduction. The central capsule becomes very irregular in its outline and the nucleus breaks up into numerous chromatin globules. Finally the capsule and the intracapsular cytoplasm become transformed into numerous small bodies, each containing several nuclei. Further changes are unknown. Swarmer-formation is known in some forms. In Thalassicolla, the central capsule becomes separated from the remaining part of the body and the nuclei divide into a number of small nuclei, around each of which condenses a small ovoidal mass of cyto- plasm. They soon develop flagella. In the meantime the capsule descends to a depth of several hundred meters, where its wall bursts and the flagellate swarmers are liberated (g). Both iso- swarmers and anisoswarmers occur. The former often contain a crystal and a few fat globules. Of the latter, the macroswarmers possess a nucleus and refringent spherules in the cytoplasm only. Some forms possess 2 flagella, one of which is coiled around the groove of the body, w^hich makes them resemble certain dino- flagellates. Further development is unknown; it is supposed that the anisoswarmers are sexual and isoswarmers asexual genera- tions. Enormous numbers of species of Radiolaria are known. An outline of the classification is given below, together with a few examples of the genera. Skeleton composed of strontium sulphate Suborder 1 Actipylea Skeleton composed of other substances Central capsule uniformly perforated; skeleton either tangential to the capsule or radiating without reaching the intracapsular region Suborder 2 Peripylea (p. 372) Central capsule not uniformly perforated Capsule monaxonic, bears at one pole a perforated plate forming the base of an inward-directed cone Suborder 3 Monopylea (p. 373) Capsule with 3 openings: 1 astropyle and 2 parapyles Suborder 4 Tripylea (p. 374) Suborder 1 Actipylea Hertwig Radial spines, 10-200, not arranged according to Mliller's law Legion 1 Actinelida Spines radiate from a common center; ancestral forms (Haeckel) . . Family 1 Actineliidae RADIOLARIA 371 Genus Actinelius (Fig. 168, a) 10-16 spines irregularly set Family 2 Acanthociasmidae Genus Acanthociasma (Fig. 168, b) Radial spines, few, arranged according to Miiller's law Without tangential skeletons Legion 2 Acanthometrida Spines more or less uniform in size Spicules circular in cross-section . . . Family 1 Acanthometridae Genus Acanthometron (Fig. 168, c) Spicules cruciform in cross-section. . . .Family 2 Acanthoniidae Genus Acanthoma (Fig. 168, d) 2 opposite spines much larger Family 3 Amphilonchidae Genus Amphilonche (Fig. 168, e) With tangential skeletons Legion 3 Acanthophractida 20 radial spines of equal size; shell composed of small plates, each with one pore Family 1 Sphaerocapsidae Genus Sphaerocapsa 2 or 6 larger spines 2 enormously large conical sheathed spines Family 2 Diploconidae ^ \\ // Fig. 168. a, Actinelius priniordialis, X25 (Haeckel); b, Acanthoci- asma ylanum, X65 (Mielck); c, Acanthotnetron elasticum (Hertwig); d, Acanthoma tetracopa, X40 (Schewiakoff) ; e, Amphilonche hydro- metrica, Xl30 (Haeckel); f, Hexaconus serratus, XlOO (Haeckel). (From Kiihn.) 372 PROTOZOOLOGY Genus Diploconus 6 large spines Family 3 Hexalaspidae Genus Hexaconus (Fig. 168, /) Suborder 2 Peripylea Hertwig Solitary; skeleton wanting or simple spicules; mostly spherical Legion 1 Collodaria Nucleus spherical with smooth membrane Vacuoles intracapsular Family 1 Physematiidae Genus Lampoxanthium (Fig. 169, a) Vacuoles extracapsular Family 2 Thalassicollidae Genus Thalassicolla (Fig. 169, h) Nuclear membrane not smoothly contoured Nuclear wall branching out into pouches; structure similar to the last Family 3 Thalassophysidae Genus Thalassophysa Fig. 169. a, Lampoxanthium pandora, X20 (Haeckel); b, Thalassicolla nucleata, Xl5 (Huth). (From Kiihn.) Nuclear wall crenate Huge double spicule Family 4 Thalassothamnidae Genus Thalassothamnus A latticed skeleton, with branching and thorny spines Family 5 Orosphaeridae Genus Orosphaera Solitary; skeleton complex, often concentric. . . . Legion 2 Sphaerellaria Central capsule and skeleton spherical Family 1 Sphaeroidae RADIOLARIA 373 Genus Hexacontium (Fig. 170, a) Central capsule and skeleton elliptical or cylindrical Family 2 Prunoidae Genus Pipetta (Fig. 170, 6) Central capsule and skeleton discoidal or lenticular Family 3 Discoidae Genus Staurocyclia (Fig. 170, c) Similar to the above, but flattened Family 4 Larcoidae Fig. 170. a, Hexacontium asleracanthion, Xl30; b, Pipetta tuha, XlOO; c, Staurocyclia phacostaurus, Xl30; d, Cenolarus primordialis, XlOO; e, Sphaerozoum ovodimare, X30 (Haeckel from Kiihn). Genus Cenolarus (Fig. 170, d) Colonial; individuals with anastomosing extracapsular cytoplasm, em- bedded in a jelly mass Legion 3 Polycyttaria Without latticed skeleton, but with siliceous spicules arranged tangentially to central capsule Family 1 Sphaerozoidae Genus Sphaerozoum (Fig. 170, e) Central capsule of each individual enclosed in a latticed skeleton . . Family 2 Collosphaeridae Genus Collosphaera Suborder 3 Monopylea Hertwig Without any skeleton Legion 1 Nassoidea Family 1 Nassoidae Genus Cystidium (Fig. 171, a) With skeleton Without a complete latticed skeleton Legion 2 Plectellaria Skeleton a basal tripod Family 1 Plectoidae 374 PROTOZOOLOGY Genus Triplagia (Fig. 171, b) Fig. 171. a, Cystidium princeps, Xl20; b, Triplagia primordialis, X25; c, Lithocircus niagnificus, XlOO; d, Dictyophiinus hertwigi,XSO (Haeckel from Kiihn). Skeleton a simple or multiple sagittal ring Family 2 Stephoidae Genus Lithocircus (Fig. 171, c) With a complete latticed skeleton Legion 3 Cyrtellaria Lattice skeleton single, without constriction Family 1 Cyrtoidae Genus Dictyophimus (Fig. 171, d) Lattice skeleton multiple Family 2 Botryoidae Genus Phormobothrys Suborder 4 Triplylea Hertwig Without skeleton; with isolated spicules. . . .Legion 1 Phaeocystina Skeleton consists of radial hollow rods and fine tangential needles Family 1 Aulacanthidae Genus Aulacantha (Fig. 172, a) With foreign skeleton covering body surface Family 2 Caementellidae Genus Caementella (Fig. 172, 6) With skeleton 1-2 (concentric) usually spherical skeletons Legion 2 Phaeosphaeria Outer lattice skeleton with triangular or areolar meshes Family 1 Sagosphaeridae Genus Sagenoscene RADIOLARIA 375 Fig. 172. a, Aulacantha scohjmantha, X30 (Kiihn); b, Caementella stapedia, X65 (Haeckel); c, Anlosphaera lahradoriensis, XlO (Haecker). (From Kiihn.) One lattice skeleton with hollow radial bars Family 2 Aulosphaeridae Genus Aulosphaera (Fig. 172, c) 2 concentric lattice skeletons connected by radial bars Family 3 Cannosphaeridae Genus Cannosphaera One skeleton, simple, but variable in shape, bilaterally symmetrical Legion 3 Phaeogromia Skeleton with fine diatomaceous graining Family 1 Challengeridae Genus Challengeron (Fig. 173, a) Skeleton smooth or with small spines. . . .Family 2 Medusettidae Genus Medusetta (Fig. 173, h) One skeleton; spherical or polyhedral, with an opening and with radiating spines Legion 4 Phaeocalpia Skeleton spherical or polyhedral, with uniformly large round pores Family 1 Castanellidae Genus Castanidium (Fig. 173, c) Skeleton similar to the last, but the base of each radial spine surrounded by pores Family 2 Circoporidae Genus Circoporus (Fig. 173, d) Skeleton flask-shaped with 1-2 groups of spines Family 3 Tuscaroridae 376 PROTOZOOLOGY Fig. 173. a, Challengeron wyvillei, Xl05 (Haeckel); b, Medusetta ansata, X230 (Borgert); c, Castanidium murrayi, x25 (Haecker); d, Circoporus octahedrus, X65 (Haeckel); e, Tuscarora murrayi, X7 (Haeckel); f, Coelodendrum ramosissimum, XlO (Haecker). (From Kuhn.) Genus Tuscarora (Fig. 173, e) Central portion of skeleton consists of 2 valves Legion 5 Phaeoconchia Valves thin, each with a conical process which divides into branched tubes Family 1 Coelodendridae Genus Coelodendrum (Fig. 173, /) References Brandt, K. 1905 Zur Systematik der koloniebildenden Radio- larien. Zool. Jahrb. Suppl., Vol. 8. Borgert, A. 1905-1913 Mehrere Arbeiten ueber Familien der Tripyleen. Ergebn. d. Planktonexpedition. Vol. 3. Haeckel, E. 1862-1887 Die Radiolarien. Eine Monographie. I, II. 1887 Rep. on the Radiolaria collected by H.M.S. Challenger. Challenger Rep. Zool. Vol. 18. Haecker, V. 1908 Tiefseeradiolarien. Wiss. Ergebn. Deutsch, Tiefsee-Exp. a.d. Dampfer "Valdivia." Vol. 14. Hertwig, R. 1879 Der Organismus der Radiolarien. Jena. Chapter 23 Class 3 Sporozoa Leuckart THE Sporozoa are without exception parasitic and bear spores in their development. Their hosts are distributed in every animal phylum, from Protozoa to Chordata. As a rule, they are incapable of locomotion, but some when immature may move about by means of pseudopodia. They possess neither cilia nor flagella, except as gametes. In the forms that are confined to one host, the spore usually is enveloped by a resistant membrane which would enable it to withstand unfavorable conditions while outside of the host body, but in those having two host animals, as in Plasmodium, the sporozoite is naked. The method of nutri- tion is saprozoic or parasitic, the food being dissolved cytoplasm, tissue fluid, body fluid, or dissolved food material of the host. Both asexual and sexual reproductions are well known in many species. Asexual reproduction by repeated binary or multiple fission or budding of intracellular trophozoites or schizonts, pro- duces far greater number of individuals than that of protozoans belonging to other classes and often is referred to as schizogony. The sexual reproduction is by isogamous or anisogamous fusion or autogamy and marks in many cases the beginning of sporogony or spore-formation, the initial stage being the zygote or sporont. Schaudinn divided the Sporozoa into two groups, Telosporidia and Neosporidia, and this scheme has been followed by several authors. Some recent writers consider these two groups as separate classes. This, however, seems to be improper, as the basis of distinction between them is entirely different from that which is used for distinguishing the other four classes: Sarcodina, Mastigophora, Ciliata, and Suctoria. For this reason, the Sporozoa are placed in a single class and divided into three sub- classes as follows: Spore simple; without polar filament Spore with or without membrane; with 1-many sporozoites Subclass 1 Telosporidia (p. 378) Spore with membrane; with one sporozoite Subclass 2 Acnidosporidia (p. 446) Spore with polar filament Subclass 3 Cnidosporidia (p. 453) 377 378 PROTOZOOLOGY Subclass 1 Telosporidia Schaudinn The spore which contains neither a polar capsule nor a polar filament, possesses one to several sporozoites and is formed at the end of the trophic life of the individual. In the forms which invade two host animals to complete their development, there occur naked sporozoites instead of spores. The infection of a new host begins with the entrance of mature spores through mouth, or with the introduction of the sporozoites by blood-sucking invertebrates directly into the blood stream. The sporozoites enter specific host cells and there grow at the expense of the latter. In the Coccidia and the Haemosporidia the schizont continues its intracellular existence, but in the Gregarinida it leaves the host cell and grows in an organ cavity. Except Eugregarinina, the vegetative form undergoes schizogony and produces a large number of schizonts which invade new host cells, thus spreading the infection within the host body. The schizonts finally develop into gametocytes. In the Coccidia and the Haemosporidia, anisogametes are, as a rule, produced. Each macrogametocyte develops into a single macrogamete and each microgametocyte, into several microgametes. Fusion of two gametes results in formation of a large number of zygotes, each of which develops either into one to many spores or into a number of naked sporozoites. In the Gregarinida, two fully mature trophozoites (or gametocytes) encyst together and the nucleus in each multiplies repeatedly to form numerous gametes, which fuse in pairs with those produced in the other individual within the common envelope. The zygotes develop into spores, each con- taining sporozoites of variable number. When these spores enter a new host, the changes outlined above are repeated. The Telosporidia are parasitic in vertebrates and higher invertebrates. Three orders are distinguished in this subclass: Mature trophozoite extracellular, large; zygote not motile; sporozoites enveloped Order 1 Gregarinida Mature trophozoite intracellular, small Zygote not motile; sporozoites enveloped . Order 2 Coccidia (p. 415) Zygote motile; sporozoites naked. .Order 3 Haemosporidia (p. 434) Order 1 Gregarinida Lankester The gregarines are chiefly coelozoic parasites in invertebrates, especially arthropods and annelids. They obtain their nourish- SPOROZOA, GREGARINIDA 379 ment from the host organ-cavity through osmosis. The vast majority of gregarines do not undergo schizogony and increase in number is carried on solely by sporogony. In a small group, however, schizogony takes place as well as sexual reproduction and this is used as the basis for grouping these protozoans into two suborders as follows: No schizogony Suborder 1 Eugregarinina Schizogony occurs Suborder 2 Schizogregarinaria (p. 409) Suborder 1 Eugregarinina Doflein This suborder includes the majority of the so-called gregarines which are common parasites of arthropods. When the spore gains entrance to a suitable host, it germinates and the sporozoites emerge and enter the epithelial cells of the digestive tract. There they grow at the expense of the host cells which they leave soon and to which they become attached by various organellae of attachment (Fig. 174). These trophozoites become detached from Fig. 174. The life-cycle of Lankesteria culicis, X about 500 (Wen- yon), a, entrance of sporozoites into the epithelial cell and growth stages of trophozoites; b, mature trophozoite; c, association of two trophozoites; d-f, gamete-formation; g, gametogony; h, development of spores from zygotes; i, a spore; j, germination of spore in host gut. the host cells and move about in the lumen of the gut. This stage, sporadin, is ordinarily most frequently recognized. It is usually large and vermiform. The body is covered by a definite pellicle 380 PROTOZOOLOGY and its cytoplasm is clearly differentiated into the ectoplasm and endoplasm. The former cotains myonemes (p. 52) which enable the organisms to undergo gliding movements. In one group, Acephalina, the body is of a single compartment, but in the other group, Cephalina, the body is divided into two compartments by an ectoplasmic septum. The smaller anterior part is the proto- merite and the larger posterior part, the deutomerite, contains a single nucleus except in Pileocephalus (p. 404) in which the nucleus is said to be located in the protomerite. The endoplasm contains numerous spherical or ovoidal bodies which are called zooamylum or paraglycogen grains and which are apparently reserve food material (p. 94). The protomerite may possess an attaching process with hooks or other structures at its anterior border, which is called the epimerite. The epimerite is usually not found on detached sporadins. Trophozoite with the epimerite will be called the cephalin. Many gregarines are solitary, while others are found often in an endwise association of two or more sporadins. This association is called syzygy. The anterior in- dividual is known as the primite and the posterior, the satellite. Sporadins usually encyst in pairs and become gametocytes. Within the cyst-membrane, the nucleus in each individual under- goes repeated division, forming a large number of small nuclei which by a process of budding transform themselves into numerous gametes. The gametes may be isogamous or anisog- amous. Each of the gametes in one gametocyte appears to unite with one formed in the other, so that a large number of zygotes are produced. The zygote becomes surrounded by a resistant membrane and its contents develop into the sporozoites, thus developing into a spore. The spores germinate when taken into the alimentary canal of a host animal and the life-cycle is re- peated. According to Wenyon, in a typical Eugregarinina, Lankestcria culicis (Fig. 174) of Aedes aegypti, the development in a new host begins when the latter ingests the spores which had been set free by infected adult mosquitoes in the water. From each spore are liberated 8 sporozoites (j), which enter the epithehal cells of the stomach and grow (a). These vegetative forms leave the host cells later and become mingled with the food material present in the stomach lumen of the host (b). When the larva pupates, the sporadins enter the Malpighian tubules, where they encyst (c). SPOROZOA, GREGARINIDA 381 The repeated nuclear division is followed by formation of large numbers of gametes (d-f) which unite in pairs (g). The zygotes thus formed develop into spores, each possessing 8 sporozoites (h). Meanwhile the host pupa emerges as an adult mosquito, and the spores which become set free in the lumen of the tubules, pass into the intestine, from which they are discharged into water. Larvae swallow the spores and acquire infection. Eugregarinina are divided into 2 tribes: Trophozoite not septate Tribe 1 Acephalina Trophozoite septate Tribe 2 Cephalina (p. 391) Tribe 1 Acephalina KoUiker The acephalines are mainly found in the body cavity and organs associated with it. The infection begins by the ingestion of mature spores by a host, in the digestive tract of which the sporo- zoites are set free and undergo development or make their way through the gut wall and reach the coelom or various organs such as seminal vesicles. Young trophozoites are intracellular, while more mature forms are either intracellular or extracellular. Spores with similar extremities Spores biconical Sporadins solitary Anterior end not differentiated .- . . Family 1 Monocystidae (p. 382) Anterior end with a conical or cylindro-conical trunk Family 2 Rhjmchocystidae (p. 384) Sporadins in syzygy Spores with thickenings at ends Family 3 Zygocystidae (p. 384) Spores without thickenings Family 4 Aikinetocystidae (p. 385) Spores not biconical Spores navicular Family 5 Stomatophoridae (p. 386) Spores round or oval No encystment Family 6 Schaudinnellidae (p. 387) 2 sporadins encyst together. . .Family 7 Diplocystidae (p. 387) Spores with dissimilar ends Spores with epispore Family 8 Urosporidae (p. 389) Spores without epispore Family 9 Allantocystidae (p. 391) Spores unobserved; grown trophozoites with cup-like depression at posterior end to effect syzygy Family 10 Ganymedidae (p. 391) 382 PROTOZOOLOGY Family 1 Monocystidae Biitschli Trophozoites spheroidal to cylindrical; anterior end not dif- ferentiated; solitary; spores bi conical, without any spines, with 8 sporozoites. Genus Monocystis Stein. Trophozoites variable in form; motile; incomplete sporulation in cyst; spore biconical, symmetrical; in coelom or seminal vesicles of oligochaetes. Numerous species. M. ventrosa Berlin (Fig. 175, a-c). Sporadins 109-183 ju by 72-135m; nucleus up to 43)u by 20/x; cysts 185-223^ by 154-182^; spores 17-25m by 8-10/^; in Lumbricus rubellus, L. castaneus and Eisenia foetida. M. lumhrici Henle (Fig. 175, d, e). Sporadins about 200/i by 60-70ju; cysts about 162ju in diameter; in Lumbricus terrestris, L. rubellus, and L. castaneus. Genus Apolocystis Cognetti. Trophozoites spherical; without principal axis marked by presence of any special peripheral organ; solitary; spore biconical; in seminal vesicles or coelom of various oligochaetes. Many species. A. gigantea Troisi (Fig. 175, /). In seminal vesicles of Helo- drilus foetidus and Lumbricus rubellus; late October to March only; fully grown trophozoites 250-800/x in diameter; whitish to naked eyes; pellicle thickly covered by 10-15/* long 'hairs'; endoplasm packed with spherical paraglycogen grains (S/j, in diameter); nucleus 35-43/i in diameter; cysts 400-800ai in diameter; spores IQyu by 8.6/x. A. minuta Troisi (Fig. 175, g). In seminal vesicles of Lumbricus terrestris, L. castaneus and L. rubellus; mature trophozoites 40- 46m in diameter; endoplasm yellowish brown, packed with spheri- cal paraglycogen grains (5.3-7^ in diameter); nucleus lO/z in diameter; cysts 68-74;u by 55-65iu; spores of 3 sizes, 11/i by 5.5/i, 18.8m by 7n and 21. 6m by 9.8m. Genus Nematocystis Hesse. Trophozoites elongate, cylindrical and shaped like a nematode; solitary. Many species. N. vermicularis H. (Fig. 175, h). In seminal vesicles of Lumbri- cus terrestris, L. rubellus, Helodrilus longus, Pheretima barba- densis; trophozoites 1 mm. by 100m; cylindrical, both ends with projections; nucleus oval; endoplasm alveolated, with para- glycogen grains; sporadins become paired lengthwise; cysts and spores unknown. Genus Rhabdocystis Boldt. Trophozoites elongate, gently SPOROZOA, GREGARINIDA 383 curved; anterior end swollen, club-shaped; posterior end at- tenuated; spores with sharply pointed ends. One species. R. claviformis B. (Fig. 175, i, j). In seminal vesicles of Odo- FiG. 175. a-c, Monocystis ventrosa (a, X260; b, Xl50; c, X830) (Berlin); d, e, M. lumbrici, X280 (Berlin); f, Apolocystis gigantea, X90 (Troisi); g, A. minuta, with attached phagocytes, X770 (Troisi); h, Nematocystis vermicularis, X80 (Hesse); i, j, Rhabdocystis claviformis (i, X220; j, X270) (Boldt) ; k, 1, Enteroajstis ensis (k, Xl40) (Zwet- kow). lasium complanatum ; sporadins extended, up to 300^ by 30ju; pellicle distinctly longitudinally striated ; zooamylum bodies 2-4/i in diameter; cysts biscuit-form, 110^ by lOfx; spores 16^ by 8/x. Genus Enterocystis Zwetkow. Early stages of trophozoites in syzygy; sporadins in association ensiform; cysts spherical without 384 I'ROTOZOOLOGY ducts; spores elongate ovoid, with 8 sporozoites; in gut of ephemcrid larvae. E. ensis Z. (Fig. 175, k, I). Sporadins in syzygy 200-510^t long; cysts 200-350^ in diameter; spores elongate ovoid; in gut of larvae of Caenis sp. Family 2 Rhynchocystidae Bhatia Trophozoites ovoid, spherical or elongate, with a conical or cylindro-conical trunk at anterior end; solitary; spore biconical, with 8 sporozoites. Genus Rhynchocystis Hesse. Trophozoites ovoid or cylindrical; plastic epimerite, conical or cylindro-conical trunk; in seminal vesicles of oligochaetes. Many species. R. pilosa Cuenot (Fig. 176, a). In seminal vesicles of Lumbricus terrestris, L. castaneus and Helodrilus foetidus; 217ju by 25.5fi; pellicle with close, longitudinal ridges from which arise 'hairs' up to 40)U in length; endoplasm viscous, packed with oval (Sjjl by 2/i) zooamylum bodies; cysts ovoid, 95)U by 84yu; spores 13. 3^ by 5m. R. porreda Schmidt (Fig. 176, b, c). In seminal vesicles of Lumbricus rubellus and Helodrilus foetidus; extremely long with an enlarged head; up to 2.5 mm. by 32-36^; sluggish; endoplasm granulated, filled with oval (4/x by 2-3 ^t) paraglycogen grains; nucleus 17-25^ in diameter; spores 27.7-28^ by 12jli; sporozoites 13-18m by 3-5^. Family 3 Zygocystidae Bhatia Trophozoites in association, spores biconical, with peculiar thickenings at extremities; with 8 sporozoites; in seminal vesicles or coelom of oligochaetes. Genus Zygocystis Stein. Sporadins pyriform, 2-3 in syzygy; in seminal vesicles or coelom of oligochaetes. Several species. Z. wenrichi Troisi (Fig. 176, d, e). In seminal vesicles of Lumbricus rubellus and Helodrilus foetidus; sporadins up to 1.5 mm. by 250/x in diameter; pellicle with longitudinal ridges which become free and form a 'tuft of hairs' at the posterior end; cysts 500-800M by 300-500^; spores 28m by 13iu. Genus Pleurocystis Hesse. Trophozoites in longitudinal or lateral association; spores biconical. One species. P. cuenoti H. (Fig. 176, /). In the ciHated seminal horn of Helodrilus longus and H. caliginosus; 2 mm. by 300^; pellicle SPOROZOA, GREGARINIDA 385 striated longitudinally, oblique near the posterior end; cysts 1.5-2 mm. in diameter; spores 28.5ai by 12^*. Family 4 Aikinetocystidae Bhatia Trophozoites solitary or in syzygy; branching dichotomously, branches with sucker-like organellae of attachment; spores biconical. Genus Aikinetocystis Gates. Trophozoites cylindrical or colum- nar, with a characteristic, regular dichotomous branching at attached end, with sucker-like bodies borne on ultimate branches ; solitary or 2 (3-8) individuals in association; spores biconical. A. singularis G. (Fig. 176, g, h). In coelom of Eutyphoeus foveatus. E. rarus, E. peguanus and E. spinulosus (Burma); trophozoites up to 4 mm. long; number of branches 8 or 16, each with an irregular sucker; ovoid nucleus near rounded end; spores of two sizes, 20-23/x long and 7-8At long; a few cysts found, ovoid and 620^ long. Family 5 Stomatophoridae Bhatia Trophozoites spherical to cyhndrical or cup-shaped; with a sucker-like epimerite; solitary; spores navicular, ends truncate; 8 sporozoites; in seminal vesicles of Pheretima (Oligochaeta). Genus Stomatophora Drzewecki. Trophozoites spherical or ovoid; anterior end with a sucker-like epimeritic organella with a central mucron; spores navicular. Several species. S. coronata (Hesse) (Fig. 176, i-k). In seminal vesicles of Pheretima rodericensis, P. hawayana and P. barhadensis ; tropho- zoites spherical, ovoid or elUptical, about 180|U by 130^; endo- plasm with ovoid zooamylum grains; cysts ellipsoid or fusiform, 70-80/i by 50-60;u; spores in 2 sizes, llyu by 6m and 7^ by 3n and in chain. Genus Astrocystella Cognetti. Trophozoites solitary; stellate with 5-9 lobes radiating from central part containing nucleus; anterior surface with a depression. One species. A. lohosa C. (Fig. 176, I). In seminal vesicles of Pheretima heaufortii (New Guinea); diameter about 200/x; spores fusiform. Genus Craterocystis Cognetti. Trophozoites solitary; rounded; a sucker-like depression on anterior end; myonemes well de- veloped, running from concave to convex side. One species. C. papua C. (Fig. 176, m). In prostate and lymphatic glands of 386 PROTOZOOLOGY Fig. 176. a, Rhynchocystis pilosa, x200 (Hesse); b, c, R. porrecta: b, Xl70 (Hesse), c, spore, X1330 (Troisi); d, e, Zygocystis wenrichi (d, X45; e, X450) (Troisi); f, Pleurocystis cuenoti, Xl90 (Hesse); g, h, Aikinetocystis singularis (h, X320) (Gates); i-k, Stomatophora coronata (i, j, X430; k, X870) (Hesse); 1, Astrocystella lobosa, Xl20 (Cognetti); m, Craterocystis papua, X Q5 {Cognetii);n, Choanocystella tentaculata, X570 (Cognetti); o, Choanocystoides costaricensis, X470 (Cognetti). Pheretima wendessiana (New Guinea); trophozoites about 360- 390/x in diameter. Genus Choanocystella {Choanocystis Cognetti). Trophozoites soHtary ; rounded or ovate ; anterior end with a mobile sucker and a tentacle bearing cytoplasmic hairs; myonemes. One species. C. tentaculata C. (Fig. 176, n). In seminal vesicles of Pheretima heaufortii (New Guinea); trophozoites 50/x by 36m. SPOROZOA, GREGARINIDA 387 Genus Choanocystoides Cognetti. Trophozoites solitary, rounded or cup-shaped; anterior end with a mobile sucker, bordered by cytoplasmic filaments. One species. C. costaricensis C. (Fig. 176, o). In seminal vesicles of Phere- tima heterochaeta (Costa Rica); trophozoites 40-45juin diameter; nucleus ovoid, large, 12^t in diameter. Genus Beccaricystis Cognetti. Mature trophozoites elongate, cylindrical, with a sucker-like depression at anterior end; nucleus at its bottom. One species. B. loriai C. (Fig. 177, a). In seminal vesicles of Pheretima sermowaiana; trophozoites cylindrical, with w^art-like growths, myonemes run lengthwise with radially arranged transverse fibrils; about 100^1 long. Genus Albertisella Cognetti. Mature trophozoites cup-shaped, with anterior sucker with a smooth wall; nucleus at its bottom. One species. A. crater C. In seminal vesicles of Pheretima sermowaiana. Family 6 Schaudinnellidae Poche Parasitic in the digestive system of oligochaetes; spores spheri- cal; trophozoites do not encyst; male trophozoites producing microgametes and female, macrogametes ; zygotes or amphionts (spores) rounded. Genus Schaudinnella Nusbaum. Trophozoites elongate spindle, free in lumen or attached to gut wall; sporadins male or female; spherical macrogametes and fusiform microgametes; zygotes or amphionts encapsulated, passed out of host or enter gut epi- thelium, dividing to produce many sporozoites (autoinfection). S. henleae N. (Fig. 177, h, c). In gut of Henlea leptodera; mature trophozoites about 70ju by Q/x; attached trophozoite with a clear wart-like epimerite; female and male sporadins; macro- gametes, 5-7.5^1 in diameter; microgametes, spindle-form, l-1.25^i long; sporozoites rounded oval, 2.5-3/x in diameter. Family 7 Diplocystidae Bhatia Coelomic or gut parasites of insects; trophozoites solitary or associated early in pairs; spores round or oval, with 8 sporozoites. Genus Diplocystis Kunstler. Trophozoites spherical to oval; association of 2 individuals begin early in spherical form; spores round or oval, with 8 sporozoites; in coelom of insects. 388 PROTOZOOLOGY D. schneideri K. (Fig. 177, d, e). In general body cavity of Periplaneta americana; young stages in gut epithelium; cysts up to 2 mm. in diameter; spores 7-8m in diameter; sporozoites 16m long. Fig. 177. a, Beccaricystis loriai, X570 (Cognetti); b, c, Schaudinnella henleae (b, X885; c, XlOOO) (Nusbaum); d, e, Diplocystis schneideri (d, Xl4;e, X2000) (Kunstler); f, Urospora chiridotae, X200 (Pixell- Goodrich) ; g-i, Gonospora minchini (g, a young trophozoite in host egg; h, a mature trophozoite, X330; i, sporadins in association, X80) (Goodrich and Pixell-Goodrich). Genus Lankesteria Mingazzini. Trophozoites more or less spatulate; spherical cyst formed by 2 laterally associated spora- dins in rotation; spores oval, with flattened ends, with 8 sporo- zoites; in gut of tunicates, flatworms and insects. Several species. L. culicis (Ross) (Fig. 174). In gut and Malpighian tubules of Aedes aegypti and A. alhopidus; mature trophozoites about 150- 200m by 31-41m; cysts spherical, in Malpighian tubules of host, about 30m hi diameter; spores 10m by 6m. SPOROZOA, GREGARINIDA 389 Family 8 Urosporidae Woodcock Coelomic parasites in various invertebrates; sporadins associa- tive; spores with unequal ends; with or without epispores of various forms, with 8 sporozoites. Genus Urospora Schneider. Large; frequently in lengthwise association of 2 individuals of unequal sizes; spores oval, with a long filamentous process at one end; in body cavity or blood ves- sel of Tubifex, Nemertinea, Sipunculus, Synapta, and Chiridota. Several species. U. chiridotae (Dogiel) (Fig. 177,/). In blood vessel of Chiridota laevis (in Canada); paired trophozoites up to about 1 mm. long; with stiff hairs. Genus Gonospora Schneider. Trophozoites polymorphic, oval, pyrif orm or vermiform ; cysts spherical ; spore with a funnel at one end, rounded at the other; in gut, coelom or ova of poly- chaetes. G. minchini Goodrich et Pixell-Goodrich (Figs. 177, g^; 178, g). In coelom of Arenicola ecaudata; young trophozoites live in host eggs which float in the coelomic fluid; fully grown trophozoites leave eggs in which they grow up to 200)u long, and encyst to- gether in pairs; spores without well-developed funnel, 8-10^ long. Genus Lithocystis Giard. Trophozoites large, ovoid or cylin- drical; attached for a long period to host tissue; pellicle with hair- like processes; endoplasm with calcium oxalate crystals; spores ovoid, with a long process at one end; in coelom of echinids. L. hrachycercus Pixell-Goodrich (Fig. 178, a, h). In coelom of Chiridota laevis (Canada); fully grown spherical trophozoites up to 200/i in diameter; spore with a short projection at one end. Genus Pterospora Racovitza et Labbe. Sporadins associative or solitary; free end drawn out into 4 bifurcated processes; cysts spherical or oval; spores with epispore drawn out into 3 lateral processes; in coelom of polychaetes. P. maldaneorum R. et L. (Fig. 178, c, d). In coelom of Liocepha- lus liopygue; trophozoites about 140^ long; cysts 288ai by 214iu; epispore 24;u in diameter; endospore 10-14ju by 3-4/i. Genus Ceratospora Leger. Sporadins elongate conical, head to head association; without encystment; spores oval with a small collar at one end and 2 divergent elongate filaments at other. One species. PROTOZOOLOGY Fig. 178. a, b, Lithocystis brachycercus, X1330 (Pixell-Goodrich); c, d, Pterospora maldaneoruvi (c, X40; d, X530) (Labb6); e, f, Cerato- spora rnirahilis (e, X45; f, X670) (L^ger); g, Gonospora minchini, X2000 (Goodrich); h, i, Cystobia irregularis (h, X65; i, X770) (Min- chin); j-m, Allantocyslis dasyhelei (j-1, X500; m, X560) (Keilin); n, Ganymedes anaspides, X570 (Huxley). C. rnirahilis L. (Fig. 178, e, /). Sporadins 500-600ju long; spore 12ix by 8m, filaments 34/x long; in general body cavity of Glycera sp. Genus Cystobia Mingazzini. Trophozoites, large, irregular; fully grown forms always with 2 nuclei, due to early union of 2 individuals; spores oval, membrane drawn out and truncate at one end; in blood vessels and coelom of Holothuria. C. irregularis (Minchin) (Fig. 178, h, i). Trophozoites irregular in form; up to 500/x long; endoplasm opaque, granulated; cysts in connective tissue of vessels; spore ovoid, epispore bottle-like, 25m long; in blood vessel of Holothuria nigra. SPOROZOA, GREGARINIDA 391 Family 9 AUantocystidae Bhatia Trophozoites elongate cylindrical; cysts elongate, sausage-like; spores fusiform, sides slightly dissimilar. Genus AUantocystis Keilin. Sporadins, head to head associa- tion; cysts sausage-like; in dipterous insects. One species. A. dasyhelei K. (Fig. 178, j-m). In gut of larval Dasyhelea ohscura; full-grown sporadins 65-75m by 20-22^; cysts 140-150/i by 20m; spores 18m by 6.5m- Family 10 Ganymedidae Huxley Trophozoites only known; mature individuals biassociative ; posterior end of primite with a cup-like depression to which the epimeritic organella of satellite fits; cysts spherical; spores un- known. Genus Ganymedes Huxley. Characters of the family; Huxley considers it as an intermediate form between Acephalina and Cephalina. G. anaspides H. (Fig. 178, n). In gut and hver-tube of the crustacean, Anaspides tasmaniae (Tasmania); trophozoites in association, 70-300m by 60-130m; cysts 85-1 15m in diameter. Tribe 2 Cephalina Delage The body of a trophozoite is divided into the protomerite and deutomerite by an ectoplasmic septum; inhabitants of the ali- mentary canal of invertebrates, especially arthropods. One host species involved Non-septate; epimerite a knob Family I Lecudinidae (p. 392) Septate Development intracellular Sporadins associative. . .Family 2 Cephaloidophoridae (p. 393) Sporadins solitary Family 3 Stenophoridae (p. 393) Development extracellular Sporadins associative Satellite non-septate Family 4 Didymophyidae (p. 393) Satellite septate Family 5 Gregarinidae (p. 394) Sporadins solitary Epimerite simple knob-like Cysts with several ducts. . .Family 6 Leidyanidae (p. 396) Cysts without or with one duct Family 7 Monoductidae (p. 396) Epimerite not simple knob-like Epimerite cup-shaped or digitate Epimerite cup-shaped . Family 8 Menosporidae''(p. 398) 392 PROTOZOOLOGY Epimerite digitate . . Family 9 Dactylophoridae (p. 398) Epimerite otherwise Spore hat-shaped. . .Family 10 Stylocephalidae (p. 401) Spore of other shapes Spore with spines Family 11 Acanthosporidae (p. 401) Spore without spines Family 12 Actinocephalidae (p. 403) Two host species involved Family 13 Porosporidae (p. 407) Family 1 Lecudinidae Kamm Epimerite simple, symmetrical; non-septate; spores ovoidal, thickened at one pole; solitary; in gut of polychaetes and ter- mites. Undoubtedly intermediate forms between Acephalina and Cephalina. Genus Lecudina Mingazzini. Epimerite simple, knob-like; in polychaetes. L. pellucida (Kolliker) (Fig. 179, a). In Nereis cultrifera and N. beaucourdrayi ; trophozoites ellipsoid; spores 7m by 5/i. Genus Polyrhabdina Mingazzini. Trophozoites flattened, ovoidal; epimerite with a corona of processes with split ends, deeply stainable; in polychaetes, Spionidae. P. spionis (Kolliker) (Fig. 179, 6). In Scololepis fuligionosa; IOOm by 35/x; epimerite with a corona of 8-10 processes; cysts(?). Genus Kofoidina Henry. Epimerite rudimentary; development intracellular; 2-14 sporadins in association; cysts and spores unknown. K. ovata H. In midgut of Zootermopsis angusticollis and Z. nevadensis; syzygy 153-672/i long; sporadins 41-105^ long. Genus Sycia Leger. Epimerite knobbed, bordered by a thick ring; protomerite subspherical; deutomerite conical, with navic- ular inclusions; in marine annelids. S. inspinata L. (Fig. 179, c). In Audouinia lamarcki. Genus Zygosoma Labbe. Trophozoites with wart-like pro- jections; epimerite a simple knob; spores oval; in gut of marine annelids. Z. glohosum Noble (Fig. 179, d, e). Trophozoites 250-500^ by 200-380/1 ; epimerite a large globule; cysts 400^ by 360^, without ducts; spores oval, with 4 sporozoites, O/t by 7ju; reduction post- zygotic, 6 chromosomes; in gut of Urechis caupo in California. Genus Ulivina Mingazzini. Elongate elhpsoid; epimerite simple, spores unknown; in gut of polychaetes. SPOROZOA, GREGARINIDA 393 U. rhynchoholi (Crawley). Sporadins up to 700/i long; in Rhynchoholus americanus. Family 2 Cephaloidophoridae Kamm Development intracellular; early association; cysts without sporoducts; spores ovoidal, with equatorial line; in gut of Crustacea. Genus Cephaloidophora Mawrodiadi. Sporadins biassociative, early; epimerite rudimentary; cysts without sporoducts; spores in chain, ovoidal. C. olivia (Watson) (Fig. 179, /). Biassociated sporadins up to 218/i long; individuals up to 118)u by 36m; cysts spheroidal, 60/x in diameter; spores(?); in gut of Libinia duhia; Long Island. C. nigrofusca (Watson). Sporadins, ovoid to rectangular, up to 125m by 75m; cysts and spores(?); in gut of Uca pugnax and U. pugilator. Family 3 Stenophoridae Leger et Duboscq Development intracellular; sporadins solitary; with a simple epimerite or none; cysts open by rupture; spores ovoid, with or without equatorial line, not extruded in chain; in Diplopoda. Genus Stenophora Labbe. With or without simple epimerite; spores ovoid with equatorial line, not in chain. S. larvata (Leidy) (Fig. 179, g). Sporadins up to 800m by 23m; protomerite small; in gut of Spiroholus spinigerus at Philadelphia. S. rohusta ElHs (Fig. 179, A). Sporadins 140-1 80m by 67m; cysts and spores both unobserved; in gut of Parajulus venustus, Orthomorpha gracilis and 0. sp.; Colorado. Genus Fonsecaia Pinto. Spores elongate ovoid; without equa- torial line; without endospore. F. polymorpha Pinto (Fig. 179, i,j). Sporadins 170m long; spores 18m by 8m; in gut of Orthomorpha gracilis; Brazil. Family 4 Didymophyidae Leger 2-3 sporadins in association; satellite without septum. Genus Didymophyes Stein. Epimerite a small pointed papilla; cysts spherical, open by rupture; spores ellipsoidal. D. gigantea S. Sporadins slender, 1 cm. by 80-100m; 2 deuto- merites; cysts spherical, 600-700m in diameter; spores oval, 6.5m by 6m; in gut of larvae of Oryctes nasicornis, 0. sp., and Phyl- lognathus sp. 394 PROTOZOOLOGY b C/^:\ d Fig. 179. a, Lecudina pellucida (Kolliker); b, Polyrhabdina spio7iis, X800 (Reichenow); c, Sycia inspinata (L^ger); d, e, Zygosoma glo- bosuni (d, X60; e, X1260) (Noble); f, Cephaloidophora olivia, Xl90 (Kamm); g, .Stenophora larvata, X50 (Leidy); h, S. robusta, Xl30 (Ellis); i, j, Fonsecaia polymorpha (i, X220; j, X430) (Pinto); k, Grega- rina blattarum, X55 (Kudo); 1, G. locustae, X65 (Leidy); m, G. oviceps, X30 (Crawley); n, Protomagalhaesia serpentula, X35 (Pinto); 0, Gamocystis tenax (Schneider). Family 5 Gregarinidae Labbe Sporadins in association; epimerite simple, symmetrical; cysts with or without ducts; spores symmetrical. Genus Gregarina Dufour. Sporadins biassociative; epimerite small, globular or cylindrical; spores dolioform to cylindrical; SPOROZOA, GREGARINIDA 395 cysts open by sporoducts; in gut of arthropods. Numerous species. G. blattarum Siebold (Fig. 179, k). Sporadins in syzygy, 500- llOOju by 160-400iu; cysts spherical or ovoidal; 8-10 sporoducts; spores cyhndrical to doUoform, truncate at ends, 8-8. 5)u by 3.5- 4jix; in gut of the cockroach. G. locustae Lankester (Fig. 179, /). Sporadins 150-350^ long; syzygy ; in Dissosteria Carolina. G. oviceps Diesing (Fig. 179, m). Sporadins up to 500^ by 225/1 ; in syzygy; spherical cysts 250^ in diameter; 2-5 sporoducts up to 1 mm. long; spores doHoform, 4.5m by 2.25At; in Gryllus ahbre- viatus and G. americanus. Genus Protomagalhaesia Pinto. Sporadins cyhndrical; in syzygy, protomerite of satellite draws in the posterior end of primite ; cysts without ducts ; spores dohof orm, with spines at ends. P. serpentula (Magalhaes) (Fig. 179, n). Sporadins up to 1.2 mm. by 180yu; in gut and coelom of Blatta orientalis. Genus Gamocystis Schneider. Septate only in trophozoites; sporadins non-septate; in syzygy; spore formation partial; with sporoducts; spores cylindrical. A few species. G. tenax S. (Fig. 179, o). Association head to head; spherical cysts with 15 or more ducts; spore cylindrical, with rounded ends; in gut of Blattella lapponica. Genus Hyalospora Schneider. Sporadins in syzygy; cytoplasm yellowish orange ; epimerite a simple knob ; cysts open by rupture ; spores fusiform. H. affinis S. Trophozoites 300 fj. long; cysts, yellow, 60^ in diameter; spores 8.7 fx by 6m ; in gut of Machilis cylindrica. Genus Hirmocystis Labbe. Sporadins associative, 2-12 or more; with a small cylindrical papilla-like epimerite; cysts without ducts; spores ovoidal. H. harpali Watson (Fig. 180, a). Total length of association up to 1060m; sporadins up to 560 by 80/x; cysts unknown; in gut of Harpalus pennsylvanicus erythropus. H. termitis (Leidy) (Fig. 180, h). Association 614-803/i long; epimerite in cephalins simple sphere; cysts rare; spores (?); in Zootermopsis angusticollis, Z. nevadensis, etc. Genus Uradiophora Mercier. Sporadins in syzygy; deutomerite with small process; epimerite an elongate papilla; cysts oval without ducts; spores spherical, in chains. 396 PROTOZOOLOGY U. cuenoti M. 2-4 sporadins in syzygy; individuals up to 700)Li long; cysts ovoid, 44/i long; spores 4/i in diameter; in gut of A tyaeph rya dcsm arcsti. Genus Pyxinoides Tregouboff. Sporadins biassociative; epi- merite with 16 longitudinal furrows, small cone at end. P. halani (Kolliker). Primite up to ISO^t; satellite 60^t long; in gut of Balanus amphitrite and B. eburneus. Genus Anisolobus Vincent. Sporadins in syzygy; epimerite lacking in cephalins; protomerite of primite expanded to form sucker-like organella; cysts ellipsoid, with thick envelope; with 6-8 sporoducts; spores barrel-shaped. One species. A. dacnecola V. (Fig. 180, c). In midgut of Dacne rufifrons; 2 sporadins in syzygy lOO-SOO^i by 20-50ju; cysts without envelope, 130-150m by 80-90/i; sporoducts 40-50/^ long; spores in chain, dolioform, 6m by 4/^. Genus Carcinoectes Ball. Sporadins in syzygy of 2 or more in- dividuals; epimerite rudimentary, cysts without sporoducts; spores round to ovoidal, not in chain; in gut of Crustacea. C. hesperus B. (Fig. 180, d, e). 2-6 sporadins in association; sporadins up to 320/i by 9^; cysts about 140^ by 123m, attached to the wall of hindgut; spores 8.6m by 7.7m, with 8 radially ar- ranged sporozoites; in gut of Pachygrapsus crassipes in California. Family 6 Leidyanidae Similar to the last two families; but sporadins are solitary and epimerite simple knob-like; cysts with several sporoducts. Genus Leidyana Watson. Solitary; epimerite a simple globular sessile knob; cysts with ducts; spores dolioform. L. erratica (Crawley) (Fig. 180, /). Sporadins up to 500m by 160m; cysts about 350m in diameter; membrane about 30m thick; 1-12 sporoducts; spores extruded in chains, 6m by 3m; in gut of Gryllus abhreviatus and G. pennsylvanicus. Family 7 Monoductidae Ray et Chakravatry As in the last family solitary; but cyst with a single sporoduct or none; spore with 8 sporozoites. Genus Monoductus R. et C. Sporadins solitary; epimerite a small elevation with prongs attached to its base; anisogamy; cyst with a single sporoduct; spores flattened fusiform, with dissimilar ends, each with 8 sporozoites. One species. SPOROZOA, GREGARIXIDA 397 Fig. 180. a, Hirmocystis harpali, XoO (Watson); b, H. termitis, X85 (Henry); c, Anisolobus dacnecola, X270 (Vincent); d, e, Carcinoedes hesperus (d, X200; e, X780) (Ball); f, Leydiana erratica, Xl70 (Wat- son); g-i, Lepismatophila fhermobiae (g, h, x85; i, spores, X200) (Adams and Tra\-is); j-1, Colepismatophila watsonae (j, k, X85; 1, spores, X200) (Adams and Travis); m-o, Monodudus limatus (m, cephalin, X240; n, cyst, Xl20; o, two ^^ews of spore, X2330) (Ray and Chakravatry). M. lunatus R. et C. (Fig. 180, m-o). Cephalins 225-445^ by 33-47ai; epimerite with about 16 prongs; nucleus parachute- shaped, with myonemes attached at posterior margin; sporadins develop posterior pseudopodial processes before association; cysts spherical, 225-230/i in diameter, voided by host; develop- ment completed in 3-4 days outside the host body, with one duct; spores 10.2om by 4:^, truncate at one end, attenuated at other and discharged in a single chain; in gut of Diplopoda sp. Genus Sphaerocystis Leger. Sporadins soUtary; without proto- merite; spherical. 398 PROTOZOOLOCiY S. simplex L. Sporadins 100-140/i in diameter; protomerite in young trophozoites; spherical cysts in which individuals are not associative, 100m in diameter; spores ovoid, 10.5/x by 7.5^; in gut of Cyphon pallidulus. Genus Lepismatophila Adams et Travis. Epimerite a simple knob; cysts without ducts; spores ellipsoidal, smooth, in chain. One species. L. thermohiae A. et T. (Fig. 180, g-i). Sporadins 67-390/i by 30-174iu; cysts white to black, ellipsoidal to subspherical, 244- 378m by 171-262^; spores brown, 13.6m by 6.8m; in ventriculus of Thermohia domestica. Genus Colepismatophila Adams et Travis. Similar to the last genus; but larger; spores in wavy chains, hat-shaped, with 2 curved filamentous processes attached at opposite ends. One species. C. watsonae A. et T. (Fig. 180, j-l). Sporadins 92-562m by 55-189m; cysts 226-464m by 158-336m; spores 16.5m by 9.7m, pro- cesses 21m long; in ventriculus of Thermohia domestica. Family 8 Menosporidae Leger Sporadins solitary; epimerite a large cup, bordered with hooks, with a long neck; cysts without sporoducts; spores crescentic, smooth. Genus Menospora Leger. With the characters of the family. M. polyacantha L. (Fig. 181, a, h). Sporadins 600-700m long; cysts 200m in diameter; spores 15m by 4m; in gut of Agrion puella. Family 9 Dactylophoridae Leger Sporadins solitary; epimerite complex, digitate; cysts dehis- cence by pseudocyst; spores cylindrical; in gut of chilopods. Genus Dactylophorus Balbiani. Protomerite wide, bordered by digitiform processes; spores cylindrical. D. robustus Leger (Fig. 181, c, d). Sporadins 700-800m long; cysts spherical, 200m in diameter; spores 11m by 4.3m; in gut of Cryptops hortensis. Genus Echinomera Labbe. Epimerite an eccentric cone with 8 or more digitiform processes; cysts without sporoducts; spores cylindrical. E. magalhaesi (Pinto) (Fig. 181, e). Sporadins up to 300m by 70m; in gut of Scolopendra sp. SPOROZOA, GREGARINIDA 399 Fig. 181. a, b, Menospora polyacantha (L^ger); c, d, Dadylophorus rohustus (c, Xl30; d, X900) (L6ger); e, Echinomera magalhaesi, Xl30 (Pinto); f, g, Rhopalonia hispida (g, X830) (L6ger); h, Dendrorhynchus system, X770 (Keilin) ; i, Trichorhynchus pulcher (Schneider) ; j, k, Nina gracilis (j, XlO) (Schneider); 1, Seticephalus elegans, X450 (Pinto); m, Acutispora macrocephala, X65 (Crawley); n, Metamera schuhergi, X270 (Duke); o, p, Hentschelia thalassemae (o, X230; p, X620) (Mackinnon and Ray); q, r, Lecyihion thalassemae (q, X270; r, X930) (Mackinnon and Ray). Genus Rhopalonia Leger. Epimerite spherical, with 10 or more digitiform processes; pseudocysts; spores cylindrical. R. hispida (Schneider) (Fig. 181, /, g). Endoplasm yellowish 400 PROTOZOOLOGY orange; cysts 200-250/^ in diameter; spores 16ai by 6.5m; in gut of Geophiles sp. and Stigmatog aster gracilis. Genus Dendrorhynchus Keilin. Elongate; epimerite a disc, sur- rounded by numerous ramified papillae; transverse fibrils con- spicuous; cysts elliptical; spores fusiform. D. system K. (Fig. 181, h). Sporadins 255m by 18.5-20/x; spores 18-1 9m by 7m; in midgut of larvae of Systenus sp., a doli- chopodid fly, found in decomposed sap of elm tree. Genus Trichorhynchus Schneider. Protomerite prolonged an- teriorly into a long neck, dilated at tip; pseudocyst; spores cylindrical to ellipsoidal. T. pulcher S. (Fig. 181, i). Cysts 303-316m in diameter; spores 9.7m by 5.8m; in gut of Scutigera sp. Genus Nina Grebnecki (Pterocephalus Schneider). Protomerite made up of 2 long narrow horizontal lobes fused and upturned spirally at one end, peripheral portion with many teeth, from which project long filaments; spores in chain; in gut of myria- pods. N. gracilis G. (Fig. 181, j, k). 4-5 mm. long; cysts spherical; spores ellipsoidal, in chain; in gut of Scolopendra cingulata. Genus Seticephalus Kamm. Protomerite with closely set brush- like bristles. S. elegans (Pinto) (Fig. 181, I). Sporadins up to 75m by 35m; cysts and spores unknown; in gut of Scolopendra sp. Genus Acutispora Crawley. Sohtary; pseudocyst; spore bicon- ical, with a thick blunt endosporal rod at each end. One species. A. macrocephala C. (Fig. 181, m). Sporadins up to 600m long; cysts spherical, 410m in diameter; spores navicular, slightly curved, 19m by 4m; in gut of Lithohius forficatus. Genus Metamera Duke. Epimerite eccentric, bordered with many branched digitiform processes; cysts without ducts; spores biconical. M. schuhergi D. (Fig. 181, 7i). Sporadins 150m by 45m; spores 9m by 7m; in gut of Glossosiphonia complanata and Placohdella marginata. Genus Hentschelia Mackinnon et Ray. Epimerite with a short neck, umbrella-like with its margin divided into 4-5 lobes, each fluted on anterior surface; 2 sporadins encyst together; gametes anisogamous; flagellate and non-flagellate; zygote gives rise to a spherical spore with 8 sporozoites. One species. SPOROZOA, GREGARINIDA 401 H. thalassemae M. et R. (Fig. 181, o, p). Cephalins 75-98/x by 30-45m; in gut of Thalassema neptuni. Genus Lecythion Mackinnon et Ray. Epimerite a low cone, sur- rounded by 14-15 petal-shaped lobes, with a neck; cysts and spores unknown. L. thalassemae M. et R. (Fig. 181, q, r). Cephalins 135/i by 52/i; epimerite about 27m long; in gut of Thalassema neptuni. Family 10 Stylocephalidae ElHs Sporadins solitary; epimerite varied; pseudocysts; hat-shaped spores in chains. Genus Stylocephalus Ellis. Epimerite nipple-like; cysts covered with papillae; in arthropods and molluscs. S. giganteus E. (Fig. 182, a). Sporadins 1.2-1.8 mm. long; cysts spherical, 450^ in diameter; spores subspherical black, 11^ by 7m; in Eleodes sp., Asida opaca, A. sp., and Eusattus sp. (Coleop- tera). Genus Bulbocephalus Watson. Epimerite a dilated papilla located in middle of a long neck. B. elongatus W. (Fig. 182, 6). Sporadins up to 1.6 mm. by 50m; nucleus diagonal; cysts and spores unknown; in gut of Cucujus larva (a coleopteran). Genus Sphaerorhynchus Labbe. Epimerite a small sphere at end of a long neck. S. ophioides (Schneider). Cephalins 1.3 mm.; epimerite 220m long; terminal part 8.5m; sporadins 3-4 mm, long; in gut of Ads sp. Genus Cystocephalus Schneider. Epimerite a large lance- shaped papilla with a short neck; spore hat-shaped. C. algerianus S. (Fig. 182, c, d). Sporadins 3-4 mm. long; spores 10-10. 5m long; in gut of Pimelia sp. Genus Lophocephalus Labbe. Epimerite sessile crateriform disc with crenulate periphery, surrounded by digitiform processes. L. insignis (Schneider) (Fig. 182, e). Sporadins 1 mm. long; cysts rounded; 430m by 330m; pseudocysts; spores 10m long; in gut of Helops striatus. Family 11 Acanthosporidae Leger Sporadins solitary; epimerite complex; cysts without sporo- ducts; spores with equatorial and polar spines. PROTOZOOLOGY Fig. 182. a, Stylocephalus giganteus, X65 (Ellis); b, Bidbocephalus elongatus, Xl5 (Watson); c, d, Cystocephalus algerianus (c, X6; d, X930) (Schneider); e, Lophocephalus i7isignis (Schneider); f, Acan- thospora polyrnorpha, X1670 (L^ger); g, h, Corycella armata (h, X860) (L^ger); i, Prismatospora evansi, X50 (Ellis); j, k, Ancrjrophora gracilis (k, X1250) (L^ger); 1, m, Cotnetoides capitahis (m, X1330) (L6ger); n, o, Actinocephalus acutispora (L^ger); p, Amphoroides calverti, XlBO (Watson); q, Asterophora philica, X65 (Leidy) ; r, Steinina rotunda. Xl30 (Watson); s, Pileocephalus striatus, XlSO (L^ger and Duboscq); t, Stylocystis praecox, X80 (L^ger). Genus Acanthospora Leger. Epimerite simple conical knob; spores with spines. A. polyrnorpha L. (Fig. 182, /). Sporadins polymorphic; up to 1 mm. long; protomerite cylindro-conical; deutomerite ovoidal; endoplasm yellowish brown; cyst 500-700^ in diameter;, spore with 6 spines at each pole and at equatorial plane, 8n by 4.4/x; in gut of Hydrous cerahoides. Genus Corycella Leger. Epimerite globular, with 8 hooks; spores biconical, with one row of polar spines. C. armata L. (Fig. 182, g, h). Sporadins 280-300)U long; cysts SPOROZOA, GREGARINIDA 403 spherical, 250^ in diameter; spores IS/x by 6.5iu; in gut of larva of Gyrinus natator. Genus Prismatospora Ellis. Epimerite subglobular with 8 lateral hooks; spores hexagonal, with one row of spines at each pole. P. evansi E. (Fig. 182, i). Sporadins broadly conical, 400m long; cysts 370/i in diameter; wdthout sporoducts; spores with 6 long spines at each pole, ll/x by 5.8m; in gut of Tramea lacerta and Sym- petrum riihicundulum ; Michigan. Genus Ancyrophora Leger. Epimerite globular with 5-10 digiti- form processes directed posteriorly; spores biconical, with spines. A. gracilis L. (Fig. 182, j, k). Sporadins 200^-2 mm. long; cysts spherical, 200^ in diameter; spores hexagonal in optical section, with 4 polar and 6 equatorial spines, 8.5m by 5m; in gut of larvae and adults of Carabus auratus, C. violaceus, C. sp., and of larvae of Silpha thoracica (Coleoptera). Genus Cometoides Labbe. Epimerite globular with 6-15 long filaments; spores with polar spines and 2 rows of equatorial spines. C. capitatus (Leger) (Fig. 182, 1, m). Sporadins up to 2 mm. long, active; epimerite with 12-15 filaments, 32-35m long; cysts 300m in diameter; spores 5.1m by 2.5m; in gut of larvae of Hydrous sp. (Coleoptera). Family 12 Actinocephalidae Leger Sporadins solitary; epimerite variously formed; cysts without sporoducts; spores irregular, biconical or cylindro-biconical; in gut of insects. Genus Actinocephalus Stein. Epimerite sessile or with a short neck, with 8-10 simple digitiform processes at its apex; spores bi- conical. A. acutispora Leger (Fig. 182, n, o). Sporadins 1-1.5 mm. long; cysts ovoid. 550-600m by 280m; spores, acutely pointed, of 2 sizes, 4.5m by 2.8m and 6.4m by 3.6m; in gut of the coleopteran, Silpha laevigata. Genus Amphoroides Labbe. Epimerite a globular sessile papil- la; protomerite cup-shaped; spores curved; in myriapods. A. calverti (Crawley) (Fig. 182, p). Sporadins up to 1670m by 120m; cysts spherical, 380m in diameter; spores unknown; in gut of Callipus lactarius. Genus Asterophora Leger. Epimerite a thick horizontal disc 404 PROTOZOOLOGY with a milled border and a stout style projecting from center; spore cylindrobiconical; in Neuroptera and Coleoptera. A. philica (Leidy) (Fig. 182, g). Sporadins 300/i-2 mm. long; cysts and spores unknown; in gut of Nydobates pennsylvanica. Genus Steinina Leger et Duboscq. Solitary; epimerite a short motile digitiform process, changing into a flattened structure; spore biconical; in Coleoptera. S. rotunda Watson (Fig. 182, r). Sporadins 180-250/x long; in gut of Amara augustata (Coleoptera). Genus Pileocephalus Schneider. Epimerite lance-shaped, with a short neck. P. striatus Leger et Duboscq (Fig. 182, s). Sporadins 150ai long; nucleus in protomerite; cysts spherical; in gut of larvae of Ptych- optera contaminata. Genus Stylocystis Leger. Epimerite a sharply pointed, curved process; spores biconical. S. praecox L. (Fig. 182, t). Sporadins up to 500/i long; cysts ovoidal, 200/i long; spores Sfx by 5m; in gut of larval Tanypus sp. Genus Discorhynchus Labbe. Epimerite a large spheroidal papilla with collar and short neck; spores biconical, sUghtly curved. D. truncatus (Leger) (Fig. 183, a, 6). Sporadins BOO/i long; cysts spherical, 140^ in diameter; in gut of larvae of Sericostoma sp. Genus Anthorhynchus Labbe. Epimerite a large flattened fluted disc; spores biconical, chained laterally. A. sophiae (Schneider) (Fig. 183, c, d). CephaKns up to 2 mm. long, with 200/i long epimerite; protomerite 150^ long; endoplasm opaque; spores 7^ by 5n; in gut of Phalangiuni opilio. Genus Sciadiophora Labbe. Epimerite a large sessile disc with crenulate border; protomerite with numerous vertical lamina- tions; spores biconical. S. phalangii (Leger) (Fig. 183, e~g). Sporadins 2-2.5 mm. long; protomerite with 15-16 plates; cysts 500/i in diameter; spores 9n by 5/x; in gut of Phalangium crassum and P. cornutum (Arach- nida). Genus Amphorocephalus Ellis. Epimerite a sessile peripherally fluted disc set upon a short neck; protomerite constricted super- ficially; spores unjinown. A. amphorellus E. (Fig. 183, h). Sporadins 500-970/i long; in gut of Scolopendra heros. SPOROZOA, GREGARINIDA 405 Fig. 183. a, b, Discorhynchus truncatus (a, Xl30) (Leger); c, d, An- thorhynchus sophiae (c, Xl5; d, X1330) (Schneider) ; e-g, Sciadiophora phalangii (g, spore, X1040) (L^ger); h, Amphorocephalus amphorellus (Ellis); i, Pyxinia bulbifera (Watson); j, Schneideria mucronata, X75 (L6ger); k, Beloides firmus (L^ger); 1, Taeniocystis mira, X85 (L^ger); m, n, Stictospora provincialis (L^ger); o, Bothriopsis histrio (L^ger); p-r, Coleorhynchus heros (p, Xl4) (Schneider); s, Legeria agilis (Schneider); t-v, Phialoides ornata (t, X45; v, X930) (L^ger); w, Ge- neiorhynchus aeschnae, X60 (Crawley). Genus Pyxinia Hammerschmidt. Epimerite flat crenulate cra- teriform disc; with a style in center; spores biconical. P. bulbifera Watson (Fig. 183, i). Sporadins up to 850m long; in gut of Dermestes lardarius. Genus Schneideria Leger. Epimerite sessile, a thick horizontal disc with milled border; a style arising from center; sporadins without protomerite; spores biconical. S. 7nucronata L. (Fig. 183, j). Sporadins 700-800^ long; agile; polymorphic; cysts 270ju by 190ju; spores fusiform, 15/x by 9^; in intestinal caeca of larvae of Bibio marci. 406 PROTOZOOLOGY Genus Beloides Labbe. Epimerite bordered by pointed lateral processes and apical style; spores biconical. B. firmus (Leger) (Fig. 183, k). Style 80/x long; cysts 180-200^ in diameter; spores 14.5m by 6m; in gut of larvae of Dermestes lardarius. Genus Taeniocystis Leger. Epimerite sessile or with a short neck; 8-10 digitiform processes at its apex; deutomerite divided by septa into many chambers; spores biconical. T. mira L. (Fig. 183, l). Sporadins tapeworm-like; 400-500^ long; epimerite with 6-8 curved hooks; cysts spherical, 130/i in diameter; spores 7m by 3m; in gut of larval Ceratopogon sol- stitialis. Genus Stictospora Leger. Epimerite with a short neck, a spher- ical crateriform ball with 12 posteriorly-directed laminations set close to neck; cysts with a gelatinous envelope; without ducts; spores biconical, slightly curved. S. 'provincialis L. (Fig. 183, m, n). Sporadins 1-2 mm. long; cysts 800m in diameter; in gut of larvae of Melolontha sp. and Rhizotrogus sp. Genus Bothriopsis Schneider. Epimerite sessile, small, oval, with 6 or more filamentous processes directed upward; spores bi- conical; cysts spherical. B. histrio S. (Fig. 183, o). Epimerite with 6 filaments,' 80-90m long; cysts 400-500m long; spores 7.2m by 5m; in gut of Hydaticus sp. Genus Coleorhynchus Labbe. Epimerite discoid, lower border over deutomerite; spores biconical. C heros (Schneider) (Fig. 183, p-r). Sporadins 2-3 mm. long; in gut of Nepa cinerea. Genus Legeria Labbe. Protomerite wider than deutomerite; epimerite unknown; cysts without duct; spores cylindro-biconi- cal. L. agilis (Schneider) (Fig. 183, s). In gut of the larvae of Co??/w- hetes sp. Genus Phialoides Labbe. Epimerite a cushion set peripherally with stout teeth, surrounded by a wider collar; with a long neck; cysts spherical, without ducts; spores biconical. P. ornata (Leger) (Fig. 183, t-v). Sporadins 500m long; cysts 300-400m in diameter; spores 10.5m by 6.7m; in gut of larvae of Hydrophilus piceus. SPOROZOA, GREGARINIDA 407 Genus Geneiorhynchus Schneider. Epimerite a tuft of short bristles at end of neck; spores cyUndrical. G. aeschnae Crawley (Fig. 183, w). Sporadins 420/i long; cysts and spores unknown; in Aeschna constricta. Family 13 Porosporidae Leger When naked or well-protected sporozoites enter the stomach and midgut of a specific crustacean host, they develop into typi- cal cephahne gregarines; 1, 2, or more sporadins become associa- ted and encyst. Repeated nuclear and cytoplasmic division re- sults in formation of an enormous number of gymnospores in hindgut. Some observers consider this change as schizogony, and hence include the family in the suborder Schizogregarinaria. When the gymnospores are voided in the faeces of crustaceans and come in contact with molluscan host, they enter, or are taken in by phagocytosis of, the epithelial cells of the gills, mantle or digestive system. These gymnospores are especially found in abundance in the lacunae of the gills. Presently they become paired and fuse (Hatt) ; the zygotes develop into naked or encap- sulated sporozoites within the phagocytes of the molluscan host, which when taken into a crustacean host, develop into cephaline gregarines. Genus Porospora Schneider. Sporozoites formed in molluscan phagocytes without protective envelope (Hatt). P. gigantea (van Beneden) (Fig. 184, a-f). Sporadins in Ho- marus gammarus, up to 10 mm. long; cysts 3-4 mm. in diameter; gymnospores spherical, 8)U in diameter (Hatt), containing some 1500 merozoites; in molluscan hosts, Mytilus minimus and Tro- chocochlea mutahilis, develop into naked sporozoites {17 /jl long) which are usually grouped within phagocytes. Genus Nematopsis Schneider. Development similar to that of Porospora (Hatt); but each sporozoite in a double envelope. N. legeri (de Beau champ) {Porospora galloprovincialis Leger et Duboscq) (Fig. 184, g-n). Hatt (1931) carried on a very careful study of its development. Sporadins in a crustacean, Eriphia spinifrons, in linear or bifurcated syzygy, 75-750jLi long; cysts about 80iu in diameter; gymnospores 7m in diameter, composed of fewer, but larger merozoites; permanent spores with a distinct one-piece shell (endospore) and a less conspicuous epispore, about 14-15^ long and circular in cross-section, develop in numerous 408 PROTOZOOLOGY Fig. 184. a-f, Porospora gigantea (Hatt). a, a cephalin attached to Homarus gut, X1250; b, gymnospore; c, d, developing sporozoites in mollusc; e, sporozoites enveloped by phagocytes; f, a sporozoite, X2250. g-n, Neviatopsis legeri (Hatt). g, h, trophozoites in Eriphia; i, associated trophozoites attached to gut-epithelium, X1250; j, gym- nospore; k, gymnospore after entering molluscan body; 1, a young sporozoite, X2250; m, cyst in mollusc with six spores; n, germination of a spore in Eriphia gut, X1250. species of molluscan hosts: Mytilus galloprovincialis, M. minimus, Lasea rubra, Cardita calyculata, Chiton caprearum, Trochocochlea turbinata, T. articulata, T. mutahilis, Phorcus richardi, Gibbula divaricata, G. rarilineata, G. adamsoni, Pisania maculosa, Ceri- SPOROZOA, GREGARINIDA 409 thium rupestre, Columhella rustica, and Conus mediterraneus in European waters. The author found in Ostrea virginica and other molluscs in North Carolina, Virginia, and Maryland, this gregarine and was the first to demonstrate on this continent the germination of the spores taken from the infected oysters in the stomach and mid- gut of Panopeus herhsti and Eurypanopeus depressus at the Bureau of Fisheries Biological Laboratory at Beaufort, N. C. in July, 1936. The vermiform sporozoites emerge from the spores in the pyloric chamber of the stomach and more abundantly in the mid-gut of the mud crabs as early as thirty minutes after intro- duction of the infected tissues of the oyster into their mouths. In the brackish water of the middle Chesapeake Bay region of Maryland, the oyster and other molluscs are only shghtly in- fected. The presence of the characteristic spores in oyster tissues is easily demonstrated by addition of 10 per cent sodium hydrate solution to the material on slides. Suborder 2 Schizogregarinaria Leger The schizogregarines are intestinal parasites of arthropods, an- nelids, and tunicates. When the spore gains entrance to the di- gestive tract of a specific host through mouth, it germinates and the sporozoites are set free (Fig. 185). These sporozoites develop into trophozoites either in the gut-lumen or within the host cells, and undergo schizogony (c), which may be binary or multiple fis- sion or budding. The fully grown trophozoites become paired as in Eugregarinina and encyst, in which condition they undergo sexual reproduction, followed by sporogony. Each individual which is now a gametocyte, produces gametes (d-e). Fusion of two gametes follows (/). The zygote develops into a spore contain- ing 1-8 sporozoites (g, a). One spore from 2 gametocytes Family 1 Ophryocystidae Two or more spores from 2 gametocytes Family 2 Schizocystidae (p. 411) Family 1 Ophryocystidae Leger et Duboscq Two gametocytes produce one spore; in Malpighian tubules of Coleoptera, gut of Ascidia and coelom of Oligochaeta. Genus Ophryocystis Schneider. Schizogony by binary or mul- tiple division; extracellular; schizonts conical, attached to host cells by pseudopods; a single spore in a pair of spheroidal gameto- 410 PROTOZOOLOGY Fig. 185. The life-cycle of Schizocystis gregarinoides, XlOOO (L^ger). a, germinating spore; b, growth of schizonts; c, schizogony; d, two gametocytes and their association; e, stages in gamete formation, f, gametogony, g, cyst containing zygotes, each of which develops into a spore shown in a. cytes; spore with 8 sporozoites; in Malpighian tubules of Coleop- tera. Several species. 0. mesnili Leger (Fig. 186, a-e). In Tenehrio molitor; schizonts 1-4 nuclei; gametocytes IIjj. in diameter; pairs 16-17/x by llju; spores biconical, 11/i by 7//. Genus Merogregarina Porter. Schizogony intracellular; troph- ozoites attached to gut epitheUum by proboscidiform organel- lae; resembles somewhat Selenidium, but 2 gametocytes giving rise to one spore containing 8 sporozoites. M. amaroucii P. (Fig. 186, /, g). In gut of the ascidian, Ama- SPOROZOA, GREGARINIDA c 411 Fig. 186. a-e, Ophryocystis mesnili (a, trophozoite attached to Mal- pighian tubule; b-e, sporogony), X1330 (L6ger); f, g, Merogregarina amaroucii, XlOOO (Porter); h, i, Spirocystis nidula (h, X770; i, X500) (L^ger and Duboscq); j, k, CauUeryeUa pipientis (j, gut of Culex pipiens with trophozoites, x200; k, a spore, X1200) (Buschkiel). roucium sp.; extracellular; trophozoites with epimerite, 27-31^ long; spore about 14/x long. Genus Spirocystis Leger et Duboscq. Schizogony intracellular; schizonts curved, one end highly narrowed; mature schizonts snail-like, with numerous nuclei; repeated schizogony (?) ; gametes in chloragogen cells, somatic and visceral peritonium; association of 2 gametes produces a spore. One species. S. nidula L. et D. (Fig. 186, h, i). In coelom and gut epithelium of Lumhricus variegatus; multinucleate schizonts about 35m long; microgametes fusiform or ovoid, 7m by 3m; macrogametes ovoid or spherical, 11m in diameter; fusion of 2 gametes produces one spore which is thick-walled, 35m long and contains one sporozoite, up to 40m long. Family 2 Schizocystidae Leger et Duboscq Two or more spores are produced in a pair of gametocytes. Genus Schizocystis Leger. Mature trophozoite multinucleate; ovoid or cyhndrical with differentiated anterior end; schizogony by multiple division; trophozoites become associated, encyst, and 412 PROTOZOOLOGY produce numerous (up to 30) spores, each with 8 sporozoites; in Diptera, AnneUda, and Sipunculoida. *S. gregarinoides L. (Fig. 185). In gut of larvae of Ceratopogon solstitialis; mature schizonts up to 400/.t by 15;u; curved or spirally coiled; gametocytes 30-50m long; cysts ovoid, 16-32/x long; spores biconical, 8m by 4^. Genus Syncystis Schneider. Schizogony and sporogony extra- cellular; young trophozoites elongate, amoeboid; mature schi- zonts more or less spheroidal, producing some 150 merozoites; cysts spherical, producing about 150 spores. One species. S. mirdbilis S. (Fig. 187, k, I). In coelomic fluid and fat bodies of Nejpa cinerea; merozoites, 7^ long; cysts spherical; spores navicular, 3-4 spines at ends, 10/x by 6^, with 8 sporozoites (Steo- poe). Genus Mattesia Naville. Schizogony in the adipose tissue cell; 2 spores produced by a pair of gametocytes. One species. M. dispora N. (Fig. 187, m). In adipose tissue cells of larvae of the flour moth, Ephestia kuhniella and Plodia interpunctella (pupa and adult also); schizonts 2.5-12^ long; cyst 8-12^ in diameter, with 2 spores, each with 8 sporozoites; spores 14^ by 7.5ai (Na- ville); llyu by 6m (maximum 13.5m by 8m) (Musgrave and Mackin- non). Highly pathogenic according to Musgrave and Mackinnon. Genus CauUeryella Keilin. Schizogony extracellular; each gametocyte gives rise to 8 gametes, a pair forming 8 zygotes or spores; spore with 8 sporozoites; in gut of dipterous larvae. Sev- eral species. C. pipientis Buschkiel (Fig. 186, j, k). Average trophozoites 50-60m by 23-26m; with paraglycogen grains; schizogony produces 30-38 merozoites. Genus Lipotropha Keilin. Schizogony and sporogony intracel- lular; cyst contains 16 spores, each with 8 sporozoites; in fat body of Systenus larvae. One species. L. macrospora K. (Fig. 187, n). Spores about 13.5m by 3m. Genus Selenidium Giard. Schizogony intracellular; many spores produced by a pair of extracellular gametocytes; spore with 4 or more sporozoites; in gut of annelids. *S. potamillae Mackinnon et Ray (Fig. 187, a-c). Trophozoites euglenoid, average size 40m by 15m; longitudinal striae; cysts oblong, producing many spores; spore, spherical with 4 (up to 10) sporozoites; in gut of the polychaete, Potamilla reniformis. SPOROZOA, GREGARINIDA 413 Fig. 187. a-c, Selenidium 'potamillae (a, X420; b, cyst with spores, X330; c, spore) (Mackinnon and Ray); d-f, Mero selenidium keilini (d, sporadin, X670; e, f, different views of spore, X930) (Mackinnon and Ray); g-j, Machadoella iriatomae (g, a schizont, X1420; h, i, a single and associated gamonts, X710; j, spore, X1920) (Reichenow); k, 1, Syncystis mirahilis: k, a cyst, X470 (Steopoe) ; 1, spore (Schneider); m, Mattesia dispora, X1480 (Naville), n, Lipotropha macrospora, X800 (Keilin). Genus Meroselenidium Mackinnon et Ray. Schizogony intra- cellular, initiated by formation of small masses which give rise to merozoites; about 20 spores from a pair of gametocytes; spores with numerous sporozoites. One species. M. keilini M. et R. (Fig. 187, d-f). Large schizonts about 150/^ by 30m; sporadins free in gut 200-300ju by 40-70^; paired gameto- cytes 85m by 40/x; spores 26-28/x by 14-1 6At, bivalve (?), trans- verse ridges, with many sporozoites; in gut of Potomilla renifor- mis. Genus Machadoella Reichenow\ Nematode-like, rigid; simple rounded anterior end; thick pellicle, longitudinally striated; schi- zogony in vermiform stage; head to head association of gameto- cytes; cysts with 3-6 spores, each with 8 sporozoites. 414 PROTOZOOLOGY M. triatomae R. (Fig. 187, g-j). Schizonts about 55/i long; gametocytes 100-1 20ai long; schizogony into 6-8 merozoites; cysts with 3-6 spores; spore 10-1 1/x by 7-7. 5At; in Malpighian tubules of Triatoma dimidiata; Guatemala. References DoFLEiN, F. and E. Reichenow 1929 Lehrbuch der Proto- zoenkunde. 5th edition. Jena. Labbe, a. 1899 Sporozoa. In Das Tierreich. Part 5. Naville, a. 1931 Les Sporozoaires. Mem. d'hist. nat. de Geneve, Vol. 41. Wenyon, C. M. 1926. Protozoology. Vols. 1, 2. Bhatia, B. L. 1930 Synopsis of the genera and classification of haplocyte gregarines. Parasitology. Vol. 22. Hatt, p. 1931 L'evolution des Porosporides chez les mollusques. Arch. zool. exp. Vol. 72. Hesse, E. 1909 Contribution a I'etude des Monocystidees des Oligochetes, Ibid., Vol. 3. Kamm, Minnie Watson 1922 Studies on gregarines. II. Illinois Biol. Monogr., Vol. 7. 1922 A list of the new gregarines described from 1911 to 1920. Trans. Amer. Micr. Soc, Vol. 41. Leger, L. 1907, 1909 Les schizogregarines des tracheates. I, II. Arch. f. Protistenk., Vols. 8, 18. and 0. DuBOSCQ 1915 Etude sur Spirocystis nidula L. et D., schizogregarine du Lumhricus variegatus Miill. Ibid. Vol. 35. Noble, E. R. 1938 The life-cycle of Zygosoma glohosum sp. nov., a gregarine parasite of Urechis caupo. Univ. Californ. Publ. Zool., Vol. 43. Troisi, R. a. 1933 Studies on the acephaline gregarines of some oligochaete annelids. Trans. Amer. Micr. Soc, Vol. 52. Watson, Minnie 1916 Studies on Gregarines. I. Illinois Biol. Mongr., Vol. 2. Chapter 24 Order 2 Coccidia Leuckart THE Coccidia show a wide zoological distribution, attacking the vertebrates and higher invertebrates ahke. The majority- are parasites of the epithelium of the digestive tract and its asso- ciated glands. Asexual reproduction is by schizogony and sexual reproduction by anisogamy in the majority of species. Both kinds of reproduction take place in one and the same host body, with the exception of such forms as Aggregata in which alternation of generations and of hosts occurs Gametocytes similar; independent; a microgametocyte developing into many microgametes Suborder 1 Eimeridea Gametocytes dissimilar; association begins during the late trophic life; a few microgametes Suborder 2 Adeleidea (p. 428) Suborder 1 Eimeridea Leger These Coccidia are, as a rule, intracellular parasites of the gut epithelium. Both asexual (schizogonic) and sexual (sporogonic) generations occur in one host, although in some there is also alter- nation of hosts. The life-cycle of Eimeria schuhergi, a gut parasite of the centipede, Lithohms forficatus, as observed by Schaudinn, is as follows (Fig. 188). The infection begins when the mature oocysts of the coccidian gain entrance into the host through the mouth. The sporozoites escape from the spores and make their way through the micropyle of the oocyst into the gut lumen (p). By active movement they reach and enter the epithelial cells (a). These schizonts grow into large rounded bodies and their nuclei multiply in number. The newly formed nuclei move to the body surface, and each becomes surrounded by a small mass of cyto- plasm, forming a merozoite. When the host cells rupture, the merozoites are set free in the gut lumen, make their way into new host cells and repeat the development (h). Instead of growing into schizonts, some merozoites transform themselves into macro- or micro-gametocytes (c). Each macrogametocyte contains refrac- tile bodies, and becomes a mature macrogamete, after extruding part of its nuclear material (d, e). In the microgametocyte, the nucleus divides several times and each division-product assumes 415 416 PROTOZOOLOGY Fig. 188. The life-cycle of Eimeria schubergi, X400 (Schaudinn). a, entrance of a sporozoite in the gut epithelial cell of host and growth of schizont; b, schizogony; c, macro- and micro-gametocyte; d, e, for- mation of macrogamete; f-h, formation of microgametes; i, mature gametes prior to fusion; j, k, fertilization; 1-n, spore-formation; o, oocyst containing four mature spores, each with two sporozoites; p, germination of spores in host's gut. a compact appearance (f-h). The biflagellate comma-shaped mi- crogametes thus produced, show activity when freed from the host cells (i). A microgamete and a macrogamete unite to form a zygote which secretes a membrane around itself (j). This stage is known as the oocyst. The nucleus divides twice and produces four nuclei (k-m). Each of the four nuclei becomes the center of a spo- roblast which secretes a membrane and transforms itself into a spore (n). Its nucleus, in the meantime, undergoes a division, so that the two sporozoites become developed in the spore (o). Thus an oocyst of this species contains four spores and eight sporo- COCCIDIA 417 zoites. Oocysts in the faecal matter become the sources of infec- tion. Body vermiform; schizogony in motile stage Family 1 Selenococcidiidae Body not vermiform Alternation of generations and of hosts Family 2 Aggregatidae No alteration of hosts Gametocytes associate early; many microgametes ^ Family 3 Dobelliidae (p. 421) Gametocytes independent Family 4 Eimeriidae (p. 421) Family 1 Selenococcidiidae Poche Vermiform body and gametic differentiation place this family on the borderline between the Coccidia and Gregarinida. Genus Selenococcidium Leger et Duboscq. Nucleus of vermi- form trophozoite divides 3 times, producing 8 nuclei; trophozoite becomes rounded after entering gut-epithelium and divides into 8 schizonts; this is apparently repeated; schizonts develop into gametocytes ; microgametocyte produces numerous microgametes ; gametic union and sporogony (?). One species. Fig. 189. Selenococcidium intermedium, X550 (L^ger and Duboscq). a, schizont in host gut; b, c, schizogony; d, microgametocj^te; e, micro- gametes; f, macrogametocyte; g, macrogamete; h, zygote (oocyst). S. intermedium L. et D. (Fig. 189). Octonucleate vermiform schizont 60-1 00/i long, and divides into vermicular merozoites in gut cells; parasitic in gut lumen of European lobster. Family 2 Aggregatidae Labbe Anisogamy results in production of zygotes which become transformed into many spores, each with 2-30 sporozoites; in 418 PROTOZOOLOGY Fig. 190. The life-cycle of Aggregata eberthi (Dobell). a, a mature spore; b, germination of spore; c-f, schizogony; g, a merozoite, swal- lowed by Sepia; h-j, development of microgametes; k-1, development of macrogamete; m, fertilization; n, o, first zygotic division, chromo- somes reduced in number from 12 to 6; p, q, development of sporo- blasts, each of which develops into a spore with three sporozoites. schizogony cytomeres first appear and then merozoites; altera- tion of generations and of hosts which are marine annelids, mol- luscs and crustaceans. Genus Aggregata Frenzel. Schizogony in a crustacean and sporogony in a cephalopod; zygote produces many spores, each with 3 sporozoites. Many species. COCCIDIA 419 A. eherthi (Labbe) (Fig. 190). Schizogony in Portunus depura- tor and sporogony in Sepia officinalis. Spores (a) germinate in the crab gut, each hberating 3 sporozoites (6) which grow and produce merozoites (lO/z by 2^) by schizogony in peri-intestinal connec- tive tissue cells (6 chromosomes) (c-/) ; when host crab is eaten by a cuttlefish, merozoites penetrate gut wall and develop into mi- cro- and macro-gametocytes (h, k), and further into gametes. (j-l); anisogamy (m) produces zygotes; zygote nucleus contains 12 chromosomes which become divided into 2 groups of 6 at first division {n, o); repeated nuclear division (p) forms many sporo- blasts (q), each transforms itself into a spherical spore with 3 sporozoites (Dobell, Naville and Belaf). Genus Merocystis Dakin. Sporogony in kidney of the whelk, Buccinum; schizogony unknown in another host (possibly a crab) ; microgametocytes produce first cytomeres which in turn form microgametes; anisogamy gives rise to zygotes, zygote forms many sporoblasts, each developing into a spore; spore spherical, with 2 sporozoites. One species. M. kathae D. (Fig. 191, a, h). In kidney of Buccinum undatum; spores spherical, about 14/i in diameter. Genus Pseudoklossia Leger et Duboscq. Anisogamy and spo- rogony in kidney of marine mussels; oocyst or zygote produces numerous spores; spore with 2 sporozoites ; no residual body; schi- zogony unknown, in another host. P. pectinis L. et D. (Fig. 191, c). In kidney of Pecten maximus in France; association of 2 sporozoites 3.5m in diameter. Genus Caryotropha Siedlecki. Both schizogony and sporogony take place in a host. One species. C. mesnili S. In coelom (floating bundles of spermatogonia) of the polychaete, Polymnia nebulosa; schizogony in bundle of sper- matogonia, in which cytomeres with 10-16 nuclei are formed and then merozoites; schizogony repeated; gametocytes undergo de- velopment also in the same host cells; macrogametes become set free in coelom, where union with microgametes takes place; each oocyst forms about 16 spores, spore with usually 12 sporozoites; cysts are extruded with reproductive cells of host worm. Genus Myriospora Lermantoff. Anisogamy and sporogony in marine snails; schizogony unknown; oocyst forms numerous spores, each with 2 sporozoites. One species. M. trophoniae L. In the cardiac body of polychaete, Trophonia 420 PROTOZOOLOGY Fig. 191. a, b, Merocystis kathae, XlOOO (Foulon); c, Pseudoklossia pedinis, two sporozoites of a spore, X1470 (L^ger and Duboscq); d-k, Eimeria stiedae: d, a schizont; e, host cell with three schizonts; f, g, schizogony; h, macrogametocyte, X1270 (Hartmann); i-k, oocysts, X830 (Wasilewski) ; 1, m, E. perforans, X750 (P^rard); n, E.faurei, X800 (Wenyon). plumosa; macrogametes, vermiform, up to 800m long, later ovoid; microgametocyte forms first about 100 cytomeres, each with some 20 nuclei; microgametes comma-shaped; anisogamy; oocyst with several hundred spores, each with about 24 sporozoites. Genus Hyaloklossia Labbe. Schizogony unknown; sporogony in kidney of marine mussels; oocyst in organ-cavity; spherical spores of 2 kinds: smaller one with 2 spirally coiled sporozoites and the other with 4-6 sporozoites. One species. H. pelseneeri Leger. Spherical oocysts 75-80yu in diameter; spores Sfx and 11-12/x in diameter; in kidney of Tellina sp. and Donax sp. Genus Angeiocystis Brasil. Schizogony unknown; sporogony in polychaetes; oocyst forms 4 spores; spore oval, mth about 30 sporozoites and residual body at a pole. One species. A. audouiniae B. In the cardiac body of Audouinia tentaculata; macrogametes vermiform, up to 65At long. COCCIDIA 421 Family 3 Dobelliidae Ikeda Numerous microgametes develop from each microgametocyte; union of gametocytes begins early. Genus Dobellia Ikeda. Schizonts sexually difTerentiated, micro- schizonts and macroschizonts; young schizonts binucleate; associ- ation of 2 gametocytes begins early as in Adeleidea (p. 428), but many microgametes are formed in each microgametocyte. One species. D. hinucleata I. In gut of Petalostoma minutum; mature oocyst 20-25m in diameter, with a thin wall, contains some 100 sporo- zoites without any spore membrane around them. Family 4 Eimeriidae Leger Macro- and micro-gametocytes develop independently; micro- gametocyte produces many gametes; an oocyst from a pair of anisogametes; oocyst with variable number of spores containing 1-many sporozoites, which condition is used as basis of generic differentiation. Oocysts as found in faeces of host are usually im- mature; time needed for completion of spore formation depends upon species, temperature, moisture, etc. Becker (1934) recom- mends the following bactericidal solutions in which oocyst may develop to maturity: 1% formaldehyde, 1% chromic acid or 2- 4% potassium dichromate. Genus Eimeria Schneider {Coccidium Leuckart). Zygote of oocyst develops 4 spores, each with 2 sporozoites. Numerous spe- cies. E. schubergi (Schaudinn) (Fig. 188). In gut of Lithohius forfi- catus; oocysts spherical, 22-25ju in diameter. E. stiedae (Lindemann) (Coccidium oviforme Leuckart) (Fig. 191, d~k). In epithelium of bile-duct and liver (with white nod- ules) of rabbits; heavy infection is believed to be the cause of death of young animals, which may occur in an epidemic form; schizonts ovoid or spherical, 15-18^ in diameter; merozoite 8-10/x long; oocysts ovoid to ellipsoid, often yellowish, micropylar end flattened; mature oocysts 28-40/x by 16-25^^; sporulation in GO- TO hours. E. perforans Leuckart (Fig. 191, I, m). In gut of rabbits; patho- genic to host ; oocysts with equally rounded ends, 24-30/i by 14- 20m; sporulation in 30-48 hours. E. zurni (Rivolta). In gut of cattle; said to be the cause of diar- 422 PROTOZOOLOGY rhoea; oocysts spherical to ellipsoidal, 12-28yLi by 10-20/^; sporu- lation in 48-72 hours. E. smithi Yakimoff et Galouzo. In gut of cattle; oocysts 25-32/x by 20-29/i; sporulation in 3-5 days in shallow dishes, and 2 weeks in deep dishes (Becker). E. ellipsoidalis Becker et Frye. In faeces of healthy calf; oocysts elhpsoidal, 20-26^ by 13-17/i; sporulation in 18 days. E. cylindrica Wilson. In faeces of cattle; oocysts cylindrical, 19-27)U by 12-15iu; sporulation in 2-10 days. E. faurei Moussu et Morotel (Fig. 191, n). In gut of sheep and goat; oocysts ovoid, 20-40/x by 17-26^1; sporulation in 24-48 hours. Christensen (1938) recognized 7 species of Eimeria in the faeces of 100 North American sheep of which 96 contained oocysts. E. arloingi Marotel. In gut of sheep and goat; oocysts with a cap, ovoid, 25-35;u by 18-25^1; sporulation in 3 days. E. intricata Spiegl. In gut of sheep and goat; oocysts with thick wall, with or without cap, ellipsoidal, 42-60ju by 30-36m; sporula- tion in about 9 days. E. debliecki Douwes (Fig. 192, a). In gut of pigs; 30-82 per cent infection in California (Henry); oocysts 12-29/x by 12-20/^; sporulation in 7-9 days. E. scahra Henry. In caecal contents of pigs; oocysts, brown, el- hpsoidal, 22-36At by 16-26^. Henry (1931) recognized 2 other spe- cies in California swine. E. caviae Sheather. In gut of guinea pigs; oocysts subspherical to ellipsoid, 13-26m by 13-22^. E. canis Wenyon (Fig. 192, h). In gut of dogs; oocysts, elhpsoid- al, 18-45ju by ll-28)Lt; spores 9.5m by 2.5a£; sporulation in 24 hours. E. felina Nieschulz. In gut of cat; oocysts 21-26^ by 13-17^. E. falciformis (Eimer) (Fig. 192, c). In gut of mice; oocysts spherical to ovoid, 16-21ju by 11-17^; sporulation in 3 days. E. nieschulzi Dieben. In small intestine of rat; oocysts 16-26.4/z by 13-21/1 ; sporulation in 65-72 hours. E. separata Becker et Hall. In caecum and colon of rat; oocysts 13-19.5ai by ll-17)u; sporulation in 27-36 hours. E. miyairii Ohira. In small intestine of rat; oocysts 16.5-29^ by 16-26/x; sporulation in 96-120 hours. E. tenella (Railliet et Lucet) (Fig. 192, d). In caecum, colon and lower small intestine of chicken; cause of acute coccidiosis (Tyz- zer) ; in caecal contents of Cahfornia quail (Henry) ; schizogony in COCCIDIA 423 caecum; oocysts 19.5-26/z by 16.5-23ju; sporulation in 48 hours; heavily infected caecum highly haemorrhagic. E. mitis Tyzzer (Fig. 192, e). In anterior region of small in- FiG. 192. a, Einieria debliecki, X1070 (Wenyon); b, E. canis, X650 (Wenyon); c, E. falciformis, x730 (Wenyon); d, E. tenella, X600 (Tyzzer); e, E. mitis, X430 (Tyzzer); f, E. acervulina, X430 (Tyzzer); g, E. maxima, X470 (Tyzzer); h, E. ranarum, X670 (Laveran and Mesnil); i, E. prevoti, X670 (Laveran and Mesnil); j, E. ranae, X670 (Dobell); k, E. sardinae, X600 (Thomson and Robertson); 1, E. clupearum, X600 (Thomson and Robertson); m, n, Jarrina paludosa, X800 (L^ger and Hesse); o, p, Wenyonella ofricana, X1330 (Hoare); q, r, Isospora hominis, X1400 (Dobell); s, /. higemina, X930 (Wen- yon), t, 7. rivolta, X930 (Wenyon). testine of chicken; oocysts subspherical, 16.2/i by 15.5ai; sporula- tion in 48 hours. E. acervulina T. (Fig. 192, /). In anterior region of small intes- tine of chicken; also in California quail (Henry); oocysts oval, 424 PROTOZOOLOGY 17.7-20.2ju by 13.7-16.3yu; .si)orulation in 20 hours; associated with serious chronic coccidiosis (Tyzzer). E. maxima T. (Fig. 192, g). In mid-gut of chicken; oocysts oval, 21.5-42.5/x by 16.5-29.8^. E. necatrix Johnson. In small intestine (schizonts) and caecum (oocysts) of chicken; cause of chromic coccidiosis; oocysts obo- vate, 13-23m by 11-18/x; sporulation in 48 hours. E. praecox J. In the upper third of small intestine of chicken; oocysts ovoid, 20-25m by 15.5-20^; sporulation in 48 hours. E. meleagridis Tyzzer. In caecum of turkey; apparently non- pathogenic; oocysts, ellipsoidal, 19-30/^ by 14.5-23iu. E. meleagrimitis T. In lower small intestine in turkey; some- what similar to E. mitis; oocysts, 16. 5-20. 5^ by 13.2-17.2^. E. truncata (Railliet et Lucet). In kidney of geese; oocysts trun- cate at one pole, ovoid, 14-23^ by 13-18^; some observers find that this coccidian is fatal to young geese. E. anseris Kotlan. In gut of geese; oocysts spherical or pyri- form, ll-lGyLt in diameter. E. Idbheana Pinto. In gut of domestic pigeon; oocysts some- times light brown, 15-26/x by 14-24^i. E. dispersa Tyzzer. In small intestine of bob-white quail and pheasant; oocysts ovate, 18.8-22.8^ (quail), smaller in pheasant, without polar inclusion; sporulation in about 24 hours. E. ranarum (Labbe) (Fig. 192, h). In gut epithelium (nuclei) of frogs; oocysts about 17ai by 12^t. E. prevoti (Laveran et Mesnil) (Fig. 192, i). In gut epithelium of frogs; oocysts about 17^4 by 12/i; when sporozoites are fully formed, the spore membranes dissolve. E. ranae Dobell (Fig. 192, j). In gut of frogs; oocysts 22^ by 18m. E. sardinae (Thelohan) (E. oxyspora Dobell) (Fig. 192, k). In testis of sardine; oocysts spherical 30-50^. E. clupearum (Thelohan) {E. wenyoni Dobell) (Fig. 192, /). In liver of herrings, mackerels, and sprats; oocysts, spherical, 18- 33m in diameter. E. gadi Fiebiger. In swim-bladder of Gadus virens, G. morrhua, and G. aeglefinus; schizogony and sporogony; germination of spores takes place in the bladder of the same host individual, bringing about a very heavy infection; oocysts 26-28m; pathogen- ic (Fiebiger). Genus Jarrina Leger et Hesse. Oocysts ovoid, one end rounded COCCIDIA 425 and the other drawn out into a short neck; 4 spores, each with 2 sporozoites. /. paludosa L. et H. (Fig. 192, m, n). In gut of Fulica atra and Gallinula chloropus; oocysts 15m by llju; sporulation in 15 days. Genus Wenyonella Hoare. Oocysts with 4 spores, each with 4 sporozoites. One species. W. africana H. (Fig. 192, o, p). In small intestine of Boaedon lineatus ("brown snake") in Uganda; oocysts ovoid or subspher- ical, 18.5-19.2/x by 16-17. 6m; spores ovoid, 9.6At by 8^; sporula- tion in 5-6 days. Genus Isospora Schneider. Oocyst produces 2 spores, each con- taining 4 sporozoites. /. hominis (Railliet et Lucet) (7. belli Wenyon) (Fig. 192, q, r). In human small intestine; oocysts 25-33yu by 12.5-16/x; spores 12- 14m by 7-9m; in one case of accidental infection, the victim suf- fered 6 days later diarrhoea with abdominal discomfort which lasted for 4 M^eeks, and recovered. I. higemina (Stiles) (Fig. 192, s). In gut of cat and dog; oocysts 10-14m by 7-9m. I. rivolta (Grassi) (Fig. 192, t). In gut of cat and dogs; oocysts 20-25M by 15-20^. I.felis Wenyon (Fig. 193, a). In cat and dog; oocysts 39-48^ by 26-37m. I. suis Blester, In swine faeces; oocysts subspherical, about 22.5m by 19.4m; sporulation in 4 days. I. lacazei Labbe. In small intestine of passarine birds (sparrows blackbirds, finches, etc.); oocysts subspherical, 18.5-30m by 18- 29.2m; heavily infected sparrow shows definite symptoms; sporu- lation in 4-5 days. I. lieberkuhni (Labbe) (Fig. 193, b). Oocyst about 40m long; in kidney of frogs. Genus Cyclospora Schneider. Development similar to that of Eimeria; oocyst with 2 spores, each with 2 sporozoites and cov- ered by a bi- valve shell. C. caryolytica Schaudinn (Fig. 193, c). In gut of mole; sporo- zoites enter and develop in the nuclei of gut epithelial cells; oocyst oval, about 15m by 11.5m. Genus Dorisiella Ray. Zygote develops (without becoming oocyst) into 2 spores, each with 8 sporozoites; macrogametocytes migratory. 426 PROTOZOOLOGY D. scolelepidis R. (Fig. 193, d). In gut of Scolelepis fuliginosa; zygote contents divide into 2 oval spores, 12-16^ by 6-10/x; spore with 8 sporozoites. Genus Caryospora Leger Oocyst develops into a single spore Fig. 193. a, Isosporafelis, X930 (Wenyon); b, /. lieberkuhni, X660 (Laveran and Mesnil); c, Cyclospora caryolytica, X1330 (Schaudinn); d, Dorisiella scolelepidis, oocyst with two spores, X1400 (Ray); e, f, Caryospora simplex, X800 (L^ger); g-i, Cryptosporidium vutris (g, h, oocysts; i, emergence of four sporozoites), X1030 (Tyzzer); j, Pfeifferinella ellipsoides, X1330 (Wasielewski) ; k, P. impudica, X800 (L^ger and Hollande); 1, Lankesterella minima, a mature cyst in endo- thelial cell, XlOOO (Noller); m, Barrouxia ornata, X1330 (Schneider); n. Echinospora labbei, XlOOO (L6ger). with 8 sporozoites and a residual mass; membrane thick and yel- low. One species. C. simplex L. (Fig. 193, e,f). In gut-epithelium of Vipera aspis; oocyst thick-walled, 10-1 5ju in diameter. Genus Cryptosporidium Tyzzer. Lumen-dwelling minute or- ganisms; oocyst with 4 sporozoites. C. muris T. (Fig. 193, g-i). In peptic glands of the mouse; both COCCIDIA 427 schizogony and sporogony in the mucoid material on surface of the epithelium; oocysts 7^ by 5/z; 4 sporozoites, 12-14ju long. C. parvum T. In glands of small intestine of the mouse; oocysts with 4 sporozoites, 4.5ju in diameter. Genus Pfeifferinella Wasielewski. Macrogamete with a "recep- tion tubule" by which microgametes enter; oocyst produces di- rectly 8 sporozoites. P. ellipsoides W. (Fig. 193, j). In liver of Planorhis corneus; oocysts oval, 13-15^ long. P. im-pudica Leger et Hollande (Fig. 193, k). In liver of Limax marginatus ; oocysts ovoid, 20jU by 10^. Genus Lankesterella Labbe. Oocyst produces 32 or more spo- rozoites directly without spore-formation; in endothelial cells of cold-blooded vertebrates; mature sporozoites enter erythrocytes in which they are transmitted to a new host individual by blood- sucking invertebrates. L. minima (Chaussat) (Fig. 193, T). In frogs; transmitted by leeches (Placohdella marginata) ; frog acquires infection through introduction of sporozoites by leech; sporozoites make their way into the blood capillaries of various organs; there they enter en- dothelial cells; schizogony produces numerous merozoites which bring about infection of many host cells; finally macro- and mi- cro-gametocytes are formed; anisogamy produces zygotes which transform into oocysts, in which a number of sporozoites develop ; these sporozoites are set free upon disintegration of cyst wall in the blood plasma and enter erythrocytes (Noller); oocyst oval, about 33^1 by 23ju. Genus Schellackia Reichenow. Oocyst spherical with 8 sporo- zoites, without spore membrane; in gut of lizards. S. holivari R. In mid-gut of Acanthodactylus vulgaris and Psam- modromus hispanicus; development similar to Eimeria schuhergi (Fig. 188); oocysts, spherical, 15-19/^ in diameter, with 8 sporo- zoites. Genus Barrouxia Schneider. Oocyst with numerous spores, each with a single sporozoite; spore membrane uni- or bi-valve, with or without caudal prolongation. B. ornata S. (Fig. 193, m). In gut of Nepa cinerea; oocysts spherical, 34-37/x in diameter, with many spores; spore with one sporozoite and bivalve shell, 17-20ai by 7-lOju. Genus Echinospora Leger. Oocyst with 4-8 spores, each with a 428 PROTOZOOLOGY sporozoite; endospore with many small spinous projections. E. lahhei L. (Fig. 193, n). In gut of Lithohius mutabilis; oocyst spherical, 30-40/i in diameter; spores, ll/x by 9.4/x, with bi-valve shell; sporulation completed in about 20 days. Suborder 2 Adeleidea Leger The Adeleidea are on the whole similar to Eimeridea in their habitat and development, but the micro- and macro-gametocytes become attached to each other in pairs during the course of de- velopment into gametes (Fig. 194), and each microgametocyte produces a few microgametes. The zygote becomes oocyst which produces numerous sporoblasts, each of which develops into a spore with 2 or 4 sporozoites. In epithelium of gut and its appended glands of chiefly invertebrates. Family 1 Adeleidae In cells of circulatory system of vertebrates Family 2 Haemogregarinidae (p. 431) Family 1 Adeleidae Leger Genus Adelea Schneider. Zygote develops into a thinly walled oocyst with numerous flattened spores, each with 2 sporozoites; in arthropods. A. ovata S. (Fig. 194). In gut of Lithohius for ficatus ; merozoites 17-22^1 long; spores ll-H^c in diameter by 6/^ thick; sporozoites 20m by 4m. Genus Adelina Hesse. Oocyst thick-walled; spores spherical, comparatively small in number; in gut or coelom of arthropods and oligochaetes. A. dimidiata (Schneider) (Fig. 195, a). In gut of Scolopendra cingulata and other myriapods; oocysts with 3-17 spores. A. odospora H. (Fig. 195, h). Spherical oocyst contains 8 spores, in coelom of Slavina appendiciilata. Genus Klossia Schneider. Oocyst with numerous spherical spores, each with 3-10 sporozoites. Several species. K. helicina S. In kidneys of various land-snails, belonging to genera Helix, Succinea, and Vitrina; oocyst with a double en- velope 120-180/1 in diameter; spores 12^ in diameter, with 5-6 sporozoites. Genus Orcheobius Schuberg et Kunze. Macrogametes vermi- form; oocyst with 25-30 spores, each with 4 (or 6) sporozoites. 0. herpobdellae S. et K. (Fig. 195, c). In testis of Herpohdella COCCIDIA 429 Fig. 194. The life-cycle of Adelea ovata, X600 (Schellack and Reiche- now). a, schizont which enters the gut epithelium of the host centi- pede; b-d, schizogony; e, larger forms of merozoites; f, microgameto- cyte (left) and macrogametocyte (right) ; g, association of gametocytes; h, i, fertilization; j, zygote; k, nuclear division in zygote; 1, mature oocyst with numerous spores. atomaria; mature macrogametes ISO^u by 30)u; microgametes 50yu by 12;u; schizogony in April and May ; sporogony in June and July. Genus Klossiella Smith et Johnson. Microgametocyte produces 430 PROTOZOOLOGY 2 microgametes; oocyst with many spores, each with numerous sporozoites; in kidney of mammals. K. muris S. et J. (Fig. 195, d, e). Oocyst with 12-16 spores; spore with about 25 sporozoites, discharged in urine; in kidney of mouse. Fig. 195. a, Adelina dimidiata, spore, XlOOO (Schellack); b, A. octo- spora, oocyst, XlOOO (Hesse); c, Orcheobius herpobdellae, X550 (Kunze) ; d, e, Klossiella muris (d, renal cell of host with 14 sporoblasts; e, spore), X280 (Smith and Johnson); f, Legerella hydropori, oocyst, X 1000 (Vincent) ; g, h, Haemogregarina of frog, X 1400 (Kudo) ; i-m, H. simondi, in the blood of the sole, Solea vulgaris, X1300 (Laveran and Mesnil); n, Hepatozoon muris, spore, X420 (Miller); o, Kary- olystis lacertarum, X700 (Reichenow). K. cobayae Seidelin. Oocyst with 8-20 spores; spore with about 30 sporozoites; in kidney of guinea pig. Genus Legerella Mesnil. Oocyst contains numerous sporo- zoites; spores entirely lacking; in arthropods. L. hydropori Vincent (Fig. 195,/). In epithelium of Malpighian tubules of Hydroporus paltistris; oocysts ovoid, 20-25/1 long, with 16 sporozoites which measure 17ju by 3/i. COCCIDIA 431 Genus Chagasella Machado. Oocyst with 3 spores, each with 4 or 6 (or more) sporozoites; in hemipteroiis insects. C. hartmanni (Chagas). In gut of Dysdercus ruficolUs; oocysts with 3 spores about 45At in diameter; spore with 4 sporozoites, about 35/i by 15m. Family 2 Haemogregarinidae Leger With 2 hosts: vertebrates (circulatory system) and inverte- brates (digestive system). Genus Haemogregarina Danilewsky. Schizogony takes place in blood cells of vertebrates; merozoites develop into gameto- cytes; when taken into gut of leech or other blood-sucking in- vertebrates, sexual reproduction takes place; microgametocyte develops 2 or 4 microgametes; sporozoites formed without pro- duction of spores. H. stepanowi D. (Fig. 196). Schizogony in Ernys orbicularis and sexual reproduction in Placohdella catenigera; sporozoites intro- duced into blood of the chelonian host by leech (a), and enter erythrocytes in which they grow (d-g) ; schizogony in bone-mar- row, each schizont producing 12-24 merozoites (A); schizogony re- peated (i); some merozoites produce only 6 merozoites (j, k) which become gametocytes (l-o); gametogony occurs in leech; 4 microgametes formed from each microgametocyte and become associated with macrogametocytes in gut of leech (p-r); zygote (s) divides three times, and develops into 8 sporozoites {t-w). Haemogregarina are commonly found in various frogs (Fig. 195, g, h) and in fishes (Fig. 195, i-m). Genus Hepatozoon Miller. Schizogony in cells of liver, spleen, and other organs of vertebrates; merozoites enter erythrocytes or leucocytes and develop into gametocytes; in blood-sucking arthropods (ticks, mites), micro- and macrogametes develop and unite in pairs ; zygotes become oocysts which increase in size and produce sporoblasts, spores, and sporozoites. H. muris (Balfour) (Fig. 195, n). In various species of rat; sev- eral specific names were proposed on the basis of difference in host, locality, and effect on the host, but they are so indistinctly defined that specific separation appears to be impossible. Schi- zogony in liver of rat; young gametocytes invade mononuclear leucocytes and appear as haemogregarines ; when blood is taken in by the mite, Laelaps echidninus, union of 2 gametes produces 432 PROTOZOOLOGY In the gut of the leech, * Placobdella catenigera Fig. 196. The hfe-cycle of Haemogregarina stepcmoivi, X1200 (Reichenow). a, sporozoite; b-i, schizogony; j-k, gametocyte-forma- tion; 1, m, microgametocytes; n, o, macrogametocytes; p, q, associa- tion of gametocytes; r, fertiHzation; s-w, division of the zygote nu- cleus to form eight sporozoites. COCCIDIA 433 vermicular body which penetrates gut-epitheUum and reaches peri-intestinal tissues and grows; becoming surrounded by a cyst-membrane, cyst contents break up into a number of sporo- blasts and then into spores, each of which contains a number of sporozoites; when a rat devours infected mites, it becomes in- fected. Genus Karyolysus Labbe. Sporoblasts formed in oocysts in gut- epitheUum of mite, vermiform sporokinetes, enter host ova and become mature; when young mites hatch, spores in gut-epithe- lium are cast off and discharged in faeces ; a lizard swallows spores ; liberated sporozoites enter endothelial cells in which schizogony takes place; merozoites enter erythrocytes as gametocytes which when eaten by a mite complete development in its gut. K. lacertarum (Danilewsky) (Fig. 195, o). In Lacerta muralis; sexual reproduction in Liponyssiis saurarum; sporokinetes 40-50/x long; spores 20-25jU in diameter. References Becker, E. R. 1934 Coccidia and coccidiosis. Ames, Iowa. BouGHTON, Ruth B. and J. Volk 1938 Avian hosts of the genus Isospora (Coccidiida). Ohio. Jour. Sci., Vol. 38. Christensen, J. F. 1938 Species differentiation in the coccidia from the domestic sheep. Jour. Parasit., Vol. 24. DoBELL, C. 1925 The life-history and chromosome cycle of Aggregata eherthi. Paras., Vol. 17. Henry Dora P. 1931 Species of Coccidia in chickens and quail in California, Uni. Cal. Publ. Zool., Vol. 36. Miller, W.W. 1908 Hepatozoon perniciosum. U. S. Publ. Health Service, Hyg. Lab. Bull., No. 46. Levine, N. D. and E. R. Becker 1933 A catalog and host index of the species of the coccidian genus Eimeria. Iowa State Coll. Jour. Sci., Vol. 8. ScHAUDiNN, F. 1900 Untersuchungen iiber den Generations- wechsel bei Coccidien. Zool. Jahrb. Abt. Morph., Vol. 13. Tyzzer, E. E. 1929 Coccidiosis in gallinaceous birds. Amer. Jour. Hyg., Vol. 10. Wen YON, C. M. 1926 Protozoology. Vol. 2. London. Chapter 25 Order 3 Haemosporidia Danilewsky THE development of the Haemosporidia is, on the whole, sim- ilar to that of the Coccidia in that they undergo asexual reproduction, or schizogony, and also sexual reproduction, or sporozoite-formation; but the former takes place in the blood of vertebrates and the latter in the alimentary canal of some blood- sucking invertebrates. Thus one sees that the Haemosporidia remain always within the body of one of the two hosts; hence, the sporozoites do not possess any protective envelope. The Haemosporidia are minute intracorpuscular parasites of vertebrates. The malarial parasites of man are tj^pical members of this order. The development of Plasmodium vivax is as follows (Fig. 197) : Infected anopheline mosquitoes introduce the sporo- zoites (a) which invade the erythrocytes (6), grow, and undergo schizogony, forming a number of merozoites (c-f). The latter upon liberation from the host cells, attack other erythrocytes. Some of the merozoites develop into macrogametocytes (g) and others, microgametocytes (i, j). No further changes ordinarily take place in the human body, but the schizogony is repeated. The protozoan produces melanin (or haemozoin) which is appar- ently the metabolic product of the organism at the expense of the haemoglobin. When the blood is taken into the stomach of a suit- able species of anopheline mosquito, the gametocytes develop into macrogametes and microgametes respectively (h, k). They unite in pairs (I) and thus ookinetes (zygotes) (w) are formed. The ookinetes penetrate the stomach wall and become lodged between the epithelium and the elastic membrane of the stomach (n). There they grow and the nuclei undergo rapid and repeated divi- sions, finally producing an enormous number of minute sporo- zoites (o, p). These sporozoites are set free through the rupture of the cyst wall in the body cavity, find their way into the sali- vary glands and wait for an opportunity of being inoculated into a new victim (q). The schizogony occurs regularly, and it is thought that the typical malarial fever is caused by some toxic substances which are liberated into the blood stream when in- numerable merozoites become set free in the latter. 434 HAEMOSPORIDIA 435 Fig. 197. The life-cycle of Plas7nodium vivax (various authors), a, sporozoite entering human blood plasma; b, sporozoite entering erythrocyte; c, young schizont; d-f, schizogony; g, h, macrogameto- cytes; i, j, microgametocytes, k, microgametes formed in the stomach of mosquito; 1, union of gametes; m, zygote or ookinete, penetrating through the gut wall; n, rounding up of an ookinete between the gut wall and elastic membrane; o, oocyst in which sporozoites are being developed; p, mature oocyst ruptured and the sporozoites are set free in the body fluid; q, sporozoites entering the salivary gland. With pigment granules Schizogony in peripheral blood of vertebrates Family 1 Plasmodiidae Gametocytes in peripheral blood; schizogony elsewhere Family 2 Haemoproteidae (p. 439) Without pigment granules; minute parasites of erythrocytes Family 3 Babesiidae (p. 442) Family 1 Plasmodiidae Mesnil Genus Plasmodium Marchiafava et Celli. Schizogony in ery- throcytes of vertebrates; anisogamy and sporozoite-formation in Anopheles or Culex mosquitoes; widely distributed. Numerous species. P. vivax (Grassi et Feletti) (Fig. 198, a-g). The organism of be- nign tertian malaria of man; schizogony completed in 48 hours; 436 PROTOZOOLOGY infected erythrocytes become enlarged, widely distributed over temperate and tropical countries. P. falciparum (Welch) (Fig. 198, h-n). The organism of malig- nant tertian, subtertian, or aestivo-autumnal malaria of man, schizogony completed in 24-48 hours; schizonts adhere to capil- lary wall, to which malignancy of the species is attributed; game- tocytes crescentic (some authors therefore place this species in genus Laverania); of more Hmited distribution in tropical and subtropical regions of the world. Fig. 198. a-g, Plasmodium vivax, XlOOO (Kudo); h-n, P. falciparum, XlOOO (Kudo); o-u, P. malariae, XlOOO (Kudo), a-e, h-1, o-s, schizogony; f, m, t, microgametocytes; g, n, u, macrogametocytes. P. malariae (Laveran) (Fig. 198, o-u). The organism of quartan malaria of man; schizogony completed in 72 hours; in tropical and subtropical countries. Numerous species of female mosquitoes belonging to the genus Anopheles transmit these organisms. In the United States, the chief species concerned is A . quadrimaculatus. The malaria parasites are usually studied in (Giemsa, Wright, or Hasting) stained blood films or smears ; the comparison of the three species of human malaria given on the following page is based upon observations of stained specimens. A number of species of Plasmodium have been reported from various avian hosts. Manwell (1935) recognizes the following spe- cies as occurring in the United States. Hegner and his colleagues (1938) have called attention to the fact that merozoites enter young red corpuscles or reticulocytes (Fig. 199,/, g). HAEMOSPORIDIA 437 P. vivax P. falciparum P. malariae Schizogony completed in 48 hours 24-48 hours Diameter of ring form ^-^ of I of ery- erythrocyte throcyte, delicate 72 hours Wof erythrocyte Size of infected cell Dots in infected cell Grown schizonts Pigment granules in organism Number of merozoites from a schizont larger than uninfected one; paler Schtiffner's dots amoeboid, large rod-shaped 15 or more same as unm- same as unm- fected one fected one; distorted Maurer's dots not seen round, small elongate oval, medium small triangu- large, irregu- lar lar about 8-10 or 8-10 more Merozoites arranged in in 2 rings or erythrocyte scattered Gametocytes rounded 2 rings or scattered crescentic one rmg aided P. praecox (Grassi et Feletti) (Fig. 199, a-e). In English and Spanish sparrows; schizogony completed in 30-36 hours; number of merozoites from a single schizont 8-15; gametocytes crescentic; pigments occur in both schizonts and gametocytes; sexual cycle takes place in female culicine mosquitoes ; organism maintains its characteristics when inoculated into canaries, Serinus canaria. P. cathemerium Hartman (Fig. 199, /-O- In sparrows, cowbirds, and red-winged blackbirds; schizogony completed in 24 hours; number of merozoites 6-24; gametocytes spherical, with rod- shaped pigment granules; pigment granules in microgametocytes longer and more pointed than those in macrogametocytes ; macro- gametocytes usually stain more deeply, schizonts without vacu- oles; pigments in schizonts amorphous mass; merozoites 1^ long; mature schizonts and gametocytes 7-8m in diameter; transmitted by, or sexual reproduction in, Culex pipiens, C. salinarius, C. ter- 438 PROTOZOOLOGY ritans, C. quinquefasciatus, C. tarsalis, Aedes aegypti and A. sol- licitans. P. elongatum Huff (Fig. 199, m-p). In English sparrows and canaries; merozoites 8-12; round pigment granules clumped in schizonts, scattered in gametocytes; gametocytes elongate; schi- FiG. 199. a-e, Plasmodium praecox (a-c, schizogony; d, microgame- tocyte; e, macrogametocyte), X1670 (Hartman); f-1, P. cathemerium (f-j, schizogony, XllOO (Hegner and Hewitt); k, microgametocyte; 1, macrogametocyte, X1670 (Hartman)); m-p, P. elongatum (m, n, schizonts; o, microgametocyte; p, macrogametocyte), X1330 (Man- well); q-t, P. vaughni (q, r, schizonts; s, microgametocyte; t, macro- gametocyte), X1330 (Manwell). zogony usually in erythrocytes of bone marrow; gametocytes numerous in peripheral blood. P. vaughni (Novy et MacNeal) (Fig. 199, q-t). In robins, Tur- dus migratorius migratorius ; schizogony completed in probably 24 hours; gametocytes similar to those of P. elongatum; number of merozoites from a schizont 4 (4-8); 1-3 pigment granules. P. nucleophilum Manwell (Fig. 200, a-d). In catbird, Duma- tella carolinensis ; schizogony completed in probably 24 hours; gametocytes elongate, sometimes curved around nucleus; mero- zoites 4-9; black pigment granules, massed in schizonts, often at one end in gametocytes. P. polare Manwell (Fig. 200, e-i). In cliff swallow, Petroche- HAEMOSPORIDIA 439 liden lunifrons lunifrons; gametocytes elongate, often broader than in P. elongatum; merozoites 8-14 pigment granules, often oval, clumped; canaries not susceptible. P. circumflexum Kikuth (Fig. 200, j-m). In red- winged black- bird, cowbird, and Juniper thrush, schizogonic cycle completed Fig. 200. a-d, Plasmodium nudeo-philum (a, b, schizonts; c, micro- gametocyte; d, macrogametocyte), X1330 (Manwell); e-i, P. polare (e-g, schizogony; h, microgametocyte; i, macrogametocyte), X1330 (Manwell); j-m, P. circumflexum (j, k, schizonts; 1, microgametocyte; m, macrogametocyte), X1330 (Manwell); n-s, Haemoproteus lophortyx (n, o, microgametocytes; p, microgamete; q, macrogametocyte; r, macrogamete; s, ookinete), X1690 (O'Roke). in 48 hours; merozoites 13-30; small pigments scattered; game- tocytes elongate, ends may curve about host cell-nucleus; sexual cycle in Theobaldia annulata and T. melaneura. Family 2 Haemoproteidae Doflein Schizogony occurs in endothelial cells of vertebrates; mero- zoites penetrate into circulating blood cells and develop into gametocytes; if blood is taken up by specific blood-sucking in- sects, gametocytes develop into gametes which unite to form zygotes that undergo changes similar to those stated above for the family Plasmodiidae. 440 PROTOZOOLOGY Genus Haemoproteus Kruse. Gametocytes in erythrocytes, with pigment granules, halter-shaped when fully formed (hence Halterium Labbe); schizogony probably in viscera of vertebrate hosts; sexual reproduction in blood-sucking insects; in birds and reptiles. H. columhae Celli et Sanfelice. In the pigeon, Columba livia; widely distributed; schizogony in endothelial cells of capillaries of lungs and other organs; sexual reproduction in, and transmission by, Lynchia maura, L. hrunea, L. lividicolor, L. capensis and Microlynchia fusilla. Fig. 201. The life-cycle of Leucocijtozoon anatis (Brumpt, modified), a-c, development of macrogamete; d-f, development of microgametes; g, fertilization; h, ookinete; i, j, ookinete piercing through the stomach wall; k-m, development of sporozoites; n, sporozoites entering endo- thelial cells; o-r, schizogony. HAEMOSPORIDIA 441 H. lophortyx O'Roke (Fig. 200, n-s). In California Valley quail, Lophortyx spp. ; gametocytes in erythrocytes, also occasionally in leucocytes; young gametocytes, spherical to elongate, about Ifi long; more developed forms, cylindrical, about S/jl by 2/a, with 2- 10 pigment granules; mature gametocytes, halter-shaped, en- circling nucleus of host erythrocyte, 18yu by 1.5-2.5ai; numerous pigment granules; 4-8 microgametes, about 13.5/x long, from each microgametocyte; on slide in one instance, gamete-formation, fertilization and ookinete formation, completed in 52 minutes at room temperature; in nature sexual reproduction takes place in the fly, Lynchia hirsuta, which process seems to be similar to that of Plasmodium in mosquitoes (p. 435); sporozoites enter salivary glands and fill central tubules; schizonts present in lungs, liver and spleen of quail after infected flies sucked blood from the bird; merozoites found in endothelial cells of capillaries of lungs, in epithelial cells of liver and rarely in peripheral blood cells ; how merozoites enter blood cells is unknown; schizonts seldom seen in circulating blood ; infected birds show pigment deposits in spleen and lungs (O'Roke). Genus Leucocytozoon Danilewsky. Schizogony in endothelial cells and cells of viscera of vertebrates; sexual reproduction in blood-sucking insects; gametocytes occur in spindle cells or retic- ulocytes. L. anatis Wickware (Fig. 201). In wild and domestic ducks; sexual cycle in the black fly, Simulium venustum. O'Roke (1934) studied the life-cycle of this sporozoan: gametocytes develop into mature gametes in 1-2 minutes after blood is obtained from an infected duck; macrogametes about S^u in diameter; 4-8 micro- gametes, 15.7-24.1^ long, from a single microgametocyte; zygotes are found in stomach contents of fly in 10-20 minutes after suck- ing in infected blood of bird; motile ookinetes abundant after 5 hours, measure 33.3/i by 3-4. 6ju; 22 hours after sucking duck blood, oocysts found on outer wall of stomach; sporozoites ma- ture probably in 24-48 hours; 5 days after a duck has been bitten by infected black flies, schizogonic stages are noticed in endo- thelial cells of capillaries of lungs, liver, spleen; on about 7th day gametocytes appear in blood; liver and spleen become hyper- trophied; the infection among ducklings is said to be highly fatal and appears often suddenly. L. simondi Mathis et Leger. Macrogametocytes oval, 14-15/1 442 PROTOZOOLOGY by 4. 5-5. 5m, often vacuolated, nucleus with a distinct endosome; microgametocyte slightly smaller; in teal duck (Querquedula crec- ca), China. Herman (1938) observed a species of Leucocytozoon in common black duck (Anas rubripes tristis), red-breasted mer- ganser (Mergus serrator) and blue-winged teal (Querquedula dis- cors) and hold that L. simondi and L. anatis are one and the same species and therefore the latter name is synonymous with the former. Family 3 Babesiidae Poche Minute non-pigmented parasites of erythrocytes of various mammals; transmission by ticks. Genus Babesia Starcovici. In erythrocytes of cattle; pear- shaped, arranged in couples; sexual reproduction in female ticks in which developing ova, hence young ticks, become infected with ookinetes, producing sporozoites which enter salivary glands (Dennis). B. Ugemina (Smith et Kilbourne) (Figs. 202; 203, a-d). The causative organism of the haemoglobinuric fever, Texas fever or red-water fever of cattle; the very first demonstration that an arthropod plays an important role in the transmission of a pro- tozoan parasite; the infected cattle contain in their erythrocytes oval or pyriform bodies with a compact nucleus and vacuolated cytoplasm; the division is peculiar in that it appears as a budding process at the beginning. We owe Dennis (1932) for our knowl- edge of development of the organism. Sexual reproduction followed by sporozoite formation occurs in the tick, Margaropus annulatus ; when infected tick takes in in- fected blood into gut lumen, isogametes, 5.5-6/x long, are pro- duced; isogamy results in motile club-shaped ookinetes, 7-12/x long, which pass through gut wall and invade larger ova (1-2, in one case about 50, ookinetes per egg) ; each ookinete rounds itself up into a sporont, 7.5-12/^ in diameter, which grows in size and whose nucleus divides repeatedly; thus are produced multinu- cleated (4-32 nuclei) amoeboid sporokinetes, up to 15yu long, which now migrate throughout embryonic tissue cells of tick, many of which cells develop into salivary gland cells; sporoki- netes develop into sporozoites before or after hatching of host tick ; sporozoites bring about an infection to cattle when they are inoculated by tick at the time of feeding. Texas fever once caused HAEMOSPORIDIA 443 Fig. 202. The life-cycle of Babesia bigemina (Dennis), a-f, division in erythrocytes of cattle; g, h, gametocytes; i, isogametes; j, fertiliza- tion; k, zygote; 1, ookinete penetrating through the gut wall; m, ookinete in host egg, n-p, sporoblast-formation; q, sporokinetes in a large embryonic cell; r, sporozoites in salivary gland. a considerable amount of damage to the cattle industry in the southern United States to which region the distribution of the tick is limited. B. hovis Starcovici (Fig. 203, e-h). In European cattle; amoe- boid form usually rounded, though sometimes stretched; 1-1. 5/i 444 PROTOZOOLOGY in diameter; paired pyriform bodies make a larger angle, 1.5-2/^ long; transmitted by Ixodes ricinus. Babesia occur also in sheep, goats, pigs and horses. B. canis (Piana et Galli-Valerio). Pyriform bodies 4.5-5yu long; the organism causes malignant jaundice in dogs; widely distrib- uted; transmitted by ticks, Haemaphysalis leachi, Rhipicephalus sanguineus, and Dermacentor reticulatus. Fig. 203. a-d, Babesia bigemina, X3000 (Nuttall); e-h, B. bovis, X3000 (Nuttall); i-1, Theileria parva, X3000 (Nuttall); m-s, Daclylo- soma ranarum (m-q), schizogony; r, s, gametocytes), X2700 (Noller). Genus Theileria Bettencourt, Franca et Borges. Schizogony takes place in endothelial cells of capillaries of viscera of mam- mals; certain forms thus produced enter erythrocytes and appear in peripheral circulation. T. parva (Theiler) (Fig. 203, i-l). In cattle in Africa, cause of African coast fever; intracorpuscular forms l-2^t in diameter; transmitted by the tick, Rhipicephalus evertsi. Genus Dactylosoma Labbe. In blood of reptiles and amphib- HAEMOSPORIDIA 445 ians; schizogony in erythrocytes; gametocytes also in erythro- cytes; invertebrate hosts unknown. D. ranarum (Kruse) (Fig. 203, m-s). In European frogs; schi- zonts 4-9a£ in diameter; merozoites 4-16, 2-3^ by 1-1. 5ju; game- tocytes 5-8yu by 1.5-3;u. References Boyd, M. F. 1930 A71 introduction to malariology. Cambridge. Dennis, E.W. 1932 The life-cycle of Babesia bigemina (Smith and Kilbourne) of Texas cattle-fever in the tick Margaropus annulatus (Say). Univ. Calif. Publ. ZooL, Vol. 36. Hartman, E. 1937 Three species of bird malaria. Arch. f. Protistenk., Vol. 60. Manwell, R. D. 1935 How many species of avian malarial parasites are there? Amer. Jour. Trop. Med., Vol. 15. Ross, R. 1928 Studies on Malaria. London. O'RoKE, E. C. 1934 A malaria-like disease of ducks caused by Leucocytozoon anatis Wickware. Univ. Michigan Sch. Forest. and Conservation Bull., No. 4. Wenyon, C. M. 1926 Protozoology. Vol. 2. Chapter 26 Subclass 2 Acnidosporidia Cepede THE sporozoa which are provisionally grouped here are mostly incompletely known, although some of them are widely dis- tributed among the higher vertebrates. They possess spores which are quite simple in their structure, while their development is so far as is known wholly different from that of the Telosporidia. Muscle parasites of higher vertebrates Order 1 Sarcosporidia Parasites of invertebrates and fish Order 2 Haplosporidia (p. 448) Order 1 Sarcosporidia Balbiani These sporozoans are characteristic muscle parasites of mam- mals, although reptiles and birds have also been found to harbor them. The spore which has been known as Rainey's corpuscle, is crescent-shaped (Fig. 205). One end is rounded and the other pointed. Near one end there is a single nucleus, and the cytoplasm contains numerous granules. Infection of a new host begins with the entrance of spores into the digestive tract of a specific animal through mouth. The delicate spore membrane ruptures and the sporozoite is liberated, which enters the gut-epithelium. After multiplying in this situation, the organism makes its way into the muscular tissue. At the beginning the parasitic mass is an elon- gated multinucleate body which may or may not divide into as Fig. 204, a, Sarcocystis tenella in the oesophagus of sheep; b, S. niiescheriana in the muscle of pig; Xl (Schueidemiihl from Doflein). many uninucleate bodies as there are nuclei. These become the centers of infection in other muscle fibers. Some trophozoites grow in size and the body becomes divided into parts, in each of which spores are formed (Fig. 205). Some authors believe that the 446 ACNIDOSPORIDIA, SARCOSPORIDIA 447 spores themselves are capable of fission. The host muscle fiber harboring the trophozoite, may vary in size from microscopic to as large as 5 centimeters (Fig. 204). They are cylindrical with more or less pointed extremities and with a somewhat lobulated surface, and opaque whitish. They were formerly called Miesch- er's tubes (Fig. 204). Muscle layer Connective tissue layer Fibrous zone External "j Median > Cyst membrane Internal j Sporoblasts Spores Fig. 205. Portion of a cyst of Sarcocystis tenella in sheep, X about 1000 (Alexeieff). As to the pathogenic effect of the parasites upon the host ani- mal, fatal cases are not uncommon. In heavily infected animals extensive muscular degeneration appears and the hosts die, soon or later, from the infection. One peculiarity of the Sarcosporidia is that these organisms contain certain toxin, sarcocystine, and which when injected is highly toxic to other animals. Genus Sarcocystis Lankester. In muscles of vertebrates; nu- merous species have been described from various mammals on the basis of difference in host species and slight difference in dimen- sions of spore. They are, however, morphologically indistinguish- able from one another. S. lindemanni (Rivolta). In man; rare; in muscle fibers of 448 PROTOZOOLOGY larynx (Baraban and St. Remy), in muscles of biceps and tongue (Darling), in cardiac muscles (Manifold), etc.; parasites in mus- cles. 1.6 mm. by 170^i, elongate spindle, wall thin, contents di- vided into numerous chambers, spores banana-form, 8-9^t long (Baraban and St. Remy); parasites 84ju by 27m, spores 4.25/x by 1.75m (Darling); parasites spherical, 500m in diameter (Mani- fold). S. tenella Railliet (Figs. 204, a; 205). In muscles of tongue, pharynx, oesophagus, larynx, neck, heart, etc., of sheep; large parasites 40m-2 cm. long with a thin membrane; spores sickle- form. S. miescheriana (Kiihn) (Fig. 204, h). In muscles of pig; para- sitic mass up to 3-4 mm. by 3 mm; envelope striated; spores reni- form, capable of division when young (Manz). *S. bertrami Doflein. In muscles of horses; similar to *S. miescher- iana; parasitic mass up to 9-10 mm; envelope striated. S. muris Blanchard. In body muscles of rats and mice; para- sitic masses up to 3 cm; spores 13-15m by 2.5-3m; transmissible to guinea pig (Negri) which shows infection in muscles in 50-100 days after feeding on infected muscles. Order 2 Haplosporidia Caullery et Mesnil This order includes those sporozoans which produce simple spores. In some species the spores may resemble superficially those of Microsporidia, but do not possess the polar filament. The exact boundaries and affinities of this order to other groups are to be determined by future investigators. The Haplosporidia are cytozoic, histozoic, or coelozoic para- sites of invertebrates and lower vertebrates. The spore is spherical or ellipsoidal in form and covered by a resistant membrane which may possess ridges or may be prolonged into a more or less long tail-like projection. In a few species the spore membrane possesses a Hd which, when opened, will enable the sporoplasm to emerge as an amoebula. The sporoplasm is uninucleate and fills the intra- sporal cavity. The development of a haplosporidian, Ichthyosporidium gigan- teum, as worked out by Swarczewsky, is as follows (Fig. 206) : The spores germinate in the alimentary canal of the host fish and the sporoplasms make their way to the connective tissue of various organs (a). These amoebulae grow and their nuclei multiply in ACNIDOSPORIDIA, HAPLOSPORIDIA a 449 Fig. 206. The development of I chthyosporidium, gigariteiim (Swarczew- sky). a-e, schizogony; f-n, sporogonj^; o, stained spore, X about 1280. number, thus forming plasmodia. The plasmodia divide into smaller bodies, while the nuclei continue to divide (b-e). Presently the nuclei become paired (/, g) and the nuclear membranes dis- appear (h). The Plasmodia now break up into numerous small bodies, each of which contains one set of the paired nuclei (^, j). This is the sporont (j) which develops into 2 spores by further differentiation (k-o). Genus Haplosporidium Caullery et Mesnil. After growing into a large form, plasmodium divides into uninucleate bodies, each of which develops into a spore ; spore truncate wdth a lid at one end ; envelope sometimes prolonged into processes; in aquatic annelids and molluscs. H. chitonis (Lankester) (Fig. 207, a, h). In liver and connective 450 PROTOZOOLOGY Fig. 207. a, b, Haplosporidiuyn chitonis, XlOOO (Pixell-Goodrich); c, H. limnodrili, XlOOO (Granata); d, H. nemertis, XlOOO (Debai- sieux); e, H. heterocirri, XlOOO (Caullery and Mesnil); f, H. scolopli, XlOOO (Caullery and Mesnil); g, H. vejdovskii, XlOOO (Caullery and Mesnil); h, i, Urosporidium ftdiginosum, XlOOO (Caullery and Mes- nil); j, k, Bertramia asperospora (j, cyst with spores; k, empty cyst), X1040 (Minchin); 1, m, Coelosporidiiim periplanetae (1, trophozoite with spores and chromatoid bodies), X2540 (Sprague). tissue of Craspidochilus cinereus; spores oval, 10/i by Q/j,; envelope with 2 prolonged projections. H. limnodrili Granata (Fig. 207, c). In gut epithelium of Lim- nodrilus udekemianus; spores 10-12^t by 8-10^. H. nemertis Debaisieux (Fig. 207, d). In connective tissue of Lineus bilineatus; spores oval with a flat operculum, but without any projections of envelope, 7^ by 4^1. H. heterocirri C. et M. (Fig. 207, e). In gut epithelium of Het- erocirrus viridis; mature organisms 50-60^ by 30-40;u; spores 6.5/x by 4ai. H. scolopli C. et M. (Fig. 207, /). In Scoloplos mulleri; fully grown form 100-150/i by 20-30/i; spores lO/i by 6.5/i. ACNIDOSPORIDIA, HAPLOSPORIDIA 451 H. vejdovskii C. et M. (Fig. 207, g). In a freshwater oligochaete, Mesenchytraevs flavus; spores 10-12^ long. Genus Urosporidium Caiillery et Mesnil. Similar to Haplo- s'poridium, but spherical spore with a long projection. U . fuliginosum C. et M. (Fig. 207, /?, i). In coelom of the poly- chaete, Syllis gracilis; rare. Genus Anurosporidium Caullery et Chappellier. Smiilar to H aplosporidiuryi, but operculate spore spherical. A. pelseneeri C. et C. In sporocyst of a trematode parasitic in Donax trunculus; schizogony intracellular; cysts extracellular, with up to 200 spores; spores about 5/^ long. Genus Bertramia Caullery et Mesnil. Parasitic in aquatic worms and rotifers; sausage-shaped bodies in coelom of host; spherical spores which develop in them, possess a uninucleate sporoplasm and a well-developed membrane. B. asperospora (Fritsch) (Fig. 207, j, k). In body cavity of roti- fers: Brachionus, Asplanchna, Synchaeta, Hydatina, etc.; fully grown vermicular body 70-90^1 with 80-150 spores. B. capitellae C. et M. In the annelid Capitella capitata; spores 2.5/x in diameter. B. euchlanis Konsuloff. In coelom of rotifers belonging to the genus Euchlanis. Genus Ichthyosporidium Caullery et Mesnil. In fish; often looked upon as Microsporidia, as the organism develops into large bodies in body muscles, connective tissue, or gills, which ap- pear as conspicuous "cysts," which are surrounded by a thick wall and contain numerous spores. /. giganteum (Thelohan) (Fig. 206). In various organs of Creni- labrus melops and C. ocellatus; cysts 30/i-2mm. in diameter; spores o-S/jL long. /. hertwigi Swarczewsky. In Crenilahrus paro; cysts 3-4 mm. in diameter in gills; spores 6jU long. Genus Coelosporidium Mesnil et Marchoux. In coelom of Cla- docera or Malpighian tubules of cockroach; body small, forming cysts; spores resemble microsporidian spores; but without a polar filament. C. periplanetae (Lutz et Splendore) (C. hlattellae Crawley) (Fig. 207, I, m). In lumen of Malpighian tubules of cockroaches; com- mon; spores 5.5-7.5/xby 3-4;u. Some authors consider this a mi- crosporidian. 452 PROTOZOOLOGY References Alexeieff, a. 1913 Recherches sur Sarcosporidies. Arch. zool. exper. et gen., T. 51. Caullery, M. and F. Mesnil 1905 Recherches sur les Haplo- sporidies. Ibid., T. 4. Crawley, H. 1914 The evolution of Sarcocystis muris in the in- testinal cells of the mouse. Proc. Acad. Nat. Sci., Phila- delphia, Vol. 66. Lambert Jr., S. W. 1927 Sarcosporidial infection of the myo- cardium in man. Amer. Jour. Path., Vol. 3. Swarczewsky, R. 1914 Ueber den Lebenscyklus einiger Haplo- sporidien. Arch. f. Protistenk., Vol. 33. Teichmann, E. 1912 Sarcosporidia. Prowazek's Handhuch der Path. Protozoen., Vol. 1. Weissenberg, R. 1921 Fischhaplosporidien. Ibid., Vol. 3. Chapter 27 Subclass 3 Cnidosporidia Doflein THE members of this subclass possess without exception re- sistant spores which are of unique structure. Each spore possesses 1-4 polar capsules and one to many sporoplasms. The membrane which envelops these structures may be a single-piece or bi- or tri-valved. Within each of the polar capsules is coiled a polar filament. In the order Myxosporidia and Actinomyxidia, there appear several cells during the process of sporulation. These cells give rise to one to many sporoplasms, or generative cells, capsuloge- nous cells, and spore membrane. This condition is not observed in other groups of Protozoa and for this reason some writers recog- nize a close affinity between these two orders and the Mesozoa. The method of multiplication in the Cnidosporidia is schizogonic and sporogonic. The schizogony is binary or multiple fission, bud- ding, or plasmotomy. The nuclear division varies from amitosis to mitosis. Isogamous, anisogamous, and autogamous reproduc- tion have been reported in a number of forms. In many forms, the zygote is the sporont, in which one to many spores become differentiated. No secondary or intermediate host has been found for any of the Cnidosporidia. They are exclusively parasites of the lower vertebrates and invertebrates. Since cnidosporidian infections oc- cur frequently in epidemic forms among such economically im- portant animals as the silkworm, honey bees, and commercial fishes, the organisms possess considerable practical significance. Spores comparatively large Shell bivalve; 1, 2, or 4 polar capsules Order 1 Myxosporidia (p. 454) Shell trivalve; 3 polar capsules. . . .Order 2 Actinomyxidia (p. 468) Spores comparatively small Shell one-piece; 1 (or 2) polar filament Order 3 Microsporidia (p. 472) Barrel-shaped; a thick filament coiled beneath the shell ; 3 sporoplasms Order 4 Helicosporidia (p. 479) 453 454 PROTOZOOLOGY Order 1 Myxosporidia Biitschli The spore of a myxosporidian is of various shapes and dimen- sions. It is covered by a bivalve chitinous spore membrane, the two valves meeting in a sutural plane which is either twisted (in three genera) or more or less straight. The membrane may possess various markings or processes. The polar capsule, with its short coiled filament, varies in number from one to four. Except in the family Myxidiidae, in which one polar capsule is situated near each of the poles of the spore, the polar capsules are always grouped at one end which is ordinarily designated as the anterior end of the spore. Below or between (in Myxidiidae) the polar cap- sules, there is almost always a sporoplasm. Ordinarily a young spore possesses two nuclei which fuse into one (autogamy) when the spore becomes mature. In Myxobolidae there is a glycogenous substance in a vacuole which stains mahogany red with iodine and which is known as the iodinophilous (iodophile) vacuole. The Myxosporidia are almost exclusively parasites of lower vertebrates, especially fishes. Both fresh and salt water fishes have been found to harbor, or to be infected by, Myxosporidia in various regions of the world. A few occur in Amphibia and Rep- tilia, but no species has been found to occur in either birds or mammals. When a spore gains entrance into the digestive tract of a specific host fish, the sporoplasm leaves the spore as an amoe- bula which penetrates through the gut-epithelium and, after a period of multiplication, enters the tissues of certain organs, where it grows into a schizont at the expense of the host tissue cells, and the nucleus divides repeatedly. Some nuclei become surrounded by masses of cytoplasm and become the sporonts (Fig. 208). The sporonts grow and their nuclei divide several times, forming 6-18 daughter nuclei, each with a small mass of cytoplasm. The number of the nuclei thus produced depends upon the structure of the mature spore, and also upon whether 1 or 2 spores develop in a sporont. When the sporont develops into a single spore, it is called a monosporoblastic sporont, and if two spores are formed within a sporont, which is usually the case, the sporont is called disporoblastic, or pansporoblast. The spore- formation begins usually in the central area of the large tropho- zoite, which continues to grow. The surrounding host tissue be- comes degenerated or modified and forms an envelope which is often large enough to be visible to the naked eye. This is ordi- CNIDOSPORIDIA, MYXOSPORIDIA 455 Fig. 208. Sporogony in Myxosoma catostomi, X2130 (Kudo). a, sporont or pansporoblast; b-h, development of two sporoblasts within the sporont; i, a nearly mature spore; j-1, views of spore. narily referred to as a myxosporidian cyst. If the site of infection is near the body surface, the large cyst breaks and the mature spores become set free in the water. In case the infection is con- fined to internal organs, the spores will not be set free while the host fish lives. Upon its death and disintegration of the body, however, the liberated spores become the source of new infection. The more primitive Myxosporidia are coelozoic in the host's organs, such as the gall bladder, uriniferous tubules of the kid- ney, urinary bladder, etc. In these forms, the liberated amoebulae make their way into the specific organ and there grow into multi- nucleate amoeboid trophozoites which are capable of forming pseudopodia of various types. They multiply by exogenous or en- dogenous budding or plasmotomy. One to several spores are de- veloped in the trophozoite. Almost all observes agree in maintaining the view that the 2 nuclei of the sporoplasm or 2 uninucleate sporoplasms fuse into one (autogamy or paedogamy), but as to the nuclear as well as 456 PROTOZOOLOGY a b Fig. 209. The development of Sphaeromyxa sabrazesi (Debaisieux). a, vegetative nuclei; b, association of two vegetative nuclei; c, the sa-me within a cell; d, primary propagative cell; e, its division; f, sec- ondary propagative cells; g, their division; h, formation of sporocyte; i, two sporocytes; j, formation of pansporoblast; k, pansporoblast at later stage; 1, pansporoblast with two spores, the sporoplasm of which contains two nuclei; m, four nuclei in sporoplasm; n, two nuclei re- main functional, the other two degenerate; o, fusion of the two nuclei. cytoplasmic changes prior to, and during, spore-formation, there is a diversity of opinions. To illustrate the views held by those who believe there is a sexual phase in the development of a myxo- sporidian, Sphaeromyxa sabrazesi (p. 465) may be taken as an CNIDOSPORIDIA, MYXOSPORIDIA 457 Fig. 210. The development of Sphaerormjxa sabrazesi (Naville). a, uninucleate amoebula enters the gall bladder; b, young multi- nucleate trophozoite; c, development of macrogametes; d, develop- ment of microgametes; e, f, plasmogamy; g-m, development of pan- sporoblast; n, fusion of the two nuclei in the sporoplasm. 458 PROTOZOOLOGY example. Debaisieux's observation on this myxosporidian is in brief as follows (Fig. 209): sporoplasms after finding their way into gall baldder of host fish develop into large trophozoites con- taining many nuclei (a), 2 vegetative nuclei become surrounded by a cytoplasmic mass (c) and this develops into a primary prop- agative cell (d) which divides (3 chromosomes are noted) (e) and forms secondary propagative cells (/). A binucleate sporocyte is formed from the latter by unequal nuclear division (g-i) and 2 sporocytes unite to form a tetranucleate pansporoblast (j) which develops into 2 spores (k, I). Sporoplasm first shows 2 nuclei, but later 4, of which 2 degenerate and the other 2 fuse into one nu- cleus. On the other hand, according to Naville (1930) uninucleate amoebula (Fig. 210, a) enters the gall bladder and develops into multinucleate trophozoite in which nuclear division reveals 4 chromosomes (6); within the trophozoite macrogametes and mi- crogametes are independently formed, during which process, chromosome number is reduced into half (2) (c, d); plasogamy be- tween a macrogamete and a microgamete results in production of a binucleate pansporoblast (e, /), from which repeated nuclear division (g-l) forms 2 spores (m); each of the 2 nuclei of the sporo- plasm is haploid and the diploid number is restored when the 2 nuclei fuse into one (n). The site of infections by Myxosporidia varies among different species. They have been found in almost all kinds of tissues and organs of host fish, although each myxosporidian has its special site of infection in one to several species of fish. The gills and gall bladder are most frequently parasitized by Myxosporidia in Fig. 211. A channel cat, heavily infected with Henneguya exilis, Xh (Kudo). freshwater fishes, while the gall bladder and urinary bladder of marine fishes harbor one or more species of Myxosporidia. When the infection is concentrated in the fins or integument, the re- svdting changes are quite conspicuous (Fig. 211). The infection in CNIDOSPORIDIA, MYXOSPORIDIA 459 the gills is usually manifest by whitish pustules which can be fre- quently detected with the unaided eye. When the wall of the ah- mentary canal, mesentery, liver, and other organs are attacked, one sees considerable changes in them. Heavy myxosporidian in- fection of the gall bladder or urinary bladder of the host fish may cause abnormal appearance and coloration or unusual enlarge- ment of the organ, but under ordinary circumstances the infec- tion is detected only by a microscopical examination of its con- tents. Certain histological changes in the host fish have been mentioned elsewhere (p. 26). Severe epidemic diseases of fishes are frequently found to be due to myxosporidian infections. According to Davis, the "wormy" halibut of the Pacific coast of North America is due to the myxosporidian, Unicapsula muscularis (Fig. 213), which in- vades the muscular tissue of the host fish. The "boil disease" of the barbel, Barbus harhus and others, of European waters, is caused by Myxoholus pfeifferi. Myxosoma cerebralis which attacks the supporting tissues of salmonoid fish, is known to be responsi- ble for the so-called "twist disease," which is often fatal, espe- cially to young fishes and which occurs in an epidemic form. The Myxosporidia are divided into three suborders : Largest diameter of spore at right angles to sutural plane; with 1 polar capsule on each side; sporoplasm without iodinophilous vacuole Suborder 1 Eurysporea Spore spherical or subspherical with 1, 2, or 4 polar capsules; sporo- plasm without iodinophilous vacuole. . . . Suborder 2 Sphaerosporea (p. 461) Sutural plane coincides with, or is at an acute angle to, largest diameter of spore; 1, 2, or 4 polar capsules; sporoplasm with or without iodinophilous vacuole Suborder 3 Platysporea (p. 404) Suborder 1 Eurysporea Kudo Spores laterally expanded; coelozoic in marine fish, except one species Family 1 Ceratomyxidae Spores less laterally expanded; in freshwater fish; holozoic or coelozoic Family 2 Wardiidae (p. 461) Family 1 Ceratomyxidae Doflein Spores are laterally prolonged and therefore sutural diameter is smaller than width; 2 polar capsules at anterior margin; one on each side of sutural plane. Genus Ceratomyxa Thelohan. Shell-valves conical and hollow, 460 PROTOZOOLOGY Fig. 212. a, Ceratotnyxa mesospora, XlOOO (Davis); b, c, C. hopkinsi, XlOOO (Jameson); d-j, Leptotheca ohlmacheri (d, section of a urinifer- ous tubule of Rana pipiens, with trophozoites and spores, X800; e, a trophozoite with a bud; f-h, disporous trophozoites; i, a spore with extruded polar filaments; j, surface view of spore, X1500) (Kudo). CNIDOSPORIDIA, MYXOSPORIDIA 461 attached on bases; sporoplasm usually not filling intrasporal cav- ity; in gall-bladder of marine fish. Numerous species. C. mesospora Davis (Fig. 212, a). In gall-bladder of Cestracion zygaena; spores, Sn in sutural diameter and 50-65^ wide. C. hopkinsi Jameson (Fig. 212, 6, c,). In gall-bladder of Paro- phrys vetulus, Microstomus pacificus and Citharichthys xanthostig- mus; trophozoites disporous; spores 5.7-7.5fj. in sutural diameter and 28.8-39ju broad. Genus Leptotheca Thelohan. Shell-valves hemispherical; in gall-bladder or urinary bladder of marine fish and one in amphib- ians. Numerous species. L. ohlmacheri (Gurley) (Fig. 212, d-j). In uriniferous tubules of kidney of frogs and toads; spores 9.5-12/i in sutural diameter and 13-14. 5)U wide. Genus M3rxoproteus Doflein. Spores pyramidal with or without distinct processes at base of pyramid; in urinary bladder of ma- rine fish. 3 species. M. cordiformis Davis (Fig. 214, a). In urinary bladder of Chae- todipterus faber ; spores 12/x by 10-1 1/z. Family 2 Wardiidae Kudo Genus Wardia Kudo. Spores isosceles triangle with 2 convex sides; oval in profile; 2 large polar capsules; tissue parasites of freshwater fish. 2 species. W. ovinocua K. (Fig. 214, h). In ovary of Lepomis humilis; spores 9-1 Iju in sutural diameter and 10-12^i wide. Genus Mitraspora Fujita. Spores circular or ovoidal in front view; somewhat flattened in profile; 2 polar capsules; shell stri- ated; with or without posterior filaments; in kidneys of freshwa- ter fishes. This genus apparently includes border-line forms be- tween this and other suborders. 3 species. M. elongata Kudo. In kidney of Apomotis cyanellus; spores 15- 17m by 5-Qfx. Suborder 2 Sphaerosporea Kudo Spore with 1 polar capsule Family 1 Unicapsulidae Spore with 2 polar capsules Family 2 Sphaerosporidae (p. 462) Spore with 4 polar capsules Family 3 Chloromyxidae (p. 464) Family 1 Unicapsulidae Kudo Genus Unicapsula Davis. Spherical spore with 1 polar capsule; 462 PROTOZOOLOGY C Fig. 213. Unicapsula muscularis (Davis), a, b, infected muscle fibers, X20; c, cross-section of an infected muscle, Xl90; d, X575; e-h, spores, X2500. shell-valves asymmetrical; sutural line sinuous'; histozoic in ma- rine fish. One species. U . muscularis D. (Fig. 213). Spore about 6/x in diameter; 2 uni- nucleate sporoplasms; in muscle fibers of halibut, Pacific coast of North America; the cause of the "wormy" halibut (Davis). Family 2 Sphaerosporidae Davis Genus Sphaerospora Thelohan. Spore spherical or subspheri- cal; sutural line straight; 2 polar capsules at anterior end; coelo- zoic or histozoic in marine or freshwater fishes. CNIDOSPORIDIA, MYXOSPORIDIA d 463 Fig. 214. a, Myxoproteus cordiformis, XlOOO (Davis); b, Wardia ovinocua, X1330 (Kudo); c, Sphaerospora polytnorpha, XlOOO (Davis); d-i, S. tincae (d, external appearance of a heavily infected young tench; e, internal appearance, X|; f, mature pansporoblast; g, h, two spores; i, germination of spore, XlOOO) (Leger); j, k, Sinuolinea dimorpha (j, trophozoite with three gemmules, X420; k, X930) (Davis); 1, m, CJdoromyxum leydigi (1, X500; m, XlOOO) (Thelohan); n, C. Irijugum, X1130 (Kudo). S. polymorpha Davis (Fig. 214, c). In urinary bladder of Opsaus tau; spores 7-1 0/x in diameter. S. tincae Plehn (Fig. 214, d-i). In pronephros and other viscera of Tinea tinea in France and Germany; cause of epidemic disease among young tench; disease is manifest by great distension of anterior portion of abdomen and up-turned mouth; infection fatal through rupture of abdominal wall; spores 7-8.75iu in diam- eter. 464 PROTOZOOLOGY Genus Sinuolinea Davis. Splierical or subspherical spores; su- tural line sinuous; with or without lateral processes; 2 spherical polar capsules; in urinary bladder of marine fish. S. dimorpha D. (Fig. 214, j, k). In Cynoscion regalis; spores 15^ in diameter. Family 3 Chloromyxidae Thelohan Genus Chloromyxum Mingazzini. Spore with 4 polar capsules, grouped at anterior end; shell surface often striated or ridged; sutural Une frequently obscure; histozoic or coelozoic in fresh- water or marine fish and also in amphibians. Numerous species. C. leydigi M. (Figs. 65, c, d; 214, I, m). In gall-bladder of vari- ous species of Raja, Torpedo and Cestracion; spores 6-9)U by 5- 6m ; widely distributed. C. trijugum Kudo (Fig. 214, n). In gall-bladder of Xenotis megalotis and Pomoxis sparoides; spores 8-10/i by 5-7//. Suborder 3 Platysporea Kudo Without indinophilous vacuole 2 polar capsules, one at each pole Family 1 Myxidiidae 1 polar capsule Family 2 Coccomyxidae (p. 466) 2 or 4 polar capsules grouped. . .Family 3 Myxosomatidae (p. 466) With an iodinophilous vacuole Family 4 Myxobolidae (p. 466) Family 1 Myxidiidae Thelohan Genus Myxidium Biitschli. Spores fusiform with pointed or rounded ends; polar filament comparatively long, fine; coelozoic or histozoic in fishes, also in amphibians and reptiles. Numerous species. M. lieberkuhni Biitschli (Figs. 65, a, h; 215, a-d). In urinary bladder of Esox spp.; spores 18-20 fj. by 5-6^; widely distributed. M. immersum (Lutz) (Fig. 215, e, /). In gall-bladder of various species of toads and frogs, including Bujo sp., and Rana pipiens, U.S.A.; trophozoites large rounded disc, thin, up to 3 mm. in diameter; disporoblastic; polysporous; spores with 7-9 conspicu- ous transverse ridges, about 12;u by 7^. M. kudoi Meglitsch. In gall-bladder of Ictalurus furcatus ; troph- ozoites large disc-like, up to 1 mm. in diameter; spores 8.5-12/1 long by 4-6//. Genus Sphaeromyxa Thelohan. Spore fusiform, but ends usu- ally truncate; polar filament short, thick; trophozoites large, dis- coid; coelozoic in marine fish. Several species. CNIDOSPORIDIA, MYXOSPORIDIA 465 S. balhianii T. (Figs. 65, e; 215, g-i). In gall-bladder of Motella and other marine fish in Europe and of Siphostoma in the United States; spores 15-20ai by 5-6ju. S. sabrazesi Laveran et Mesnil (Figs. 209, 210; 215,^-0. In gall- bladder of Hippocampus, Motella, etc.; spores 22-28/x by 3-4/i. Fig. 215. a-d, Myxidium lieberkuhni (a, a trophozoite, X220 (Lieberkiihn) ; b, a small trophozoite, XlOOO; c, d, spores, X1400) (Kudo) ; e, f, M. immersum, X 1400 (Kudo) ; g-i, Sphaero7nyxa balbianii (g, X§; h, a spore, X1400 (Davis); i, spore with extruded polar fila- ments, X840 (Thelohan)); j-l,».S. satmzesi (j, X 10; k,l, spores, XlOOO) (Schroder); m, n, Zschokkella hildae (m, X600; n, X1060) (Auerbach); o-t, Coccomyxa morovi (o, a young binucleate trophozoite; p-s, devel- opment of sporoblast; t, a spore with the extruded polar filament), X665 (Ldger and Hesse). Genus Zschokkella Auerbach. Spore hemi-circular in front view; fusiform in profile; circular in cross-section; ends pointed obliquely; polar capsules large, spherical; sutural line usually in S-form, coelozoic in fish or amphibians. A few species. 466 PROTOZOOLOGY Z. hildae A. (Fig, 215, m, n). In urinary bladder of Gadus spp.; spores 16-29m by 13-18//. Family 2 Coccomyxidae Leger et Hesse Spore ellipsoidal ; one polar capsule at one end ; circular in cross- section; undoubtedly a border-line form between Myxosporidia and Microsporidia. Genus Coccomyxa Leger et Hesse. Polar filament long, fine; coelozoic parasite in marine fish. C. morovi L. et H. (Fig. 215, o-t). In gall-bladder of Clwpea pil- chardus; spores 14/^ by 5-6ac. Family 3 Myxosomatidae Poche 2 or 4 polar capsules at anterior end; sporoplasm without any iodinophilous vacuoles. Genus Myxosoma Thelohan (Lentospora Plehn). Spore circu- lar, oval or ellipsoid in front view, lenticular in profile; 2 polar capsules at anterior end; histozoic in marine or freshwater fish. Several species. M. catostomi Kudo (Figs. 54; 208). In muscle and connective tissue of Catostomus commersonii; spores 13-15/x by 10-1 1.5^. M. cerebralis (Hofer) (Fig. 216, a). In cartilage and perichon- drium of salmonoid fish; young fish are especially affected by in- fection, the disease being known as the "twist-disease" (Dreh- krankheit) ; spores 6-lOju in diameter. Genus Agarella Dunkerly. Spore elongate oval; 4 polar cap- sules at anterior end ; shell prolonged posteriorly into long proc- esses. One species. A. gracilis D. (Fig. 216, h). In testis of South American lung- fish, Lepidosiren paradoxa. Family 4 Myxobolidae Thelohan 1, 2, or 4 polar capsules grouped at anterior end; sporoplasm with iodinophilous vacuole. Genus Myxobolus Biitschli. Spores ovoidal or ellipsoidal, flat- tened ; 2 polar capsules at anterior end ; sporoplasm with an iodin- ophilous vacuole; sometimes with a posterior prolongation of shell; exclusively histozoic in freshwater fish or amphibians. Numerous species. M. pfeifferi Thelohan (Fig. 216, e,f). In muscle and connective CNIDOSPORIDIA, MYXOSPORIDIA 467 Fig. 216. a, Mijxosoma cerebralis, X800 (Plehn); b, Agarella gracilis, X1660 (DunkerlejO; c, d, Thelchanellus notatus, X1530 (Kudo); e, f, Myxobolus pfeifferi (e, section of a cj'st; f, spore treated with Lugol, X1780) (Kej^sselitz); g-i, M. orbiculatus (g, infected muscle, X600; h, a fresh spore; i, Lugol-treated spore, XlOOO) (Kudo); j, k, M. conspicuus, X1530 (Kudo); l-o, M. squamosus (1, a cyst under a scale, X6.5) (Kudo); p, Henneguya psorospermica, X1330 (Thelo- han); q-s, H. exilis, X1530 (Kudo). tissue of body and various organs of Barb us harbus, B. fluviatilis, and B. plebejus; tumor up to a diameter of 7 cm; most of infected fish die from the effect (Keysselitz) ; spores 12-12. 5iu by 10-10. 5^. M. orbiculatus Kudo (Fig. 216, g-i). In muscle of Notropis gil- berti; spores 9-10^ in diameter by 6.5-7)U thick. M. conspicuus K. (Fig. 216, j, k). In corium of head of Moxo- stoma breviceps; tumors 1/2-4 mm. ; spores 9-11. 5/x by 6.5-8m- 468 PROTOZOOLOGY M. intestinalis K. (Fig. 1, o). In the intestinal wall of Pomoxis sparoides; (fixed unstained) spores, 12-13/x by 10-12.5/x; the his- tological changes brought about by this protozoan have been mentioned elsewhere (p. 26). M. squamosus Kudo (Fig. 216, Ir-o). In connective tissue below scales of HyJjopsis kentuckiensis ; spore circular in front view, 8- 9m in diameter, 4.5-5m thick. Genus Thelohanellus Kudo. Pyriform, flattened spores, each with one polar capsule; sporoplasm with an iodinophilous vacu- ole; histozoic in freshwater fish. 11 species. T. notatus (Mavor) (Figs. 1, h; 216, c, d). In subdermal connec- tive tissue of Pimephales notatus, Cliola vigilax, Notropis cornu- tus, N. blennius, and Leuciscus rutilus; tumor up to 7 mm. in diameter; spores 17-18^ by 7.5-10/x; host tissue surrounding the organism becomes so greatly changed that it appears as an epi- thelium (p. 26). Genus Henneguya Thelohan. Spore circular or ovoidal in front view; flattened; 2 polar capsules at anterior end; each shell- valve prolonged posteriorly into a long process; sporoplasm with an iodinophilous vacuole: mostly histozoic in freshwater fish. Nu- merous species. H. psorospermica T. (Fig. 216, p). In gills of Esox and Perca; cyst formation; total length of spores 35-40ai. H. exilis Kudo (Figs. 211; 216, q-s). In gills and integument of Ictalurus punctatus; cysts up to 3 mm. in diameter, conspicuous; spores, total length 60-70/x, spore proper 18-20/i by 4-5^4 wide by 3-3.5m thick. H. mictospora Kudo. In urinary bladder of Lepomis spp. and Micropterus salmoides; spores 13.5-15ai long, 8-9/x wide, 6-7.5)Lt thick; caudal prolongation 30-40/x long. Order 2 Actinomyxidia Stole The Cnidosporidia placed in this order have been less frequent- ly studied and, therefore, not so well known as the Myxosporidia. The spore is enveloped by a membrane, or shell composed of 3 valves which are sometimes drawn out into simple or bifurcated processes. There are also 3 polar capsules in the spore and the polar filaments are plainly visible w vivo. One to several sporo- plasms occur in each spore. In the fully grown stage, the body is covered by a membrane and contains always 8 sporoplasts which CNIDOSPORIDIA, ACTINOMYXIDIA 469 develop in turn into 8 spores. Whether the pansporoblast is formed by the union of 2 cells or not, is yet to be confirmed. The nuclei and cytoplasm divide and isogamy takes place. The zygote thus formed is the sporont, from which a single spore is produced by repeated nuclear division combined with cytoplasmic differ- entiation. The Actinomyxidia inhabit the body cavity or the gut-epithe- lium of fresh or salt water annelids. Spore with a double membrane; inner membrane a single piece, the outer trivalve; a single binucleate sporoplasm Famil}^ 1 Tetractinomyxidae Spore membrance a single trivalve shell; a single octonucleate sporo- plasm or 8 uninucleate sporoplasms Family 2 Triactinomyxidae Family 1 Tetractinomyxidae Poche Genus Tetractinomyxon Ikeda. In coelom of the sipunculid Petalostoma minutum; spores tetrahedron, without processes; trophozoite a rounded body, when mature; pansporoblast devel- ops 8 spores. Seemingly borderline forms between the Myxo- sporidia and the Actinomyxidia. T. intermedium I. (Fig. 217, a). Spherical pansporoblasts 20- 25ju in diameter; spores 7-8/x in diameter; in coelom of the sipun- culid, Petalostoma minutum. Family 2 Triactinomyxidae Genus Triactinomyxon Stole. Each of 3 shell-valves drawn out into a long process, the whole anchor-like; spore with 8 or more uninucleate sporoplasms; in gut-epithelium of oligochaetes. T. ignotum S. (Fig. 217, d). Spore with 8 sporoplasms; in Tubi- fex tuhifex. T. magnum Granata. Spore with 16 sporoplasms; in Limno- drilus udekemianus. T. legeri Mackinnon et Adams. Spore with 24 sporoplasms; in Tuhifex tuhifex. T. duhium G. Spore with 32 sporoplasms; in Tuhifex tuhifex. T. mrazeki M. et A. Spore with 50 sporoplasms; in Tuhifex tuhifex. Genus Sphaeractinomyxon Caullery et Mesnil. In coelom of oligochaetes; spores rounded, without any processes; in early stage of development, there are 2 uninucleate bodies surrounded 470 PROTOZOOLOGY by a binucleate envelope; 2 inner cells multiply into 16 cells which unite in pairs; nucleus of zygote or sporont divides first into 2; 1 of the nuclei divides into 6 which form 3 shell-valves and 3 polar capsules, while the other nucleus together with a portion of cyto- FiG. 217. a, Tetractinomyxon intermedium, X800 (Ikeda); b, Sphae- ractinomyxon stolci, X600 (Caullery and Mesnil); c, S. gigas, X665 (Granata); d, Triactinomyxon ignolum, Xl65 (Leger); e, Hexaclino- myxon psammoryctis, X300 (Stole); f, g, Synactinomyxon tubificis, X600 (Stole); h, Neoactinomyxum globosum, X860 (Granata); i, Guy- enotia sphaerulosa, X2095 (Naville). plasm remains outside the envelope, and undergoes multiplica- tion; multinucleate sporoplasm migrates into spore; sporoplasm later divides into a large number of uninucleate sporoplasms which, when spores gain entrance into a new host, begin develop- ment. CNIDOSPORIDIA, ACTINOMYXIDIA 471 S. stolci C. et M. (Fig. 217, h). Spore spherical; in Clitellis are- narius and Hemituhifex henedii. S. gigas Granata (Fig. 217, c). In coelom of Limnodrilus hoff- meisteri. Genus Hexactinomyxon Stole. Each of 3 shell-valves prolonged into 2 processes ; spore appears as a 6-armed anchor. H. psammorydis S. (Fig. 217, e). In gut-epithelium of Psam- moryctes harhatus; sporoplasm multinucleate. Genus Synactinomyxon Stole. Spore with 2 prolonged shell- valves and 1 conical valve. S. tuhificis S. (Fig. 217,/, g). In gut-epitheUum of Tubifex tubi- jex. Genus Neoactinomyxum Granata. 3 shell-valves without any process, distended to hemisphere. N. globosum G. (Fig. 217, h). In gut-epithelium of Limnodrilus udekemianus; spore with numerous sporoplasms. Genus Guyenotia Naville. Pansporoblast with 8 spores; spore spherical with 3 shell- valves, each drawn out into digitiform proc- ess posteriorly, longer than diameter of spore; sporoplasm with 32 nuclei. G. sphaerulosa N. (Fig. 217, i). In gut-epithelium of Tubifex tubifex; spores 15)u in diameter; appendages of mature spore 40iu long. References AuERBACH, M. 1910 Die Cnidosporidien. Leipzig. Caullery, M. and F. Mesnil 1905 Recherches sur les Acti- nomyxidies. Arch. f. Protistenk., Vol. 6. Davis, H. S. 1917 The Myxosporidia of the Beaufort region. Bull. U.S. Bureau Fish., Vol. 35. Granata, L. 1924 Gh Attinomissidi. Arch. f. Protistenk., Vol. 50. Kudo, R. 1920 Studies on Myxosporidia. lUinois Biol. Monogr., Vol. 5. 1933 A taxonomic consideration of Myxosporidia. Trans. Amer. Micr. Soc, Vol. 52. 1934 Studies on some protozoan parasites of fishes of Illinois. Illinois Biol. Monogr., Vol. 32. Naville, A. 1930 Le cycle chromosomique d'une nouvelle Actinomyxidie : Guyenotia sphaerulosa n.gen., n.sp. Quart. Jour. Micr. Sci., Vol. 73. Chapter 28 Order 3 Microsporidia Balbian THE Microsporidia are far more widely distributed as para- sites among various animal phyla than are the Myxosporidia. They are, however, typically parasites of arthropods and fishes. Aside from 1 or 2 species, all Microsporidia invade and destroy host cells. Frequently these infected cells may show enormous hypertrophy of both the cytoplasmic body and the nuclei (Fig. 218), a characteristic feature of the host reaction toward this particular group of protozoan p9,rasites. Fig. 218. Effects of microsporidian infection upon hosts, a, the cen- tral nervous system of Lophius piscatoris infected by Nosema lophii (Doflein) ; b, a smelt infected by Glugea hertwigi (Schrader) ; c, larva of Culex territans infected by Thelohania opacita, XlO (Kudo); d, a Simulium larva infected by T. multispora, X8 (Strickland); e, part of testis of Barbus barbies infected by Plistophora longifilis, Xl (Schu- berg); f, g, normal and hypertrophied nucleus of adipose tissue of larval Culex pipiens, the latter due to infection by Stempellia magna, XIOOO (Kudo). The microsporidian spore is relatively small. In the vast ma- jority it measures 3-6m long. The spore membrane, which is ap- parently of a single piece, envelops the sporoplasm and the polar filament, a very long and fine filament. The latter may directly be coiled in the spore or may be encased within a polar capsule which is similar to that of a myxosporidian or actinomyxidian 472 MICROSPORIDIA 473 spore in structure, but which is mostly obscure in vivo, because of the minuteness of the object. When such spores are taken into the digestive tract of a specif- ic host (Fig. 219), the polar filaments are extruded and perhaps anchor the spores to the gut-epithelium. The sporoplasms emerge through the opening after the filaments become completely de- tached. By amoeboid movements they penetrate through the in- testinal epithelium and enter the blood stream or body cavity and reach their specific site of infection. They then enter the host cells and undergo schizogonic multiplication at the expense of the Fig. 219. The life-cycle of Stempellia magna, X800 (Kudo), a, b, ger- mination of spore in the mid-gut of culicine larva; c-k, schizogony; 1-p, sporont formation; q-t, formation of 1, 2, 4, and 8 sporo blasts; u, sporoblast; v-x, development of sporoblast into spore. latter. The schizonts become sporonts, each of which produces a number of spores characteristic of each genus. Some spores seem to be capable of germinating in the same host body, and thus the number of infected cells increases. When heavily infected, the host animal dies as a result of the degeneration of enormous num- bers of cells thus attacked. Such fatal infections may occur in an epidemic form, as is well known in the case of the pebrine disease 474 PROTOZOOLOGY of silkworms, the nosema-disease of honoy bees, microsporidiosis of mosquito larvae, etc. Spore with a single polar filament Suborder 1 Monocnidea Spore with 2 polar filaments Suborder 2 Dicnidea (p. 478) Suborder 1 Monocnidea Leger et Hesse Spore oval, ovoid, or pyriform; if subcylindrical length less than 4 times breadth Family 1 Nosematidae Spore spherical or subspherical Family 2 Coccosporidae (p. 477) Spore tubular or cylindrical, width less than 1/5 length; straight or curved Family 3 Mrazekiidae (p. 477) Family 1 Nosematidae Labbe The majority of Microsporidia belong to this family. Genus Nosema Nageli. Each sporont develops into a single spore. Numerous species. A^. bombycis N. (Fig. 220, a, h). In all tissues of embryo, larva, pupa and adult of Bombyx mori; spores 3-4)u by 1.5-2/i, polar filament 57-72ijl long ; the causative organism of the pebrine dis- ease of the silkworm. A^. bryozoides (Korotneff) (Fig. 220, c, d). In germ cells and cavity of Plumatella fungosa and P. repens; spores 7-10/x by 5-6/x. Fig. 220. a, b, Nosema bombycis (a, spore, X1470; b, an infected silk-worm larva, X f ) (Kudo) ; c, d, A'', bryozoides (c, infected funiculus, X270 (Braem); d, a spore, X1200 (Schroder)); e, f, N. apis, X1560 (Kudo); g-i, iV. cyclopis, X1560 (Kudo); j, k, A^. anophelis, X1600 (Kudo); 1, m, Glugea anomala (1, section of an injected G aster osteus aculeatus (Th^lohan) ; m, a spore, X1500 (Stempell)); n, G. hertwigi, X1670 (Weissenberg); o, Perezia mesnili, X800 (Paillot); p, q, Gurleya richardi, X1200 (C^pede). MICROSPORIDIA 475 A'', apis Zander (Fig. 220, e, /). In gut of honey bees; spores 4- 6m by 2-4/x. A'', cyclopis Kudo (Fig. 220, g^). In Cyclops fuscus; spores 4.5m by 3m. N. anophelis K. (Fig. 220, j, k). In Anopheles quadrimaculatus (larva) ; spores 5-6m by 2-3m. Genus Glugea Thelohan. Each sporont develops into 2 spores; the infected host cells become extremely hypertrophied, and transform themselves into the so-called Glugea cysts. Many spe- cies. G. anornala (Moniez) (Fig. 220, I, m). In connective tissue of stickle backs; spores 4-6m by 2-3m. G. midleri Pfeiffer. In muscles of Gammarus; spores 5-6m by 2- 3m- G. hertwigi Weissenberg (Figs. 218, h; 220, n). In various tissue cells of Osmerus; spores 4-5. 5m by 2-2. 5m. Genus Perezia Leger et Duboscq. Each sporont produces 2 spores as in Glugea, but infected host cells are not hypertrophied. A few species. P. mesnili Paillot (Fig. 220, o). In cells of silk glands and Mal- pighian tubules of larvae of Pieris hrassicae; spores 3.4m by 1.5-2m. Genus Gurleya Doflein. Each sporont develops into 4 sporo- blasts and finally into 4 spores. Not common. G. richardi Cepede (Fig. 220, p, q). In Diaptomus castor; spores 4-6m by 2.8m. Genus Thelohania Henneguy. Each sporont develops into 8 sporoblasts and ultimately into 8 spores ; sporont membrane may degenerate at different times during spore formation. Numerous species. T. legeri Hesse (Figs. 68; 221, a-e). In fat-bodies of anopheline larvae; spores 4-6m by 3-4m; heavily infected larvae die without metamorphosing into adults; widely distributed. T. opacita Kudo (Figs. 218, c; 221, f-h). In fat-bodies of culi- cine larvae; spores 5.5-6m by 3.5-4m. Genus Stempellia Leger et Hesse. Each sporont produces 1, 2, 4, or 8 sporoblasts and finally 1, 2, 4, or 8 spores. 2 species. S. magna Kudo (Figs. 218, /, g; 219; 221, i-l). In fat-bodies of various culicine larvae; spores 12. 5-16. 5m by 4-5m; polar capsule visible in life; polar filament when extruded under mechanical pressure, measures up to 350-400m long. 476 PROTOZOOLOGY ■ >^;'^''^*j?'''5*-o*' '=%fefev*;if Fig. 221. a-e, Thelohania legeri (a, b, sporogony; c, d, mature pan- sporoblasts; e, a spore), X1570 (Kudo); f-h, T. opacita (f, g, octo- sporous and tetrasporous pansporoblasts; h, a spore), X1570 (Kudo); i-1, Stempellia magna (i-k, spores; 1, a spore with the extruded polar filament), X1570 (Kudo); m, n, Trichoduboscqia epeori (m, pansporo- blast with mature spores, X1330; n, a spore, X2670) (Leger); o, p, Plistophora longifilis (Schuberg). Genus Duboscquia Perez. Sporont develops into 16 sporoblasts and finally 16 spores. One species. D. legeri P. In body cavity of ReticuUtermes lucifugus; spores 5/z by 2.5/i. Genus Tricho duboscquia Leger. Similar to Duboscquia in num- ber of spores produced from each sporont; but spore with 4 (or 3) rigid transparent prolongations of shell, difficult to see in fife. One species. T. epori L. (Fig. 221, w, n). In fat-bodies of nymphs of Epeorus torrentium and Rhithrogena semicolorata ; sporonts spherical, 9-IOm in diameter, with usually 16 spores; prolongations of shell, 20- 22/i long; spores pyriform, 3.5-4jU long. Genus Plistophora Gurley. Sporont develops into variable number of (often more than 16) sporoblasts, each of which be- comes a spore. Several species. MICROSPORIDIA 477 P. Simula (Lutz et Splendore). In larvae of Simulium spp.; spores 4.5-8^1 by 3.5m. P. longifilis Schuberg (Figs. 218, e; 221, o, p). In testis of Bar- bus fluviatilis; spores 3m by 2m up to 12m by 6m; extruded polar filaments up to 510m long. Genus Pyrotheca Hesse. Schizogony and sporogony unknown; spores elongate pyriform, anterior end attenuated, posterior end rounded, slightly curved; sporoplasm in posterior region, with 1-2 nuclei; polar capsule large. One species. P. incurvata H. (Fig. 222, a, h). In fat-bodies and haemocoele of Megacyclops viridis; spores 14m by 3m; polar filament 130m long. Family 2 Coccosporidae Kudo Genus Coccospora Kudo {Cocconema Leger et Hesse). Spore spherical or subspherical. Several species. C. slavinae (L. et H) (Fig. 222, c, d). In gut-epithelium of Sla- vina appendiculata ; spores about 3m in diameter. Family 3 Mrazekiidae Leger et Hesse Genus Mrazekia L. et H. Spore straight, tubular; long or short process at one extremity. M. caudata L. et H. (Fig. 222, e, /). In lymphocytes of Limno- drilus and Tubifex; spores 16-18m by 1.3-1. 4m. Genus Bacillidium Janda. Spore cylindrical, without any proc- ess; one end narrowed in a few species. 8 species. B. limnodrili JiTovec (Fig. 222, g). In lymphocytes within gon- ads of Limnodrilus claparedeanus in Bohemia; spores 22-24m by 1.5m. Genus Cougourdella Hesse. Spore cylindrical, with an enlarged extremity, resembling fruit of Lagenaria cougourda. 3 species. C. magna H. (Fig. 222, h, i). In haemocoele and fat body of Megacyclops viridis; spores 18m by 3m; polar filament 110m long; sporoplasm with 1-2 nuclei or 2 uninucleate sporoplasms. Genus Octosporea Flu. Spore cylindrical; more or less curved; ends similar. 2 species. 0. muscae-domesticae F. (Fig. 222, j). In gut and germ cells of Musca and Drosophila; spores 5-8m long. Genus Spiroglugea Leger et Hesse. Spore tubular and spirally curved; polar capsule large. One species. S. octospora L. et H. (Fig. 222, k, I). In fat body of larvae of Ceratopogon sp. ; spores 8-8. 5m by 1m. 478 PROTOZOOLOGY ,7^^„ f i •& ( m s (h i Fig. 222. a, b, Pyrotheca incurvata, X2000 (Hesse); c, d, Coccospora slavinae (d, with extruded polar filament), X2000 (Leger and Hesse); e, f, Mrazekia caudata (e, an infected host cell, X700 (Mrazek); f, a spore, X1750 (L6ger and Hesse)); g, Bacillidium limnodrili, X1400 (Jirovec); h, i, Cougourdella magna, X2000 (Hesse); j, Octosporea mtis- cae-domesHcae, X2150 (Chatton and Krempf); k, 1, Spiroglugea octo- spora (k, XlOOO; 1, X3000) (Leger and Hesse); m, n, Toxoglugea vibrio (m, XlOOO; n, X3000) (Leger and Hesse) ; o, p, Telotnyxa glugeiformis, X3000 (L^ger and Hesse). Genus Toxoglugea Leger et Hesse. Minute spore curved or arched in semi-circle. One species. T. vibrio L. et H. (Fig. 222, m, n). In fat body of Ceratopogon sp.; spores 3.5/x by less than O.S^u. Suborder 2 Dicnidea Leger et Hesse Family Telomyxidae Leger et Hesse Genus Telomyxa Leger et Hesse. Spore with 2 polar capsules ; sporont develops into 8, 16, or more sporoblasts and finally 8, 16, or more spores. One species. T. glugeiformis L. et H. (Fig. 222, o, p). Li fat body of larva of Ephemera vulgata; spores 6.5^i by 4/^. HELICOSPORIDIA 479 Order 4 Helicosporidia Kudo This order has been created to inckide the interesting organism, HeUcosporidium, observed by Keilin. Although quite pecuHar in the structure of its spore, the organism seems to be best placed in the Cnidosporidia, if it is a protozoan. Fig. 223. Diagram illustrating the probable development of Helico- sporidia, X about 1600 (Keilin). a-c, schizont and schizogony; d, sporont(?); e, three stages in formation of four-celled stage; f, hypo- thetical stage; g, young spore before the spiral filament is formed; h, mature spore; i, j, opening of spore and liberation of sporozoites. a-h, in living host larva; i, j, in dead host body. The minute spore is composed of a thin membrane of one piece and of three uninucleate sporoplasms, around which is coiled a long thick filament. Young trophozoites are found in the host tis- sues or body cavity. They undergo schizogony, at the end of which uninucleate sporonts become differentiated. A sporont 480 PROTOZOOLOGY divides apparently twice and thus forms four small cells which develop into a spore. The complete life-history is still unknown. Genus Helicosporidium Keilin. Parasitic in insects; schizogony and sporogony; spore with central sporoplasms and a single thick coiled filament. One species. H. parasiticum K. (Fig. 223). In body cavity, fat body, and nervous system of larvae of Dasyhelea ohscura and Mycetohia pal- lipes (Diptera), and Hericia hericia (Acarina), all of which inhabit wounds of elm and horse-chestnut trees; schizonts minute; spores 5-6)u in diameter; extruded filament 60-65^ by 1^ thick. References Debaisieux, p. 1928 fitudes cytologiques sur quelques Micro- sporidies. La Cellule, Vol. 38. Hesse, E. 1935 Sur quelques Microsporidies parasites de Mega- cyclops viridis Jurine. Arch. zool. exp. et gen., Vol. 75. JfROVEC, O. 1936 Studien iiber Microsporidien. Mem. Soc. Zool. Tchecoslovaque de Prague. Vol. 4. Keilin, D. 1921 On the life-history of Helicosporidium para- siticum. Parasit., Vol. 13. Kudo, R. 1924 A biologic and taxonomic study of the Micro- sporidia. Illinois Biol. Monogr., Vol. 9. ScHRADER, F. 1921 A microsporidian occurring in the smelt. Jour. Paras. Vol. 7. Chapter 29 Subphyliim 2 Ciliophora Doflein THE Ciliophora possess cilia which serve as cell-organs of loco- motion and food-capture. In Suctoria the cilia are present only during early developmental stages. The members of this subphylum possess a unique organization not seen in the Plas- modroma; namely, except Protociliata, the Ciliophora contain two kinds of nuclei, the macronucleus and the micronucleus. The former is large and massive, and controls the metabolic activities of the organism, while the latter is minute and usually vesicular or less compact, and is concerned with the reproductive proc- esses. Nutrition is holozoic or parasitic; holophytic in a few forms. Sexual reproduction is mainly by conjugation, and asexual reproduction is by binary fission or budding. The majority are free-living, but a number of parasitic forms also occur. The Ciliophora are divided into two classes : Cilia present throughout trophic life Class 1 Ciliata Adult with tentacles; cilia only while young Class 2 Suctoria (p. 628) Class 1 Ciliata Perty The class Ciliata includes Protozoa of various habitats and body structures, though all possess cilia or cirri during the trophic stage of life. They inhabit all sorts of fresh and salt water bodies by free-s\^^mming, creeping, or being attached to other objects; some are endozoic in other animals. Free-swimming forms are usually spherical to elliptical, while the creeping forms are, as a rule, flattened or compressed. The cilia are extremely fine, comparatively short, and as a rule arranged in rows. In some forms they diminish in number and are replaced by cirri. The cilia are primarily cell-organs of loco- motion, but secondarily through their movements bring the food matter into the cytostome. Moreover, certain cilia appear to be tactile organellae. The food of free-living ciliates consists of small plant and animal organisms which ordinarily abound in the water; thus their nutrition is holozoic. The ciliates vary in size from less than lO^t up to 2 mm. in large forms (as in an extended 481 482 PROTOZOOLOGY Spirostomuin or Stciitor). The cytoplasm is distinctly differen- tiated into the ectoplasm and the endoplasm. The ectoplasm gives rise to the cilia and trichocysts and is covered by a pellicle. The endoplasm contains nuclei, food vacuoles, contractile vacuoles, pigment granules, crystals, etc. In the majority of ciliates, the anterior and posterior extremities are permanent and distinct; in all cytostome-possessing forms, the oral and aboral surfaces are distinguishable, while in numerous creeping forms the dorsal and ventral sides are differentiated. The body is covered by a very thin yet definite membrane, the pellicle, which is ordinarily uniformly thin and covers the entire body surface so closely that it is not recognizable in life. In some forms, such as Coleps, it develops into numerous platelets and in others, such as Trichodina, into hook-like processes. The outer half of the ectoplasm may show alveolar structure which, in sec- tion, exhibits radiating and parallel lines. In this portion the myonemes (p. 51) are lodged. The deeper layer of the ectoplasm is structureless and free from granules. In the ectoplasm are em- bedded the basal granules of cilia, which are arranged in longi- tudinal, oblique, or spiral rows. In recent years complex fibrillar systems have been recognized in many ciliates (p. 55-59). The cilia may fuse to form cirri, membranellae, and undulating membranes which occur in certain groups. In many euciliates contractile vacuoles with one to several collecting canals are one of the prominent structures. The endoplasm is more fluid and the ground substance is finely granulated or reticulated; it undergoes rotation movement or cyclosis. Two types of nuclei are present in all euciliates. The massive macronucleus is of various forms. The chromatin granules which may reach 20^ in diameter (p. 34) fill compactly the intranuclear space. The macronucleus multiplies by amitosis. The micronu- cleus is ordinarily so minute that it is difficult to see in a living specimen. It is vesicular in strusture, although in some it appears to be compact, and consists of an endosome, the nucleoplasm, and the membrane. The number of micronuclei present in an indi- vidual varies among different species. At the time of reproduction it increases in size and divides mitotically; during conjugation it undergoes a meiotic division (p. 158). The protociliates possess from one to many hundreds of nuclei of a uniformly same structure and numerous ovoid or spindle- CILIOPHORA, PROTOCILIATA 483 shaped bodies, the nature of which is open to speculation. Some authors think that they are nuclei — micronuclei (after Hickson) or macronuclei (after Konsuloff). Metcalf considers that each nucleus possesses both metabolic chromatin and reproductive chromatin, the former being seen as large flattened peripheral masses and the latter, as smaller spheroidal granules. In all except protociliates and a comparatively small number of astomous euciliates, there is a cytostome which in its simplest form is represented by a small opening on the pellicle, and may or may not be closed when the animal is not feeding. The cyto- stome opens into the cytopharynx (or gullet), a canal which ends in the deeper portion of the endoplasm. In the cytopharynx there may be present one or more undulating membranes to facilitate intaking of the food. Occasionally the cytostome is surrovmded by trichites or trichocysts (p. 62). When the cytostome is not at the anterior region as, for instance, in Paramecium, there is a peristome (or oral groove) which starts at or near the anterior end and runs posteriorly. The peristome is ciliated so that food par- ticles are thrown down along it and ultimately into the cytostome which is located at its posterior end. Solid waste particles are ex- truded from the cytopyge, or cell-anus, which is usually notice- able only at the time of actual defecation (p. 92). Following Metcalf, Ciliata are here divided into 2 subclasses: 2-many nuclei of one kind; sexual reproduction permanent fusion. . . Subclass 1 Protociliata Macronucleus and micronucleus; sexual reproduction conjugation. . . Subclass 2 Euciliata (p. 487) Subclass 1 Protociliata Metcalf The protociliates are exclusively inhabitants of the intestine of Anura, excepting 3 species, 2 of which occur in Urodeles and one in a marine fish. The body is covered uniformly by cilia of equal length. There is no cytostome and the nutrition is parasitic (saprozoic). The number of nuclei varies from 2 to several hun- dreds, all of which are of one type. Asexual reproduction is by binary fission. In a number of species sexual fusion of 2 gametes has been observed (Fig. 225, a-d). Encystment is common. One ^' Family Opalinidae Claus Genus Opalina Purkinje et Valentin. Highly flattened; multi- nucleate; in amphibians. Numerous species. 484 PROTOZOOLOGY 0. hylaxena Metcalf (Fig. 224, a). In Hyla versicolor; larger individuals about 42{)/i long, 125/x wide, 28/i thick. Several sub- species (Metcalf). 0. ohtrigonoidea M. (Fig. 224, b-f). 400-840^ long, ITS-lSO/z wide, 20-25yu thick; in various species of frogs and toads (Rana, Hyla, Bufo, Gastrophryne, etc.). North America. Numerous sub- species (Metcalf). Fig. 224. a, 3 individuals of Opalina hylaxena, X230; b-f, 0. oh- trigonoidea, X60 (b, c, from Bufo fowleri; d-f, from Rana pipiens); g, Cepedea cantabrigensis, X230; h, Zelleriella scaphiopodos, X230. (All after Metcalf.) 0. carolinensis M. 90-400ju by 32-170;u; in Rana pipiens spheno- cephala. 0. pickeringii M. 200-333At by 68-100^; in Hyla pickeringii. 0. oregonensis M. o26/x by 123)u; in Hyla regilla. 0. spiralis M. 300-355m long, 130-140m wide, 25-42m thick; in Bufo compactilis. 0. chorophili M. About 470m by lOOju; in Chorophilus triseriatus. 0. kennicotti M. About 240/i by 85^; in Rana areolata. CILIOPHORA, PROTOCILIATA 485 Genus Cepedea Metcalf. Cylindrical or pyriform; circular in cross-section; multinucleate; all in Amphibia. Numerous species. C. cantahrigensis M. (Fig. 224, g). About 350m by 84/i; in Rana cantabrigensis. C. hawaiensis M. 170-200jli by 43-60/z; in Rana catesbeiana; Hawaii. C. ohovoidea M. About 315At by 98/i; in Bufo lentiginosus. C. floridensis M. About 230^ by 89/z; in Scaphiopus alhus. w^m Wil Fig. 225. a-d, stages in sexual reproduction in Protoopalina intes- tinalis (Metcalf); e, f, P. saturnalis, X500 (L^ger and Duboscq); g, P. mitotica, X380 (Metcalf). 486 PROTOZOOLOGY Genus Protoopalina Mctcalf. Cylindrical or spindle-shaped, circular in cross-section; 2 nuclei; in rectum of various species of Amphibia with one exception. Numerous species. P. intestinalis (Stein) (Fig. 225, a-d). About 330^ by 68^; in intestine of Bomhina bomhina, and B. pachypa, Europe. P. saturnalis Leger et Duboscq (Fig. 225, e, /). In intestine of the marine fish, Box hoops; 100-152)U by 22-60^. P. mitotica (M.) (Fig. 225, g). 300m by 37^; in intestine of Amhy stoma tigrinum. Genus Zelleriella Metcalf. Greatly flattened; 2 similar nuclei; all in Amphibia. Numerous species. Z. scaphiopodos M. (Fig. 224, h). In Scaphiopus solitarius; about 150m long, 90/x broad, 13m thick. Z. antilliensis (M.). About 180m long, 113m wide, 32m thick; in Bufo marinus. Z. hirsuta M. About 113m long, 60m wide, 22m thick, in Bufo cognatus. Z. intermedia M. (Fig. 61). About 94m by 50m ^y 16m; in Bujo intermedicus and B. valliceps. References BtJTSCHLi, 0. 1887-1889 Protozoa. In: Bronn's Klassen und Ordnungen des Thier-reichs. Vol. 1. DoFLEiN, F. and E. Reichenow 1929 Lehrbuch der Protozoen- kunde. Jena. Kahl, a. 1930-1935 Urtiere oder Protozoa I : Wimpertiere odcr Ciliata (Infusoria). In Dahl: Die Tierwelt Deutschlands und der angrenzenden Meeresteile nach ihren Merkmalen und nach ihrer Lebensweise. Parts 18, 21, 25, 30. Kent W. S. 1880 to 1882 A manual of Infusoria. Stein, F. 1867 Der Organismus der Infusionsthiere. Vol. 2. Stokes, A. C. 1888 A preliminary contribution toward a history of the fresh-water Infusoria of the United States. Jour. Trenton Natural Hist. Soc, Vol. 1. Metcalf, M. M. 1923 The opalinid ciliate infusorians. Smith- sonian Inst. U.S. Nat. Museum, Bull., No. 120. Chapter 30 Subclass 2 Euciliata Metcalf THE most conspicuous group of Protozoa containing 2 nuclei : macronucleus and micronucleus. Sexual reproduction is through conjugation. We owe Kahl a great deal for his series of comprehensive taxonomic studies of free-living ciliates. The eucil- iates are grouped under the following four orders : Without adoral zone of membranellae Order 1 Holotricha With adoral zone of membranellae Adoral zone winds clockwise to cytostome Peristome not extending beyond general bod}^ surface Order 2 Spirotricha (p. 573) Peristome extending out like funnel Order 3 Chonotricha (p. 614) Adoral zone winds counter-clockwise to cytostome Order 4 Peritricha (p. 616) Order 1 Holotricha Stein The members of this order show uniform ciliation over the en- tire body surface. Adoral zone does not occur. The majority possess a cytostome, which varies among different forms. Nutrition is holo- zoic or saprozoic. Asexual reproduction is usually by transverse fission and sexual reproduction by conjugation. Encystment is common. The holotrichous ciliates are parasites or free-living in all sorts of fresh, brackish, and salt waters. The order is here divided into 6 suborders : Without cytostome Suborder 1 Astomata (p. 488) With cytostome Cytostome not rosette-like Without special thigmotactic ciliated field Cytostome on body surface or in peristome, without strong cilia Suborder 2 Gymnostomata (p. 496) Cystome in peristome, bearing special cilia or membranes Peristome lined with rows of free cilia Suborder 3 Trichostomata (p. 531) Peristome with membrane; with or without free cilia Suborder 4 Hymenostomata (p. 547) With well-developed thigmotactic ciliated field; commensals in mussels Suborder 5 Thigmotricha (p. 560) Cytostome rosette-like small aperture or obscure; endoparasitic. . . Suborder 6 Apostomea (p. 567) 487 488 PROTOZOOLOGY Suborder 1 Astomata Schewiakoff The ciliates placed under this suborder possess no cytostome, although there may occur slit-like organella which has been looked upon as a vestigial cytostome. Of various forms and sizes, the body ciliation is uniform. Asexual division is carried on by transverse fission and often by budding which results in chain formation. Sexual reproduction is conjugation and in some en- cystment was noticed. These organisms are parasitic in various invertebrates in fresh or salt water. Without attaching organellae or skeletal structures Macronucleus round to elongate Family 1 Anoplophryidae Macronucleus irregular network. .Family 2 Opalinopsidae (p. 491) With attaching organellae or skeletal structures Contractile vacuole, a long dorsal canal; usually with a sucking organella Family 3 Haptophryidae (p. 491) Contractile vacuoles not canal-like; with various attaching or- ganellae or skeletal structures Family 4 Intoshellinidae (p. 493) Family 1 Anoplophryidae Cepede Genus Anoplophrya Stein (CoUinia Cepede). Oval, elongate, ellipsoid or cylindrical; macronucleus ovoid to cylindrical; micro- nucleus small; one to several contractile vacuoles; ciliation dense and uniform; in coelom and gut of Annelida and Crustacea. Numerous species. A. marylandensis Conklin (Fig. 226, a). 36-72^ by 16-42;u; in intestine of Lumhricus terrestris and Helodrilus caliginosus ; Bal- timore, Maryland. A. orchestii Summers et Kidder (Fig. 226, h). Polymorphic ac- cording to size; pyriform to broadly ovoid; 7-45 ciliary rows meridional, unequally spaced, and more on one surface; macro- nucleus voluminous, a compact micronucleus; body 6-68^ long; in the body of the sand-flea, Orchestia agilis; Woods Hole, Massa- chusetts. Summers and Kidder (1936) made careful observation on its conjugation and reorganization. Genus Rhizocaryum Caullery et Mesnil. With hollowed ventral surface which serves for attachment; macronucleus drawn out like a tree-root. One species. R. concavum C. et M. (Fig. 226, c). In gut of Polydora caeca and P. flava (polychaetes). Genus Metaphrya Ikeda. Pyriform, anterior end bent slightly EUCILIATA, HOLOTRICHA 489 I^J-V^K ^' •" °.'-''°.- _!:^»^-.;';rr^ ^m M "."c" °'!. a ^ "^"i X'^^ ^^j^fey,'!,--;./*^ -*^i%' ^ '^'^ ^ K o' -^"o ■'"''' ' ' '■?" ■-*^^^' ■ ■■•^*^ } -^i^s f '.■•-s ^■yI°l'v-f.>°.S"'-°'^"'''' ^^i^^^!^'.;-V..;:J .>^ k i'mio,/,, m \^ ^ Fig. 226. a, Atioplophrya marylandensis, X500 (Conklin); b, A. orchestii, X500 (Summers and Kidder); c, Rhizocaryum concavum, X670 (Cepede); d, Metaphrya sagittae, Xl20 (Ikeda); e, Perezella pelngica, X340 (Cepede); f, Dogielella sphaeni, X470 (Poljansky); g, D. minuta, X670 (Poljansk}'^) ; h, D. Virginia, X670 (Kepner and Carroll); i, Orchitophryn stellarum, X870 (Cepede); j, Kofoidella elu- theriae, X270 (Cepede); k, Butschliella opheliae, X350 (Cepede); 1, m, Protophrya ovicola (m, a young Littorina rudis with the ciliate), X80 (Cepede). 490 PROTOZOOLOGY to one side; 12 longitudinal ciliary furrows; below ectoplasm, a layer of refringent material; endoplasm sparse; macronucleus basket-like, large, with a spacious hollow; a micronucleus; no contractile vacuoles. One species. M. sagittae I. (Fig. 226, d). About 250m by 130^; in the body- cavity of Sagitta sp. Genus Perezella Cepede. Ovoid; ventral surface concave, serves for attachment; macronucleus ellipsoid; contractile vacu- ole terminal; longitudinally, uniformly, ciliated. A few species. P. pelagica C. (Fig. 226, e). In coelom of copepods (Ascartia, Clausia, Paracalanus) ; about 48/x long. Genus Dogielella Poljansky. Pyriform; longitudinal ciliary rows; contractile vacuole terminal; macronucleus spherical, with a spherical or elliptical micronucleus; in parenchyma of flat- worms or molluscs. 3 species. D. sphaerii P. (Fig. 226, /). 40-100^ by 25-54/^; in Spaerium corneum. D. minuta P. (Fig. 226, g). 12-28^ by up to 20)u; in Stenostomun leucops. D. Virginia (Kepner et Carroll) (Fig. 226, h). 40-50)u long; in the same host animal; Virginia. Genus Orchitophrya Cepede. Elongate pyriform; ciliary rows oblique; macronucleus spherical, central. One species. 0. stellarum C. (Fig. 226, i). In gonads of the echinoderm, Asteracanthion (Asterias) ruhens; 35-65)U long. Genus Kofoidella Cepede. Pyriform; macronucleus broadly oval; contractile vacuole, subterminal. One species. K. eleutheriae C. (Fig. 226, j). In gastro-vascular cavity of the medusa, Eleutheria dichotoma; 30-80/x long. Genus Herpetophrya Siedlecki. Ovoid; with a pointed, mobile, tactile, non-ciliated cone; macronucleus globular; without con- tractile vacuole. One species. H. astomata S. In coelom of Polymnia (annelid). Genus Butschliella Awerinzew. Elongate with pointed anterior end, with non-ciliated retractile anterior cap; cilia in compara- tively few (about 10) slightly spiral rows; macronucleus band- form; several contractile vacuoles in a longitudinal row. Several species. B. opheliae A. (Fig. 226, k). In Ophelia limacina; 280-360ju by 35-50m. EUCILIATA, HOLOTRICHA 491 B, chaetogastri Penard. Elongate lanceolate, slightly flattened; longitudinal rows of long cilia; cytoplasm colorless; macronucleus elongate; micronucleus voluminous, vesicular; without contrac- tile vacuole; 60-120/4 long; in the oesophagus of Chaetogaster sp. Genus Cepedella Poyarkoff. Pyriform with pointed anterior end, where there is a depression apparently used for fixation of body, from which longitudinal myonemes arise; macronucleus globular; without contractile vacuole. One species. C. hepatica P. 16-26^ long; intracellular parasite of liver of the cyclad mollusc, Sphaerium corneum. Genus Protophrya Kofoid (Isselina Cepede). ElHpsoid to pyri- form; spheroidal macronucleus; contractile vacuole terminal. 2 species. P. ovicola K. (Fig. 226, Z, w). About 60At long; in uterus of the mollusc, Littqrina rudis. Genus Protanoplophrya Miyashita. Similar to Anoplophrya ; but with rudimentary oral apparatus, a long sht, an undulating membrane and cytopharynx in anterior region of body; macro- nucleus elongate band; numerous contractile vacuoles. One spe- cies. P. stomata Miyashita (Fig. 227, a). Cylindrical; up to 1.5 mm. by about 70/^; in hind-gut of Viviparus japonicus and V. mallea- Family 2 Opalinopsidae Hartog Genus Opalinopsis Foettinger. Oval or ellipsoid; macronucleus fragmented; ciliation uniform and close; parasite in liver of cepha- lopods. A few species. 0. sepiolae F. (Fig. 227, h). 40-80/x long; in Hver of Sepiola ron- deletii and Octopus tetracirrhus. Genus Chromidina Gonder {Benedenia Foettinger). Elongate; anterior region broader, ends pointed; uniform ciliation; macro- nucleus in irregular network distributed throughout body; micro- nucleus obscure; budding and encystment; Cheissin holds that this is identical wdth Opalinopsis. One species. C. elegans (Foettinger) (Fig. 227, c, d). 500-1500^ by about 30- 60/i; in kidney and gonad of cej^halopods : Sepia elegans, Loligo SD etc ' Family 3 Haptophryidae Cepede Genus Haptophrya Stein. Elongate; uniformly ciliated; an- terior end with a neck-hke constriction; a circular sucker sur- rounded by 1-2 rows of cilia. A few species. 492 PROTOZOOLOGY Fig. 227. a, Protanoplophrya stomata, XlOO (Miyashita); b, Opali- nopsis sepiolae, X670 (Gonder); c, d, Chromidina elegans (c, X330 (Chatton and Lwoff); d, X220 (Wermel)); e, Haplophrya michiganen- sis, X35 (Woodhead); f, Lachmannella recurva, XlOO (Cepede); g, Sieholdiellina planariarum, XlOO (Cepede); h, i, Intoshellina poljan- skyi (h, X300; i, attaching organella seen from ventral side, X870) (Cheissin); j, k, Monodontophrya kijenskiji (j, XlOO; k, anterior end in profile, X870) (Cheissin). H. michiganensis Woodhead (Fig. 227, e). 1.1-1.6 mm. long; in gut of the four-toed salamander, Hemidactylium scutatum; Michi- gan. Genus Steinella Cepede. Anterior end broad; sucker-like de- EUCILIATA, HOLOTRICHA 493 pression without encircling cilia, but with 2 chitinous hooks. One species. S. uncinata (Schultze). Up to 200/x long; in gastro-vascular cavity of Planaria ulvae, Gunda segmentata and Proceros sp. Genus Lachmannella Cepede. With a chitinous hook at ante- rior end; elongate pyriform, anterior end curved; ciliation longi- tudinal and dense. One species. L. recurva (Claparede et Lachmann) (Fig. 227, /). In gastro- vascular cavity of Planaria limacina; about 200^ long. Genus Sieboldiellina Collin (Discophrya Stein). Vermiform, with neck-like constriction; simple sucker at anterior end. One species. S. planariarum (Siebold) (Fig. 227, g). Up to 700/x long; in gas- tro-vascular cavity of various fresh- and salt-water turbellarians, most frequently Planaria torva. Family 4 Intoshellinidae Cepede Genus Intoshellina Cepede. Elongate; ciliary rows slightly spiral; macronucleus voluminous, highly elongate; 5-7 contractile vacuoles scattered in posterior region; a complicated attaching organella at anterior end (Fig. 227, i); vestigial cytopharynx. /. poljanskyi Cheissin (Fig. 227, h, i). 170-280/x long; in intes- tine of Limnodrilus arenarius. Genus Monodontophrya Vejdowsky. Elongate; anterior end with thick ectoplasm; attaching organella at anterior end, with fibrils; macronucleus elongate; contractile vacuoles, numerous in a longitudinal row. M. kijenskiji Cheissin (Fig. 227, j, k). 400-800^ long; in ante- rior portion of intestine of Tuhifex inflatus. Genus Maupasella Cepede. Ellipsoid; close longitudinal ciliary rows; with a spinous attaching organella at anterior end, with fibrils; contractile vacuoles in 2 irregular rows; macronucleus elongate. One species. M. nova C. (Fig. 228, a). 70-130/i long; in intestine of Alloloho- phora caliginosa (annelid). Genus Schultzellina Cepede. Similar to Maupasella; but with attaching organella set obliquely; macronucleus voluminous, reni- form. S. mucronaia C. (Fig. 228, 6). In intestine of Allurus tetraedurus (annelid). 494 PROTOZOOLOCIY Fig. 228. a, Maupasella nova, X280 (C^pede); b, SchuUzellina mu- cronata, X670 (C^pede); c, Hoplitophrya lumbrici, Xl40 (C^pede); d, e, Radiophrya hoplites (d, X130; e, anterior end in profile, X300) (Cheissin) ; f, Protoradiophrya fissispiculata, X330 (Cheissin); g, Mraze- kiella intermedia, X210 (Cheissin); h, Mesnilella rostrata, X470 (Cheis- sin); i, M. clavata, X290 (Penard). Genus Hoplitophrya Stein. Ovoid to ellipsoid; chitinous pro- trusible attaching organella imbedded near anterior end; macro- nucleus an elongate band; contractile vacuoles in 2 longitudinal rows. Several species. H. lumbrici (Dujardin) (Fig. 228, c). About 200;u long; in in- testine of Lumhricus terrestris. Genus Radiophrya Rossolimo. Elongate; attaching organella composed of arrowhead, tooth and ectoplasmic fibrils. Many species. R. hoplites R. (Fig. 228, d, e). 100-1000^ long; in intestine of Lamprodrilus, Teleuscolex, Styloscolex and other oligochaetes. EUCILIATA, HOLOTRICHA 496 Genus Protoradiophrya Rossolimo. Elongate; near anterior end, a shallow depression, along which is found a spicule which may be split posteriorly. A few species. P. fissispiculata Cheissin (Fig. 228, /). 180-350^ long; in ante- rior portion of intestine of Styloscolex sp. Genus Mrazekiella Kijenskij. Elongate; anterior portion broad with sucker-like depression, posterior region cylindrical; anterior end with attaching organella composed of arrowhead and skeletal ribs; macronucleus an elongate band; contractile vacuoles dis- tributed. A few species. M. intermedia Cheissin (Fig. 228, g). 180-260/x long; in anterior portion of intestine of Branchiura coccinea. Genus Mesnilella Cepede. Elongate; with one or more long spicules imbedded in endoplasm ; contractile vacuoles in 1-2 rows. Numerous species. M. rostrata Rossolimo (Fig. 228, h). 100-1200^ long; in intes- tine of various oligochaetes (Styloscolex, Teleuscolex, Lampro- drilus, Agriodrilus, etc.). M. clavata (Leidy) (Fig. 228, i). 100-200^ long; in intestine of Lumbricus variegatus. References C^PEDE, C. 1910 Recherches sur les Infusoires astomes. Arch. zool. exp., Vol. 3 (ser. 5). Cheissin, E. 1930 Morphologie und systematische Studien iiber Astomata aus dem Baikalsee. Arch. f. Protistenk., Vol. 70. Heidenreich, E. 1935 Untersuchungen an parasitischen Ci- liaten aus Anneliden. I, II. Arch. f. Protistenk. Vol. 84. Chapter 31 Order 1 Holotricha Stein (continued) Suborder 2 Gymnostomata Blitschli Cy tostome at or near anterior end Tribe 1 Prostomata Cytostonie not at or near anterior end Cytostome lateral, narrow or round Tribe 2 Pleurostomata (p. 517) Cytostome ventral, in anterior half .Tribe 3 Hypostomata (p. 522) Tribe 1 Prostomata Schewiakoff Free-living Cytostomal region con>pressed; bearing trichites Family 1 Spathididiidae Cytostomal region not compressed Cytostome opens into anterior receptaculum; with lorica Family 2 Metacystidae (p. 499) Cytostome at tip of apical cone. . . .Family 3 Didiniidae (p. 499) Cytostome otherwise Body covered with regularly arranged, perforated, ectoplasmic plates Family 4 Colepidae (p. 501) Body not covered with plates With radially arranged tentacles Family 5 Actinobolinidae (p. 503) Without tentacles Family 6 Holophryidae (p. 503) Parasitic in mammalian gut Family 7 Butschliidae (p. 513) Family 1 Spathidiidae Kahl Genus Spathidium Dujardin. Flask- or sack-shaped; com- pressed; anterior region slightly narrowed into a neck, and trun- cate; cihation uniform; cytostome occupies whole anterior end; contractile vacuole posterior; macronucleus elongate; several micronuclei; trichocysts around cytostome and scattered through- out; fresh or salt water. Numerous species. S. spathula (Mliller) (Figs. 21; 229, a, h). Up to 250^ long; fresh water. Woodruff and Spencer (1922) made a careful study of the organism. Genus ParaspathidiumNoland. Form resembles that of Spathid- ium; but cytostome an elongate slit, bordered on one side by strong cilia and on the other by weaker ones and a shelf-hke, non- undulatory membrane; 2 longer cilia on dorsal edge near anterior 49) HOLOTRICHA 497 tip; anterior 1/3 compressed; posterior 2/3 nearly cylindrical; 2 oval macronuclei, each with a micronucleus; cytoplasm filled with numerous ref ractile granules (metabolic reserves) ; about 70 rows of cilia; contractile vacuole terminal; salt water. One species. P. trichostomum N. (Fig. 229, c-e). About 220^ long; macro- nuclei 44/i long each; salt water; Florida. Fig. 229. a, b, Spathidium spathula, X200 (Woodruff and Spencer); c-e, Paraspathidiimi trichostomum (c, Xl30; d, cytostomal region, X400; e, part of pellicle, XlOOO) (Noland); f, Spathidioides sulcata, X260 (Brodsky); g, Enchelydium fusidens, X240 (Kahl); h, Homalo- zoon vermiculare, X80 (Stokes); i, Cranotheridium taeniatum, X300 (Schewiakoff); j, PenardieUa crassa, X210 (Kahl); k, Perispira strephosoma, X280 (Kahl); 1, Legendrea bellerophon, Xl90 (Penard). Genus Spathidioides Brodsky (Spathidiella Kahl). Somewhat similar to Spathidium; but oral ridge highly flattened on ventral end, and most developed into wart-like swelling on dorsal end; this knob contains trichocysts; sapropelic. S. sulcata B. (Fig. 229,/). 65-85/x long; posterior end pointed. 498 PROTOZOOLOGY highly flattened; anterior end elevated at one side where cyto- stome and cytopharynx with 10 rods are located. Genus Enchelydium Kahl. Somewhat similar to Spathidium; but oral ridge forms a swollen ring with trichocysts, which is circular or elongated in cross-section; when swimming, the or- ganisms appear as if cytostome is opened; with dorsal bristle; fresh water. E.fusidens K. (Fig. 229, g). Cylindrical, contractile; ciUa dense and rather long; macronucleus reniform, often appears as com- posed of 2 spherical parts; contractile vacuole terminal; oral ring with spindle-like trichocysts; food vacuoles not seen; extended body llO^i long; contracted 75//; sapropelic. Genus Homalozoon Stokes. Elongate; cilia only on flattened right side; left side swollen or keeled; fresh water. H. vermiculare (S.) (Fig. 229, h). Extended body 450-850^ long; vermiform; numerous macronu clear parts in band form; contractile vacuoles about 30 or more in a row; standing pond water. Genus Cranotheridium Schewiakoff. Spathidium-like organ- isms; anterior end obliquely truncate, near the extended side of which are located the cytostome, and cytopharynx surrounded by a group of trichites or trichocysts ; fresh water. C. taeniatum S. (Fig. 229, i). Anterior end flattened; with a group of trichites; macronucleus long band-form; with many micronuclei; contractile vacuole terminal; ciliation and striation close; colorless; movement slow; about 170/x long; fresh water. Genus Penardiella Kahl. Ellipsoid, somewhat compressed; oral ridge slightly oblique; from this a girdle with trichocysts encircles body; fresh water. P. crassa (Penard) (Fig. 229, j). Elongate elhpsoid, flattened; trichocysts in posterior portion of girdle are longer and those in the dorsal region are fewer in number and shorter; macronucleus sausage-form; contractile vacuole posterior, in front of the girdle; body lOOju by 50/^; sapropeHc. Genus Perispira Stein. Ovoid or cylindrical; oral ridge turns down right-spirally to posterior end. P. strephosoma Stokes (Fig. 229, k). Oval to cylindrical; about 85/i long; standing water, with sphagnum. Genus Legendrea Faure-Fremiet. Ellipsoid or ovoid; a periph- eral zone with small tentacular processes bearing trichocysts. HOLOTRICHA 499 L. hellerophon Penard (Fig. 229, I). 100-180^; fresh water. Genus Teuthophrys Chatton et Beauchamp. Body rounded posteriorly, anterior end with 3 radially equidistant, spirally curved arms (counter-clockwise when viewed from posterior end) ; the depressions between arms form furrows; cytostome apical, at the inner bases of arms; contractile vacuole terminal; cihation uniform, except the inner surfaces of arms where longer ciha as well as trichocysts are present; with zoochlorellae; macronucleus rope-shaped and wound; micronucleus unobserved. One species. T. trisnla C. et B. (Fig. 230, a). 150-300^ long; length: width 3 : 1-2 : 1 ; ponds in Pennsylvania and California (Wenrich). Family 2 Metacystidae Kahl Genus Metacystis Cohn. Oblong; definite; ciliation general, except posterior end; ciliary circle around cytostome; usually one caudal cilium; with a large posterior vesicle containing turbid fluid. M. truncata C. (Fig. 230, h). Elongate, not much difference in body width at different levels; with about 12 furrow rings; body length up to 30^; salt water. Genus Vasicola Tatem (Pelamphora Lauterborn). Ovoid with caudal cilia; lorica flask-shape, highly ringed; cytostome at an- terior end, its lip with 4 rows of long ciha; body surface with short- er cilia; macronucleus round, central, with a micronucleus; con- tractile vacuole near macronucleus and nearer body surface; fresh or salt water. V. ciliata T. (Pelamphora butschlii Lauterborn) (Fig. 230, c). Body about 100/x long; sapropelic in fresh water. Genus Pelatractus Kahl. Somewhat similar to Vasicola; but without caudal cilia; with a large terminal vacuole; without lip of Vasicola; sapropelic. P. (Vasicola) grandis (Penard) (Fig. 230, d). Free-swimming; elongated fusiform; numerous contractile vacuoles on side; body 1 25-220^1 long ; sapropelic in fresh water. Family 3 Didiniidae Poche Genus Didinium Stein (Monodinimn Fabre-Domergue). Bar- rel-shaped; one to several girdles of cilia (pectinellae) ; expansible cytostome at tip of cone-like elevation at anterior end, containing long trichites; macronucleus horseshoe-shaped; contractile vacu- 500 PROTOZOOLOGY Fig. 230. a, Teuthophrys trisula, X330 (Wenrich); b, Metacystis Iruncata, X270 (Cohn); c, Vasicola ciliata, X250 (Kahl); d, Pelatradus grandis, Xl70 (Penard) ; e-g, Didinium nasutuni, Xl70 (Kudo); h, D. balbianii, X290 (Biitschli); i-k, Mesodinium pulex (i, X670; j, oral view; k, oral tentacles, X1330) (Noland); 1, m, M. acarus (1, XG70; m, oral tentacles, X1330) (Noland); n, Askenasia volvox, X530 (Faure-Fremiet); o, Cyclolrichium meunieri, X780 (Powers). ole posterior; feeds on other ciliates, especially Paramecium; fresh or salt water. Several species. D. nasutum (Miiller) (Fig. 230, e-g). 80-200ai long; endoplasm highly granulated ; with 2 girdles of pectinelles ; fresh water. D. balbianii (Fabre-Domergue) (Fig. 230, h). 60-1 OOju long; a single girdle of pectinelles near anterior end; fresh water. HOLOTRICHA 501 Genus Mesodinium Stein. Ovoid; an equatorial furrow divides conical anterior and spherical posterior parts; in the furrow are in- serted 2 (or 1) rings of strong cilia; one directed anteriorly and the other posteriorly; with tentacle-like retractile processes around the cytostome; fresh or salt water. M. pulex (Claparede et Lachmann) (Fig. 230, i-k). Oral ten- tacles with trifurcate tips; body 20-3 l/x long; salt water; Florida. Noland states that the freshwater forms are 21-38^ long. M. acarus Stein (Fig. 230, I, m). Oral tentacles with capitate tips; 10-16/i long; salt water, Florida (Noland). Genus Askenasia Bloohmann. Resembles Didinium; ovoid; with 2 closely arranged rings of long cilia; anterior ring made up of some 60 pectinelles which are directed anteriorly; posterior ring composed of about the same number of membranellae or cirri, directed posteriorly and arranged parallel to body surface; fresh or salt water. A. volvox (Claparede et Lachmann) (Fig. 230, n). Body oval, posterior end broadly rounded; anterior region conical ; pectinelles about 13^ long; below the second ring of cirri are found long (40/x) bristles; a spherical macronucleus with a micronucleus; body about 50-60m long; fresh water. Genus Cyclotrichium Meunier. Body spheroid to ellipsoid with a large non-ciliated oral field which is surrounded by a pectinelle- ring, the remaining part naked or slightly ciliated; macronucleus sausage-form; cytopharynx not recognized; endoplasm highly vacuolated; in marine plankton. C. meunieri Powers (Fig. 230, o). Anterior end broadly rounded; posterior region conical; cytostome obscure; oral funnel at ante- rior end in a depression; broad ciliated band at about middle; ectoplasm with concave chromatophore (haematochrome) plates on surface, below which numerous pyrenoids occur in vacuoles; endoplasm with numerous granules; 25-42^1 by 18-34/x; Powers (1932) found that the 'red water' in Frenchman Bay in Maine was caused by the swarming of this organism. Family 4 Colepidae Claparede et Lachmann Genus Coleps Nitzsch. Body-form constant, barrel-shaped; with regularly arranged ectoplasmic plates; cytostome at ante- rior end, surrounded by slightly longer ciha; often spinous pro- jections at or near posterior end; 1 or more caudal cilia, often overlooked; fresh or salt water. Many species. 502 PROTOZOOLOGY C. hirtus (Miiller) (Fig. 231, a). 40-65ju long; 15-20 rows of platelets; 3 posterior processes; fresh water. C. elongatus Ehrenberg (Fig. 231, h). 40-55^ long; slender; about 13 rows (Noland) or 14-17 rows (Kahl) of platelets; 3 posterior processes; fresh water. Fig. 231. a, Coleps hirtus, X530 (Noland); b, C. elongatus, X530 (Noland); c, C. bicuspis, X530 (Noland); d, C. octospinus, X530 (Noland); e, C. spiralis, X400 (Noland); f, C. heter acanthus, X400 (Noland); g, Tiarina fuscus, x53Cf (Faur6-Fremiet); h, Actinoholina vorax, X300 (Wenrich); i, Dactylochlamys pisciformis, X330 (Kahl); j, Enchelyomorpha vermiciilaris, X670 (Kahl). C. bicuspis Noland (Fig. 231, c). About 55ju long; 16 rows of platelets ; 2 posterior processes ; fresh water. C. octospinus N. (Fig. 231, rf). 80-1 10m long; 8 posterior spines; HOLOTRICHA 503 about 24 rows of platelets; Geiman (1931) found this organism in an acid marsh pond and noted variation in number and location of accessory spines ; fresh water. C. spiralis N. (Fig. 231, e). About 23 longitudinal rows of platelets slightly spirally twisted; posterior spines drawn to- gether; a long caudal cilium; about 50/x long; salt water; Florida. C. heteracanthus N. (Fig. 231,/). Anterior processes only on one side; posterior spines; caudal cilium; about 90/x by 35/^; salt wa- ter; Florida. Genus Tiarina Bergh. Somewhat similar to Coleps, but pos- terior end tapering to a point; salt water. T.fuscus (Claparede et Lachmann) (Fig. 231, g). 85-135^ long. Family 5 Actinobolinidae Kent Genus Actinobolina Strand {Actinoholus Stein). Ovate or spherical; ciliation uniform; extensible tentacles among cilia; contractile vacuole terminal; macronucleus curved band; fresh water. A. vorax (Wenrich) (Fig. 231, h). 100-200^ long; elongate oval to spheroid; Hght yellowish brown in color; Wenrich (1929) found this ciliate in pond water and studied its behavior. Genus Dactylochlamys Lauterborn. Body spindle-form, though variable; posterior end drawn out into tail; pellicle with 8-12 undulating spiral ridges on which tentacle-like processes and long ciUa are alternately situated; these processes are retractile (Kahl) and similar in structure to those of Suctoria; cytostome has not been detected; possibly allied to Suctoria; fresh water. One species. D. pisciformis L. (Fig. 231, i). Body 80-120^ long. Genus Enchelyomorpha Kahl. Conical, compressed; posterior end broadly rounded; anterior portion narrow; cilia on ring- furrows; anterior half with unretractile short tentacles; cyto- stome not noted; macronucleus with a central endosome sur- rounded by radiating spherules; contractile vacuole terminal, large. E. vermicularis (Smith) (Fig. 231, j). Body 30-45/^; fresh and brackish water. Family 6 Holophryidae Schouteden Genus Holophrya Ehrenberg. Oval, globose or ellipsoidal; 504 PROTOZOOLOGY ciliation uniform; sometimes longer cilia at anterior or posterior region; eytostome circular, simple, without any ciliary ring around it; cytopharynx with or without trichites or trichocysts; fresh or salt water. Numerous species. H. simplex Schewiakoff (Fig. 233, a). Ellipsoidal; 18-20 ciliary rows; ciha uniformly long; eytostome small; cytopharynx without trichocysts or trichites; contractile vacuole and cytopyge pos- terior; macronucleus large, round; 34/x by 18m; fresh water. Genus Lagynophrya Kahl. Resembles Holophrya; small elon- gate ovoid to short cylindrical ; one side convex, the other more or less flattened; cytopharynx terminates anteriorly in a small cone-like process found in cross-section, which may or may not be distinct; stagnant fresh or salt water. Several species. L. mutans K. (Fig. 233, h). Body plastic; oval to cylindrical; colorless; narrowly striated; oval cone hemispherical without any trichocysts; body about 90^ long, when contracted; about 65/i in diameter; among decaying leaves in fresh water. Genus Ichthyophthirius Fouquet. Body oval; ciliation uni- form; pellicle longitudinally striated; eytostome at anterior end, with a short cytopharynx with cilia; horseshoe-shaped macro- nucleus; micronucleus adhering to macronucleus, during encyst- ment migrates toward surface of endoplasm; macronucleus undergoes reorganization by discarding small chromatin masses (Haas); multiplication by binary fission during actively motile stage or by multiple division in encysted condition, which pro- duces 200 or more individuals (30-45)U long); conjugation also reported ; parasitic in the integument of various freshwater fishes confined to aquarium or small pond; widely distributed. /. multifiliis F. (Fig. 232). 300-800/x long; forms pustules in epidermis or gills; when heavily infected, the host fish suffer fatal effects; Pearson (1932) and Kudo (1934) reported an ex- tensive ichthyophthirius-disease among fishes in large outdoor ponds in Indiana and Illinois. Genus Bursella Schmidt. Oval; anterior end broadly and obliquely truncate where a large ciliated groove-like pit occurs; ridges of pit contractile; cilia short; macronucleus, spherical to ellipsoidal; several micronuclei; endoplasm reticulated; with symbiotic algae; ectoplasm with trichocysts; fresh water. B. spumosa S. 240-560)u long; freshwater pond. Genus Spasmostoma Kahl. Somewhat similar to Holophorya; HOLOTRICHA 505 Fig. 232. Ichtkyophthirius multifiliis. a, free-swimming individual, X75 (Blitschli); b-e, development within cyst; f, a young individual, X400 (Fouquet); g, section through a fin of infected carp showing numerous parasites, XlO (Kudo); h, a catfish, Ameiurus albidus, heavily infected by the ciliate (Stiles). but without caudal cilia; cytostome with flaps which beat alternately; ciliation uniform. S. viride K. (Fig. 233, c). Spherical or oval; always with green food vacuoles containing Euglena and allied flagellates; cytostome at anterior end; cytopharynx with trichocysts, which are ex- tensible at the time when food is taken in; cilia on about 20 rows, near cytostome somewhat longer; macronucleus round; body 50-75^t long; sapropelic. 506 PROTOZOOLOGY Genus Urotricha Claparede et Lachmann (Balanitozoon Stokes). Body oval to ellipsoidal or conical; with 1 or more longer caudal cilia; ciliation uniform, except posterior region which may be without ciha; cytostome at or near anterior end, surrounded by ring of heavier cilia; contractile vacuole, posterior; macro- nucleus spherical; fresh water. U. agilis (Stokes) (Fig. 233, d). Body small; about 15-20/x long; swimming as well as leaping movement; standing fresh water with sphagnum. U. farcta C. et L. (Fig. 233, e). Body 20-30^ long; fresh water; Kahl considers U. parvula Penard and Balanitozoon gyrans Stokes are identical with this species. Genus Plagiocampa Schewiakoff. Ovoid, spindle-form or cylin- drical; slightly asymmetrical; cytostome at anterior end in a slit; right ridge thickened and lip-like, with about 8 long cilia; with or without long caudal cilium; fresh or salt water. Several species. P. marina Kahl (Fig. 233,/, g). Cylindrical; oval macronucleus central; contractile vacuole terminal; a caudal cilium; 55-90m long; salt water; Florida (Noland). Genus Chilophrya Kahl. Ovoid or ellipsoid; cytostome at anterior end, surrounded by protrusible rods; on one side there is a lip-like ectoplasmic projection; fresh or salt water. C. (Prorodon) utahensis (Pack) (Fig. 233, h). Body ellipsoid, somewhat asymmetrical; comparatively small number of furrows; ciliation uniform; a finger-like process in front of cytostome; macronucleus small, central; contractile vacuole terminal; endo- plasm with zoochlorellae; encystment common; cysts highly sensitive to light; 50/x long; Great Salt Lake; Utah (Pack). C. ( Urotricha) labiata (Edmondson) (Fig. 233, i). Body ovoid; a lip-like process in front of cytostome; macronucleus oblong, central; contractile vacuole terminal; 30^ long; fresh water. Genus Platyophrya Kahl. Compressed; flask-like or elongate ovoid; asymmetrical; dorsal surface convex, ventral surface flat or partly concave; spiral striation; position and direction of cytostome variable; macronucleus round; contractile vacuole terminal; fresh water. P. lata K. (Fig. 233, j). Highly compressed; colorless; many striae; on left edge of cytostome 5-6 cirrus-like projections and on right edge many short bristles; 105^ long; fresh water with sphagnum. HOLOTRICHA 507 Fig. 233. a, Holophrya simplex, X800 (Roux); b, Lagynophrya mu- tans, X380 (Kahl); c, Spasmostoma viride, X330 (Kahl); d, Urotricha agilis, X530 (Stokes); e, U. far da, X470 (Lieberkiihn) ; f, g, Plagio- campa marina (f, X400; g, anterior end, X670) (Noland); h, Chilo- phrya utahensis, X840 (Pack); i, C. labiata, X500 (Edmondson); j, Platyophrya lata, X280 (Kahl); k, Stephanopogon colpoda, non- ciliated side, X500 (Kahl); 1, Prorodon discolor, X330 (Butschli); m, Pseudoprorodon farctus, X270 (Roux); n, o, Placus socialis (o, an- terior end view), X530 (Noland). Genus Stephanopogon Entz. Somewhat resembles Platyo- phrya; compressed; cytostome at anterior extremity which is drawn out; cytostome surrounded by lobed membranous struc- tures ; salt water. S. colpoda E. (Fig. 233, k). Longitudinal striae on 'neck' 4-8 in number; 2 contractile vacuoles; 50-70/i long; creeping move- ment; salt water among algae. 508 PROTOZOOLOGY Goniis Prorodon Ehrenberg {Rhag ado stoma Kahl). Ovoid to cylindrical; ciliation uniform, with sometimes longer caudal cilia; oral basket made up of double trichites which end deep in ecto- plasm, oval in cross-section; contractile vacuole terminal; macro- nucleus massive, spherical or oval ; fresh or salt water. Numerous species. P. discolor (E.) (Fig. 233, I). Ovoidal; 45-55 ciliary rows; macronucleus ellipsoid; micronucleus hemispherical; contractile vacuole terminal; 100-130^ long; fresh water; Kahl (1930) states that it occurs also in brackish w^ater containing 2.5 per cent salt; sapropelic form in salt water is said to possess often long caudal cilia. P. griseus Claparede et Lachmann. Oblong; 165-200^ long; fresh water. Genus Pseudoprorodon Blochmann. Similar to Prorodon; usually flattened; one side convex, the other concave; ectoplasm conspicuously alveolated; trichocysts grouped; 1 or more con- tractile vacuoles posterior-lateral or distributed, wdth many pores; macronucleus elongate; cytopharynx with trichites; fresh or salt water. P. farctus (Claparede et Lachmann) (Fig. 233, w). Ellipsoid; cytostome surrounded by long trichocysts; contractile vacuole posterior, with secondary vacuoles; macronucleus elongate; body 150-200^ long; fresh w^ater. Genus Placus Cohn (Spathidiopsis Fabre-Domergue; Thoiaco- phrya Kahl). Body small; ellipsoid or ovoid; somewhat com- pressed; pellicle with conspicuous spiral furrows; cytostome a narrow slit at anterior extremity; with strong cilia on right margin of slit; cytopyge a long narrow slit with cilia on both sides; macronucleus ellipsoid to sausage-form; contractile vacuole pos- terior; salt, brackish or fresh water. P. socialis (Fabre-Domergue) (Fig. 233, n, o). 40-50^ by 28- 32/1, about 22/i thick; salt water; Florida. Genus Lacrymaria Ehrenberg. Polymorphic; cylindrical, spindle- or flask-shaped; with a long contractile proboscis; cyto- stome round; ciliary rows meridional or spiral to right; near cytostome a ring-like constriction with a circle of longer cilia; cy topharjmx usually distinct ; contractile vacuole terminal ; fresh or salt water. Numerous species. L. olor (M tiller) (Fig. 234, a). Elongate; highly contractile; HOLOTRICHA 509 2 macroniiclei; 2 contractile vacuoles; extended forms 400-500/^ up to 1.2 mm. long; when dividing, long neck is formed sidewise so that it appears as oblique division (Penard); fresh and salt water. L. lagenula Claparede et Lachmann (Fig. 234, b). Body flask- shape; neck highly extensible; striation distinct, spiral when contracted; macronucleus short sausage-like or horseshoe-shape; endoplasm granulated; body 70/x long, up to loOfj, (Kahl); salt water. L. coronata C. et L. (Fig. 234, c). Large; neck extensible; body form variable, but usually with bluntly pointed posterior end; endoplasm appears dark; striae spiral; 85-100^ long; salt and brackish water. Genus Enchelys Hill. Flask-shape; anterior end obliquely truncate; cytostome slit-like, rarely round; fresh or salt water. Several species. E. curvilata (Smith) (Fig. 234, d). Elongate ovoid; posterior end rounded; longitudinal striation; macronucleus band-form; contractile vacuole terminal; endoplasm yellowish, granulated; about loOyu long; fresh water among algae. Genus Crobylura Andre. Body when extended spindle-form, with truncate ends; when contracted, thimble-form; cilia short and thick; several long caudal cilia; slit-like cytostome at anterior end; no apparent cytopharynx; macronucleus irregularly rounded, hard to stain; micronucleus not observed; contractile vacuole latero-posterior; fresh water. One species. C. pelagica A. (Fig. 234, e). Body 65-95^ long; in freshwater plankton. Genus Microregma Kahl. Small, ovoid; dorsal side convex; ventral side flat; with a small slit-like cytostome near anterior end; with or without caudal bristle; fresh or salt water. M. (Enchelys) auduboni (Smith) (Fig. 234, /). Body plastic; coarsely cihated; caudal bristle thin; cytostome at anterior end, surrounded by longer ciha; cytopharynx small with trichocysts; round macronucleus central; contractile vacuole near posterior end; 40-55)u; fresh water. Genus Chaenea Quennerstedt. Elongate; anterior end drawn out into a narrow truncated 'head'; but without any ring furrow; 'head' spirally or longitudinally furrowed; often with longer cilia directed anteriorly; cytostome terminal, not lateral; cytopharynx 510 PROTOZOOLOGY #* 'iSiu^HMB' '^ I'v'at"'- Fig. 234. a, Lacrymaria olor, X170 (Roux); b, L. lagenula, X400 (Calkins); c, L. coronata, X530 (Calkins); d, Enchelys curvilata, X200 (Smith); e, Crobylura pelagica, X500 (Andr6); f, Microregma auduhoni X500 (Smith); g, Chaenea limicola, X310 (Penard); h, Pithothorax ovatus, X550 (Kahl); i, Tracheloj)hxjllum davatum, XlOO (Stokes). with trichocysts; body striation meridional, or slightly right spiral; macroniicleus often distributed; fresh or salt water. C. limicola Lauterborn (Fig. 234, g). Anterior half of body broad; posterior end drawn out into a point; contractile; cyto- pharynx with trichocysts; many trichocysts in endoplasm; contractile vacuoles in chain form; 130-150;u long; stagnant fresh water. Genus Pithothorax Kahl, Slender, barrel-shaped; with firm pellicle; a fairly long caudal bristle; contractile vacuole in pos- terior half; ciliation coarse and not over entire body surface; resembles somewhat Coleps; fresh water. P. ovatus K. (Fig. 234, h). Caudal bristle breaks off easily; body 30/i long; fresh water among decaying vegetation. HOLOTRICHA 511 Genus Rhopalophrya Kahl. Cylindrical; furrows widely sepa- rated; slightly asymmetrical; curved ventrally; dorsal surface convex; ventral surface flat or slightly concave; anterior end with 'neck'; 2 spherical macronuclei; fresh or salt water; sapropelic. R. salina Kirby (Fig. 235, a). Cyhndrical, tapering gradually to a truncated anterior end, shghtly curved ventrally; ciha (6-10m long) sparsely distributed; 2 macronuclei, spherical; 29-55m l^ong; 16-21/^ in diameter; in concentrated brine (salts 34.8 per cent; pH 9.48) from Searles Lake; Cahfornia. Genus Enchelyodon Claparede et Lachmann. Elongated; cylindrical, ovoid or flask-shaped; some with head-hke prolonga- tion; cytopharynx with trichites; ciha long at anterior end; fresh or salt water. Several species. E. farctus C. et L. (Fig. 21, h). Ellipsoid; ectoplasm thick, yellowish, with trichocyst layer; cilia dense and short; oral cone flat; cytopharynx with about SOju long trichites; macronucleus long; contractile vacuole terminal; 180-400)U long; fresh water among decaying vegetation. E. calif ornicus Kahl. 120-130^ long; elongate ovoid to nearly cylindrical; not distinctly flattened; macronucleus horseshoe-Kke, with a large micronucleus ; in mosses; California. Genus Trachelophyllum Claparede et Lachmann. Elongate; flattened; flexible, ribbon-like; anterior end neck-Uke and tip truncate, cytopharynx narrow, round in cross-section, with trichocysts; ciliary rows widely apart; 2 macronuclei, each with a micronucleus; contractile vacuole terminal; fresh or salt water. Several species. T. clavatum Stokes (Fig. 234, i). About 180m long; fresh water. Genus Ileonema Stokes {Monomastix Roux). Body flattened; flask-shaped; somewhat similar to Trachelophyllum, but diifers by the fact that there is a remarkable flagellum-like process ex- tending from anterior end; cytopharynx with trichocysts; fresh water. I. dispar S. (Fig. 235, h). Highly contractile; anterior flagellum half body length, whose basal portion spirally furrowed; cyto- stome at base of the flagellum; cytopharynx spindle-form with trichites; 2 contractile vacuoles and cytopyge posterior; ovoid macronucleus; movement slow creeping; about 120/i long; fresh water among algae. /. ciliata (Roux) (Fig. 235, c). 75/i by 14^; fresh water. Genus Trachelocerca Ehrenberg. Elongate, vermiform or 512 PROTOZOOLOGY flask-shaped; more or less extensible, with drawn-out anterior end; without rinp;-furrow which n)arks 'head' of Lacrijmaria, and when contracted pellicular striae not spiral and no neck as is the case with Chaenea; salt water. Many species. T. phoenicopterus Cohn (Fig. 235, d, e). Elongate; extensible and contractile; neck and tail distinct when contracted; cyto- FiG. 235. a, Rhopalophrya salma, X870 (Kirby); b, Ileonema dispar, Xl60 (Stokes); c, /. ciliata, X670 (Roux); d, e, Trachelocerca phaeni- copteriis (d, XlOO; e, anterior end, X220) (Kahl); f, g, T. suhviridis (f, X130; g, nucleus, X400) (Noland); h, Parachaenia myae, X670 (Kofoid and Bush). stome at anterior end, surrounded by a ridge containing indis- tinctly visible short trichocysts; cytopharynx with trichocysts; macronuclei made up of 4 radially arranged endosomes suspended in nucleoplasm (Gruber, Kahl); micronucleus difficult to make out; contractile vacuoles apparently in chain, rarely seen; salt water; Woods Hole (Calkins). T. suhviridis Sauerbrey (Fig. 235,/, g). Highly extensible and contractile; nucleus contains pecvdiar crystal-like bodies; size HOLOTRICHA 513 variable; when extended 320-480iu long; salt water. Noland ob- served the organism in a salt spring in Florida. Genus Parachaenia Kofoid et Bush. Small; compressed: ven- tral surface slightly concave; dorsal surface greatly convex; cilia long, differentiated into 2 areas, a ventral area consisting of close-set rows and a dorso-lateral area consisting of 7 rows; cytostome circular or slightly oval, at anterior tip; cytopharynx long, narrow; without contractile vacuole. One species. P. myae K. et B. (Fig. 235, h). 40-100m long; 7 rows of long cilia on dorso-lateral surfaces, 8 rows of shorter cilia on ventral surface; cytopharynx half body length; in pericardial cavity and siphon of Mija arenaria; San Francisco Bay. Family 7 Butschliidae Poche This family includes forms which are intestinal parasites of mammals; circular cytostome at anterior end, cytopyge usually located at posterior end; ciliation uniform or in a few zones; with refractile concretion vacuole or vesicle (Fig. 30, d) in anterior portion; one or more contractile vacuoles. Genus Butschlia Schuberg. Ovoid, anterior end truncate, pos- terior end rounded; cytostome at anterior end, surrounded by long cilia; thick ectoplasm at anterior end; macronucleus spherical, micronucleus(?) ; concretion vacuole; ciliation uniform; in stomach of cattle. B. parva S. (Fig. 236, a). 30-50/^ by 20-30ju. Genus Blepharoprosthium Bundle. Pyriform, anterior half contractile, ciliated; caudal cilia; macronucleus reniform; in caecum and colon of horse. B. pireum B. (Fig. 236, h). 54-86m by 34-52/x. Genus Didesmis Fiorentini. Anterior end neck-like, with large cytostome; anterior and posterior ends ciliated; macronucleus ellipsoid; in caecum and colon of horse. D. quadrata F. (Fig. 236, c). 50-90^ by 33-68/x; with a deep dorsal groove. Genus Blepharosphaera Bundle. Spherical or ellipsoidal; cilia- tion uniform except posterior region; caudal cilia; in caecum and colon of horse. B. intestinalis B. (Fig. 236, d). 38-74/i in diameter. Genus Blepharoconus Gassovsky. Oval; small cytostome; cilia on anterior 1/3-1/2; caudal cilia; macronucleus ovoid; 3 con- tractile vacuoles; cytopharynx with rods; in colon of horse. 514 PROTOZOOLOGY b ..^l)j//„ e Fig. 236. a, Butschlia parva, X670 (Schuberg); b, Blepharoprosthium pireum, X470 (Hsiung); c, Didesniis quadrata, X270 (Hsiung); d, Blepharosphaera intestinalis, X600 (Hsiung); e, Blepharoconus cervi- calis, X360 (Hsiung); f, Bundleia postciliata, X530 (Hsiung); g, Bleph- arozoum zonatum, X200 (Gassovsky). B. cervicalis Hsiung (Fig. 236, e). 56-83ju by 48-70^1; Iowa. Genus Bundleia da Cunha et Muniz. Ellipsoid; cytostome small; cilia at anterior and posterior ends, posterior cilia much less numerous; in caecum and colon of horse. B. 'postciliata (Bundle) (Fig. 236, /). 30-56m by 17-32^. Genus Polymorpha Dogiel. Flask-shaped; ciliation on anterior region, a few caudal cilia; macronucleus disc-shaped; contractile vacuole terminal; in caecum and colon of horse. P. amvulla D. (Fig. 237, a). 22-36^ by 13-21/i. Genus Holophryoides Gassovsky. Oval, with comparatively large cytostome at anterior end; ciliation uniform; macronucleus small, ellipsoid; contractile vacuole subterminal; in colon and caecum of horse. H. ovalis (Fiorentini) (Fig. 237, h). 95-140m by 65-90/^. HOLOTRICHA 515 Fig. 237. a, Polymorpha ampulla, X1170 (Hsiung); b, Holophry- oides ovalis, X410 (Gassovsky) ; c, Prorodonopsis coli, X700 (Gassov- sky); d, Paraisotrichopsis composita, X450 (Hsiung); e, Sulcoarcus pellucididus, X410 (Hsiung); f, Alloiozona trizona, X450 (Hsiung). Genus Blepharozoum Gassovsky. Ellipsoid, with attenuated posterior end; ciliation uniform; cytostome near anterior tip; 2 contractile vacuoles; macronucleus small, reniform; in caecum of horse. B. zonatum G. (Fig. 236, g). 230-245^ by 115-122^. Genus Prorodonopsis Gassovsky. Pyriform; ciliation uniform; 3 contractile vacuoles; macronucleus sausage-shaped; in colon of horse. P. coli G. (Fig. 237, c). 55-67^ by 38^5/t. Genus Paraisotrichopsis Gassovsky. Body uniformly ciliated; spiral groove from anterior to posterior end; in caecum of horse. P. composita G. (Fig. 237, d). 43-56M.by 31-40^. Genus Sulcoarcus Hsiung. Ovoid, compressed; a short spiral 516 PROTOZOOLOGY groove at anterior end; cytostomc at ventral end of the groove; cytopyge terminal; concretion vacuole mid-ventral, contractile vacuole posterior to it; cilia on groove, posterior end and mid- ventral region. S. pellucidulus H. (Fig. 237, e). 33-56m by 30-40^; in faeces of mule. Genus AUoiozona Hsiung. Cilia in 3 (anterior, equatorial and posterior) zones; in caecum and colon of horse. A. trizona H. (Fig. 237,/). 50-90m by 30-60/z. Genus AmpuUacula Hsiung. Flask-shaped; posterior half bearing fine, short cilia; neck with longer cilia, in caecum of horse. A. ampulla (Fiorentini). About 110/x by 40/x. References Hsiung, T. S. 1930 A monograph on the Protozoa of the large intestine of the horse. Iowa St. Coll. Jour. Sci., Vol. 4. Kahl, a. 1930 In Dahl's Die Tierwelt Deutschlands. Part 18. KiRBY Jr., H. 1934 Some ciliates from salt marshes in California. Arch. f. Protistenk., Vol. 82. NoLAND, L. E. 1925 A review of the genus Coleps with descrip- tions of two new species. Trans. Amer. Micr. Soc, Vol. 44, 1937 Observations on marine ciliates of the Gulf coast of Florida. Ibid., Vol. 56. Penard, E. 1922 Etudes sur les Infusoires d'eau douce. Geneva. Roux, J. 1901 Faune infusorienne des eaux stagnantes de en- virons de Geneve. Mem. cour. fac. sci. I'Uni. Geneve. Stokes, A. C. 1888 A preliminary contribution toward a history of the freshwater Infusoria of the United States. Jour. Trenton Nat. Hist. Soc, Vol. 1. Wenrich, D. H. 1929 The structure and behavior of Actinoholus vorax. Biol. Bull., Vol. 56. Chapter 32 Order 1 Holotricha Stein (continued) Suborder 2 Gymnostomata Biitschli (continued) Tribe 2 Pleurostomata Schewiakoff Cytostome on convex ventral surface Cytostome a long slit Family 1 Amphileptidae Cj^tostome round, at base of trichocyst-bearing neck Family 2 Tracheliidae (p. 519) Cytostome on concave ventral side Family 3 Loxodidae (p. 521) Family 1 Amphileptidae Schouteden Genus Amphileptus Ehrenberg. Flask-shaped; somewhat com- pressed; ciliation uniform and complete; slit-like cytostome not reaching the middle of body; without trichocyst-borders ; many contractile vacuoles; 2 or more macronuclei; fresh or salt water. A. claparedei Stein (A. rneleagris Claparede et Lachmann) (Fig. 238, a). Slightly flattened; broadly flask-shaped; with round posterior and neck-like anterior end; cytostome about 2/5 from ventral margin; trichocysts indistinct; dorsal ciliary rows also not distinct; contractile vacuoles irregularly distributed; 120- 150^1 long; fresh and salt water, on stalks of Zoothamnium, Carchesium, Epistylis, etc. A. hranchiarum Wenrich (Fig. 238, h). On integument and gills of frog tadpoles; swimming individuals killed with iodine, 100- 135m by 40-60m. Genus Lionotus Wrzeniowski {Hemiophrys W.). Flask-shape; elongate, flattened; anterior region neck-like; cilia only on right side; without trichocyst-borders; cytostome with trichocysts; 1 (terminal) or many (in 1-2 rows) contractile vacuoles; 2 macro- nuclei; I micronucleus; fresh or salt water. L. fasciola (Ehrenberg) (Fig. 238, c). Elongate flask in form; hyaline; with flattened neck and tail, both of which are moder- ately contractile ; posterior end bluntly rounded ; without tricho- cysts; neck stout, bent toward the dorsal side; cytostome a long slit; contractile vacuole posterior; 2 spherical macronuclei be- tween which a micronucleus is located; IOO/jl long; fresh water and probably also in salt water. 517 518 PROTOZOOLOGY Fig. 238. a, Amphileptiis claparedei, X370 (Roux); b, A. branchi- arum, flattened, X490 (Wenrich); c, Lionotus fasciola, X540(Kahl); d, Loxophylluyn meleagris, Xl20 (Penard); e, L. setigerum, X570 (Sauerbrey); f, Bryophylluvi vorax, X360 (Stokes); g, h, Kentrophoros fasciolatum [g, X50; h, XllO) (Noland). Genus Loxophyllum Dujardin {Opisthodon Stein). Generally similar to Lionotus in appearance; but ventral side with a hya- line border, reaching posterior end and bearing trichocysts ; dorsal side with either similar trichocyst-border or with trichocyst- warts; maeronueleus a single mass or in many parts; contractile vacuoles, 1 to many; fresh or salt water. Many species. L. meleagris (D.) (Fig. 238, d). Form and size highly variable; flask-shape to broad leaf -like; broad ventral seam with tricho- HOLOTRICHA 519 cysts and often undulating; dorsal seam narrow and near its edge, groups of trichocysts in wart-like protuberances; macro- nucleus divided into small ellipsoidal parts; micronuclei, of the same number (Penard) ; contractile vacuole terminal, with a long canal; 300-400^ long, up to 700/x (Penard); feeds mainly on rotifers; fresh water, L. setigerum Quennerstedt (Fig. 238, e). 100-350^ long; average 150^1 by 60m; form variable; 1-4 macronuclei; several contractile vacuoles in a row; salt and brackish water. Genus Bryophyllum Kahl. Similar to Loxophyllum; but uni- formly cihated on both broad surfaces; ventral ridge with closely arranged trichocysts, extends to the posterior extremity and ends there or may continue on the opposite side for some distance; macronucleus ovoid to coiled bandform; in mosses. B. (Loxophyllum) vorax (Stokes) (Fig. 238, /). Elongate; trichocyst-bearing ventral ridge turns up a little on dorsal side; contractile vacuole posterior; macronucleus oval; 130/x long; in fresh water among sphagnum and mosses. Genus Kentrophoros Sauerbrey. Extremely elongate, nema- tode-like; anterior end greatly attenuated; posterior end pointed; body surface longitudinally striated; ciliation uniform; 1-3 macronuclei; numerous contractile vacuoles in 2 rows; cytostome not observed. K. fasciolatum S. (Fig. 238, g, h). About 270m by 38m. Noland (1937) observed 2 specimens in sediment taken from sandy bot- tom in Florida; contracted 650m long; extended 1 mm. long. Family 2 Tracheliidae Kent Genus Trachelius Schrank. Oval to spherical; anterior end drawn out into a relatively short finger-like process or a snout; posterior end rounded; round cytostome at base of neck; cyto- pharynx with trichites; contractile vacuoles many; macronucleus simple or band-form; fresh water. T. ovum Ehrenberg (Fig. 239, a). Spheroidal to ellipsoid; right side flattened and with a longitudinal groove; left side convex; proboscis about 1/4-1/2 the body length; ciha short and closely set; numerous contractile vacuoles; macronucleus short sausage- form, often divided into spherules; endoplasm penetrated by branching cytoplasmic skeins or bands and often with numerous small brown excretion granules; 200-400m long; fresh water. 520 •KOTOZOOLOGY Fig. 239. a, Trachelinus ovum, Xl30 (Roux); b, Dileptus mnericanus, X250 (Kahl); c, D. anser, X310 (Hayes); d, Paradileptus conicus, X340 (Wenrich); e, P. robustus, X340 (Wenrich); f, Branchioecetes gammari, X200 (Penard); g, Loxodes vorax, Xl90 (Stokes); h, L. magnus, XSO (Kahl); i, j, Remanella rugosa (i, dorsal side, Xl30; j, anterior part showing the endoskeleton) (Kahl). Genus Dileptus Dujardin. Elongate; snout or neck-like pro- longation conspicuous; somewhat bent dorsally; along convex ventral side of neck many rows of trichocysts; a row of strong HOLOTRICHA 521 cilia; dorsal surface with 3 rows of short bristles; cytostome sur- rounded by a ring; cytopharynx with long trichocysts; posterior end drawn out into a tail; contractile vacuoles, 2 or more; body ciliation uniform; macronucleus bandform, moniliform or divided into numerous independent bodies; fresh or salt water. Many species. D. americanus Kahl (Fig. 239, h). Proboscis bent dorsally sickle-like; macronucleus made up of 2 sausage-shaped or often horseshoe-shaped parts; 2 contractile vacuoles on dorsal side; 200 iu long; in mosses. D. anser (Mtiller) (Figs. 22, c, d; 239, c). Proboscis slightly flat- tened; macronucleus divided into numerous bodies; contractile vacuoles in a row on dorsal side with 2-3 contractile vacuoles in proboscis; 250-400^, sometimes up to OOO^t long; fresh water. Genus Paradileptus Wenrich {TentacuUfera Sokoloff). Body broader at the level of cytostome; with a w4de peristomal field which bears the cytostome and is surrounded for 2/3-3/4 its circumference by a raised rim which is continuous anteriorly with the spirally wound proboscis; trichocyst-zone traversing rim and anterior edge of proboscis; contractile vacuoles small, numerous, distributed; macronucleus segmented, fresh water. P. conicus W. (Fig. 239, d). 100-200^ by 50-100;u. P. rohustus W. (Fig. 239, e). 180-450^ long. Genus Branchioecetes Kahl. Preoral part somewhat like that of Amphileptus, and bent dorsally; ventral side of neck with 2 rows of trichocysts; cytostome at posterior end of neck; cyto- pharynx with trichocysts; ectocommensals on Asellus or Gam- marus. B. gammari (Penard) (Fig. 239, /). 130-200^ long; on Gam- marus. Family 3 Loxodidae Roux Genus Loxodes Ehrenberg. Lancet-like; strongly compressed; anterior end curved ventrally, and usually pointed; right side slightly convex; uniform ciliation on about 12 longitudinal rows; ectoplasm appears brownish, because of closely arranged brown- ish protrichocysts ; endoplasm reticulated; 2 or more vesicular macronuclei; 1 or more micronuclei; 5-25 Miiller's vesicles (p. 77; Fig. 30, a, 6) in dorsal region; fresh water. L. vorax Stokes (Fig. 239, g). 125-140^ long; yellowish brown, a row of slightly longer cilia; sapropelic in standing fresh water. 522 PROTOZOOLOGY L. magnus S. (Fig. 239, h). Extended about 700/^ long; dark brown; 12-20 or more Mliller's vesicles in a row along dorsal border; standing pond water. Genus Remanella Kahl. Similar to Loxodes in general appear- ance; but with endoskeleton consisting of 12-20/x long spindle- form needles lying below ciliated broad surface in 3-5 longitudinal strings connected with fibrils; Miiller's vesicles (Fig. 30, c) in some, said to be different from those of Loxodes (Kahl); sandy shore of sea. R. rugosa K. (Fig. 239, ^, j). 200-300^ long. Tribe 3 Hypostomata Schewiakoff Without furrow; free-living; conspicuous oral or pharyngeal basket Ciliation complete; dorsal cilia usually less dense than those on ventral surface Family 1 Nassulidae Ciliation incomplete; dorsal surface without cilia or with a few sensory bristles Posterior ventral surface with a style Family 2 Dysteriidae (p. 523) Without a style Family 3 Chlamidodontidae (p. 525) Furrow from anterior end of cytostome; parasitic Family 4 Pycnothricidae (p. 528) Family 1 Nassulidae Schouteden Genus Nassula Ehrenberg. Oval to elongate; ventral surface flat, dorsal surface convex; usually brightly colored, due to food material; cytostome 1/3-1/4 from anterior end; body often bent to left near cytostome; opening of oral basket deep, in a vestibule with a membrane; macronucleus spherical or ovoid, central; a single micronucleus; contractile vacuole large, with accessory vacuoles and opens ventrally through a tubule-pore; fresh or salt water. Many species. N. aurea E. (Fig. 240, a). 200-250^ long; fresh and brackish water (Kahl). Genus Paranassula Kahl. Similar in general appearance to Nassula; but with preoral and dorsal suture line; longer caudal cilia on dorsal suture; pharyngeal basket not funnel-like, with 16-18 trichites; about 75 cihary rows; trichocysts especially in anterior region. P. microstoma (Claparede et Lachmann) (Fig. 240, 6). Pellicle roughened by a criss-cross of longitudinal and circular furrows; macronucleus elongate oval, posterior; contractile vacuole near HOLOTRICHA 523 middle and right-dorsal; about 80-95/x long; salt water, Florida (Noland). Genus Cyclogramma Petty. Somewhat resembling Nassula; but conspicuous oral basket in pyriform depression and opens toward left on ventral surface; depression with a short row of small membranes at its anterior edge; trichocysts usually better developed than in Nassula; fresh water. C. (Nassula) trichocystis (Stokes) (Fig. 240, c). Body colorless or slightly rose-colored; trichocysts thick and obliquely arranged; one contractile vacuole; usually full of blue-green food vacuoles; actively motile; about 60/1 long; in fresh water among algae. Genus Chilodontopsis Blochmann. Elongate ellipsoid; color- less; ventral surface flattened, dorsal surface slightly convex; both sides ciliated; oral basket without vestibule; cytostome with a membranous ring; usually with a postoral cihary furrow; fresh water. C. (Chilodon) vorax (Stokes) (Fig. 240, d). Elongate elhpsoid; anterior region sHghtly curved to left; snout fairly distinct; oral basket with about 16 rods; several contractile vacuoles dis- tributed, a large one terminal; macronucleus large, lenticular, granulated; with a closely attached micronucleus; 50-160jli long; fresh water. Genus Eucamptocerca da Cunha. Elongate; posterior part drawn out into a caudal prolongation; dorso-ventrally flattened; cihation on both sides; round cytostome with basket in anterior ventral surface. One species. E. longa de C. (Fig. 240, e). 300 fj. by 25^; macronucleus ovoid, with a micronucleus; contractile vacuole(?); in brackish water (salt contents 3 per cent); Brazil. Genus Orthodon Gruber. Oval; contractile; colorless; much flattened; anterior region curved toward left; striation on both dorsal and ventral sides; cytostome toward right border; oral basket long; macronucleus oval; contractile vacuole terminal; fresh or salt water. 0. hamatus G. (Fig. 240,/). Extended 20-260ai long, contracted 90-1 50/i long; flask-shaped; oral basket with 16 trichites; salt water. Family 2 Dysteriidae Kent Genus Dysteria Huxley (Ervilia, Dujardin; Iduna, Aegyria, Claparede et Lachmann; Cypridium, Kent). Ovate; dorsal sur- .524 PROTOZOOT.Or.Y Fig. 240. a, Nassula aurea, Xl90 (Schewiakoff) ; b, Paranassula viicrostoma, X400 (Noland); c, Cyclogramma trichocystis, X510 (Stokes); d, Chilodoidopsis vorax, X200 (Stokes); e, Eucamptocerca loriga, X320 (da Cunha); f, Orthodon hamatus, Xl60 (Entz); g, Dys- teria calkinsi, X540 (Calkins); h, Trochilia paliistris, X1070 (Roux); i, Trochilioides recta, XlAQ (Kahl);], Hartmannulaentzi, x220(Entz); k, Chlamidodon mnemosyne, X520 (MacDougall); 1, Phascolodon vorti- cella, X340 (Stein). face convex, ventral surface flat or concave; left ventral side with non-ciliated ventral plate; postoral ciliation is continuation of preoral to right of cytostome and parallel to right margin; cyto- HOLOTRICHA 525 stome in a furrow near right side; posterior style or spine con- spicuous; macronucleus spheroid or ovoid, central; with a micronucleus; usually 2 contractile vacuoles; fresh or salt water. Numerous species. D. calkinsi Kahl (Fig. 240, g). About 45^ by 27 /j,; salt water; Woods Hole. Genus Trochilia Dujardin. Similar to Dysteria; but ciliated right ventral side free; fresh or salt water. Several species. T. palustris Stein (Fig. 240, h). 25^ long; fresh water. Genus Trochilioides Kahl. Rounded at anterior end, narrowed posteriorly; right side more convex than left; cytostome anterior with cytopharynx and preoral membrane; conspicuous longi- tudinal bands on right half with longitudinal striae, becoming shorter toward left; fresh or salt water. T. recta K. (Fig. 240, i). 40-50^ long; sapropelic in fresh and brackish water. Genus Hartmannula Poche (Onchodactylus Entz). Ventral surface uniformly ciHated; cytopharynx with short rods; in salt water. H. entzi Kahl (Fig. 240, j). 80-140m long; salt water. Family 3 Chlamidodontidae Glaus Genus Chlamidodon Ehrenberg. Ellipsoid, reniform, elongate triangular, etc.; cilia only on ventral surface, anterior cilia longer; cytostome elongate oval and covered with a membrane bearing a slit; oral basket made up of closely arranged rods with apical processes; along lateral margin, there is a characteristic striped band which is a canalicule of unknown function; fresh or salt water. C. mnemosyne E. (Fig. 240, k). Ellipsoid or reniform; right side convex, left side concave; ventral side flat, dorsal side greatly convex; a band of trichites, 'railroad track,' parallel to body out- line; oral basket with 8-10 rods; macronucleus oval; 4-5 contrac- tile vacuoles distributed; 60-90^ long; salt water. MacDougall (1928) observed it in the brackish water at Woods Hole and studied its neuromotor system. Genus Phascolodon Stein. Ovoid; with broad anterior end and bluntly pointed posterior end; ventral side concave or flat, dorsal side convex; ciliated field on ventral surface narrowed laterally behind cytostome, forming V-shaped ciliary area (about 12 rows); 526 PROTOZOOLOGY cytostome ellipsoid with oral basket; macronucleus oval with a micronucleus; 2 contractile vacuoles; fresh water. P. vorticella S. (Fig. 240, 1). 80-1 lOju long, cytostome covered by a slit-bearing membrane; with 2 preoral membranes; fresh water. Genus Cryptopharynx Kahl. Ellipsoid, anterior third bent to left; ventral surface flat, dorsal surface with hump; spiral inter- ciliary furrows ridged; oval cytostome at anterior end; no cyto- pharynx; dorsal hump yellowish, granulated with gelatinous cover; 2 macronuclei; 1 micronucleus; 2 contractile vacuoles, one posterior and the other toward left side at bend of body. One species. C. setigerus K. (Fig. 241, a, h). Elongate ellipsoid; anterior region bent to left; ventral surface flat, dorsal surface with a hump; about 15 ventral ciliary rows; 2 vesicular macronuclei and 1 micronucleus, dorso-central; 33-96^ by 21-45^ (Kirby). Kirby found the organism in salt marsh pools (salinity 1.2-9.7 per cent) with purple bacteria in California. Genus Chilodonella Strand {Chilodon Ehrenberg). Ovoid; dorso-ventrally flattened; dorsal surface convex, ventral surface flat ; ventral surface with ciliary rows ; anteriorly flattened dorsal surface with a cross-row of bristles; cytostome round; oral basket conspicuous, protrusible; macronucleus rounded; con- tractile vacuoles variable in number; fresh or salt water or ecto- commensal on fish and amphipods. Many species. C. cucullulus (Miiller) {Chilodon steini Blochmann) (Figs. 50; 241, c-e). 19-20 ventral ciliary rows; oral basket with about 12 rods and with 3 preoral membranes; macronucleus oval, a characteristic concentric structure; micronucleus small; body 100-300/x long, most often 130-150^ long; fresh and brackish water. C. caudata (Stokes) (Fig. 241, /). About 42^ long; standing water. C. fluviatilis (S.) (Fig. 241, g). About 50m long; fresh water. C. uncinata (Ehrenberg) (Fig. 81). 50-90/x long; about 11 ventral ciliary rows ; some 7 dorsal bristles ; widely distributed in various freshwater bodies; several varieties. MacDougall (1925) studied conjugation and mutation (p. 164) of this organism. C. cyprini (Moroff) (Fig. 241, /i). 50-70m by 30-40^; in integu- ment and gills of cyprinoid fishes; the organism, if freed from the host body, dies in 12-24 hours. HOLOTRICHA 527 Fig. 241. a, b, Cryptopharynx setigerus, X650 (Kirby); c-e, Chilo- donella cucullulus (c, X270 (Stein) ; d, oral region; e, nucleus (Penard)) ; f, C. caudata, XlOOO (Stokes); g, C. fluviatilis, XSOO (Stokes); h, C. cyprini, X670 (Moroff); i, Allosphaerium palustris, XlOOO (Kidder and Summers). C. longipharynx Kidder et Summers. 17-21ju (average 19/i) long; cytopharynx long, reaches posterior end; ectocommensal on amphipods, Talorchestia longicornis and Orchestia palustris; Woods Hole. C. hyalina K. et S. 40/i (36-47ju) long; ectocommensal on Orchestia agilis; Woods Hole. C. rotunda K. et S. 29/i (27-34/i) long; ectocommensal on Orchestia agilis; Woods Hole. 528 PROTOZOOLOGY Genus Allosphaerium Kiddor et Summers. Oval; right side concave, left side more or less flat; body highly flattened; arched dorsal surface devoid of cilia; ventral surface slightly concave with 12-27 ciliary rows; right and left margins of ventral surface with a pellicular fold; cytostome anterior- ventral, oval or irregu- lar, surrounded by ridge on posterior border, extending to left margin; in front of it the peristome; 3 groups of ciliary membranes extending out of cytostome; macronucleus oval, central or an- terior; a micromicleus; 2 (or 1) contractile vacuoles; a refractile spherule regularly joresent in posterior portion of endoplasm; ectocommensal on carapace and gills of amphipods. A. palustris K. et S. (Fig. 241, i). 46-59^i long; 27 ventral ciliary rows; on Orchestia palustris and Talorchestia longicornis; Woods Hole. A. sulcatum K. et S. 24-32/x long; 12 ciliary rows; on carapace of Orchestia agilis and 0. palustris; Woods Hole. A. granulosum K. et S. 32-42^i long; rotund; 17 ciliary rows; cytoplasm granulated; on carapace of Orchestia agilis and 0. palustris; Woods Hole. A. caudatum K. et S. Resembles A. palustris; 35-45^ long; 14 cihary rows; 1 contractile vacuole; ectoplasm at posterior end, drawn out into a shelf; on Orchestia agilis; Woods Hole. A. convexa K. et S. 24-36iu long; 17 ciliary rows; on carapace and gill lamellae of Talorchestia longicornis; Woods Hole. Family 4 Pycnothricidae Poche Ciliation uniform; ectoplasm thick and conspicuous; a furrow^ or groove connects the cytostome with the anterior end; parasitic in alimentary canal of mammals. Genus Pycnothrix Schubotz. Large, elongate; with broadly rounded anterior and narrowed posterior end; somewhat flat- tened; short thick cilia throughout; ectoplasm thick; macro- nucleus spherical, in anterior 1/6; micronucleus(?) ; 2 longitudinal grooves, one beginning on each side near anterior end, united at the notched posterior end; a series of apertures in grooves con- sidered as cytostomes; at posterior 1/3, a pore gives rise to branching canals running through endoplasm, and is considered as excretory in function; in colon of Procavia capensis and P. hrucei. One species. P. monocystoides S. (Fig. 242, a). 300At-2 mm. long. HOLOTRICHA 529 Genus NicoUella Chatton et Perard. Elongate; a narrow groove extends from the anterior end to cytostome, located at middle of body; bilobed posteriorly; contractile vacuole terminal; macronucleus ellipsoid, anterior; a micronucleus; ectoplasm thick Fig. 242. a, Pycnothrix monocystoides, X50 (Chatton and Perard); b, NicoUella ctenodadyli, Xl70 (Chatton and Perard); c, Collinella gundi, Xl70 (Chatton and Perard); d, Buxtonella sulcata, X400 (Jameson). anteriorly; ciliation uniform; in colon of Ctenodactylus gundi. One species. N. denodactyli C. et P. (Fig. 242, 6). 70-550m by 40-150^. Genus Collinella Chatton et Perard. More elongate than NicoUella; uniform cihation; a groove extends from end to end; cytostome at posterior end of the groove; contractile vacuole 530 PROTOZOOLOGY terminal; macronucleus much elongated, central or posterior; in colon of Ctenodactylus gundi. C. gundi C. et P. (Fig. 242, c). 550-600/x by lOO/z. Genus Buxtonella Jameson. Ovoid; a prominent curved groove bordered by 2 ridges from end to end; cytostome at anterior end; ciliation uniform; in caecum of cattle. One species. B. sulcata J. (Fig. 242, d). 55-124^ by 40-72^. References Chatton, E. and C. Perard 1921 Les Nicollelidae, infusoires intestinaux des gondis et des damans, et le 'cycle evolutif des cilies.' Bull. biol. Fr. et Bel., Vol. 55. Kahl, a. 1931 Urtiere oder Protozoa. Dahl's Die Tierwelt Deutschlands. Part 21. Kent, W. S. 1880-1882 A manual of Infusoria. Stein, F. 1867 Der Organismus der Infusionstiere. Vol. 2. Stokes, A. C. 1888 A preliminary contribution toward a history of the freshwater Infusoria of the United States. Jour. Trenton Nat. Hist. Soc, Vol. 1. Wenrich, D, H. 1929 Observations on some freshwater ciliates. II Paradileptus, n.gen. Trans. Amer. Micr. Soc, Vol. 48. Chapter 33 Order 1 Holotricha Stein (continued) Suborder 3 Trichostomata Biitschli With gelatinous lorica; swimming backward Family 1 Marynidae (p. 532) Without lorica Compressed; armor-like pellicle; ciliation sparse, mainly on flat right side in 2-9 broken rows on semicircular or crescentic keel ; cytostome on flattened ventral surface, with an obscure membrane Family 2 Trichopelmidae (p. 532) Body form and ciliation otherwise With a long caudal cilium; cilia in 3-4 spiral rows on anterior half, very small forms Family 3 Trimyemidae (p. 534) Without a caudal cilium; form and ciliation otherwise With a spiral zone of special cilia, from cytostome to posterior end Spiral zone extends from anterior right to posterior left. . . . Family 4 Spirozonidae (p. 534) Spiral zone extends from anterior left to posterior right. . . . Family 5 Trichospiridae (p. 534) Without spiral zone of special cilia Ciliated cross-furrow in anterior 1/5 on ventral surface, leads to cytostome Family 6 Plagiopylidae (p. 534) Without ciliated cross-furrow Cytostome in flat oval groove with heavily ciliated ridge in anterior 1/4 Family 7 Clathrostomidae (p. 536) Cytostome funnel-like, deeply situated Cytostomal funnel with strong cilia; peristome from anterior left to middle right Family 8 Parameciidae (p. 537) Without such a peristome Free-living; oral funnel deep; cilia at bottom and top Family 9 Colpodidae (p. 540) Endozoic Commensal in vertebrates Family 10 Entorhipidiidae (p. 541) Parasitic in vertebrates Ciliation uniform With concrement vacuoles Family 11 Paraisotrichidae (p. 543) Without the vacuoles Family 12 Isotrichidae (p. 544) 531 532 PROTOZOOLOGY Ciliation not uniform Cytostome occupies the entire anterior end; cilia only in anterior region Family 13 Cyathodiniidae (p. 544) Cytostome not terminal; tufts of cilia above and below cytostome and in posterior region Family 14 Blepharocoridae (p. 544) Family 1 Marynidae Poche Genus Maryna Gruber. Peristome makes a complete circle, thus the cone is entirely separated from anterior edge of body; cytostome left ventral, elongate slit; ridge also with a slit; gelat- inous lorica, dichotomous. M. socialis G. (Fig. 243, a, b). About 150m long; in infusion made from long-dried mud. Genus Mycterothrix Lauterborn (Tnchorhynchus Balbiani). Anterior cone continuous on dorsal side with body ridge; hence free edge of body only on ventral side; no ventral slit. M. erlangeri L. (Fig. 243, c). Nearly spherical with zoochlorel- lae; 50-55^ by 40-50)u; fresh water. Family 2 Trichopelmidae Kahl Genus Trichopelma Lavender. Compressed; surface with longi- tudinal furrows, seen as lines in end-view; coarse ciliation throughout; cytostome toward left edge about 1/3 from the anterior end; cytopharynx tubular; macronucleus spheroid, central ; 2 contractile vacuoles ; fresh water. T. sphagnetorum (L.) (Fig. 243, d). 25-40^ long; in fresh water. Genus Pseudomicrothorax Mermod {Craspedothorax Sond- heim). More or less compressed; cytostome opens in anterior half toward left side, in a depression surrounded by ciliary rows ; body surface marked with a broad longitudinal ridge with cross stria- tion; furrows canal-like; cilia on ventral side; cytopharynx tubular, with elastic rods; fresh water. P. agilis M. (Fig. 243, e, /). Ellipsoid; 48-58m long; in fresh water. Genus Drepanomonas Fresenius (Drepanoceras Stein). Highly flattened; aboral surface convex; oral surface flat or concave; with a few deep longitudinal furrows; ciliation sparse; cytostome and a small cytopharynx simple, near the middle of body; fresh water. Several species. HOLOTRICHA 533 D. dentata F. (Fig. 243, g). With a small process near cyto- stome; 2 rows of ciliary furrows on both oral and aboral surfaces; cilia on both ends of oral surface; 40-65m long; in fresh water. Fig. 243. a, b, Maryna socialis (a, X40; b, Xl60) (Gruber); c, Myc- terothrix erlangeri, X310 (Kahl); d, Trichopelma sphagnetorum, X570 (Kahl); e, f, Pseudomicrothorax agilis (e, X340; f, X670) (Kahl); g, Drepanomonas dentata, X540 (Penard); h, Microthorax simulans, X620 (Kahl); i, Trirmjema compressum, X410 (Lackey); j, Spirozona caudata, X370 (Kahl); k, Trichospira inversa, X360 (Kahl). Genus Microthorax Engelmann (Kreyella Kahl). Small, flat- tened; with dehcate keeled armor which is more or less pointed anteriorly and rounded posteriorly; ventral armor with 3 ciliary rows; oral depression posterior-ventral, with a stiff ectoplasmic lip on right side, below which there is a small membrane, and 534 PROTOZOOLOGY with a small tooth on left margin; no cytopharynx; macronucleus spherical; 2 contractile vacuoles; in fresh water. Many species. M. simulans Kahl (Fig. 243, h). 30-35^1 long; decaying plant infusion, also in moss. Family 3 Trimyemidae Kahl Genus Trimyema Lackey {Sciadostoma Kahl). Ovoid, more or less flattened; anterior end bluntly pointed, posterior end similar or rounded; with a long caudal cilium; cilia on 3-4 spiral rows which are usually located in the anterior half of body; round cyto- stome near anterior end with a small cytopharynx; spherical macronucleus central with a small micronucleus ; one contractile vacuole; active swimmer; fresh or salt water. T. compressum L. (Fig. 243, i). About 65/x by 35/i; Lackey found it in Imhoff tank; fresh and salt water (Kahl); Klein (1930) studied its silverline system. Family 4 Spirozonidae Kahl Genus Spirozona Kahl. Short spindle-form; anterior end trun- cate, posterior region drawn out to a rounded end, with a group of longer cilia; spiral ciliation; beginning at right posterior end the central ciliary row runs over ridge to left and then reaches the cytostome; other rows are parallel to the above; cytostome in anterior 1/4, with cytopharynx; ellipsoid macronucleus nearly central; contractile vacuole terminal; fresh water, sapropelic. S. caudata K. (Fig. 243, j). 80-100m long. Family 5 Trichospiridae Kahl Genus Trichospira Roux. Body cylindrical; posterior end rounded, anterior end conical in profile, where the cytostome sur- rounded by 2 spiral rows of ciUa, is located; a special ciliary band beginning in the cytostomal region runs down on ventral side, turns spirally to left and circles partially posterior region of body; ciliary rows parallel to it; macronucleus oval, with a micronucleus; contractile vacuole posterior; fresh water, sapropelic. T. inversa (Claparede et Lachmann) (Fig. 243, k). 70-100^ long. Family 6 Plagiopylidae Schewiakoff Genus Plagiopyla Stein. Peristome a broad ventrally opened groove from which body ciliation begins; peristomal cilia short, HOLOTRICHA 535 except a zone of longer cilia at anterior end; cytostome near median line at the end of the peristome; cytopharynx short; a peculiar 'stripe band' located on dorsal surface has usually its origin in the peristomal groove, after taking an anterior course for a short distance, curves back and runs down posteriorly near right edge and terminates about 1/3 the body length from posterior end; macronucleus rounded; a micronucleus ; contractile vacuole terminal; free-living or endozoic. P. nasuta S. (Fig. 244, a). Ovoid; tapering anteriorly; peristome at right angles or sUghtly oblique to the edge; trichocysts at right angles to body surface; macronucleus round to irregular in shape; body about 100m (80-180^) long; sapropelic in brackish water. Lynch (1930) observed this cihate in salt water cultures in Cali- fornia and found it to be 70-1 14^ by 31-56^ by 22-37m. P. minuta Powers (Fig. 244, 6). 50-75/x by 36-46^; in intestine of Strongylocentrotus droehachiensis ; the Bay of Fundy. Genus Lechriopyla Lynch. Similar to Plagiopyla; but with a large internal organella, furcula, embracing the vestibule from right, and a large crescentic motorium at left end of peristome; in the intestine of sea-urchins. L. mystax L. (Fig. 244, c). 113-174/x long; in gut of Strongylo- centrotus purpuratus and S. franciscanus; California. Genus Sonderia Kahl. Similar to Plagiopyla in general appear- ance; ellipsoid; flattened; peristome small and varied; body covered by 2-4^ thick gelatinous envelope which regulates os- mosis, since no contractile vacuole occurs (Kahl) ; with or without a striped band; trichocysts slanting posteriorly; in salt or brackish water. Kirby (1934) showed that several species of the genus are common in the pools and ditches in salt marshes of California, salinities of which range 3.5-10 per cent or even up to 15-20 per cent. S. pharyngea Kirby (Fig. 244, d). Ovoid to ellipsoid; flattened; 84-1 lOju by 48-65^; gelatinous layer about 2/i thick, with bac- teria; about 60 longitudinal ciliary rows, each with 2 borders; peristome about 35ai long, at anterior end, obUque; with closely set cilia from the opposite inner surfaces ; cytopharynx conspicu- ous; spherical macronucleus anterior, with a micronucleus; trichocysts (7-9iu long) distributed sparsely and unevenly, oblique to body surface; a group of bristle-like cilia at posterior end; often brightly colored because of food material; in salt marsh, Cali- fornia. 536 PROTOZOOLOGY Fig. 244. a, Plagiopyla nasuta, X340 (Kahl); b, P. minuta, X400 (Powers); c, Lechriopyla mystax, X340 (Lynch); d, Sonderia pharyn- gea, X590 (Kirby); e, S. vorax, X310 (Kahl); f, Clathrostoma viminale, X220 (Penard); g, Physalophrya spumosa, Xl60 (Penard). S. vorax Kahl (Fig. 244, e). Broadly ellipsoid; size variable, 70-180^1 long; ventral surface flattened; posterior border of peri- stomal cavity extending anteriorly; in salt marsh; California (Kirby). Family 7 Clathrostom.idae Kahl Genus Clathrostoma Penard. Ellipsoid; with an oval pit in anterior half of the flattened ventral surface, in which occur 3-5 concentric rows of shorter cilia; cytostome a long slit located at the bottom of this pit; with a basket composed of long fibrils on the outer edge of pit; in fresh water. C. viminale P. (Fig. 244, /). Resembles a small Frontonia leucas; macronucleus short sausage-form; 4 micronuclei in a com- HOLOTRICHA 537 pact group; endoplasm with excretion crystals; 5 preoral ciliary- rows; 130-180/x long; in fresh water. Family 8 Parameciidae Grobben Genus Paramecium Hill {Paraynaecium M tiller ). Cigar-shaped; circular or ellipsoid in cross-section; with a single macronucleus and 1 to many vesicular or compact micronuclei ; peristome long, broad, and conspicuous; in fresh or brackish water. Several species. P. caudatum Ehrenberg (Figs. 22, e; 35; 39, a-e; 48; 74; 245, a). 200-260 ju long; with a compact micronucleus, a massive macro- nucleus; 2 contractile vacuoles on aboral surface; posterior end bluntly pointed; in fresh water. The most widely distributed species. P. aurelia Miiller (Figs. 77; 79; 245, h). 120-250/x long; 2 small vesicular micronuclei, a massive macronucleus; 2 contractile vacuoles on aboral surface; posterior end more rounded than P. caudatum; in fresh water. P. niuUimicronucleata Powers et Mitchell (Figs. 19; 20; 28; 29; 245, c). Slightly larger than P. caudatum; 3-7 contractile vacuoles ; 4 or more vesicular micronuclei ; a single macronucleus ; in fresh water. P. bursaria (Ehrenberg) (Fig. 245, d). Foot-shaped, somewhat compressed; about 100-200^ by 50-60^; with zoochlorellae as symbionts; micronucleus compact; 2 contractile vacuoles; in fresh water. P. putrinum Claparede et Lachmann (Fig. 245, e). Similar to P. hursaria, but a single contractile vacuole and an elongated macronucleus; no zoochlorellae; 80-1 50^ long; in fresh water. P. calkinsi Woodruff (Fig. 245,/). Foot-shaped; posterior end broadly rounded; 100-130;u by 50;u; 2 vesicular micronuclei; 2 contractile vacuoles; rotation of body clockwise when viewed from posterior end; in fresh and brackish water. P. trichium Stokes (Fig. 245, g). Oblong; somewhat compressed; 70-100/x long; micronucleus compact; 2 contractile vacuoles deeply situated, each with a convoluted outlet; in fresh water. P. -polycaryum Woodruff et Spencer (Fig. 245, h). Form similar to P. hursaria; 70-110^ long; 2 contractile vacuoles; 3-8 vesicular micronuclei; in fresh water. P. woodruffi Wenrich (Fig. 245, i). Similar to P. polycaryum; 538 PROTOZOOLOGY Fig. 245. Semi-diagrammatic drawings of nine species of Parame- cium in oral surface view, showing distinguishing characteristics taken from fresh and stained specimens, X230 (several authors), a, P. caudatum; b, P. aurelia; c, P. muUimicronudeata; d, P. bursaria; e, P. putrinum; f, P. calkinsi; g, P. irichium; h, P. polycaryum; i, P. woodruffi.. 150-210^1 long; 2 contractile vacuoles; 3-4 vesicular micronuclei; brackish water. Although Paramecium occurs widely in various freshwater bodies throughout the world and has been studied extensively by numerous investigators by mass or pedigree culture method, there are only a few observations concerning the process of encystment. Biitschli considered that Paramecium was one of the Protozoa HOLOTRICHA b 539 Fig. 246. a-c, encystment in a species of Paramecium (Curtis and Guthrie); d-f, encystment of P. caudatum, X380 (Michelson). in which encystment did not occur. Stages in encystment were observed in P. hursaria (by Prowazek) and in P. pidrinuni (by Lindner). In recent years, four observers recorded their findings on the encystment of Paramecium. Curtis and Guthrie (1927) give figures in their textbook of zoology, showing the process (of P. caudatum?) (Fig. 246), while Cleveland (1927) injected Para- mecium culture (species not mentioned) into the rectum of frogs and observed that the ciliate encysted within a thin membrane. Michelson (1928) found that if P. caudatum is kept in Knop-agar medium, the organism becomes ellipsoidal under certain condi- tions, later spherical to oval, losing all organellae except the nuclei, and develops a thick membrane; the fully formed cyst is elongated and angular, and resembles a sand particle (Fig. 246). Michelson considers its resemblance to a sand grain as the chief cause of the cyst having been overlooked by workers. In all these cases, however, it may be added that excystment has not been established. Genus Physalophrya Kahl. Without peristome; but cytostome located near the anterior half of body, resembles much that of Paramecium; although there is no membrane, a ciliary row occurs in the left dorsal wall of cytopharynx; in fresh water. Taxonomic status is not clear; but because of its general resemblance to 540 PROTOZOOLOGY Paramecium, the genus with only one species is mentioned here. P. spiwiosa (Penard) (Fig. 244, g). Oval to cyhndrical; highly plastic; cytoplasm reticulated; numerous contractile vacuoles; 150-320/x long; in fresh water. Family 9 Colpodidae Poche Genus Colpoda Mtiller. Reniform; flattened; right border semi- circular; posterior half of left border often convex; oral funnel in the middle of flattened ventral side, but toward left border where depression occurs, which leads into peristome cavity and gives rise dorsally to a diagonal groove; left edge of cytostome bears a cross-striped ciliated area, but no protruding membrane as in Bryo'phrya; macronucleus spherical or oval, central; con- tractile vacuole terminal; in fresh water. Many species. C. cucullus M. (Fig. 247, a, b). About 80/x (50-120m) long; an- terior keel with 8-10 indentations; macronucleus with a stellate endosome; trichocysts rod-form; food vacuoles dark; in fresh water with decaying plants and infusion. C. inflata (Stokes) (Fig. 247, c). 50-80/x long; anterior keel with 6-8 indentations; macronucleus similar to that of C. cucullus; in fresh water in vegetation. C. calif ornica Kahl (Fig. 247, d). About 30/x long; highly flat- tened; cytostome small; protrichocysts very granular; cilia deli- cate, long, in a few rows; macronucleus with a stellate endosome; in moss; California. C. steini Maupas. 25-45/i long; 5-6 preoral ridges; in fresh water. Reynolds (1936) found that it adopts itself to various organs of the land slug, Agriolimax agrestis. Genus Tillina Gruber. Similar to Colpoda in general appearance and structure; but cytopharynx a long curved, ciliated tube; in fresh water. T. magna G. (Fig. 247, e,f). 180-200m long (Gruber) ; up to 400m long (Bresslau) ; macronucleus oval, with 6 micronuclei ; contrac- tile vacuole terminal, with 6 long collecting canals; in stagnant water and also coprozoic. Genus Bresslaua Kahl. General body form resembles Colpoda; but cytopharynx large and occupies the entire anterior half. B. vorax K. (Fig. 247, g). 80-120)U long; in fresh water. Genus Bryophrya Kahl. Ovoid to ellipsoid; anterior end more or less bent toward left side; cytostome median, about 1/3 from HOLOTRICHA d 541 Fig. 247. a, b. Colpoda cucullus (a, X340; b, oral region) (Kahl); c, C. inflata, X540 (Stokes); d, C. calif ornica, X670 (Kahl); e, f, Tillina magna, XlOO (Bresslau); g, Bresslaua vorax, XlOO (Kahl); h, Bry- ophryabavariensis, X280 (Kahl);i, Woodruffia rostrata, Xl90 (Kahl). anterior end, its right edge continues in horseshoe form around the posterior end and half of the left edge ; anterior portion of left edge of the cytostome with posteriorly directed membrane; macronucleus oval or spherical; micronuclei; in fresh water, B. havaricnsis K. (Fig. 247, h). 50-120m long. Genus Woodruffia Kahl. Form similar to Chilodonella (p. 526); highly flattened snout bent toward left; cytostome, a narrow diagonal slit, its left edge w^th a membranous structure and its right edge with densely standing short cilia; macronucleus spheri- cal, many (?) micronuclei; contractile vacuole flattened, terminal; in salt water. W. rostrata K. (Fig. 247, i). 120-180m long; salt water culture with Oscillatoria. W. metaholica Johnson et Larson. 85-400|U long; division cysts 85-155/i in diameter; resting cysts 40-62^ in diameter; in fresh water pond; California. Family 10 Entorhipidiidae Madsen Genus Entorhipidium Lynch. Triangular in general outUne; colorless; large (155-350^ long); flattened; posterior end drawn out with a bristle; anterior end bent to left; cytostome in depres- sion close to left anterior border, with long cilia; with or without 542 PROTOZOOLOGY d Fig. 248. a, Entorhipidium echini, X270 (Lynch); b, Entodiscus indomitus, X380 (Madsen); c, E. borealis, X380 (Powers); d, Biggaria bermudense, X380 (Powers); e, B. echinometris, X380 (Powers); f, Anophrys elongata, X390 (Powers); g, A. aglycus, X390 (Powers). a cross-groove from preoral region; cytopharynx inconspicuous; trichocysts; macronucleus oval to sausage-form; 1 to several micronuclei; several (excretory) vacuoles left-ventral; in intestine of the starfish, Strongylocentrotus purpuratus. Four species. E. echini L. (Fig. 248, a). About 253)U by 125/1; Cahfornia. Genus Entodiscus Madsen. Broadly or narrowly lancet-hke, without narrowed posterior portion; cytostome small on left narrow side, about 2/5 the body length from anterior end; without trichocysts; macronucleus central, with a micronucleus; con- HOLOTRICHA 543 tractile vacuole siibterminal; swimming movement rapid without interruption. Two species. E. indomitus M. (Fig. 248, h). 80-117^ by 20-23^; in intestine of Strongylocentrotus droehachiensis. E. horealis (Hentschel) (Fig. 248, c). Oval; cytostome nearer anterior end; 105-170ju by 60-1 15^; in gut of Strongylocentrotus droehachiensis and Echinus esculentus; Powers (1933) studied this species in the first-named host from Maine, and found a support- ing rod which is imbedded in the margin along the right wall of the oral cavity and which he named stomato style. Genus Biggaria Kahl. Scoop-like form; anterior 2/3 thin, pos- terior region thickened, terminating in a rudder-like style; cilia in longitudinal rows; longer cilia on caudal prolongation; cyto- stome in posterior half, opening into a vestibule, into which long cilia project from the roof; aperture to cytopharynx with 2 membranes; contractile vacuole subterminal; in the intestine of sea-urchins. B. hermudense (Biggar) (Fig. 248, d). 90-185^ by 48-82ju; in Lytechinus variegatus; Bermuda (Biggar), North Carolina (Powers); Powers (1935) found the organism further at Tortugas in Lytechinus variegatus, Centrechinus antillarum, Echinometra lucunter, Tripneustes esculentus and Astrophyga magnifica. B. echinometris (B.) (Fig. 248, e). 80-195^ by 33-70ai; in Echi- nometris suhangularis (Bermuda) .and Lytechinus variegatus (North Carolina). Genus Anophrys Cohn. Cigar-shaped; flexible; longitudinal ciliary rows; peristome begins near the anterior end, parallel to body axis and about 1/3 the body length; a row of free cilia on right edge of peristome; cytostome inconspicuous; spherical macronucleus central; contractile vacuole terminal; in sea- urchins. A. elongata Biggar (Fig. 248,/). About 96m long (Powers); 166/x long (Biggar); in gut of Lytechinus variegatus and Echino- metris suhangularis ; Bermuda (Biggar); Powers (1935) found this species also in the hosts mentioned for Biggaria hermudense. A. aglycus Powers (Fig. 248, g). 56-120^ by 16-35/z; in gut of Centrechinus antillarum and Echinometra lucunter; Tortugas. Family 11 Paraisotrichidae da Cunha Genus Paraisotricha Fiorentini. Uniformly ciliated in more or 544 PROTOZOOLOGY less spiral longitudinal rows; longer cilia at anterior end; cyto- stome near anterior tip; contractile vacuole posterior; in caecum and colon of horse. P. colpoidea F. (Fig. 249, a). 70-100^ by 42-60ai. P. heckeri Hsiung (Fig. 249, h). 52-98m by 30-52ju. Family 12 Isotrichidae Biitschli This family includes those forms which possess a thick pellicle and a dense ciliation. Genus Isotricha Stein. Ovoid; flattened; dense longitudinal ciliary rows; cytostome at or near anterior end; several con- tractile vacuoles; reniform macronucleus and a micronucleus connected with, and suspended by, fibrils, karyophore; locomo- tion with posterior end directed forward; in stomach of cattle and sheep. /. prostoma S. (Fig. 249, c). 80-195m by 53 85^. 7. intestinalis S. (Fig. 249, d). 97-130iu by 68-88m. Genus Dasytricha Schuberg. Oval, flattened; cilia in longitudi- nal spiral rows; no karyophore; in stomach of cattle. D. ruminantium S. (Fig. 249, e). 50-75^ by 30-40/^. Family 13 Cyathodiniidae da Cunha Genus Cyathodinium da Cunha. Conical or pyriform; broad cytostome occupies the entire anterior end and extends pos- teriorly 1/4-3/4 the body length; deep with prominent ridges; oral ciha in a single row on left ridge; body cilia comparatively long, confined to anterior half; macronucleus round or ellipsoid; a micronucleus; 1 to several contractile vacuoles; in caecum and colon of guinea pigs. C. conicum da C. Inverted cone; 50-80// by 20-30/x; in caecum of Cavia aperea and C. porcella. C. piriforme da C.( Fig. 249,/). Typical form inverted pyriform; second form conical with tapering anterior end; contractile vacuole posterior; 30-40)U by 20~30)u; in caecum of Cavia aperea and C. porcella; Lucas (1932) who made a cytological study of the organism, found some 52 per cent of guinea pigs which she examined in Philadelphia and St. Louis to harbor this ciliate. Family 14 Blepharocoridae Hsiung Elongate; cytostome anterior- ventral ; cytopharynx long, cili- HOLOTRICHA 545 ated; ciliary tufts at both ends; contractile vacuole terminal; in colon of horse or stomach of ruminants. Genus Blepharocorys Bundle. Oral groove deep, near anterior end; 3 (oral, dorsal and ventral) ciliary zones at anterior end; Fig. 249. a, Paraisotricha colpoidea, X270 (Hsiung); b, P. beckeri, X360 (Hsiung); c, Isotricha prostoma, X500 (Becker and Talbott); d, /. intestinalis, XoOO (Becker and Talbott); e, Dasytricha rmninan- tiurn, X330 (Becker and Talbott); f, Cyathodinium piriforme, X1290 (Lucas); g, Blepharocorys uncinata, X540 (Reichenow); h, B.bovis, X850 (Dogiel); i, Charon equi, X570 (Hsiung). caudal ciHary zone single; in caecum and colon of horse or stomach of cattle. Many species. B. uncinata (Fiorentini) {B. equi Schumacher) (Fig. 249, g). With a screw-hke anterior process; 55-74^t by 22-30/z; in caecum and colon of horse. B. bovis Dogiel (Fig. 249, h). 23-37m by 10-17m; in stomach of cattle. 546 PROTOZOOLOGY Genus Charon Jameson. Two caudal ciliary zones; in colon of horse or in stomach of ruminants. C. equi Hsiung (Fig. 249, i). 30-48m by 10-14^; in colon of horse. References Lackey, J. B. 1925 The fauna of Imhoff tanks. Bull. N. J. Agr. Exp. Stat., No. 417. Lucas, Miriam S. 1932 A study of Cyathodinium piriforme. Arch. f. Protistenk., Vol. 77. Lynch, J. 1929 Studies on the ciliates from the intestine of Strongylocentrotus. 1. Univ. Calif. Publ. Zool., Vol. 33. 1930 n. Ibid., Vol. 33. Powers, P. B. A. 1933 Studies on the ciliates from sea urchins. I, n. Biol. Bull., Vol. 65. 1935 Studies on the ciliates of sea urchins. Papers from Tortugas Lab., Vol. 29. Wenrich, D. H. 1928 Eight well-defined species of Paramecium. Trans. Amer. Micr. Soc, Vol. 47. Chapter 34 Order 1 Holotricha Stein (continued) Suborder 4 Hymenostomata Hickson Cytostome not connected with peristome. .Family 1 Frontoniidae Cytostome at end or bottom of peristome Peristome sickle-form, ciliated slit; sunk at right angles to body sur- face Family 2 Ophryoglenidae (p. 555) Peristome long, begins at anterior end of body Peristome with a one-layered membrane which forms a pocket surrounding cytostome on right edge and a row of cilia or membrane on left Family 3 Pleuronematidae (p. 555) Peristome otherwise Peristome with 2 one-layered membranes; no distinct ecto- plasmic pocket around cytostome Family 4 Cohnilembidae (p. 558) Peristome furrow either covered densely with cilia, besides an undulating membrane on right edge, or with only a thick undulating membrane on the right edge Family 5 Philasteridae (p. 559) Family 1 Frontoniidae Kahl Genus Frontonia Ehrenberg. Ovoid to ellipsoid; anterior end more broadly rounded than posterior end; flattened; oral groove lies in anterior third on more or less flattened ventral surface, to right of median line; lancet-like with pointed anterior and trun- cate posterior end; left edge more curved than right edge, and posteriorly becomes a prominent ectoplasmic lip ; cytostome with a complex organization (on left edge a large undulating mem- brane composed of 3 layers, each being made up of 4 rows of cilia; on right, semi-membranous groups of cilia; 3 outer rows of cilia form the postoral suture; along this suture ectoplasm is discon- tinuous so that large food matter is taken in; wdth a small triangu- lar ciliated field posterior to cytostome and left of suture); cytopharynx with numerous strong fibrils; ciliary rows close and uniform; ectoplasm with numerous fusiform trichocysts; macro- nucleus oval; 1 to many micronuclei; 1-2 contractile vacuoles, with collecting canals and an external pore; fresh or salt water. Many species. 547 548 PUOTOZOOLOGY F. leucas E. (Figs. 22, a, h; 250, a). 150- 600^ long; fresh water. F. hranchiostomae Codreanu (Fig. 250, b). 75-100/i by 55-95^*; commensal in the branchial cavity of Amphioxus. Genus Disematostoma Lauterborn. Somewhat similar to Frontonia; pyriform; with broadly rounded, truncate or concave anterior end and bluntly rounded narrow posterior end; preoral canal wide; a dorsal ridge in posterior region of body; macronu- cleus sausage-form; a micronucleus; contractile vacuole in middle of body toward left, with long collecting canals; in fresh water. D. hutschlii L. (Fig. 250, c). 135-155^ long; with or without zoochlorellae; in fresh water. Genus Lembadion Perty. Oval ; dorsal side convex, ventral side concave; cytostome 3/4-4/5 the body length; on its left with a large membrane composed of many ciliary rows and on its right, numerous narrow rows of short free cilia; an undulating mem- brane and ciliary rows near posterior end; contractile vacuole in mid-dorsal region with a long tubule opening at posterior-right side; close ciliation uniform; macronucleus ellipsoid, subterminal; a micronucleus; long caudal cilia; in fresh water. L. hullinum P. (Fig. 250, d). 120-200^ long; posterior cilia 40- 50/i long. Genus Glaucoma Ehrenberg {Dallasia Stokes). Ovoid or ellip- soid; ventral surface more or less flattened; dorsal surface convex; cytostome about 1/4 the body length from anterior end, oblong or crescentic, with 3 undulating membranes; ectoplasmic ridge sur- rounds cytostome; ciliation and striation uniform; macronucleus rounded; a single micronucleus; with or without 1 or more caudal bristles; a single contractile vacuole; fresh water. G. pyriformis E. (Fig. 250, e). Oval with short rounded anterior end; contractile vacuole near posterior end; somewhat flattened; cytostome near anterior end with a distinct membrane; cyto- pharynx short; body 45-55ai by 30-40ai (Schewiakoff ) ; 38-80m long (Kahl) ; in fresh water. This ciliate has been reported to in- habit naturally and experimentally the body cavity of certain in- sects (p. 27-28). G. frontata (Stokes). 65-140^ long; in fresh water. G. ficaria Kahl. 50-65m long; fig-like in form; a small ectoplas- mic fringe; striae widely apart; contractile vacuole in posterior 1/5 and right-dorsal; in fresh water. Genus Lambornella KeiUn. EUipsoid; densely cihated; close HOLOTRICHA 549 Fig. 250. a, Frontonia leucas, XllO (Kahl); b, F. hranchiostomae, X490 (Codreanu); c, Disematostoma butschlii, X340 (Kahl); d, Lem- badion bullinum, X170 (Kahl); e, Glaucoma pyriformis, X380 (Schewi- akoff); f, g, Lambornella stegoniyiae, X340 (Keilin); h, Colpidium col- poda, Xl80 (Kahl); i, C. campylum, X150 (Kahl); j, Paraglaucoma rostrata, X400 (Kahl); k, Malacophrys rotans, X550 (Kahl). longitudinal striation; small oral pit in anterior half; macronu- cleus spherical; a mieronucleus; cysts hemispherical; parasitic. One species. L. stegomyiae K. (Fig. 250, /, g). 50-70^ long; cysts 30-40/i in diameter; in haemocoele of Stegotnyia scutellaris. Genus Colpidium Stein. Elongated; slightly flattened; dorsal surface more convex; cytostome 1/4 from the anterior end on right side; preoral region curved to right; cytostome similar to Glaucoma; longitudinal striation close; macronucleus spherical; a mieronucleus; a single contractile vacuole; fresh or salt water. C. {Paramaecium) colpoda (Ehrenberg) {Tillina helia Stokes) (Figs. 10, c; 250, h). Ellipsoid; anterior end bent toward right; 550 PKOTOZOOLOOY preoral suture curves to left; niacronucleus round; a micronucleus ; body 100-150m long; in stagnant water and infusion. C. (Tillina) camipylum (Stokes) (Fig. 250, i). Ellipsoid to oval; ciliary furrows further apart than the last-named species; preoral suture not curved; 50-120/i long; in fresh and brackish water. C. striatum (Stokes). Similar to the last species; contractile vacuole further posterior; 50/i long; in standing water. Genus Paraglaucoma Kahl. Somewhat similar to Glaucoma; but without perioral ectoplasmic ridge; a membrane on right ridge of the cytostome; anterior end drawn out to a point in pro- file, posterior end rounded; a stiff posterior bristle; a contractile vacuole; rapid zig-zag movement. One species. P. rostrata K. (Fig. 250, j). 60-80ju long; in fresh water (often in dead rotiferan body); California, Wisconsin (Kahl). Genus Malacophrys Kahl. EUipsoid or cyhndrical; plastic; cilia uniformly close-set in longitudinal rows ; slit-like cytostome at an- terior extremity; in fresh water. M. rotans K. (Fig. 250, k). Oval; close and dense ciliation; spherical niacronucleus central; a micronucleus; a single con- tractile vacuole; body 40-50 ju long; fresh water. Genus Espejoia Burger (Balantiophorus Penard). Ellipsoid; an- terior end obliquely truncate; large cytostome at anterior end; postoral groove on ventral side, 1/4-1/3 the body length; a con- spicuous membrane on the left edge of groove; in gelatinous envelope of eggs of insects and molluscs. E. musicola (P.) (Fig. 251, a). Elongate; right side fiat, left side convex; 80-100^ long. Genus Cryptochilidium Schouteden. Ellipsoid; Avith rounded anterior end, posterior end pointed in profile; highly compressed; uniform and close ciliation; cytostome near middle; one or more longer cilia at posterior end; contractile vacuole posterior; macro- nucleus round; a micronucleus; commensal. C. echini Maupas (Fig. 252, b). 70-140)U long; in gut of Echinus lividus. Genus Eurychilum Andre. Elongate ellipsoid; anterior end somewhat narrowed; cilia short; dense ciliation not in rows; con- tractile vacuole terminal; niacronucleus band-form; cytostome about 2/5 from anterior end and toward right, with a strong un- dulating membrane on left; no cytopharynx; actively swimming. One species. HOLOTRICHA 551 E. actiniae A. (Fig. 251, c). About 155m long; in gastrovascular cavity of Sagartia parasitica. Genus Monochilum Schewiakoff. Ovoid to ellipsoid; medium large; uniform and dense ciliation in rows; oblong cytostome left of median line, in about 1/4 the body length from anterior end; short cytopharynx conical, with an undulating membrane; con- tractile vacuole near middle , in fresh water. M. frontatum S. (Fig. 251, d). Anterior end broader; ventrally flattened, dorsally somewhat convex; macronucleus ellipsoid; a micronucleus ; feeds on algae; 80/x by 30^. Genus Dichilum Schewiakoff. Similar to Monochilum; but membrane on both edges of the cytostome; in fresh or salt water. D. cuneiforme S. (Fig. 251, e). Ellipsoid; cytostome about 1/5 the body length from anterior end; right membrane larger than left; small cytopharynx; macronucleus ellipsoid; about 40/i by 24/x; in fresh water. Genus Loxocephalus Eberhard. Ovoid to cylindrical; often compressed; crescentic cytostome on slightly flattened area near anterior end, with 2 membranes; often a zone of cilia around body; usually 1 or more long caudal setae; endoplasm granulated, yellowish to dark brown; macronucleus ovoid; a single contractile vacuole; in fresh or brackish water. Many species. L. plagius (Stokes) (Fig. 251, /). 50-65^ long; nearly cyhndrical; 15-16 cihary rows; endoplasm usually darkly colored; in fresh water among decaying vegetation. Genus Balanonema Kahl. Similar to Loxocephalus; but with plug-like ends; cytostome difficult to see; a caudal seta; macro- nucleus oval; contractile vacuole; ciliation uniform or broken in the middle zone; fresh water. B. biceps (Penard) (Fig. 251, ^f). Ellipsoid; no ciha in the middle region; contractile vacuole central; macronucleus posterior to it; 42-50m long. Genus Platynematum Kahl. Ovoid or elHpsoid; highly flattened; with a long caudal seta; contractile vacuole posterior-right; small cytostome more or less toward right side, with 2 outer mem- branes; ciliary furrows horseshoe-shaped; in fresh or salt water. P. sociale (Penard) (Fig. 251, h). Anterior half more flattened; ventral side concave; cytostome in the anterior third; yellowish and granulated; 30-50iU long; sapropelic in fresh and brackish water. 552 PROTOZOOLOGY Fig. 251. a, Espejoia niusicola, X300 (Penard); b, Cryptochilidium echini, X380 (Powers); c, Eurychilum actiniae, X360 (Andre); d, Monochihimfrontatum, X440 (Schewiakoff) ; e, Dichilum cuneiforme, X700 (Schewiakoff); f, Loxocephalus plagius, X380 (Stokes); g, j5a- lanonema biceps, X600 (Penard); h, Platynematum sociale, X500 (Kahl); i, Saprophilus agitatus, X450 (Stokes); j, *S. muscorum, X440 (Kahl); k, Cinetochilum margaritaceum, X440 (Kahl). Genus Saprophilus Stokes. Ovoid or pyriform; compressed; cy- tostome in anterior 1/4-1/3 near right edge; with 2 outer mem- branes; macronucleus spherical; contractile vacuole posterior; in fresh water. S. agitatus S. (Fig. 251, i). Ellipsoid; ends bluntly pointed; com- pressed; plastic; close striation; about 40^ long; in fresh water in decomposing animal matter such as Gammarus. S. muscorum Kahl (Fig. 251, j). Cytostome large, with a large membrane; trichocysts; contractile vacuole with a distinct canal; body about 35ju long; in fresh water. Genus Cinetochilum Perty. Oval to ellipsoid; highly flattened; cilia on flat ventral surface only; cytostome right of median line in posterior half, with a membrane on both edges, which forms a pocket; oblique non-ciliated postoral field leads to left posterior HOLOTRICHA 553 end; with 3-4 caudal cilia; macronucleus spherical, central; con- tractile vacuole terminal; in fresh or salt water. C. niargaritaceum P. (Fig. 251, k). 15-45^ long; in fresh and brackish water. Genus Dexiotrichides Kahl (Dexiotricha Stokes). Reniform; compressed ; cytostome near middle, with 2 membranes ; long cilia sparse; a special oblique row of cilia; a single caudal seta; contrac- tile vacuole terminal; spheroidal macronucleus anterior; a micro- nucleus; in fresh water. One species. D. centralis (Stokes) (Fig. 252, a). About 30-45m long; in de- caying vegetable matter. Genus Cyrtolophosis Stokes. Ovoid or ellipsoid; with a muci- laginous envelope in which it lives, but from which it emerges at will; cytostome near anterior end with pocket-forming mem- brane; on right side a short row of special stiff cilia, bent ven- trally; sparse ciliation spiral to posterior-left; spherical macronu- cleus central; a contractile vacuole; in fresh water, C. mucicola S. (Fig. 252, h). 25-28/x long; in infusion of leaves. Genus Urocentrum Nitzsch. Short cocoon-shaped, constricted behind the middle; ventral surface flat; 2 broad girdles of cilia; fused cilia at posterior end; with a zone of short ciha in the con- stricted area; cytopharynx directed toward left, with a stiff ecto- plasmic membrane which separates 2 undulating membranes (on left) and cihated zone (on right) ; macronucleus, horseshoe-shape, posterior; a micronucleus; contractile vacuole terminal, with 8 long canals which reach the middle of body; in fresh water. U. turho (Muller) (Fig. 252, c). 50-80^ long; Kidder and Diller (1934) studied its fission. Genus Urozona Schewiakoff. Ovoid, both ends broadly round- ed; a distinct constriction in middle where occur cilia; this ciliary band composed of 5-6 rows of cilia, directed anteriorly and ar- ranged longitudinally; cytostome with a membrane; rounded macronucleus and a micronucleus posterior; contractile vacuole subterminal; in fresh water. U. hutschlii S. (Fig. 252, d). 20-25ju long (Kahl) ; 30-40^ (Schew- iakoff) ; in stagnant water. Genus Uronema Dujardin (Cryptochilum Maupas). Oval to elongate ovoid; slightly flattened; anterior region not ciliated; inconspicuous peristome with ciliated right edge; cytostome on the ventral side close to left border in the anterior half, with a 554 PROTOZOOLOGY h Aidf b Fig. 252. a, Dexiotrichides centralis, X500 (Kahl); b, Cyrtolophosis mucicola, X670 (Kahl); c, Urocentrum turbo, X200 (Biitschli); d, Urozona butschlii, X440 (Kahl);e, Uronema marina, X490 (Kahl); f, g, U. pluricaudatuni, X940 (Noland); h, Homalogastra setosa, X450 (Kahl); i, j, Stokesia vernalis, X340 (Wenrich); k, Ophrxjoglena collini, Xl50 (Lichtenstein); 1, 0. pyriformis, Xl80 (Rossolimo); m, 0. in- testinalis, X55 (Rossolimo). small tongue-like membrane; cytopharynx indistinct; macro nu- cleus spherical, central; contractile vacuole terminal; in salt or fresh water. U. marina D. (Fig. 252, e). 30-50^ long; in salt water in de- caying algae. U. pluricaudatuni Noland (Fig. 252, f, g). Body appears to be HOLOTRICHA 555 twisted in dorsal view, due to a spiral depression that runs ob- liquely down toward cytostome; with about 8 caudal setae; in salt water; Florida. Genus Homalogastra Kahl. Broad fusiform; furrows spiral to left; a long caudal seta; a group of cilia on right and left sides of it; macronucleus spherical, anterior; contractile vacuole posterior; in fresh water. H. setosa K. (Fig. 252, h). About 30^ long; fresh water. Genus Stokesia Wenrich. Oblique cone with rounded angles; flat anterior surface uniformly ciliated; mth peristome bearing zones of longer cilia, at the bottom of which is located the cyto- stome; a girdle of longer cilia around the organism in the region of its greatest diameter; pellicle finely striated; with zoochlorel- lae; trichocysts; free-swimming; in freshwater pond. One species. S. vernalis W. (Fig. 252, i, j). 100-1 60^ in diameter; macronu- cleus ; 2-4 micronuclei ; fresh water. Family 2 Ophryoglenidae Kent Genus Ophryoglena Ehrenberg. Ellipsoidal to cylindrical; ends rounded or attenuated; preoral depression in form of '6' due to an ectoplasmic membrane extending from the left edge, cilia on the right edge; cytostome deep-seated; 1 (or 2) contractile vacuole with long radiating canals, opens through pores on right ventral side; macronucleus of various forms \\ith several endosomes; a micronucleus ; fresh or salt water or parasitic. Many species. 0. collini Lichtenstein (Fig. 252, k). Pyriform; macronucleus horseshoe-shape; 200-300^ by 120-230^t; in the caecum of Baetis larvae. 0. ^parasitica Andre. Ovoid; dark; micronucleus (?); 170-350^ by 180-200yu; in 'intestine' of Dendrocoelutn lacteum. 0. pyriformis Rossolimo (Fig. 252, I). Flask-shape; 240-300m long; in intestinal caeca of various Turbellaria. 0. intestinalis R. (Fig. 252, m). Up to 1.5 mm. by 450-500/^; smallest 60ju long; in the main intestinal canal of Dicotylus sp. Family 3 Pleuronematidae Kent Genus Pleuronema Dujardin, Ovoid to ellipsoid; peristome be- gins at anterior end and extends for 2/3 the body length ; a con- spicuous membrane at both edges; semicircular swelling to left near oral area; no cytopharynx; close striation longitudinal; 1 to 556 PROTOZOOLOGY Fig. 253. a, Pleuronema crassum, X240 (Kahl); b, P. anodontae, X290 (Kahl); c, d, P. setigerum, X540 (Noland); e, P. coronatum, X540 (Noland); f, P. marinum, X400 (Noland); g, Cyclidimn litome- suni, X300 (Stokes); h, Cristigera phoenix, X500 (Penard); i, C. media, X400 (Kahl). many posterior sensory bristles; macronucleus round or oval; a micronucleus ; a contractile vacuole; trichocysts in some species; fresh or salt water, also commensal in freshwater mussels. P. crassum D. (Fig. 253, a). 70-120^ long; somewhat com- pressed; Woods Hole (Calkins). P. anodontae Kahl (Fig. 253, 6). About 55ju long; posterior bristle about 1/2 the body length; in Sphaerium, Anodonta. P. setigerum Calkins (Fig. 253, c, d). Ellipsoid; flattened; ven- tral surface slightly concave; about 25 ciUary rows; 38-50m long (Noland); in salt water; Massachusetts, Florida. P. coronatum Kent (Fig. 253, e). Elongate ovoid; both ends equally rounded; caudal setae long; about 40 ciliary rows; 47-75^ long (Noland); in fresh and salt water; Florida. P. marinum D. (Fig. 253, /). Elongate ovoid; trichocysts dis- tinct; caudal setae medium long; about 50 ciliary rows; 5 1-1 26m long (Noland); in salt water; Florida. HOLOTRICHA 557 Genus Cyclidium Mliller. Small (15-60^ long); ovoid; usually with refractile pellicle; with a caudal bristle; peristome near right side; on its right edge occurs a membrane which forms a pocket around cytostomal groove and on its left edge either free cilia or a membrane which unites with that on right; no semicircular swelling on left of oral region; round macronucleus with a micro- nucleus; contractile vacuole posterior; fresh or salt water. Numer- ous species. C. litomesum Stokes (Fig. 253, g). About 40)Li long; dorsal sur- face slightly convex with a depression in middle; ventral surface more or less concave; cilia long; in fresh water. Genus Cristigera Roux. Similar to Cyclidium; much com- pressed; with a postoral depression; peristome closer to mid- ven- tral line; fresh or salt water. Several species. C. -phoenix Penard (Fig. 253, h). 37-45At long; fresh water. C. media Kahl (Fig. 253, i). 45-50/i long; in salt water. Genus Ctedoctema Stokes. Similar to Cyclidium in body form; peristome nearer median Une, diagonally right to left; right peri- stomal ridge with a sail-like membrane which surrounds the cyto- stome at its posterior end; trichocysts throughout; fresh water. C. acanthocrypta S. (Fig. 254, a). Ovoid; anterior end truncate; macronucleus round, anterior; about 35/^ long; in fresh water among vegetation. Genus Calyptotricha Philhps. Somewhat resembles Pleuronema or Cyclidium; but dwelling in a lorica which is opened at both ends; with zoochlorellae; fresh w^ater. C. pleuronemoides P. (Fig. 254, h). Lorica about 85ai high; body about 50 fjL long; Kellicott's (1885) form is more elongated; in fresh water. Genus Histiobalantium Stokes. Ovoid; ventral side flattened; ciliation uniform ; long stiff cilia distributed over the entire body surface; peristome deep; both anterior and posterior regions with a well-developed membrane, connected with the undulating membrane ; macronucleus in 2 parts ; 1-2 micronuclei ; several con- tractile vacuoles distributed; fresh water. H. nutans (Claparede et Lachmann) (Fig. 254, c). 70-1 10^ long. H. semisetatum Noland (Fig. 254, d). Elongate ellipsoid; pos- terior end bluntly rounded; macronucleus spherical; longer setae on posterior half only; contractile vacuoles on dorsal side; 126- 205^1 long; salt water; Florida. 558 PROTOZOOLOGY Genus Pleurocoptes Wallengren. Ovoid, dorsal side hemispher- ical, ventral side flattened; peristome large, reaching the posterior 1/3; cytopharynx indistinct; longer cilia along peristome; macro- nucleus spherical; several micronuclei; contractile vacuole ter- minal; ectocommensal. P. hydractiniae W. (Fig. 254, e). 60-70/x long; on Hydractinia echinata. Fig. 254. a, Ctedodema acanthocrypta, X840 (Kahl); b, C alyptotricha pleuro7iemoides, XlSO (Kahl);c, Histiobalantiumnatans, X420 (Kahl); d, H. semiselatum, X270 (Noland) ; e, Pleurocoptes hydractiniae, X470 (Wallengren); f, Cohnilemhus fusiformis, X560 (Kahl); g, C. caeci, X390 (Powers); h, Philaster digitiformis, X220 (Kahl); i, P. armata, X240 (Kahl); j, Helicostoma biiddenbrocki, Xl90 (Kahl). Family 4 Cohnilembidae Kahl Genus Cohnilembus Kahl {Lembiis Cohn). Slender spindle- form; flexible; peristome from anterior end to middle of body or longer, curved to right, with 2 membranes on right edge; a caudal seta or a few longer cilia at posterior end; macronucleus oval, near middle; in salt or fresh water, some endozoic. HOLOTRICHA 559 C . fusiformis (C.) (Fig. 254,/). Striation spiral; peristome about 1/6 the body length; a few cilia at posterior end; oval macronu- cleus central; contractile vacuole posterior; about GO/i long; in fresh water. C. caeci Powers (Fig. 254, g). About 32-92^t long; in intestine of Triyneustes esculentus and other echinoids; Tortugas. Family 5 Philasteridae Kahl Genus Philaster Fabre-Domergue {Philasterides Kahl). Body cyhndrical; peristome about 1/3-2/5 the body length, broader near cytostome and with a series of longer cilia; cytostome with a triangular membrane; cytopharynx (?); ciliation uniform; a caudal seta; trichocysts; oval macronucleus with a micronucleus in middle ; contractile vacuole terminal or central ; in salt or fresh water. P. digitiforniis F.-D. (Fig. 254, h). Anterior region bent dor- sally; contractile vacuole terminal; 100-150/x long; salt water. P. armata (K.) (Fig. 254, i). Anterior end more or less straight; peristome difficult to see; contractile vacuole central; 70-80)u long; fresh water. Genus Helicostoma Cohn. Similar to Philaster in general ap- pearance; preoral side-pouch curved around posterior edge of peristome and separated from it by a refractile curved band; with or without pigment spot near cytostome; macronucleus oval or band-form ; contractile vacuole terminal ; in salt water. H. huddenhrocki Kahl (Fig. 254, j). 130-200/i long; in salt and brackish water. References IvAHL, A. 1931 Urtiere oder Protozoa. In Dahl's Die Tierwelt Deutschlands., Part 21. NoLAND, L. E. 1937 Observations on marine ciliates of the Gulf coast of Florida. Trans. Amer. Micr. Soc, Vol. 56. Wenrich, D. H. 1929 Observation on some freshwater ciliates. I. Teutophrys trisula Chatton and de Beauchamp and Stokesia vernalis n.sp. Ibid., Vol. 48. Chapter 35 Order 1 Holotricha Stein (continued) Suborder 5 Thigmotricha Chatton et Lwoff THE majority of the ciliates placed in this suborder inhabit the mantle cavity of mussels. They possess thigmotactic cilia with which they attach themselves to the host body. Though ap- pearing heterogeneous, Chatton and Lwoff hold that there is a phylogenetic unity among them, which has been brought about by the degenerative influence because of the similar conditions of habitat. Without tentacles Ciliation uniform; ciliary rows meridional, close; peristome does not begin near the anterior end Thigmotactic cilia on entire broad side; with large peristome. . . . Family 1 Conchophthiridae Thigmotactic cilia only on a small field of left broad side; peri- stome small Family 2 Thigmophryidae (p. 561) Ciliation unequal on 2 broad sides or spirally arranged, or greatly rudimentary Cytostome with conspicuous peristome bearing long cilia Family 3 Ancistrumidae (p. 562) Cytostome rudimentary Family 4 Sphenophryidae (p. 565) With tentacular attaching organella . Family 5 Hypocomidae (p. 566) Family 1 Conchophthiridae Reichenow Genus Conchophthirus Stein. Oval to elUpsoid; flattened; right margin concave at cytostomal region, left margin convex; ventral surface somewhat flattened, dorsal surface convex; cytostome on right side near middle in a depression with an undulating mem- brane; macronucleus ; micronucleus; contractile vacuole opens through a canal to right side; in mantle cavity and gills of various mussels. Kidder made careful studies of several species. C. anodontae (Ehrenberg) (Figs. 60; 255, a). Ovoid; cytostome on dorsal surface in anterior third, with an overhanging projec- tion in front; cytopharynx, surrounded by circular fibrils, con- tinues down as a fine, distensible tubule, to behind the macronu- cleus; with peristomal basket; cihary grooves originate in a wide ventral suture near anterior end; anterior region filled with re- 560 HOLOTRICHA 561 fractile granules; macronucleus posterior; contractile vacuole be- tween nuclei and peristome, with a slit-like aperture (Fig. 27); 65-1 25Ai by 47-86^; in mantle cavity, gills and on non-ciliated surface of palps of Elliptio cornplanatiis; Woods Hole. C. curtus Engelmann. Somewhat broader; 60-125^ by 50-90^1; peristomal field smaller; cytopharynx less conspicuous, but long- er; ciliation dense; endoplasmic granules are more closely packed and do not extend as far out toward anterior end; macronucleus central; Kidder found this ciliate in the mantle cavity of Anodon- ta marginata, A. implicata, A. catareda, Lampsilis radiata, L. cariosa and Alasmidonta undulata which were obtained from the freshwater lakes of Massachusetts and New York. C. magna Kidder. Much larger; 123-203ju by 63-116//; closer cihation; anterior 1/3 filled with smaller granules; irregularly outlined macronucleus, 25-30)U in diameter, central; 2 (or 1) micronuclei ; aperture for contractile vacuole large ; mantle cavity of Elliptio complanatus ; Massachusetts. C. caryoclada K. (Fig. 255, h). Oval; extremely flattened; leaf- like ; cytostome small, in posterior fourth ; macronucleus conspic- uously branched; 2 (1) micronuclei; 140-250^ by 90-160/^; mantle cavity of the edible clam, Siliqua patula; Oregon. C. mytili De Morgan (Fig. 53). Reniform; 130-202^ by 76- 16 1m; peristomal groove on right side; trichocysts conspicuous along frontal margin; macronucleus oval; 2 micronuclei. Kidder (1933) found the organism on the foot of the common mussel, Mytilus edulis, in New York and studied its division and conju- gation. Genus Myxophyllum Raabe. Oval or spheroid; pellicle elastic and flexible; peristome on posterior right, without undulating membrane; 7 macronuclei; a micronucleus; ciliation uniform; in the slime covering land pulmonates. M. steenstrupi (Stein) (Fig. 255, c). 120m by 100-120^; on Suc- cinea putris, etc. Family 2 Thigmophryidae Chatton et Lwoff Genus Thigmophrya Chatton et Lwoff. Elongate; round or ob- long in cross-section; cytostome in posterior third; contractile vacuole opens in cytopharynx; on gills or palps of lamellibranchs. T. macomae C. et L. Elongate ovoid; flattened; ventral surface slightly concave; oral funnel opened; contractile vacuole opens at 562 PROTOZOOLOGY ■^.<-TTTmS^^ Fig. 255. a, Conchophthirus anodontae, X400 (Kidder); b, C. caryoclada, X270 (Kidder); c, Myxophyllum steenstrupi, X370 (Raabe); d, e, Ancistruma mytili, X670 (Kidder); f, A. isseli, X670 (Kidder). the bottom of cytopharynx; numerous ciliary rows; about llO^i by 40^t; on gills of Macoma (Tellina) halthica. Family 3 Ancistrumidae Issel Genus Ancistruma Strand (Ancistrum Maupas). Ovoid, pyri- form or somewhat irregular; flattened; right side with more numerous large ciha than the left; peristome on right side; cyto- HOLOTRICHA 563 stome near posterior extremity; macroniicleiis round or sausage- shape, central; a micronucleus; contractile vacuole posterior; commensal in mantle cavity of various marine mussles. Many species. A. mytili (Quennerstedt) (Figs. 18; 255, d, e). Oval; dorsal sur- face convex, ventral surface concave; dorsal edge of peristome curves around the cytostome; peristomal floor folded and pro- truding; longitudinal ciliary rows on both surfaces; 3 rows of long cilia on peristomal edges ; macronucleus sausage-form ; a compact micronucleus anterior; 52-74;u by 20-38/^; Kidder (1933) found it in abundance in the mantle cavity of Mytilus edulis at Woods Hole and New York. A. isseli Kahl (Fig. 255, /). Pointed at both ends; 70-88^ by 31-54/x; Kidder (1933) observed it abundantly in mantle cavity of the solitary mussel, Mediola mediolus, Massachusetts and New York, and made clear its conjugation and nuclear reorganiza- tion. Genus Eupoterion MacLennon et Connell. Small ovoid; slightly compressed; cilia short, in longitudinal rows; rows of long cilia in peristome on mid- ventral surface and extends posteriorly, making a half turn to left around cytostome ; small conical cytostome lies in postero-ventral margin of body; contractile vacuole terminal; large round macronucleus anterior; a micronucleus; commensal. E. pernix M. et C. (Fig. 156, a). 46-48 ciliary rows; 6 rows of heavy peristomal cilia; 38-56yu long; in intestinal contents of the mask limpet, Acfnaea persoria; California. Genus Ancistrina Cheissin. Ovoid; anterior end attenuated; peristomal field along narrow right side; 15-18 ciliary rows paral- lel to peristomal ridges; cytostome right-posterior, marked with oral ring, with a membrane and a zone of membranellae ; right ridge of peristome marked by 2 adoral ciliary rows; macronucleus anterior, spheroidal; a micronucleus; commensal. A. ovata C. (Fig. 256, b). 38-48|U by 15-20ai; in mantle cavity of molluscs: Benedictia hiacalensis, B. Umneoides and Choanom- phalus sp. Genus Ancistrella Cheissin. Elongate; ends rounded; ventral surface less convex than dorsal surface; 16-17 longitudinal ciliary rows; cihation uniform, except anterior-dorsal region, bearing bristle-like longer cilia; 2 adoral ciliary rows on right of peristome, curved dorsally behind cytostome; contractile vacuole posterior; 564 PROTOZOOLOGY Fig. 256. a, Eupoterion pernix, X670 (MacLennan and Connell); b, Ancislrina ovata, XS40 (Cheissin); c, Ancistrella choanomphali, X840 (Cheissin); d, Boveria teredinidi, X550 (Pickard); e, Plagiospira crinita, X740 (Issel); f, Hemispeira asteriasi, X940 (Wallengren) ; g, h, Hypocoma acinetamm, X400 (Collin); i-k, H. patellarum (i, j, X820; k, X670) (Lichtenstein). macronucleus single or divided into as many as 7 parts; a micro- nucleus; commensal. A. choanomphali C. (Fig. 256, c). 55-90m by 18-20/^; in mantle cavity of Choanomphalus sp. Genus Ancistrospira Chatton et Lwoff. Ciliation meridional to spiral; peristome right spiral; commensal. HOLOTRICHA 565 A. veneris C. et L. 50-60^ by 22-28;u; ovoid; anterior end point- ed; ciliary rows meridional; thigmotactie field on left side, sharply marked from body ciliation ; on gills of Ve7ius fasciata. Genus Boveria Stevens (Tiarella Cheissin). Conical; cytostome at posterior end; peristome spiral posteriorly; macronucleus oval, in anterior half; a micronucleus; contractile vacuole posterior; ectocommensal on gills of various marine animals such as Teredo, Bankia, Tellina, Capsa and Holothuria. Several species. B. teredinidi Pickard (Fig. 256, d). 27-173m by 12-31/^; on gills on Teredo navalis; California. Genus Plagiospira Issel. Conical; anterior end attenuated; peristome runs spirally from middle of body to cytostome, with long cilia; macronucleus oval, anterior; a micronucleus; contrac- tile vacuole near middle of body; somewhat spirally arranged striae widely apart on right side; commensal. P. crinita I. (Fig. 256, e). 32-58/i by 18-34ai; in Cardita calycu- lata and Loripes lacteus. Genus Hemispeira Fabre-Domergue. Nearly spherical; flat- tened; longitudinal non-ciliated furrow on ventral surface, which encircles thigmotactie posterior cilia; 4-5 cross-furrows of cilia; a huge adoral membrane at anterior end; macronucleus, micro- nucleus large; contractile vacuole, anterior-right; commensal. H. asteriasi F.-D. (Fig. 256,/). 20-30^ long; ectocommensal on Asierias gracilis. Genus Hemispeiropsis Konig. Oval; body surface not cihated, except the aboral end which bears 1-2 cross-rows of cilia and thig- motactie cilia; adoral membrane double; macronucleus large, spherical, with an imbedded micronucleus; contractile vacuole central; ectocommensal. H. comatulae K. About 23-27^ long, excluding membrane; on Comatula mediterranea. Family 4 Sphenophryidae Chatton et Lwoff Genus Sphenophrya Chatton et Lwoff. Triangular to crescen- tic; in mature state, basal rows of cilia distinct on a broad side, converging toward middle, from which budding takes place side- wise; in gills of mussels. S. dosiniae C. et L. 120/x by 15-20ju; fijied to interfilamental space of gills of Dosinia exoleta. 566 PROTOZOOT.OGY Family 5 Hypocomidae Biitschli Genus Hypocoma Gruber. Cilia confined, or reduced, to hold- fast organella at anterior end, arranged in longitudinal rows; with a sucking tentacle which probably serves for obtaining nourish- ment; cytostome apparently vestigial; commensal. The genus has been placed in Suctoria; but Chatton and Lwoff showed that ciHation is lengthwise and not crosswise as in Suctoria. H. acinetarum Collin (Fig. 256, g, h). On Acineta papillifera. H. patellar mn Lichtenstein (Fig. 256, i-k). On gills of Patella caerulea; about 30/^ long. H. cardii Chatton et Lwoff. On Cardium edule. Genus Hypocomides Chatton et Lwoff. Ovate; slightly flat- tened; anterior end attenuated, a few meridional striae; adoral rows reduced; commensal in mussels. H. zyrphaeae C. et L. 25-30;u by 12-15^; in gills of Zyrphaea crispata. References Chatton, E. and A. Lwoff 1926 Diagnoses de cilies thigmo- triches nouveaux. Bull, soc, zool. Fr., Vol. 5L Cheissin, E. 1931 Infusorien Ancistridae und Boveridae aus dem Baikalsee. Arch. f. Protistenk., Vol. 73. Kahl, a., 1931, 1935 Dahl's Die Tierwalt Deutschlands. Parts 21, 30. Kidder, G. W., 1933 Studies on Conchophthirus myiili De Morgan. I, II. Arch. f. Protistenk., Vol. 79. 1933 On the genus Ancistruma Strand (Ancistrum Maupas). I. Biol. Bull. Vol. 64; II. Arch. f. Protistenk., Vol. 81. 1934 Studies on the ciliates from freshwater mussels. I, II. Biol. Bull., Vol. 66. MacLennan, R. F. and F. H. Connell 1931 The morphology of Eupoterion pernix gen. nov., sp. nov. Uni. Calif. Publ. Zool., Vol. 36. Stevens, N. M. 1903 Further studies on the ciliate Infusoria, Licnophora and Boveria. Arch. f. Protistenk., Vol. 3. Chapter 36 Order 1 Holotricha Stein (continued) Suborder 6 Apostomea Chatton et Lwoff ASYMMETRICAL forms with a rosette-like cytostome ^ through which hquid or small solid particles are taken into the body; sparse ciHary rows spiral; adoral rows short; macronu- cleus oval to band-form; a micronucleus; a single contractile vacuole. The life-cycle of the ciliates grouped here appears to be highly complex and Chatton and Lwoff (1935) distinguished several developmental phases (Fig. 257), as follows: 1) Trophont or vege- tative phase: right-spiral ciliary rows; nucleus pushed aside by food bodies; body grows, but does not divide. 2) Protomont: transitory stage between 1 and 3 in which the organism does not nourish itself, but produces "vitelloid" reserve plates; nucleus central, condensed; ciliary rows become straight. 3) Tomont: the body undergoes division usually in encysted condition into more or less a large number of small ciliated individuals. 4) Pro- tomite: a stage in which a renewed torsion begins, and which leads to tomite stage. 5) Tomite: small free-swimming and non- feeding stage, but serves for distribution. 6) Phoront: a stage which is produced by a tomite when it becomes attached to a crustacean and encysts; within the cyst a complete transforma- tion to trophont takes place. Family Foettingeriidae Chatton Genus Foettingeria Caullery et Mesnil. Trophonts large, up to 1 mm. long; sublenticular, anterior end attenuated; dorsal sur- face convex, ventral surface concave; right side less convex than left side; 9 spiral ciliary rows nearly evenly arranged; in gastro- vascular cavity of various actinozonas; tomont on outer surface of host body, gives rise to numerous tomites with meridional ciliary rows; each tomite becomes a phoront by encysting on a crustacean, and develops into a trophont when taken into gastro- vascular cavity of an actinozoan. One species. F. actiniarum (Claparede) (Fig. 258, a). Phoronts on Copepoda, Ostracoda, Amphipoda, Isopoda and Decapoda; trophonts in 567 568 PROTOZOOLOGY (Idyaea furcata) •?(:, Phoront //y^>A \ >\ -'V^ Young trophont (Cladonema radiatum) Fig. 257. Diagramjillustrating the life-cycle of Spirophrya subparasitica (Chatton and Lwoff). Actinia mesemhryanthemum, A. equina, Anemonia sulcata and other actinozoans in European waters; Chatton and Lwoff found Metridium marginatum, Sagartia leucolena and Astrangia danae of Woods Hole free from this cihate. Genus Spirophrya Chatton et Lwoff. Trophonts ovoid, pointed anteriorly; 16 uninterrupted ciUary rows of which striae 1 and 2 HOLOTRICHA 569 Fig. 258. a, Foettingeria actiniarum, a trophont; b, Spirophrya suparasitica, a trophont, XlOOO; c, Phoretrophrya nebaliae, X1180; d, Synophrya hypertrophica (All, Chatton and Lwoff). approach each other in posterior-dorsal region; phoronts at- tached to a crustacean; when eaten by Cladonema, trophonts enter the crustacean body and complete growth; protomonts up- on leaving the host body encyst and each divides into 4-82 to- mites (Fig. 257). One species. S. suhparasitica C. et L. (Figs. 257; 258, 6). Phoronts attached 570 PROTOZOOLOCxY * to Idyaea fiircata; ovoid tro])honts enter the copopod when eaten by Cladnema radiatuni,. Genus Gymnodinioides Minkiewicz {Physophaga Percy; Oospi- ra Chatton et Lwoff; Hyalospira Miyashita). Trophonts twisted along equatorial plane; generally 9 ciliary rows, in some a rudi- mentary row between striae 5 and 6 at anterior end. Many spe- cies. G. calkinsi Chatton et Lwoff. Phoronts on gills and trophonts in the moult of Palaemonetes sp. ; Woods Hole. Genus Phoretrophrya Chatton et Lwoff. Trophonts generally with 9 ciliary rows; striae 1, 2, and 3, close to one another. One species. P. nehaliae C. et L. (Fig. 258, c). Phoronts and tomonts on appendages, and trophonts in the moult, of Nehalia geoffroyi. Genus Synophrya Chatton et Lwoff. Trophonts and tomonts similar to those of Gymnodinioides; but development highly com- plicate. One species. S. hypertrophica C. et L. (Fig. 258, d). Phoronts in branchial lamellae, and trophonts in the moult, of Portunus depurator, etc. Geniis Ophiurespira Chatton et Lwoff. Trophonts ovoid; 10 ciliary rows; striae 9 and 10 interrupted. One species. 0. weilli C. et L. (Fig. 259, a). Trophonts in intestine of Ophio- thrix fragilis and Amphiura squamata. Genus Photorophrya Chatton et Lwoff. Trophonts small; cilia- tion approximately that of Ophiurespira; massive macronucleus; with peculiar trichocysts comparable with the nematocysts of Polykrikos (p. 228); ecto- or endo-parasitic in encysted stages of other apostomeans. Several species. P. insidiosa C. et L. (Fig. 259, 6). Phoronts, trophonts and tomites in phoronts of Gymnodinioides. Genus Polyspira Minkiewicz. Trophonts reniform ; 9 rows and several extra rows; striae 1-4 and 5-9 with 2 others in 2 bands. P. delagei M. (Fig. 260, a). Phoronts on gills and trophonts in the moult of Eupagurus berhardus. Genus Pericaryon Chatton. Trophonts ellipsoid; 14 ciliary rows. P. cesticola C. (Fig. 259, d). Trophonts in gastro-vascular cav- ity of the ctenophore, Cestus veneris; other stages unknown. Genus Calospira Chatton et Lwoff. Trophonts resemble those of Spirophrya; 20 ciliary rows; macronucleus twisted band-form; a micronucleus. HOLOTRICHA 571 Fig. 259. a, Ophiurespira weilli; h, Photorophrya insidiosa, a troph- ont in a phoront of Gymnoidioides, X800; c, Vampyrophrya pelagica, a trophont, X740; d, Pericaryon cesticola, a trophont (All, Chatton and Lwoff). C. minkiewiczi C. et L. (Fig. 260, 6). Phoronts attached to in- tegument of Harpacticus gracilis (copepod); trophonts in its fresh carcass; tomonts and tomites in water. Genus Vampyrophrya Chatton et Lwoff. Trophonts ovoid; 10 ciliary rows, of which striae 3-8 are uninterrupted. One species. V. pelagica C. et L. (Fig. 259, c; 260, c). Phoronts on Paracala- nus parvus, Clausocalanus furcatus, etc., and trophonts in their fresh carcasses. 572 PROTOZOOLOGY Fig. 260. a, Polyspira delagei; b, Calospira minkiewiczi, a trophont, X1300; c, Vamfyro-phrya pelagica; d, Traumatiophtora punctata, X1300 (All, Chatton and Lwoff). Genus Traumatiophtora Chatton et Lwoff. Trophonts oval; 11 ciliary rows. One species. T. punctata C. et L. (Fig. 260, d). Trophonts in fresh carcass of Acartia clausi. Reference Chatton, E. and A. Lwoff 1935 Les cilies apostomes. Arch, zool. exp. et gen., Vol. 77. Chapter 37 Order 2 Spirotricha. Butschli With free cilia only; exceptionally with small groups of cirrus-like pro- jections in addition to cilia Uniformly ciliated; in Peritromidae dorsal surface without cilia or with a few cilia; in Licnophoridae cilia only on edge of attaching disk; peristome usually extended; peristomal field mostly cili- ated Suborder 1 Heterotricha Ciliation much reduced or none at all Rounded in cross-section; cilia usually much reduced; adoral zone encloses a non-ciliated peristomal field in spiral form Suborder 2 Oligotricha (p. 587) Compressed; carapaced; peristomal zone reduced to 8 membra- nellae which lie in a oval hollow Suborder 3 Ctenostomata (p. 600) Cirri only, on ventral side; dorsal side usually with rows of short slightly movable bristles Suborder 4 Hypotricha (p. 603) Suborder 1 Heterotricha Stein Body ciliation complete and uniformly the same Peristome sunk in a funnel-like hollow at anterior end, thus mostly covered Family 1 Bursariidae (p. 574) Peristome lies almost completely free, leading to a short and narrow oral funnel (absent in one family) A narrow non-ciliated zone on right of adoral zone; usually an undulating membrane or ciliary row to right of this non- ciliated zone and anterior to cytostome; a small peristomal field between the membrane and adoral zone Adoral zone extends diagonally to posterior-right on ventral surface; highly developed forms, with a long zone twisting spirally around body Family 2 Metopidae (p. 576) Adoral zone parallel to body axis on flat ventral surface, turns somewhat to right in front of cytostome; oral funnel dis- tinct; typically an undulating membrane or a double ciliated furrow in front of cytostome Family 3 Spirostomidae (p. 578) Without the non-ciliated zone; a large peristomal field with a half or completely spiral adoral zone Peristomal field not ciliated ; with a large undulating membrane on its right edge Family 4 Condylostomidae (p. 581) Peristomal field ciliated; without undulating membrane Peristomal field not drawn out in 2 wings; free-swimming or secretes gelatinous lorica Family 5 Stentoridae (p. 581) 573 574 PROTOZOOLOGY Peristomal field drawn out into 2 wings; with flask-shaped, thin-walled pseudochitinous lorica Family 6 Folliculinidae (p. 584) Body ciliation either confined to ventral side or lacking Free-living; flattened; cilia only on ventral surface; adoral zone sur- rounds anterior region of ventral surface; cytostome on left edge near middle of body Family 7 Peritromidae (p. 584) Ectocommensal; extremities discoid; body narrowed; anterior disk surrounded spirally by adoral zone; posterior disk bears mem- branous cilia Family 8 Licnophoridae (p. 586) Family 1 Bursariidae Perty Genus Bursaria Miiller. Ovoid; anterior end truncate, posterior end broadly rounded; dorsal surface convex, ventral surface flattened; deep peristome begins at anterior end and reaches about central part of body, where it gives rise to cytostome and cytopharynx, which is bent to left; lengthwise fold divides peri- stome into 2 chambers; striation longitudinal; ciliation complete and uniform; macronucleus band-form; many micronuclei; many contractile vacuoles distributed along lateral and posterior bor- ders; cysts with a double envelope; fresh water. One species. B. truncatella M. (Fig. 261, a). 500-IOOOm long. Genus Thylacidium Schewiakoff. Similar to Bursaria in general appearance; but smaller in size, peristome simple in structure without longitudinal fold; with zoochlorellae; fresh water. One species. T. truncatum S. (Fig. 261, h). 60-100m long. Genus Bursaridium Lauterborn. Similar to Bursaria; peri- stome funnel turns to right , fresh water. B. difficile Kahl (Fig. 261, c). Anterior end truncate, slanting toward right; about 130/i long. Genus Balantidium Claparede et Lachmann {Balantidiopsis Biitschli; Balantiod aides Alexeieff). Oval, ellipsoid to subcylindri- cal; peristome begins at or near anterior end; cytopharynx not well developed; longitudinal ciliation uniform; macronucleus elongated; a micronucleus; contractile vacuole and cytopyge ter- minal; in gut of vertebrates and invertebrates. Numerous species. Hegner (1934) states that the size and shape of body and macro- nucleus could be made a satisfactory basis for specific identifica- tion. B. coli (Malmsten) (Fig. 261, d, e). Ovoid or pyriform; 30 150^ by 25-120/i; oblique peristomal depression below anterior tip; SPIROTRICHA, HETEROTRICHA 575 adoral zone distinct; macronucleus sausage-form; 1-2 contractile vacuoles; cytopyge terminal; food vacuoles with red blood cor- puscles, leucocytes, etc.; cysts 50-60/x long; in colon of man, pigs, and chimpanzees. The infection in man is presumably acquired Fig. 261. a, Bursaria truncatella, X60 (Kahl); b, Thylacidium trun- catum, X440 (Schewiakoff ) ; c, Bursaridiwm dijficile, X210 (Kahl); d, e, Balantidium coli, X540 (Kudo); f, B. duodeni, Xl70 (Stein); g, B. praenudeatum, X950 (Kudo and Meglitsch). through cysts from pigs in which the organism is, as a rule, quite common and is responsible for the balantidiosis in unfortunate patients; widely distributed. B. suis McDonald. Ellipsoid; 35-120;u by 20-60ju; macronu- 576 PROTOZOOLOGY cleus more elongate and narrow; in pigs, apparently not infectious to man. Other domestic and wild animals harbor various species of Balantidium. B. duodeni Stein (Fig. 261,/). 70-80m by 55-60^; in intestine of the frog. B. praenucleatum Kudo et Meglitsch (Fig. 261, g). 42-127/i long, 32-102/x thick, 25-80At wide; macronucleus close to anterior end; in colon of Blatta orientalis. Family 2 Metopidae Kahl Genus Metopus Claparede et Lachmann. Body form change- able because of soft ectoplasm ; when extended oblong or fusiform ; peristome conspicuous, slightly spirally diagonal, beginning at anterior end and reaching middle of body; when contracted, peri- stome much spirally coiled; cytopharynx short; body ciliation uniform, longitudinal or in some, spiral; longer cilia at ends; con- spicuous contractile vacuole terminal; macronucleus ovoid to elongate; fresh or salt water, some parasitic. Numerous species. M. es (Miiller) (Figs. 76; 262, a). 120-200^ long; sapropehc. Noland's (1927) study on its conjugation has been described (p. 152). M. striatus McMurrich (Fig. 262, h). 80-120^ long; fresh water. M. fuscus Kahl (Fig. 262, c). 180-300)U long by 60/i wide and 40/i thick; fresh water. M. circumlahens Biggar (Fig. 262, d). 70-1 65m by 50-7 5^; in digestive tract of sea urchins, Diadema setosum and Echinometris suhangularis ; Bermuda (Biggar). Powers observed it in Centre- chinus antillarum, etc., at Tortugas. Genus Spirorhynchus da Cunha. Fusiform; somewhat flat- tened; anterior end drawn out and curved toward left; posterior end also drawn out; spiral peristome; cytopharynx small with an undulating membrane; cilia uniformly long; contractile vacuole posterior; longitudinally striated; body surface mth closely ad- hering bacteria (Kirby); 3 spherical macronuclei; micronucleus (?); in brackish water. S. verrucosus d. C. (Fig. 262, e). 122-140/i by 20-22^; Kirby observed it in salt marsh with 3 per cent salinity; California. Genus Caenomorpha Perty (Gyrocoris Stein). Bell-shaped; car- apaced ectoplasm in some species bears protrichocysts; strong SPIROTRICHA, HETEROTRICHA 577 marginal zone of about 8 rows of cilia; 1-2 dorsal rows of longer cilia and a dense spiral field around caudal prolongation; peri- stome long; cytostome posterior; cytopharynx directed anteri- FiG. 262. a, Metopus es, X260 (Kahl); b, M. striatus, X220 (Kahl); c, M. fuscus, X150 (Kahl); d, M. circumlahens, X370 (Powers); e, Spirorhynchus verrucosus, X360 (Kirby); f, Caenomorpha medusula, X200 (Blochmann); g, Blepharisma lateritium, Xl60 (Penard); h, B. persicinum, X290 (Penard); i, B. steini, X340 (Penard); j, Protocruzia pigerrima, X390 (Faria, da Cunha and Pinto); k, Phacodinium metschnicoffi, X270 (Kahl). orly; a single elongate or 2 spherical macronuclei; a micronucleus; fresh or salt water (sapropelic). Several species. C medusula P. (Fig. 262, /). 150^ by 130^; fresh and brackish water. Several varieties. 578 PROTOZOOLOGY Family 3 Spirostomidae Kent Genus Spirostomum Ehrenberg. Elongated; cylindrical; some- what compressed; ectoplasm with highly developed myonemes which are arranged lengthwise independent of ciliary rows, hence highly contractile; yellomsh to brown; excretory vacuole terminal large, with a long dorsal canal; macronucleus either ovoid or chain form; cilia short; rows longitudinal; caudal cilia are thigmo- tactic, secrete mucous threads (Jennings) ; peristome lined closely with short membranellae ; fresh or salt water. Several species. S. amhiguum E. (Fig. 263, a). 1-3 mm. long (length: width, 10:1); macronucleus chain-form; peristome 2/3 the body length; fresh water. S. minus Roux (Figs. 36; 263, h). 500-800^ long; macronu- cleus chain-form; in fresh and salt water (Kahl). S. loxodes Stokes (Fig. 263, c). About 300/x long (length : width, 6-7:1); peristome about 1/3 the body length; obhque striation longer cilia at ends; macronucleus chain-form; fresh water. S. intermedium. Kahl (Fig. 263, d). Slender; 400-600^ long macronucleus chain-form; fresh water. S. teres Claparede et Lachmann (Fig. 263, e). 150-400/i long macronucleus oval; in fresh w^ater and also reported from salt water. S. filum (E.) (Fig. 263, /). Peristome 1/4 the body length; pos- terior end drawn out; 200-300// up to 700/x long; fresh water. Genus Gruberia Kahl. Similar to Spirostomum. in general ap- pearance; but posterior end drawn out; slightly contractile; con- tractile vacuole posterior; macronucleus compact or beaded; salt water. G. calkinsi Beltran (Fig. 263, g). 200-800/^ long; peristome 2/3 the body length; many (contractile ?) vacuoles distributed; Woods Hole. Genus Blepharisma Perty. Pyriform, spindle-form or ellipsoid; somewhat narrowed anteriorly; compressed; peristome on left border, which is twisted to right at posterior end and connected with oral funnel with membrane; in front of cytostome a 2-lay- ered undulating membrane on right edge; ciliary rows longitudi- nal; ciliation dense; contractile vacuole and cytopyge terminal; macronucleus one or divided into several parts; several species rose-colored; fresh or salt water. Many species. B. lateritium (Ehrenberg) (Fig. 262, g). 130-200/x long; pyri- SPIROTRICHA, HETEROTRICHA 579 Fig. 263. a, Spirostomum ambiguum, X65 (Kahl); b, S. minus, Xl40 (Kahl); c, S. loxodes, X240 (Stokes); d, S. intermedium, Xl40 (Kahl); e, S. teres, X200 (Kahl); f, S. filum, Xl90 (Penard); g, Gru- beria calkinsi, Xl40 (Bertran); h, Pseudoblepharisma tenuis. X310 (Kahl); i, Parablepharisma pellitum, X340 (Kahl). form; macronucleus oval; a micronucleus; rose-colored; fresh wa- ter among decajdng leaves. 580 PROTOZOOLOGY B. perisimim P. (Fig. 262, h). 80-1 20/x long; elongate oval; posterior end pointed; left peristomal edge sigmoid; preoral mem- brane large; macronucleus in 3-7 parts; rose-colored; fresh water among decaying vegetation. B. steini Kahl (Fig. 262, i). 80-200^ long; macronucleus ovoid; reddish to colorless; fresh water in sphagnum. B. undulans Stein. 150-300^ long; macronucleus in 2 parts; undulating membrane long; cytopharynx directed posteriorly; fresh water among decaying vegetation. Moore (1934) studied its contractile vacuole and Giese (1938) observed the influence of light upon its coloration (p. 37). Genus Protocruzia Faria, da Cunha et Pinto. Peristome does not turn right, leads directly into cytostome; convex left side not ciliated, but bears bristles; flat right side with 3-5 faintly marked ciliary rows; peristome begins at pointed anterior end and ex- tends 1/4-1/3 the body length; cytopharynx (?); macronucleus simple; contractile vacuole subterminal; salt water. P. pigerrima (Cohn) (Fig. 262, j). About 20m (da Cunha); 50- 60/i long (Kahl); peristome 1/4-1/3 the body length; salt water. Genus Phacodinium Prowazek. Oval; marked grooves on body surface; cilia in cirrus-like fused groups; peristome long on left margin; cytostome posterior; contractile vacuole terminal; mac- ronucleus horseshoe-shape; 5-9 micronuclei; fresh water. One species. P. metchnicoffi (Certes) (Fig. 262, k). About lOOw long. Genus Pseudoblepharisma Kahl. Body form intermediate be- tween Spirostomum and Blepharisvia ; right peristomal edge with 2 rows of cilia; fresh water. P. tenuis K. (Fig. 263, h). 100-200^ long. Genus ParablepharismaKahl. Similar to Blepharisma; but peri- stome-bearing anterior half narrowed neck-like and pointed; ec- toplasm covered with gelatinous layer in which symbiotic bacteria are imbedded; salt water. P. pellitum K. (Fig. 263, i). 120-180^ long. Genus Nyctotherus Leidy. Oval or reniform; compressed; peri- stome begins at anterior end, slightly turns to right and ends in cytostome located midway between the ends; cytopharynx runs dorsally and posteriorly, a long tube with undulating membrane; ciliary rows longitudinal and close-set; massive macronucleus in anterior half with a micronucleus ; in some, nuclei are suspended SPIROTRICHA, HETEROTRICHA 581 by karyophore; endoplasm with discoid glycogenous substance, especially in anterior region, hence yellowish to brown; contrac- tile vacuole and cytopyge terminal; in colon of Amphibia and various invertebrates. Numerous species. N. ovalis L. (Figs. 3; 264, a, h). Ovoid; anterior half com- pressed; macronucleus elongate, at right angles to dorso-ventral axis at anterior 1/3; micronucleus in front of macronucleus; dis- tinct karyophore; glycogen bodies; 90-1 85^ by 62-95/^; giant forms up to 360^t by 240/^; cysts 72-106ai by 58-80//; in colon of cockroaches. The chromatin spherules of the macronucleus are often very large (p. 35). N. cordiformis (Ehrenberg) (Figs. 75; 264, c). 60-200^ by 40- 140/^; ovoid; micronucleus behind macronucleus; no karyophore; in colon of frogs and toads. Wichterman (1936) studied its life- cycle in Hyla versicolor (Fig. 75). Family 4 Condylostomidae Kahl Genus Condylostoma Dujardin. Ellipsoid; anterior end trun- cate, posterior end rounded or bluntly pointed; slightly flattened; peristome wide at anterior end and V-shaped, peristomal field not ciliated; a large membrane on right edge and adoral zone on left; macronucleus moniliform; one to several contractile vacuoles often with canal; cytopyge posterior; fresh or salt water. Many species. C. vorticella (Ehrenberg) (Fig. 264, d). 100-200^ long; fresh wa- ter. C. patens (Mtiller). 350-550^ long; salt water; Woods Hole (Calkins). Family 5 Stentoridae Carus Genus Stentor Oken. When extended, trumpet-shaped or cylin- drical; highly contractile; some with mucilaginous lorica; usually oval to pyriform while swimming; conspicuous peristomal field frontal; adoral zone encircles peristome in a spiral form, leaving a narrow gap on ventral side ; the zone and field sink toward cyto- stome and the former continues into cytopharynx; macronucleus round, oval or elongated, in a single mass or in divided parts; con- tractile vacuole anterior-left; free-swimming or attached; fresh water. S. coeruleus Ehrenberg (Figs. 14; 264, e). Fully extended body 582 PROTOZOOLOGY Fig. 264. a, b, Nydotherus ovalis, X340 (Kudo); c, A^. cordiformis, Xl70 (Stein); d, Condylostoma vorticella, X120 (Penard); e, Stentor coeruleiis, somewhat contracted, X70 (Roux); f, S. polymorphus, X60 (Roux); g, S. mulleri, XoO (Kahl); h, S. roeseli, X75 (Roux); i, S. igneus, Xl60 (Kahl); j, S. amethystinus, XlOO (Kahl). SPIROTRICHA, HETEROTRICHA 583 1-2 mm. long; anterior end greatly expanded; the beautiful blue color is due to a pigment, stentorin, lodged in interstriation gran- ules; macronucleus beaded; Burnside (1929) studied its body and nuclear sizes (p. 114). S. striatus Barraud-Maskett. Dark bluish green; funnel-shape; peristomal edge irregularly undulating; striation conspicuous; macronucleus beaded; up to 2.2 mm. long. S. yolymor-phus (Miiller) (Fig. 264,/). Colorless; with zoochlo- rellae; 1-2 mm. long when extended; macronucleus beaded; an- terior end expanded. S. mulleri (Bory) (Fig. 265, g). Colorless; with zoochlorellae; 2-3 mm. long; anterior end expanded; posterior portion drawn out into stalk, often housed in a gelatinous tube; on body surface 3-4 longer and stiff cilia grouped among cilia; macronucleus moniliform. *S. roeseli Ehrenberg (Fig. 264, h). 0.5-1 mm. long; anterior end expanded; body surface with groups of longer ciha; posterior por- tion, drawn out and often housed in a gelatinous tube; macronu- cleus long band-form. S. igneus E. (Fig. 264, i). Rose-colored or colorless; 200-400m long; macronucleus oval; ciliation uniform. S. niger (Miiller). Yellowish or brown; macronucleus oval; 200- 300)u long. S. multiformis (Miiller). Dark blue to bluish green; anterior end not expanded; 150-200^ long; macronucleus oval. S. amethystinus Leidy (Fig. 264, j). Habitually pyriform (con- tracted); amethyst-blue; with zoochlorellae; 300-600^ long; macronucleus oval. S. pyriformis Johnson. When extended 500/u long; anterior end 200ju in diameter. Genus Fabrea Henneguy. Pyriform; posterior end broadly rounded, anterior end bluntly pointed; peristome extends down from anterior end 2/5 or more the body length, its posterior por- tion closely wound; peculiar black spot beneath membranellae in anterior portion of spiral adoral zone, composed of numerous pigment granules; without contractile vacuole; macronucleus, a sausage-shaped body or in 4 parts ; in salt water. F. salina H. (Fig. 265, a, h). 120-220m by 67-125m (Kirby); 130-450^ by 70-200m (Henneguy) ; cysts ovoidal, with gelatinous envelope; 89-11 l^i by 72-105^. Ivirby (1934) found the organism 584 PROTOZOOLOGY in ditches and pools in salt marshes, showing salinities 7.5-20.1 per cent in California. Genus Climacostomum Stein. Oval; flattened; right edge of peristome without membrane, left edge, semicircular or spiral with a strong adoral zone; peristomal field cihated; cytopharynx long curved tube with a longitudinal row of cilia; macronucleus band-form; contractile vacuole terminal, with 2 long canals; fresh or brackish water. C. virens Ehrenberg (Fig. 265, c). 100-300/x long; with or with- out zoochlorellae; fresh and brackish water. Family 6 Folliculinidae Dons Genus FoUiculina Lamarck. Lorica attached on broad surface; neck oblique to perpendicular; sometimes with collar or spiral ridge; neck uniform in diameter; salt water. F. moehiusi Kahl. (Fig. 265, d). Lorica about 500^ high. F. producta (Wright) (Fig. 265, e). Lorica yellowish brown; 250;u long; neck often long; Atlantic coast. Genus Microfolliculina Dons. Posterior end or sides of lorica with sack-like protuberances. M. limnoriae (Giard). Lorica dark blue; pellicle faintly striated; salt water. Genus PseudofoUiculina Dons. Lorica attached with posterior end; more or less vertical; without ring-furrow in middle; with or without style; salt water. P. ardica D. (Fig. 265,/). Lorica about 430^1 high, with spiral ridge; off Norwegian coast 15-28 m. deep. Genus ParafoUiculina Dons. Neck of lorica with a basal swell- ing ; attached either with posterior end or on a lateral surface ; salt water. P. violacea (Giard) (Fig. 265, g). 200-300^ long; salt water. Family 7 Peritromidae Stein Genus Peritromus Stein. Ovoid; ventral surface flattened, dor- sal surface with hump of irregular outhne bearing a few dorsal setae; ciliary rows only on ventral surface; a small undulating membrane at posterior end of peristome; short marginal spines; 2 macro- and 2 micro-nuclei; salt water. P. californicus Kirby (Fig. 265, h). Peristome short; left mar- gin slightly concave; dorsal hump with wart-like protuberances, SPIROTRICHA, HETEROTRICHA 585 ^ %- <-; ."%: '^ -. < '-: ■ > i' ^ %: \ N ,/i, \,' 'y/' r- fi 1: Fig. 265. a, b, Fabrea salina (a, Xl70; b, X330) (Kirby); c, Clima- costomum virens, XlOO (Stein); d, Folliculina moebiusi, Xl70 (Stein); e, F. -produda, XllO (Wright); f, Pseudofolliculina arclica, X50 (Dons); g, Parafolliculina violacea, XlOO (Dons); h, Peritromus cali- fornicus, X360 (Kirby); i, Lichnophora macfarlandi, X420 (Stevens); j, L. conklini, X340 (Stevens). 586 PROTOZOOLOGY bearing spines (about 12^ long); 16-19 or more ventral ciliary- rows; 2 spherical macronuclei, one anterior right and the other posterior left of hump; micronuclei 4 (2-5); 89-165yu by 60-96^; salt marsh pools with salinity 1.2-6 per cent in California. P. emmae S. 90-lOOju long; creeping on bottom; Woods Hole. Family 8 Licnophoridae Stevens Genus Licnophora Claparede. Discoid; body roughly divisible into foot, neck and head; foot an attaching disc, with several con- centric ciliary coronas; neck flattened, contractile narrowed part with or without a ventral furrow and fibril-bundles (both running from oral groove to foot); head highly flattened, round or ovoid; edge with membranellar zone which extends to pharyngeal fun- nel; macro nucleus long chain-form; without contractile vacuole; free-swimming or commensal in fresh or salt water animals. L. macfarlandi Stevens (Fig. 265, i). 140-180^ long; attaching disc round; macronuclei in 25-35 parts in 4 groups; commensal in respiratory organs of Holothuria California. L. conklini S. (Fig. 265, j)- 100-135m long; commensal in Crepi- dula plana of Atlantic coast. References Hegner, R. 1934 Specificity in the genus Balantidium based on size and shape of body and marconucleus, with description of six new species. Amer. Jour. Hyg., Vol. 19. Kahl, a. 1932 Urtiere oder Protozoa. In Dahl's Die Tierwelt Deutschlands. Part 15. KiRBY Jr., H. 1934 Some ciliates from salt marshes in Cali- fornia. Arch. f. Protistenk., Vol. 82. Kudo, R. R. 1936 Studies on Nydotherus ovalis Leidy, with special reference to its nuclear structure. Ibicf., Vol. 87. and P. A. Meglitsch 1938 On Balantidium praenucte- atum n.sp., inhabiting the colon of Blatta orientalis. Ibid., Vol. 91. McDonald, J. D. 1922 On Balantidiurn coli (Malmsten) and B. suis (sp. nov.). Uni. Calif. Publ. Zool., Vol. 22. Powers, P. B. A. 1935 Studies on the ciliates of sea urchins. Papers from Tortugas Lab., Vol. 29. Stevens, N. M. 1903 Further studies on the ciliate Infusoria, Licnophora and Boveria. Arch. f. Protistenk., Vol. 3. Chapter 38 Order 2 Spirotricha Biitschli (continued) Suborder 2 Oligotricha Biitschli THE cilia are greatly reduced in number in the Ohgotricha and the adoral zone encloses a non-ciliated spiral peristomal field. Free-living Oral portion of peristome lies free on ventral surface Family 1 Halteriidae Adoral zone encloses frontal peristomal field in a closed spiral Without lorica Family 2 Strobilidiidae (p. 589) With lorica or test Family 3 Tintinnidiidae (p. 589) Parasitic Adoral and dorsal zones, both directed anteriorly and retractile; no other cilia Family 4 Ophryoscolecidae (p. 590) In addition to adoral and dorsal zones, groups of cirri in posterior half of body, directed posteriorly and nonretractile Family 5 Cycloposthiidae (p. 596) Family 1 Halteriidae Claparede et Lachmann Genus Halteria Dujardin. Spherical or broadly fusiform; an- terior border bears conspicuous adoral zone; oral part of peri- stome with a small membrane on right edge and cirri on left ; with an equatorial zone of small oblique grooves, each bearing 3 long cirri or bristles; macronucleus oval; a micronucleus; contractile vacuole left of cytostome ; fresh water. A few^ species. H. grandinella (Miiller) (Fig. 266, a). About 7 bristle-bearing grooves; 15 frontal and 7 adoral membranellae ; 20-40^ long. Kahl (1932) distinguishes 2 varieties: var. cirrifera (Fig. 266, h), 25-50^ long, with huge cirri instead of fine body cirri; and var. chlorelligera (Fig. 266, c), 40-50^ long, with bristles and large zoochlorellae ; fresh water. Genus Strombidium Claparede et Lachmann. Ovoid to spher- ical; adoral zone very conspicuous (2-4 conspicuous sickle-form frontal membranellae and adoral membranellae extend down cytopharynx, the first section surrounding an apical process) ; no body bristles or cirri; trichocysts; macronucleus oval or band- form ; a micronucleus ; a contractile vacuole ; salt or fresh water. Numerous species. 587 588 PROTOZOOLOGY b Fig. 266. a, Halteria grandinella, X490 (Kahl); b, H. g. var. cirrifera, X370 (Kahl); c, H. g. var. chlorelligera, X260 (Kahl); d, Strombidiuin calkinsi, X900 (Calkins); e, Tontonia gracillvma, X540 (Faur^- Fremiet); f, Slrohilidium gyrans, X340 (Kahl); g, Tintinnidmm fluviatile, Xl40 (Kent); h, i, T. semiciliatum, Xl40 (Sterki); j, Strom- hidinopsis gyrans, X270 (Kent); k, Tintinnopsis cijlindrata, X440 (Daday); 1, T. illinoisensis, X420 (Hempel); m, Codonella cratera, X540 (Faure-Fremiet). S. calkinsi Faure-Fremiet (Fig. 266, d). 35-60/1 long; brackish and salt water, Calkins (1902) first observed it at Woods Hole. Genus Tontonia Faure-Fremiet. With well-developed apical collar; a long cytoplasmic (contractile) caudal process; salt water. T. gracillirna F.-F. (Fig. 266, e). 48-52ju long; caudal process 250-300/x long; macro nucleus moniliform; with zoochlorellae. SPIROTRICHA, OLIGOTRICHA 589 Family 2 Strobilidiidae Kahl Genus Strobilidium Schewiakoff. Pyriform or turnip-shaped; cytostome at anterior end; without cytopharynx; horseshoe- shaped macronucleus anterior; a micronucleus; a contractile vacuole; fresh or salt water. Several species. S. gyrans (Stokes) (Fig. 266, /). Lateral border with rounded elevation near anterior end, posterior end truncate; 40-70^i long; in standing fresh water. Family 3 Tintinnidiidae Claparede et Lachmann Conical or trumpet-like, attached inside a lorica of various forms, composed of gelatinous or pseudochitinous substances; with longitudinal rows of cilia, and 2 (1-4) macro- and micro- nuclei; mostly pelagic, a few inhabiting fresh or brackish water. Kofoid and Campbell (1929) distinguished more than 300 species and placed them in 12 famihes and 51 genera, of which 23 genera were created by them. A few genera and species are mentioned here. Genus Tintinnidium Kent. Elongated lorica, highly irregular in form; soft; aboral end closed or with a minute opening; wall viscous and freely agglomerates foreign bodies; salt or fresh wa- ter. T. fl.uviatile (Stein) (Fig. 266, g). Lorica 100-200m by 45^; on vegetation in fresh water. T. semiciliatum (Sterki) (Fig. 266, h, i). 40-60^ long; on plants in fresh water. Genus Strombidinopsis Kent. Lorica often absent; ovate or pyriform; frontal border with numerous long cirrus-like cilia; body covered by fine ciUa; contractile vacuole posterior; fresh water. S. gyrans K. (Fig. 266, j). 30-80/i long; fresh water pond. Genus Tintinnopsis Stein. Lorica bowl-shaped; always with a broad aperture; aboral end closed; wall thin and covered with foreign bodies ; salt or fresh water. T. cylindrata Kofoid et Campbell (Fig. 266, k). Lorica 40-50;i long; lake water. T. illinoisensis Hempel (Fig. 266, I). Lorica 59^ long, in river. Genus Codonella Haeckel. Lorica urn- to pot-shaped; sharply divided externally and internally into a collar and bowl; collar without spiral structure; in fresh water. 590 PROTOZOOLOGY C. cratera (Leidy) (Fig. 266, m). Lorica 60-70ju by 40/x; a num- ber of varieties are often mentioned. Family 4 Ophryoscolecidae Stein Elongate oval, asymmetrical; with 1 or 2 (adoral and dorsal) zones of membranellae; in digestive tract of mammals. Sharp (1914) instituted use of "forma" to distinguish forms in Entodi- nium with common characteristics differing in certain others, which scheme was extended to the whole family by Dogiel (1927). It is most probable that many species are varieties of a single species as judged by the work of Poljansky and Strelkow (1934); but since information is still incomplete, the present work ranks various formae with species, in agreement with Kofoid and Mac- Lennan (1930). Genus Ophryoscolex Stein. Ovoid; with adoral and dorsal zones of membranellae; dorsal zone some distance behind anterior end, encircling 3/4 the body circumference at middle, broken on right ventral side; 3 skeletal plates extend the body length on right-ventral side; 9-15 contractile vacuoles in 2 (anterior and posterior) circles; macronucleus simple, elongate; in stomach of cattle, sheep, goat and wild sheep (Ovis orientalis cycloceros). Sev- eral species. Dogiel (1927) designated the following species as 3 formae of 0. caudatus Eberlein. 0. hicoronatus Dogiel (Fig. 267, a). 120-170^ by 81-90^; pri- mary spine 38-58/z long; in sheep. 0. caudatus Eberlein (Fig. 267, h). 137-162ai by 80-98^; preanal spines 47-60)u long; in sheep, goat, and cattle. 0. quadricoronatus Dogiel (Fig. 267, c). 128-180m by 86-100^; preanal spines 48-63iu long; in sheep and Ovis orientalis cyclo- ceros. Genus Caloscolex Dogiel. Ovoid; anterior end truncate, post- erior end rounded with or without processes; 2 zones of mem- branellae; dorsal zone encircles the body completely; 3 skeletal plates variously modified; 7 contractile vacuoles in a single circle; nucleus elongate; in stomach of Canielus dromedarius. Several species. C. cuspidatus D. (Fig. 267, d). 130-1 60m by 73-90^. Genus Entodinium Stein. Without dorsal zone; adoral zone at truncate anterior end; without skeleton; contractile vacuole an- terior; macronucleus, cyUndrical or sausage-form, dorsal; mi- SPIROTRICHA, OLIGOTRICHA 591 Fig. 267. a, Ophryoscolex bicoronatus, X340 (Dogiel); b, 0. caudatus, X310 (Dogiel); c, 0. quadricoronatus, X340 (Dogiel); d, Caloscolex cuspidatus, XBIO (Dogiel); e, Entodinium caudatum, X500 (Becker and Talbott); f, E. bursa, X390 (Schuberg); g, Amphacanthus ovum- rajae, X350 (Dogiel). cronucleus anterior to middle and on left- ventral side of macro- nucleus; in cattle and sheep. Numerous species. E. caudatum S. (Fig. 267, e). 50-80^ long; in cattle and sheep. E. bursa S. (Fig. 267, /). 55-1 14^ by 37-78m (Schuberg); 80m by 60m (Becker and Talbott) ; in stomach of cattle. Genus Amphacanthus Dogiel. Similar to Entodinium; but spinous processes at both anterior and posterior ends ; in stomach of Camelus dromedarius. One species. A. ovum-rajae D. (Fig. 267, g). 46-55m by 32-48m. 592 PROTOZOOLOGY Genus Eodinium Kofoid et MacLennan, Dorsal zone on the same level as adoral zone; without skeleton; macronucleus a straight, rod-like body beneath dorsal surface; 2 contractile vacuoles; in cattle and sheep. Several species. E. lohaium K. et M. (Fig. 268, a). 44-60m by 29-37//; in Bos indicus. Genus Diplodinium Schuberg. Adoral and dorsal zones on the same level; without skeletal plates; macronucleus beneath right side, its anterior third bent ventrally at an angle of 30°-90°; 2 contractile vacuoles; in cattle, antelope, Camelus dromedarius, reindeer, goat, Numerous species. D. dentatum (Stein) (Fig. 268, b). 65-82^ by 40-50^; in cattle (including Bos indicus). Genus Eremoplastron Kofoid et MacLennan. Adoral and dor- sal zones at anterior end; a single narrow skeletal plate beneath right surface; triangular or rod-like macronucleus, anterior end of which often bent ventrally; 2 contractile vacuoles; in cattle, antelope, sheep, reindeer. Numerous species. E. hovis (Dogiel) (Fig. 268, c). 52-100/x by 34-50^; in cattle and sheep. Genus Eudiplodinium Dogiel. Adoral and dorsal zones at an- terior end; a single, narrow, skeletal plate beneath right sur- face; rod-like macronucleus with anterior end enlarged to form a hook opening dorsally; pellicle and ectoplasm thick; 2 con- tractile vacuoles with heavy membranes and prominent pores ; in cattle. E. maggii (Fiorentini) (Fig. 268, d). 104-255/x by 63-170/1 ; in cattle, sheep and reindeer. Genus Diploplastron Kofoid et MacLennan. Adoral and dorsal zones at anterior end; 2 skeletal plates beneath right surface; macronucleus narrow, rod-like; 2 contractile vacuoles below dor- sal surface, separated from macronucleus. One species. D. affine (Dogiel et Fedorowa) (Fig. 268, e). 88-1 20/i by 47- 65/i; in stomach of cattle, sheep, and goat. Genus Metadinium Awerinzew et Mutafowa. Adoral and dor- sal zones at anterior end; 2 skeletal plates beneath right surface sometimes fused posteriorly; macronucleus with 2-3 dorsal, lobes; 2 contractile vacuoles; pellicle and ectoplasm thick; con- spicuous oesophageal fibrils beneath dorsal and right sides; in stomach of cattle, sheep, goat, and reindeer. SPIROTRICHA, OLIGOTRICHA 593 Fig. 268. a, Eodinium lobatum, X540 (Kofoid and MacLennan); b, Diplodinium dentatum, X250 (Kofoid and MacLennan); c, Eremo- plastron bovis, X550 (Kofoid and MacLennan); d, Eudiplodinium maggii, X500 (Dogiel); e, Diploplastron affine, X320 (Dogiel); f, Metadinium medium, X320 (Dogiel). M. medium A. et M. (Fig. 268, /). 180-272^ by 111-175m; in cattle. Genus Pol3T)lastron Dogiel. Adoral and dorsal zones at anterior end; 2 skeletal plates beneath right surface, separate or fused; 3 594 PROTOZOOLOGY longitudinal plates beneath left surface, with anterior ends con- nected by cross bars; contractile vacuoles beneath dorsal surface in a longitudinal row, also with additional vacuoles; in stomach of cattle and sheep. P. midtivesicnlatum (D. et Fedorowa) (Fig. 269, a). 120-190yu by 78-140/i; in cattle and sheep. MacLennan (1934) found that the skeletal plates are made up of small, roughly prismatic blocks of glycogen, each with a central granule. Genus Elytroplastron Kofoid et MacLennan. 2 zones at ante- rior end, 2 skeletal plates beneath right surface, a small plate be- neath ventral surface, and a long plate below left side; pellicle and ectoplasm thick; conspicuous fibrils beneath dorsal and right sides. One species. E. huhali (Dogiel) (Fig. 269, h). 110-160^ by 67-97^; in cattle, sheep, Buffelus buhalus and Bos indicus. Genus Ostracodinium Dogiel. 2 zones at anterior end; broad skeletal plate beneath right side; 2-6 contractile vacuoles in a dorsal row; cytopharyngeal fibrils thick, extend to posterior end; in cattle, sheep, antelope, steenbock, and reindeer, Numerous species. 0. dentatum (Fiorentini) (Fig. 269, c). 52-1 lO/x by 31-68^; in stomach of cattle. Genus Enoploplastron Kofoid et MacLennan. 2 zones near an- terior end; 3 skeletal plates beneath right and ventral sides, either separate or partly fused; 2 contractile vacuoles; heavy pharyn- geal fibrils; in cattle, reindeer and antelope. E. triloricatum (Dogiel) (Fig. 269, d). Dogiel (1927) mentions size differences in those occurring in different host species, as fol- lows: in cattle, 85-1 12^ by 51-70yu; in reindeer, 75-103^ by 40- 58/^; in antelope (Rhaphiceros sp.), 60-110^ by 37-56^. Genus Epidinium Crawley. Elongate; twisted around the main axis; 2 zones; dorsal zone not at anterior end; 3 skeletal plates, with secondary plates; simple macronucleus club-shaped; 2 con- tractile vacuoles; in cattle, sheep, reindeer, camels, etc. E. caudatum (Fiorentini) (Fig. 269, e). 113-151iu by 45-61/i; in cattle, camels, Cervus canadensis and reindeer. E. (Diplodinium) ecaudatum (F.) (Figs. 16; 269,/). 112-140/x by 40-60^1 (Becker and Talbott); in cattle, sheep, and reindeer. The classical observation of Sharp (1914) on its neuromotor sys- tem has been described elsewhere (p. 55). SPIROTRICHA, OLIGOTRICHA 595 Fig. 269. a, Poly-plastron multivesiculatum, X360 (Dogiel); b, Elytro- j)lastron bubali, X340 (Dogiel); c, Ostracodinium dentatum, X440 (Dogiel); d, Enoploplastron triloricatum, X370 (Dogiel); e, Epidinium caudatum, X340 (Becker and Talbott); f, E. ecaudatum, X340 (Becker and Talbott); g, Epiplaslron africanum, X300 (Dogiel). Genus Epiplastron Kofoid et MacLennan. Elongate; 2 zones, dorsal zone behind anterior end; 5 skeletal plates, with secondary plates; macronucleus simple, elongate; 2 contractile vacuoles; in antelopes. E. africanum (Dogiel) (Fig. 269, g). 90-140m by 30-55yu; in Rhaphiceros sp. Genus Ophisthotrichum Buisson. 2 zones, dorsal zone at mid- dle or near posterior end of body; one-piece skeletal plate well developed; 2 contractile vacuoles posterior; conjugation (Dogiel); in many African antelopes. One species. 0. janus (Dogiel) (0. thomasi B.) (Fig. 270, a). 90-150m by 42- 60m. 596 PROTOZOOLOGY Fig. 270. a, Ophisthotrichum janus, X370 (Dogiel); b, Cunhaia curvata, X670 (Hasselmann); c, Cydoposthium bipalmatum, X300 (Bundle); d, C. dentiferum, X270 (Hsiung); e, Spirodinium equi, X270 (Hsiung); f, Triadiniuvi caudatum, X300 (Hsiung); g, T. minimum, X440 (Hsiung); h, Tetratoxum unifasciculatum., X280 (Hsiung). Genus Cunhaia Hasselmann. Cytostome near anterior end, ^\ith adoral zone; dorsal zone on 1/3 of anterior-dorsal surface; 2 contractile vacuoles; skeleton (?); in caecum of guinea pig, Cavia aperea. One species. C. curvata H. (Fig. 270, h). 60-80^ by 30-40/^; in Brazil. Family 5 Cycloposthiidae Poche Pellicle firm and body rigid ; zones of membranellae at anterior and posterior ends; more or less compressed; cytopharynx short SPIROTRICHA, OLIGOTRICHA 597 and wide; macroniicleus elongate; a single micronucleus; 2 or more contractile vacuoles; in horse and anthropoid apes. Genus Cycloposthium Bundle. Large, elongate barrel-shaped; cytostome in center of a retractile conical elevation at anterior end; adoral zone conspicuous; an open ring-zone of membranellae near posterior end on both dorsal and ventral sides; pellicle ridged; skeleton club-shaped; several contractile vacuoles in a row along band-form macronucleus; in caecum and colon of horse. Many species. C. hipalmatum (Fiorentini) (Fig. 270, c). 80-127/x by 35-57/z. C. dentiferum Gassovsky (Fig. 270, d). 140-222^ by 80-1 10^. Genus Spirodinium Fiorentini. Elongate, more or less fusiform; adoral zone at anterior end; zone making at least one complete spiral near anterior end; posterior zone only half-spiral; in caecum and colon of horse. One species. S. equi F. (Fig. 270, e). 77-180^ by 30-74ai; widely distributed. Genus Triadinium Fiorentini. More or less helmet-shaped; compressed; adoral zone at anterior end; 2 posterior (ventral and dorsal) zones; with or without a caudal projection; in caecum and colon of horse. T. caudatum F. (Fig. 270, /). 59-86/x by 50-68/^. T. galea Gassovsky. 59-78/i by dO-QO/i. T. viinimum G. (Fig. 270, g). 35-58^ by 30-40/^. Genus Tetratoxum Gassovsky. Slightly compressed; 2 anterior and 2 posterior zones of membranellae; in colon of horse. T. imifasciculatum (Fiorentini) (Fig. 270, h). 104-168/i by 62-100^; widely distributed. T. escavatum Hsiung. 95-1 35^ by 55-90At. T. parvum H. 67-98m by 39-52^. Genus Tripalmaria Gassovsky {Tricaudalia Buisson). Adoral zone at anterior end; 2 dorsal and 1 ventro-posterior zones in tuft-form; macronucleus inverted U-shape; in colon of horse. T. dogieli G. (Fig. 271, a). 77-123m by 47-62/i. Genus Cochliatoxum Gassovsky. Adoral zone near anterior end; 3 additional zones, I antero-dorsal, 1 postero-dorsal and 1 postero-ventral; macronucleus with curved anterior end; in colon of horse. One species. C. periachtum G. (Fig. 271, b). 210-370/x by 130-210/i. Genus Ditoxum Gassovsky. Large adoral zone near anterior end; 2 dorsal (anterior and posterior) zones; macronucleus curved club-shaped; in colon of horse. 598 PROTOZOOLOGY Fig. 271. a, Tripalmaria dogieli, XlSO (Gassovsky); b, Cochlia- toxum periachtum, X270 (Hsiung); c, Ditoxum funinudeum, X270 (Hsiung); d-f, Troglodytella abrassarti (d, X670 (Swezey); e, ventral and f, dorsal view, X210 (Brumpt and Joyeaux)). SPIROTRICHA, OLIGOTRICHA 599 D. funinudeum G. (Fig. 271, c). 135-203m by 70-101^. Genus Troglodytella Brurapt et Joyeux. Ellipsoid; flattened; adoral zone; 3 additional zones (anterior zone continuous or not continuous on ventral surface; posterior zone continuous on dorsal surface; between them a small zone on each side); skeletal plates in anterior region; macronucleus L-form; contractile vacuoles in 2 circles; in colon of anthropoid apes. T. abrassarti B. et J. (Fig. 271, d-f). About 145-220^ by 120- 160/i; in colon of chimpanzees. Reichenow (1927) distinguished var. acuminata on the basis of drawn-out posterior end, which however was found by Swezey (1932) as simply a variant of T. abrassarti. T. gorillae Reichenow. 200-280m by 120-160/1; in colon of gorilla; with anterior zone not reaching the right side. References Becker, E. R. and Mary Talbott. 1927 The protozoan fauna of the rumen and reticulum of American cattle. Iowa St. Coll. Jour. Sci., Vol. 1. DoGiEL, V. 1927 Monographic der Familie Ophryoscolecidae. I. Arch. f. Protistenk., Vol. 59. HsiuNG, T. S. 1930 A monograph on the Protozoa of the large intestine of the horse. low^a St. Coll. Jour. Sci., Vol. 4. Kahl, a. 1932 Dahl's Die Tierwelt Deutschlands. Part 25. KoFoiD, C. A. and A. S. Campbell 1929 A conspectus of the marine and freshwater Ciliata, belonging to the suborder Tintinnoinea, etc. Uni. Calif. Publ. Zool., Vol. 34. and J. F. Christenson 1934 Ciliates from Bos gaurus H. Smith. Ibid., Vol. 39. and R. F. MacLennan 1930, 1932, 1933 Ciliates from Bos indicus Linn. I, II, III. Ibid., Vols. 33, 37, 39. Sw^EZEY, W. W. 1934 Cytology of Troglodytella abrassarti, an intestinal ciliate of the chimpanzee. Jour. Morph., Vol. 56. Chapter 39 Order 2 Spirotricha Butschli (continued) Suborder 3 Ctenostomata Kahl THE ciliates placed under this group are carapaced and com- pressed forms with a very sparse cihation. The adoral zone is also reduced to about 8 membranellae. These organisms are exclusively free living and sapropelic in fresh, brackish, or salt water. Posterior half of carapace with 4 ciliated rows on left and at least 2 rows on right; with anterior row of cilia on left side near frontal edge Family 1 Epalcidae Posterior half of carapace with cirrus-like groups on left only, none on right; without frontal cilia Long ciliated band extends over both broad sides Family 2 Discomorphidae (p. 601) Short ciliated band ventral, extending equally on both broad sides Family 3 Mylestomidae (p. 602) Family 1 Epalcidae Wetzel Genux Epalxis Roux. Rounded triangular; anterior end pointed toward ventral surface, posterior end irregularly truncate; dorsal surface more convex; right carapace with 1 dorsal and 1 ventral ciliary row in posterior region; usually 4 (2-3) median teeth; all anal teeth without spine; with comb-like structures posterior to oral aperture; 1-2 oval macronuclei dorsal; contrac- tile vacuole posterior-ventral; sapropelic in fresh or salt water. Many species. E. mirahilis R. (Fig. 272, a). 38-45m by 27-30/x; fresh water. Genus Saprodinium Lauterborn. Similar to Epalxis; but some of anal teeth (left and right) with spines; sapropelic in fresh or salt water. Several species. S. dentatum L. (Fig. 272, b). QO-SOfx long; fresh water. S. 'putrinium Lackey (Fig. 272, c). 50ju long, 40ai wide, about 15/i thick; in Imhoff tanks. Genus Pelodinium Lauterborn. Right carapace with 2 median rows of cilia, its median anal teeth fused into one so that there appear only three teeth. One species. P. reniforme L. (Fig. 272, d). 40-50/i long; sapropeUc. 600 SPIROTRICHA, CTENOSTOMATA 601 Fig. 272. a, Epalxis mirabilis, X1200 (Roux); b, Saprodinium den- tatum, X430 (Kahl); c, S. putrinium, X470 (Lackey); d, Pelodinium renijorme, X600 (Lauterborn); e, f, Discomorpha pectinata, (e, X500; f, X220) (Kahl); g, Mylestoma bipartiturn, X470 (Kahl); h, Alopo- dinium fibulatum, X520 (Kahl). Family 2 Discomorphidae Poche Genus Discomorpha Levander. Oval; ventrally directed an- terior spine long; posterior end without teeth or ridges; ciUated 602 PROTOZOOLOGY bands on both lateral surfaces; 2 spines on right side; 2 cirrus- like groups on posterior-left; sapropelic. A few species. D. pectinata L. (Fig. 272, e,f). 70-90/i long; sapropelic. Family 3 Mylestomidae Kahl Genus Mylestoma Kahl. Posterior margin without any inden- tation, though sometimes a small one on right side, but none on left; 3 often long ribbon-like cirri on peristome; fresh or salt water. Several species. M. hipartitum (Gourret et Roesner) (Fig. 272, g). 35-50^1 long; salt water. Genus Atopodinium Kahl. Posterior left side with one large, and right side with 2 indentations; macronucleus spherical; sapropelic. A.fihulatum K. (Fig. 272, h). 40-50m long. References Kahl, A. 1932 Ctenostomata (Lauterborn) n. subord. Arch. f. Protistenk., Vol. 77. 1932 Urtiere oder Protozoa. In Dahl's Die Tierwelt Deutschlands. Part 25. T Chapter 40 Order 2 Spirotricha Blitschli (continued) Suborder 4 Hypotricha Stein HE members of this suborder are, as a rule, flattened and strong cilia or cirri are restricted to the ventral surface. Except the family Aspidiscidae, the dorsal surface possesses rows of short slightly moveable tactile bristles. The peristome is very large with a well-developed adoral zone. The cirri on the ventral surface are called, according to their location, frontals, ventrals, marginals, anals (transversals), and caudals, as was mentioned before (Fig. 11, 6). Asexual reproduction is by binary fission and sexual reproduction by conjugation (p. 148). Encystment is common. Mostly free-living in fresh, brackish or salt water; a few parasitic. Adoral zone fullj^ formed; dorsal surface with bristles Ventrals in rows, though in some reduced; 2 rows of marginals. . . . Family 1 Oxytrichidae Ventrals and marginals not in long'itudinal rows Family 2 Euplotidae (p. 611) Adoral zone reduced; without dorsal bristles Family 3 Aspidiscidae (p. 613) Family 1 Oxytrichidae Kent Genus Oxytricha Ehrenberg ( Histrio Sterki ; Opisthotricha Kent; Steinia Diesing). Ellipsoid; flexible; ventral surface flat- tened, dorsal surface convex; 8 frontals; 5 ventrals; 5 anals; short caudals ; marginals may or may not be continuous along posterior border; macronucleus in 2 parts, rarely single or in 4 parts; fresh or salt water. Numerous species. 0. fallax Stein (Fig. 273, a). Posterior region broadly rounded; about 150m long; fresh water. 0. hifaria Stokes (Fig. 273, h). Right side convex; left side flattened; posterior end pointed; about 250^ long; fresh water infusion. 0. Iudibu7ida S. (Fig. 273, c). Elhpsoid; flexible; 100m long; fresh water among sphagnum. 603 604 PROTOZOOLOGY Fig. 273. a, Oxytricha fallax, X230 (Stein); b, 0. bifaria, X180 (Stokes); c, 0. ludibunda, X400 (Stokes); d, 0. setigera, X870 (Stokes) e, T achy soma parvistyla, x490 (Stokes); f, Urosoma caudata, X250 (Stokes); g, Aniphisiella thiophaga, X380 (Kahl); h, Eschaneustyla brachytona, X240 (Stokes); i, Gonostomum strenuum, X160 (Engel- mann); j, Hemicyclostyla sphagni, XlOO (Stokes); k, 1, Cladotricha koltzowiiik, X170;1, x300) (Kahl). 0. setigera S. (Fig. 273, d). Elongate ellipsoid; 5 frontals; ventrals shifted anteriorly; 50)Lt long; fresh water. Genus Tachysoma Stokes {Actinotricha Cohn). Flexible; frontals 8-10, of which anterior three are usually the largest; 5 ventrals scattered; 5 anals; marginals at some distance from lateral borders, interrupted posteriorly ; fresh or salt water. T. parvistyla S. (Fig. 273, e). 10 frontals scattered; about 63/x long; in shallow freshwater pools. Genus Urosoma Kowalewski. Similar to Oxytricha; but pos- terior portion drawn out and much narrowed; fresh water. SPIROTRICHA, HYPOTRICHA 605 U. caudata (Stokes) (Fig. 273, /). 200-250/i long; pond water. Genus Amphisiella Goiirret et Roeser. With a single row of ventrals and 2 marginal rows; salt or fresh water. Several species. A. thiophaga (Kahl) (Fig. 273, g). 70-1 00^ long; salt water. Genus Eschaneustyla Stokes. Elliptical or ovate; narrow peri- stome 1/3 the body length; frontals numerous, about 22 in addi- tion to 2 at anterior margin; ventrals small and numerous in 3 oblique rows; no anals; marginals uninterrupted; contractile vacuole a long canal near left border; fresh water. One species. E. hrachytona S. (Fig. 273, h). 170-220m long. Genus Gonostomum Sterki (Plagiotricha Kent). Flexible; 8 or more frontals; 1-2 oblique ventral rows of short cirri; 4 or 5 caudals ; 2 marginal rows ; fresh water. G. strenuum (Engelmann) (Fig. 273, i). Elongate; with caudal bristles; about 150^ long; fresh water. Genus Hemicyclostyla Stokes. Elongate oval; flexible; ends rounded; 20 or more frontals, arranged in 2 semicircular rows; adoral row begins near center of right side of peristomal field; ventral surface entirely covered with fine cilia; no anals; one or more contractile vacuoles; nucleus distributed; fresh water. H. sphagni S. (Fig. 273, j). About 400-500ju long; marsh water with sphagnum. Genus Hypotrichidium Ilowaisky. 2 ventral rows of cirri and marginals spirally arranged; peristome large, extends 1/2 the body length, with a large undulating membrane; 2 macro- and micro-nuclei; contractile vacuole anterior-left; fresh water. H. conicum I. (Fig. 274, a). 90-150^ long. Genus Cladotricha Gajevskaja. Elongate band-form; anterior end rounded, posterior end rounded or attentuated; frontals only 2 featherly cirri; macronucleus spheroidal; micronucleus; without contractile vacuole; salt water, with 5-20 per cent salt content. One species. C. koltzowii G. (Fig. 273, k, I). Band-form up to about 200^ long; posteriorly attenuated forms up to about 100/i long. Genus Psilotricha Stein. Oval to ellipsoid; frontals and anals undifferentiated; ventrals and marginals long bristles, few; ven- trals in 2 rows and a rudimentary row toward left ; with or v/ithout zoochlorellae; fresh water. A few species. P. acuminata S. (Fig. 274, h). 80-100/i long. Genus Kahlia Horvath, Frontal margin with 3-4 strong cirri; 5-8 ventral longitudinal rows ; marginals ; sapropelic in freshwater. QOQ PROTOZOOLOGY K. acrohates H. (Fig. 274, c). 100-200ju long; soil infusion. Genus Uroleptus Ehrenberg. Elongate body drawn out into a tail-like portion, 3 frontals; 2-4 rows of ventral cirri; marginals; no anals; sometimes rose- or violet-colored; fresh or salt water. Many species. U. limnetis Stokes (Fig. 274, d). About 200/x long; fresh water among vegetation. U. longicaudatus S. (Fig. 274, e). About 200/li long; marsh water with sphagnum. U. dispar S. (Fig. 274, /). 150-170^ long; fresh water. U. halseyi Calkins (Fig. 276, a). About 160/x by 20/1 ; peristome 1/6-1/7 the body length; 3 ventrals; macronucleus divided into many (up to 26) parts; 2 (1-3) large macronuclei; fresh water. Genus Uroleptopsis Kahl. Ventrals in 2 uninterrupted rows; salt water. A few species. U. citrina K. (Fig. 274, g). Elongate; flexible; ectoplasm with pale-yellow ringed bodies which give the organism yellowish color; marginals discontinuous posteriorly; 2 contractile vacuoles near left border; nucleus distributed (?); 150-250^ long; salt water. Genus Strongylidium Sterki. 2-5 ventral rows of cirri, margi- nals spirally arranged; 3-6 frontals; 2-many macronuclei; fresh or salt water. Many species. 8. calif ornicum Kahl (Fig. 274, h). 4-5 frontals; macronuclei about 30 in number; 4 micronuclei; contractile vacuole with short canals; about 250yu long; fresh water among vegetation. Genus Stichotricha Perty. Slender ovoid or fusiform; peristome- bearing part narrowed; not flexible; usually 4 spiral rows of cirri; sometimes tube-dwelling, and then in groups ; fresh or salt water. Many species. aS. secunda P. (Fig. 274, i). 130-200^ long; in fresh water. Genus Chaetospira Lachmann. Similar to Stichotricha; but peristome-bearing part flexible; fresh or salt water. C. midleri L. 150-250/x long; in lorica; fresh water. Genus Urostyla Ehrenberg. Ellipsoid; flexible; ends rounded; flattened ventral surface with 4-10 rows of small cirri and 2 marginal rows; 3 or more frontals; 5-12 anals; macronucleus a single body or in many parts; fresh or salt water. Numerous species. SPIROTRICHA, HYPOTRICHA 607 Fig, 274. a, Hypotrichidium conicum, X200 (Kahl); b, Psilotricha acuminata, X230 (Stein); c, Kahlia acrobates, X240 (Kahl); d, Urolep- tus limnetis, X240 (Stokes); e, U. longicaudatus, X240 (Stokes); f, U. dispar, X240 (Stokes); g, Uroleptopsis citrina, X260 (Kahl); h, Stron- gylidium californicutn, X200 (Kahl); i, Stichotricha secunda, X340 (Kahl); j, Urostyla grandis, Xl40 (Stein); k, U. trichogaster, Xl50 (Kahl). U. grandis E. (Figs. 45; 274:, j). 300-400^ long; macronucleus in 100 or more parts; 6-8 micronuclei; fresh water. U. trichogaster Stokes (Fig. 274, k). 250-330ai long; fresh water. U. caudata S. (Fig. 275, a). Elongate ellipsoid; flexible; nar- rowed anterior part bent to left; peristome 1/3 the body length; macronucleus in many parts; contractile vacuoles on left margin; about 600m long; fresh water with sphagnum. Genus Kerona Ehrenberg. Reniform; no caudals; 6 obhque rows of ventral cirri; commensal. One species. 608 PROTOZOOLOGY Fig. 275. a, Urostyla caudata, X90 (Stokes); b, Kerona polyporum, X200 (Stein); c, Keronopsis rubra, X270 (Entz); d, Epiclintes pluvi- alis, XlOO (Smith); e, Holosticha vernalis, X220 (Stokes); f, H. hy- menophora, Xl80 (Stokes); g, Paraholosticha herbicola, X200 (Kahl); h, Trichotaxis stagnatilis, Xl90 (Stokes); i, Balladyna elongala, X800 (Roux); j, Pleurotricha lanceolata, X250 (Stein); k, Gastrostyla musco- rum, X200 (Kahl). K. polyporum E. (Fig. 275, 6). 120-200/i long; commensal on Hydra, Genus Keronopsis Penard. 2 ventral rows of cirri reaching frontal field; caudals variable; macronucleus usually in several (rarely 2) parts; fresh or salt water. Numerous species, K. rubra (Ehrenberg) (Fig. 275, c). Reddish; 200-300^ long; salt water. Genus Epiclintes Stein. Elongate; spoon-shaped; flattened ven- SPIROTRICHA, HYPOTRICHA 609 tral surface ■wdth more than 2 rows of cirri; 2 marginal rows; frontals undifferentiated; anals; no caudals; salt or fresh water. A few species. E. pluvialis Smith (Fig. 275, d). About 375m long; fresh water. Genus Holosticha Wrzesniowski. 3 of frontals along anterior margin; 2 ventral and 2 marginal rows of cirri; anals; fresh or salt water. Numerous species. H. vernalis Stokes (Fig. 275, e). 7 anals; about 180/x long; shal- low pools with algae. H. hymenophora S. (Fig. 275,/). 5 anals; 2 contractile vacuoles; 160-200/i long; shallow pools. Genus Paraholosticha Kahl. Elongate-oval; flexible; ventral cirri in 2 parallel oblique rows; with a row of stiff cirri along frontal margin, posterior to it 2 short rows of cirri; marginals continuous or interrupted at posterior border; fresh water. P. herhicola K. (Fig. 275, g). 150-1 90m long; fresh water among algae. Genus Trichotaxis Stokes. Similar to Holosticha; but wdth 3 rows of ventral cirri; fresh or salt water. T. stagnatilis S. (Fig. 275, h). About IGO/x long; elUpsoid; in fresh water among decaying vegetation. Genus Ballad3ma Kowalewski. Ellipsoid; frontals not well de- veloped or lacking; 1 ventral and 2 marginal rows of cirri; long dorsal and lateral bristles; fresh water. B. elongata Roux (Fig. 275, i). 32-35m by 11-12^; fresh water among plants and detritus. Genus Pleurotricha Stein. Oblong to ellipsoid; marginals con- tinuous; 8 frontals; 3-4 ventrals; 7 anals of which 2 are more posterior ; 2 rows of ventral cirri ; between ventrals and marginals 1-3 rows of few coarse ciha; fresh water. P. lanceolata (Ehrenberg) (Fig. 275, j). 100^165^ long; 2 macro- and 2 micro-nuclei; Manwell (1928) studied its conjuga- tion, division, encystment and nuclear variation. Genus Gastrostyla Engelmann. Frontals distributed except 3 along the frontal margin; ventrals irregular; 5 anals; macro- nucleus divided into 2-8 parts; fresh or salt water. G. muscorum Kahl (Fig. 275, k). 130-200/i long; macronucleus in 8 parts; fresh water in vegetation. Genus Stylonychia Ehrenberg. Ovoid to reniform; not flexible; ventral surface flat, dorsal surface convex; 8 frontals; 5 ventrals; 610 PROTOZOOLOGY 5 anals; marginals; 3 caudals; with short dorsal bristles; fresh or salt water. Many species. S. mytilus (Muller) (Fig. 276, 6). 100-300^ long; fresh, brackish and salt water. Fig. 276. a, Uroleptus halseyi, X470 (Calkins); b, Stylomjchia my- tilus, X200 (Stein); c, S. pustulata, X400 (Roux); d, S. putrina, X200 (Stokes); e, S. notophora, X200 (Stokes); f, Onychodroinus grandis, X230 (Stein); g, Onychodromopsis flexilis, X240 (Stokes); h, i, Eti- plotes patella, X290 (Kahl); j, E. plumipes, X270 (Stokes). S. pustulata E. (Fig. 276, c). About ISO/x long; fresh water; nuclear changes studied by Summers (1935). SPIROTRICHA, HYPOTRICHA 611 ,S. putrina Stokes (Fig. 276, d). 125-150/i long; fresh water. S. notophora S. (Fig. 276, e). About 125yu long; standing water. Genus Onychodromus Stein. Not flexible; somewhat rectangu- lar; anterior end truncate, posterior end rounded; ventral surface flat, dorsal surface convex; peristome broadly triangular in ven- tral view; 3 frontals; 3 rows of cirri parallel to right edge of peristome; 5-6 anals; marginals uninterrupted; 4-8 macronuclei; contractile vacuole; fresh water. One species. 0. grandis S. (Fig. 276, /). 100-300^ long. Genus Onychodromopsis Stokes. Similar to Onychodromus; but flexible; 6 frontals of which the anterior three are the largest; fresh water. One species. 0. flexilis S. (Fig. 276, g). 90-1 25m long; standing pond water. Family 2 Euplotidae Glaus Genus Euplotes Ehrenberg. Inflexible body ovoid; ventral surface flattened, dorsal surface convex; longitudinally ridged; peristome broadly triangular; frontal part of adoral zone lies in flat furrow; 9 or more f rontal-ventrals ; 5 anals; 4 scattered caudals; macronucleus band-like; a micronucleus; contractile vacuole posterior; fresh or salt water. Numerous species. E. patella (Miiller) (Figs. 11, a; 12; 17; 51; 276, h, i). 9 frontal- ventrals; polymorphic; about 80-1 50^ long; fresh and salt water (experimentally by Bullington). Its neuromotor system studied by Yocom (1918), Taylor (1920) and Turner (1933) (p. 55-56); macronuclear division, by Turner (1930) (p. 120). E. plumipes Stokes (Fig. 276, j). About 125m long; fresh water. E. carinatus S. (Fig. 277, a). About 70)U by 50m; fresh water. E. charon (Miiller) (Fig. 277, 6). 70-90m long; salt water. Genus Euplotidium Noland. Cyhndrical; 9 frontal- ventrals in 2 rows toward right; 5 anals; a groove extends backward from oral region to ventral side, in which the left-most anal cirrus lies; peristome opened widely at anterior end, but covered posteriorly by a transparent, curved, flap-like membrane; adoral zone made up of about 80 membranellae; longitudinal ridges (carinae) 3 dorsal and 2 lateral; a row of protrichocysts under each carina; a broad zone of protrichocysts in antero-dorsal region; cytoplasm densely granulated; salt water. One species. E. agitatum N. (Fig. 277, c, d). 65-95m long; erratic movement rapid; observed in half -dead sponges in Florida. 612 PROTOZOOLOGY Fig. 277. a, Euplotes carinatus, X430 (Stokes); b, E. charon, X440 (Kahl); c, d, Euplotidmm agitatum, X540 (Noland); e, Certesia quad- rinucleata, X670 (Sauerbrey); f, Diophrys appendiculatus, X570 (Wallengren) ; g, Uronychia setigera, X870 (Calkins); h, Aspidisca lynceus, X300 (Stein); i, A. polystyla, X290 (Kahl). SPIROTRICHA, HYPOTRICHA 613 Genus Certesia Fabre-Domergue. Ellipsoid; flattened; dorsal surface slightly convex, ventral surface flat or concave; 5 frontals at anterior border; 7 ventrals; 5 anals; no caudals; marginals small in number; 4 macronuclei; salt water. One species. C. qimdrinucleata F.-D. (Fig. 277, e). 70-100m by about 45^. Genus Diophrys Dujardin. Peristome relatively large, often reaching anals; 7-8 f rontal- ventrals ; 5 anals; 3 strong cirri right-dorsal near posterior margin; salt water. D. appendicidatus (Ehrenberg) (Fig. 277, f). 60-100ai long; salt water; Woods Hole (Calkins). Genus Uronychia Stein. Without frontals and ventrals; 5 anals; 3 right-dorsal cirri (as in Diophrys); 2 left-ventral cirri near posterior margin; peristome, oval with a large undulating membrane on right edge; salt water. Several species. U. setigera Calkins (Fig. 277, g). 40/i by 25)u; salt water; Woods Hole. Family 3 Aspidiscidae Claus Genus Aspidisca Ehrenberg. Small; ovoid; inflexible; right and dorsal side convex, ventral side flattened; adoral zone reduced or rudimentary; 7 f rontal- ventrals ; 5-12 anals; macronucleus horse- shoe-shaped or occasionally in 2 rounded parts; contractile vacuole posterior; fresh or salt water. Numerous species. A. lynceus E. (Figs. 52; 277, h). 30-50/i long; fresh water. Division studied by Summers (1935). A. polystyla Stein (Fig. 277, i). About 50^ long; salt water; Woods Hole (Calkins). References Calkins, G. N. 1902 Marine Protozoa from Woods Hole. Bull. U. S. Fish. Comm., Vol. 21. Kent, S. 1881-1882 A manual of Infusoria. London. NoLAND, L. E. 1937 Observations on marine ciliates of the Gulf coast of Florida. Trans. Amer. Micr. Soc, Vol. 56. Roux, J. 1901 Faune infusorienne des eaux stagnantes des environs de Geneve. Mem. fac. sci. TUniv. Geneve. Stein, F. 1867 Der Organismus der Infusionstiere. Vol. 2. Stokes, A. C. 1888 A preliminary contribution toward a history of the freshwater Infusoria of the United States. Jour. Trenton N. H. Soc, Vol. 1. Chapter 41 Order 3 Chonotricha Wallengren THESE ciliates live attached to aquatic animals, especially crustaceans and have developed a peculiar organization. The body is, as a rule, vase-form with an apical peristome, around which extends a more or less complicated ectoplasmic collar or funnel and along which are found ciliary rows that lead to the deeply located cytostome and cytopharynx. The macronucleus is oval and situated centrally; there is a contractile vacuole usually near the cytopharynx. Asexual reproduction is by lateral budding, and conjugation has been observed in a few species. Family Spirochonidae Stein Genus Spirochona Stein. Peristome funnel spirally wound; ciliary zone on floor of spiral furrow, attached to Gammarus in fresh water. Several species. Swarczewsky (1928) described several species from Lake Baikal in Siberia. S. gemmipara S. (Fig. 278, a). 80-120/x long; attached to gill- plates of Gammarus pulex and other species. Genus Stylochona Kent. Peristomal funnel with an inner fun- nel. One species. S. coronata K. (Fig. 278, h). About 60/^ long on marine Gam- marus. Genus Kentrochona Rompel ( Kentrochonopsis Doflein). Peri- stomal funnel wide, simple, membranous; with or without a few (2) spines. K. nebaliae R. (Fig. 278, c). About 40ai long; much flattened, with its broad side attached by means of gelatinous substance to epi- and exo-podite of Nehalia geoffroyi; salt water. Genus Heliochona Plate. Peristomal funnel with numerous needle-like spines. H. scheuteni (Stein) (Fig. 278, d). About 80-90;u long; on ap- pendages of Gammarus locusta; salt water. H. sessilis P. (Fig. 278, e). About 60/i long; on Gammarus locusta; salt water. Genus Chilodochona Wallengren. Peristome drawn out into 2 lips; with a long stalk. 614 CHONOTRICHA 615 Fig. 278. a, Spirochona gemmijyara, X300 (Hertwig); b, Stylochona coronata, X400 (Kent); c, Kentrochona nebaliae, X970 (Rompel); d, Heliochona scheuteni, Xo50 (Wallengren) ; e, H. sessilis, X510 (Wallengren) ; f, Chilodochona quennerstedti, X400 (Wallengren). C. quennerstedti W. (Fig. 278,/). 60-115/x long; stalk, 40-160//; on Ehalia turnefacta and Portunus depurator; salt water. Reference Kahl, a. 1935 Urtiere oder Protozoa. In Dahl's Die Tier welt Deutschlands. Part 30. Chapter 42 Order 4 Peritricha Stein THE peritrichous ciliates possess a much enlarged disk-like anterior region which is conspicuously ciliated. The adoral zone is counter-clockwise to the cytostome viewed from the anterior end. The body ciliation is more or less limited. The stalked forms produce free-swimming individuals, telotrochs. Asexual reproduction is by binary fission; and conjugation occurs commonly. The majority are free-living, often attached to various aquatic animals and plants, although a few are parasitic. Attached to submerged objects; usually no body cilia, though telotroch possesses a posterior ring of cilia Suborder 1 Sessilia Free-swimming; but with highly developed attaching organellae on aboral end which are ciliated permanently Suborder 2 Mobilia (p. 625) Suborder 1 Sessilia Kahl Without lorica, although some with a gelatinous or mucilaginous en- velope Tribe 1 Aloricata With definite pseudochitinous lorica Tribe 2 Loricata (p. 623) Tribe 1 Aloricata Kahl Posterior end with 1-2 short spines; swimming with peristome-bearing end forward Family 1 Astylozoonidae Posterior end, directly or indirectly through stalk, attached to sub- merged objects Anterior region a long cylindrical, highly contractile neck; con- tractile vacuole posterior, connected with vestibule by a long canal; reservoir of contractile vacuole distinct; with or without a thin stalk Family 2 Ophrydiidae (p. 618) Anterior portion not drawn out into a neck Without stalk Family 3 Scyphidiidae (p. 618) With stalk Stalk non-contractile Family 4 Epistylidae (p. 619) Stalk contractile Family 5 Vorticellidae (p. 621) Family 1 Astylozoonidae Kahl Genus Astylozoon Engelmann (Geleiella Stiller). Free-swim- ming; pyriform or conical; aboral end attenuated, with 1-2 616 PERITRICHA 617 Fig. 279. a, Astijlozoon fallax, X170 (Engelmann); b, Hastatella aesculacantha, X580 (Jarocki); c, Opistho7iecta henneguyi, X500 (Lynch and Noble); d, e, Ophridium sessile (d, Xl.5; e, X65) (Kent); f, 0. vernalis, X160 (Stokes); g, Scyphidia constrida, X360 (Stokes); h, Paravorticella clymetiellae, X65 (Shuinway). thigmotactic bristles; pellicle smooth or furrowed; with or with- out gelatinous envelope; in fresh water. A few species. A. fallax E. (Fig. 279, a). 70-100^; fresh water. Genus Hastatella Erlanger, Free-swimming; body surface with 2-4 rings of long conical ectoplasmic processes; fresh water. 618 PROTOZOOLOCY H. aesciilacantha Jarocki ot Jacubowska (Fig. 279, h). 30-52;u by 24-40;u; in stagnant water. Genus Opisthonecta Faiire-Fremiet. Conical; ends broadly rounded; a ring of long cilia close to aboral end; adoral zone about 1.1 turns, composed of 2 parallel rows; a papilla with about 12 long cilia, just above the opening into vestibule; macronucleus sausage-form; micronucleus; 3 contractile vacuoles connected with cytopharynx; fresh water. One species. 0. henneguyi F.-F. (Fig. 279, c). 148-170^ long. The organisms studied by Lynch and Noble (1931) were infected by endopara- sitic suctorian, Endosphaera engelmanni (p. 638). Family 2 Ophrydiidae Kent Genus Ophrydium Ehrenberg {Gerda Claparede et Lachmann). Cylindrical with a contractile neck; posterior end pointed or rounded; variable number of individuals in a common mucilagi- nous mass; pellicle usually cross-striated; fresh water. 0. sessile Kent (Fig. 279, d, e). Fully extended body up to 300/i long; colorless or slightly brownish; ovoid colony up to 5 mm. by 3 mm.; attached to freshwater plants. 0. vernalis (Stokes) (Fig. 279,/). About 250At long; highly con- tractile; in shallow freshwater ponds in early spring (Stokes). Family 3 Scyphidiidae Kahl Genus Scyphidia Dujardin. Cylindrical; posterior end attached to submerged object by an attaching disk; cross-striated; fresh or salt water. S. constricta Stokes (Fig. 279, g). About 55-60/i long; pond water. Genus Paravorticella Kahl. Similar to Scyphidia; but posterior portion is much elongated and contractile; salt water, attached or parasitic. P. clymenellae (Shumway) (Fig. 279, h). lOO/x long; in colon of Clymenella troquata; Woods Hole. Genus Glossatella Biitschli. With a large adoral membrane; often attached to fish and amphibian larvae. G. tintinnahulum (Kent) (Fig. 280, a). 30-43^ long; attached to epidermis and gills of young Triton. Genus Ellobiophrya Chatton et Lwoff. Posterior end drawn out into 2 arm-like processes by means of which the organism PERITRICHA 619 holds fast to gill bars of the mussel, Donax vittatus. One spe- cies. E. donacis C. et L. (Fig. 280, h). 50/z by 40^1, excluding the processes. Family 4 Epistylidae Kent Genus Epistylis Ehrenberg. Inverted bell-form; usually indi- viduals on dichotomous non-contractile stalk, forming large colonies; attached to fresh or salt water animals. Numerous species. E. plicatilis E. (Fig. 280, c). OO-IOOaj long; colony often up to 3 mm. in height; fresh water. E. fugitans Kellicott (Fig. 280, d). 50-60/i long; attached to Sida in early spring; Niagara river, N. Y. E. cambari K. (Fig. 280, e,f). About 50/x long; attached to gills of Cambarus; Niagara river, N. Y. Genus Rhabdostyla Kent. Similar to Epistylis; but solitary with a non-contractile stalk; attached to aquatic animals in fresh or salt water. Numerous species. R. vernalis Stokes (Fig. 280, g). About 50/^ long; attached to Cyclops and Cypris in pools in early spring. Genus Opisthostyla Stokes. Similar to Rhabdostyla; but stalk long and bent at its point of attachment to submerged object, and acts like a spring; fresh or salt water. 0. annulata S. (Fig. 280, h). Body about 23/x long; fresh water. Genus Campanella Goldfuss. Similar to Epistylis; but adoral double zone turns 4-6 times; fresh water. C. umhellaria (Linnaeus) (Fig. 280, i). Colony may reach several millimeters in height; individuals 130-350ai long (Kent). Genus Pyxidium Kent. Stalk simple, not branching; peristome even when fully opened, not constricted from the body proper; frontal disk small, oblique, supported by style-like slender process arising from peristome; attached to freshwater animals and in vegetation. P. vernale Stokes (Fig. 280, j). Solitary or few together; 70-85/: long; fresh water among algae. P. urceolatum S. (Fig. 280, k). About 90/: long; fresh water on plants. Genus Opercularia Stein. Individuals similar to Pyxidium; but short stalk dichotomous; peristome border like a band. G20 PROTOZOOLOGY 0. stcnustonia S. (Fig. 280, I). When extended uj) to 125/x long; attached to Asellits aqnaticus and others. Fig. 280. a, Glossatella tinlinnahulum, X610 (Penard); b, Ellohi- ophrya donacis, X900 (Chatton and Lwoff); c, Epistylis plicatilis, X200 (Stein) ; d, E.fugitans, X260 (Kellicott); e, f, E. cambri (e, Xl40; f, X340) (Kellicott); g, Rhabdostyla vernalis, X320 (Stokes); h, Opis- thostyla annulata, X440 (Stokes); i, Campanella umhellaria, XlSO (Schroder); j, Pyxidhim vernale, X240 (Stokes); k, P. urceolatum, Xl40 (Stokes); 1, Opercularia stenostoma, X140 (D'Udekem); m, n, 0. plicatilis (m, X40; n, X60) (Stokes). 0. plicatilis Stokes (Fig. 280, m, n). About 254/x long; colony 1.25-2.5 mm, high; pond water. PERITRICHA 621 Family 5 Vorticellidae Fromental Genus Vorticella Linnaeus. Inverted bell-form; colorless, yel- lowish, or greenish; peristome more or less outwardly extended; pellicle sometimes annulated; with a contractile stalk, macro- FiG. 281. a-c, Vorticella campanula (a, X400; b, part of stalk, X800; c, telotroch, X200); d, e, V. convallaria (d, X400; e, XSOO); f-p, V. microstoma (f, g, X400; h, X840; i, telotroch, X400; j-p, telo- troch-formation in vitro, X270); q, r, V. picta (q, X400; r, X800); s, t, V. monilata (s, X400; t, X800) (All, Noland and Finley). nucleus band-form; micronucleus; 1-2 contractile vacuoles; soli- tary; in fresh or salt water, attached to submerged objects. Noland and Finley (1931) gave an excellent taxonomic considera- tion of the genus. Numerous species. 622 PROTOZOOLOGY V. campanula Ehrenberg (Fig. 281, a-c). Usually in groups; cndoplasm filled with refractile reserve granules; vestibule very large with an outer pharyngeal membrane; 50-157/t by 35-99^; peristome 60-125ju wide; stalk 50-4150/i by 5.6-12;u; fresh water. V. convallaria (L.) (Fig. 281, d, e). Resembles the last-named species; but anterior end somewhat narrow; usually without re- fractile granules in endoplasm; 50-95/x by 35-53/i; peristome 55- 75^1 wide; stalk 25-460/^ by 4-6. 5^; fresh water. V. microstoma Ehrenberg (Fig. 281, /-p). 35-83ju by 22-50^; peristome 12-25/i wide; stalk 20-385/z by 1.5-4^t; common in freshwater infusion. V. picta (E.) (Fig. 281, q, r). 41-63^ by 20-37/^; peristome 35-50/x; stalk 205-550yii by 4-7m; 2 contractile vacuoles; with refractile granules in stalk; fresh water. V. monilata (Tatem) (Fig. 281, s, t). Body with pellicular tubercles; 2 contractile vacuoles; 50-78)U by 35-57/i; peristome 35-63jU wide; stalk 50-200ju by 5-6.5 fx; fresh water. Genus Carchesium Ehrenberg. Similar to Vorticella; but colonial; myonemes in stalk not continuous, and therefore indi- vidual stalks contract independently; attached to fresh or salt water animals or plants; occasionally colonies up to 4 mm. high. Several species. C. polypinum (Linnaeus) (Figs. 34; 282, a). 100-1 25/i long; fresh water. Fig. 282. a, Carchesium polypinum, X200 (Stein); b, C. granulatum, X220 (Kellicott); c, Zoothamnium arbuscula, X200 (Stein); d, Z. adamsi, Xl50 (Stokes). PERITRICHA 623 C. granulatum Kellicott (Fig. 282, h). About 100^ long; 2 con- tractile vacuoles anterior; on Cambarus and aquatic plants; Niagara river, N. Y. Genus Zoothamnium Bory. Similar to Carchesiiim; but myonemes (Fig. 15) of all stalks of a colony are continuous with one another, so that the entire colony contracts or expands simul- taneously; fresh or salt water; colonies sometimes several milli- meters high. Numerous species. Z. arhuscula Ehrenberg (Fig. 282, c). 40-60;U long; colony up to more than 6 mm. high; fresh water. Z. adamsi Stokes (Fig. 282, d). About 60/i long; colony about 250m high; attached to Cladophora; Niagara river, N. Y. Tribe 2 Loricata Kahl Peristomal margin not connected with lorica; body attached only at posterior end, and extends out, of lorica Family 1 Vaginicolidae Peristomal margin connected with inner margin of aperture of lorica; stalked disk extends out of lorica only Family 2 Lagenophryidae fp. 625) Family 1 Vaginicolidae Kent Genus Vaginicola Lamarck. Lorica without stalk, attached to substratum directly with its posterior end; body elongate and cyHndrical; fresh or salt water. Numerous species. V. leptostoma Stokes (Fig. 283, a). Lorica about 160/x high; when extended, about 1/3 of body protruding; on algae in pond water. V. annulata S. (Fig. 283, h). Lorica about 120At high; below middle, a ring-Hke elevation; anterior 1/3 of body protruding, when extended; pond water. Genus Cothurnia Ehrenberg. Similar to Vaginicola; but lorica stands on a short stalk; fresh or salt water. Numerous species. C. canthocampti Stokes (Fig. 283, c). Lorica about 80m high; on Canthocamptus minutiis. C. annulata S. (Fig. 283, d). Lorica about 55m high; fresh water. Genus Thuricola Kent. Body and lorica as in Vaginicola; but lorica with a simple or complex valve-like apparatus which closes obliquely after the manner of a door when protoplasmic body contracts; salt or fresh water. 024 PROTOZOOLOGY T. folliculata (Muller) (Fig. 283, e). Lorica 127-170/i high (Kent); 160-200/x high (Kahl); salt and fresh water. Genus Thuricolopsis Stokes. Lorica with an internal, narrow, flexible valve-rest, adherent to lorica wall and projecting across cavity to receive and support the descended valve; protoplasmic body attached to lorica by a pedicle; on freshwater plants. Fig. 283. a, Vaginicola leptostoma, Xl30 (Stokes); b, V. annulata, Xl70 (Stokes); c, Cothurnia canthocampti, Xl50 (Stokes); d, C. an- nulata, X340 (Stokes); e, Thuricola folliculata, XllO (Kahl);f, Thuri- colopsis kellicottiana, XllO (Stokes); g, Caulicola valvata, X760 (Stokes); h, i, Pijxicola affitiis, Xl70 (Kent); j, P. socialis, X170 (Kent); k, Platycola longicollis, X200 (De Fromentel); 1, Lagenophrys vaginicola, X380 (Penard); m, L. patina, Xl50 (Stokes); n, L. labiata, X340 (Penard). T. kellicottiana S. (Fig. 283, /). Lorica about 220;u long. Genus Caulicola Stokes. Similar to Thuricola; but lorica-lid attached to aperture; fresh or brackish water. 2 species. C. valvata S. (Fig. 283, g). Lorica about 50/i high; stalk about 1/2; body protrudes about 1/3 when extended; brackish water. Genus Pyxicola Kent. Body attached posteriorly to a corneous lorica; lorica colorless to brown, erect, on a pedicle; a discoidal corneous operculum developed beneath border of peristome, PERITRICHA 625 which closes lorica when organism contracts; fresh or salt water. Many species. P. affinis K. (Fig. 283, h, i). Lorica about 85/i long; in marsh water. P. socialis (Gruber) (Fig. 283, j). Lorica about lOO^u long; often in groups; salt water. Genus Platycola Kent. Body similar to that of Vaginicola; but lorica always decumbent and attached throughout entire one side to its fulcrum of support; fresh or salt water. Many species. P. longicollis K. (Fig. 283, k). Lorica yellow to brown when older; about 126/^ long; fresh water. Family 2 Lagenophryidae BiitschU Genus Lagenophrys Stein. Lorica with flattened adhering sur- face, short neck and convex surface; "striped body" connects body with lorica near aperture; attached to fresh or salt water animals. Many species. L. vaginicola S. (Fig. 283, I). Lorica 70^1 by 48/i; attached to caudal bristles and appendages of Cyclops minutus and Cantho- camptus sp. L. patina Stokes (Fig. 283, m). Lorica 55/i by 50 fx; on Gam- marus. L. lahiata S. (Fig. 283, )i). Lorica 60^1 by 55^; on Gammarus. Suborder 2 Mobilia Kahl Family Urceolariidae Stein Genus Urceolaria Lamarck. Peristome more or less obhquely placed; external ciliary ring difficult to see; horny corona of attaching disk with obliquely arranged simple teeth without radial processes; commensal. A few species. U. niitra (Siebold) (Fig. 284, a). 80-140/x long; on planarians. U. paradoxa (Claparede et Lachmann) (Fig. 284, h). 70-80/i in diameter; colonial forms; in respiratory cavity of Cyclostoma elegans. Genus Trichodina Ehrenberg. Low barrel-shaped; with a row of posterior cilia; horny ring of attaching disk with radially ar- ranged hooked teeth; commensal on, or parasitic in, aquatic animals. Several species. T. pediculus (Miiller) (Fig. 284, c). A shallow constriction in middle of body; 50-70^ in diameter; on Hydra, amphibian larvae 626 PROTOZOOLOGY Fig. 284. a, Urceolaria mitra, X340 (Wallengren) ; b, U. paradoxa, X270 (Claparede and Lachmann); c, Trichodina pediculus, X530 (James-Clark); d, T. urinicola, X590 (Fulton); e, T. sp., X600 (Diller); f, Cydochaeta spongillae, X600 (Jackson); g, C. domerguei, X800 (Wallengren). and probably fish. Those found on Hydra and gills of Necturiis and Triturus larvae are probably identical (Fulton, 1923). T. urinicola Fulton (Fig. 284, d). 50-90^ long; teeth 28-36; in urinary bladder of a moribund Bufo sp. and Triturus. T. sp. Diller (Fig. 284, e). 30-40/i in diameter; on skin and gills of frog and toad tadpoles. Genus Cydochaeta Jackson. Similar to Trichodina; but bristles or cirri surrounding attaching organella distinctly visible; com- PERITRICHA 627 mensal on, or parasitic in, fresh or salt water animals. Several species. C. spongillae J. (Fig. 284,/). About 60^ in diameter; in inter- stices of Spotigilla fluviatilis. C. domerguei Wallengren (Fig. 284, g). About 55/i in diameter; on freshwater fishes. References Fulton, Jr., J. F., 1923 Trichodina pediculus and a new closely- related species. Proc. Boston Soc. Nat. Hist., Vol. 37. Kahl, a. 1935 Dahl's Die Tierwelt Detdschlands. Part 30. Kent, S. 1881-1882 A manual of Infusoria. NoLAND, L. E. and H. E. Finley 1931 Studies on the taxonomy of the genus Vorticella. Trans. Amer. Micr. Soc, Vol. 50. Penard, E. 1922 Etudes sue les Infusoires d'eau douce. Geneva. Stokes, A. C. 1888 A preliminary contribution toward a history of the freshwater Infusoria of the United States. Jour. Trenton Nat. Hist. Soc, Vol. 1. Chapter 43 Class 2 Suctoria Claparede et Lachmann THE Suctoria which are also known as Acineta, Acinetaria, TentacuHfera, etc., do not possess any ciha or any other cell- organs of locomotion in the mature stage. The cilia are present only on young individuals which are capable of free-swimming, and lost with the development of a stalk or attaching disk, and of tentacles. Therefore, an adult suctorian is incapable of active movement. The body may be spheroidal, elliptical, or dendritic; and is covered with a pellicle and occasionally possesses a lorica. There is no cytostome, and the food-capturing is carried on ex- clusively by the tentacles. Tentacles are of tw^o kinds: one is suctorial in function and bears a rounded knob on the extremity and the other is for piercing through the body of a prey and more or less sharply pointed. The tentacles may be confined to limited areas or may be distributed over the entire body surface. The food organisms are usually small ciliates and nutrition thus is holozoic. Asexual reproduction is by binary fission or by budding. The buds which are formed by either exogenous or endogenous gem- mation are ciliated, and swim around actively after leaving the parent individual. Finally becoming attached to a suitable ob- ject, the buds metamorphose into adult forms. Sexual reproduc- tion is through fusion. The Suctoria live attached to animals, plants or non-living matter submerged in fresh or salt water, although a few are para- sitic. With only suctorial tentacles Body irregular or branching Without proboscis or special arms; often with stolen; without stalk Family 1 Dendrosomidae (p. 629) With proboscis or special arms With retractile processes bearing tentacles Family 2 Ophryodeudridae (p. 632) With branched arms Family 3 Dendrocometidae (p. 632) Body more or less bilaterally symmetrical Exogenous budding and division Family 4 Podophryidae (p. 632) 628 SUCTORIA 629 Endogenous budding Pellicle thin; with or without lorica; with or without stalk. . . Family 5 Acinetidae (p. 634) Pellicle thick; without lorica; tentacles a few, variable in form; stalk short, stout Family 6 Discophryidae (p. 638) With suctorial and prehensile. tentacles; with or without lorica; exog- enous budding; commensal on marine hydroids Family 7 Ephelotidae (p. 641) Family 1 Dendrosomidae Blitschli Genus Dendrosoma Ehrenberg. Dendritic; often large; nucleus band-form, branched; numerous contractile vacuoles; fresh water. D. radians E. (Fig. 285, a). Brownish; 1.2-2.5 mm. high; on vegetation. Genus Trichophrya Claparede et Lachmann. Body small; rounded or elongate, but variable; without stalk; tentacles in fascicles, not branching; endogenous multiple budding; fresh or salt water. T. epistylidis C. et L. (T. sinuosa Stokes) (Fig. 285, h). Form irregular; with, many bundles of tentacles; nucleus band-form, curved; numerous vacuoles; up to 240^1 long; on Epistylis, etc., in fresh water. T. salparum Entz (Fig. 285, c). On various tunicates such as Molgula manhattensis ; 40-60^ long; tentacles in 2 groups; salt water; Woods Hole (Calkins). T. columhiae Wailes (Fig. 285, d). Q0-75fx by 40-48^ in diame- ter; cylindrical; tentacles at ends; nucleus spherical; in marine plankton; Vancouver (Wailes). Genus Astrophrya Awerinzew. Stellate; central portion drawn out into 8 elongate processes, each with a fascicle of tentacles; body covered by sand grains and other objects. One species. A. arenaria A. (Fig. 285, e). 145-188/i in diameter; processes 80-190)u long; in Volga river plankton. Genus Lernaeophrya Perez. Body large; with numerous short prolongations, bearing very long multifasciculate tentacles; nucleus branched; brackish water. One species. L. capitata P. (Fig. 285, /). Attached to hydrozoan, Cordylo- phora lacustris in brackish water; 400-500/^ long; tentacles 400At long. Genus Dendrosomides Collin. Branched body similar to Dendrosoma, but with a peduncle; reproduction by budding of vermicular form; salt water. One species. 630 PROTOZOOLOCIY Fig. 285. a, Dendrosonia radians, X35 (Kent); b, Trichophrya epistylidis, X250 (Stokes); c, T. salparum, Xl70 (Collin); d, T. columbiae, X200 (Wailes); e, Astrophrya arenaria, X65 (Awerinzew); f, Lernaeophrya capitata, X35 (P^rez); g, Dendrosomides paguri, X200 (Collin). D. paguri C. (Fig. 285, g). 200-300/^ long; vermicular forms 350/i long; on the crabs, Eupagurus excavatus and E. cuanensis. Genus Rhabdophrya Chatton et Collin. Elongate, rod-form; with short peduncle, not branched; tentacles distributed over entire surface; macronucleus ellipsoid; micronucleus small; 2-3 contractile vacuoles; salt or brackish water. Several species. R. trimorpha C. et C. (Fig. 286, a). Up to 150/^ long; on the copepod, Cletodes longicaudatus. SUCTORIA 631 Fig. 286. a, Rhabdophrya trimorpha, X650 (Collin); b, Staurophrya elegans, X300 (Zacharias); c, Ophryodendron porcellanum, X330 (Collin); d, 0. belgicum, X270 (Fraipont); e, Dendrocometes paradoxus, X270 (Wrzesnowski); f, g, Podophrya fixa (f, X600 (Wailes); g, X330 (Collin)); h, P. gracilis, XlOOO (Collin); i, P. elongata, X240 (Wailes). Genus Staurophrya Zacharias. Rounded body drawn out into 6 processes. S. elegans Z. (Fig. 286, h). Tentacles not capitate; macronucleus round; 1-2 contractile vacuoles; about 50/i in diameter; in fresh water. 032 PROTOZOOLOGY Family 2 Ophryodendridae Stein Genus Ophryodendron Claparede et Lachmann. With one long or 3-6 shorter retractile processes, bearing suctorial tentacles; on Crustacea, Annelida, etc.; salt water. Several species. 0. porcellanum Kent (Fig. 286, c). 60-100/1 long; on Porcellana platycheles, etc. 0. helgicum Fraipont (Fig. 286, d). 38-1 14/x long; vermicular form lOOfx; on Bryozoa and hydrozoans; Vancouver (Wailes). Family 3 Dendrocometidae Stein Genus Dendrocometes Stein. Body rounded; with variable number of branched arms; fresh water. D. paradoxus S. (Fig. 286, e). Up to 100/x long; on gills of Gammarus pulex, G. puteanus, etc. Genus Stylocometes Stein. Arms not branched; tentacles finger-like; fresh water. S. digitatus (Claparede et Lachmann). Up to 110^ long; on gills of Asellus aquaticus and on Aphrydium versatile. Family 4 Podophryidae Biitschli Genus Podophrya Ehrenberg. Subspherical; normally with a rigid stalk; suctorial tentacles in fascicles or distributed on entire body surface; encystment common; fresh or salt water. Many species. P. fixa Mliller (Fig. 286, /, g). Spherical; tentacles of various lengths; stalked; nucleus spheroid; one contractile vacuole; 10- 28fx long; fresh water. P. collini Root. Ovoid; stalked; 30-60 capitate tentacles, dis- tributed; nucleus pherical; one contractile vacuole; 40-50/i in diameter; in swamp. P. gracilis Calkins (Fig. 286, h). Small; spherical; long filiform stalk; 1-2 contractile vacuoles; nucleus near attachment of stalk; Sn in diameter; stalk 40/x long; salt water; Woods Hole. P. elongata Wailes (Fig. 286, i). Elongate; flattened; with a pedicel; tentacles distributed; nucleus cylindrical; 95-105/u long; stalk 65-85;u by 7-9fx; on the marine copepod, Euchaeta japonica; Vancouver. Genus Parapodophrya Kahl. Spherical; tentacles radiating, a few long, more or less conical at proximal portion; stalk thin; salt water. SUCTORIA 633 P. typha K, (Fig. 287, a). 50-60At in diameter; salt water. Genus Sphaerophrya Claparede et Lachmann. Spherical, with- out stalk; with or without distributed tentacles; multiplication by binary fission or exogenous budding; fresh water, free-living or parasitic. S. soliformis Lauterborn (Fig. 287, h). Spherical; numerous tentacles about 1/4-1/3 the body diameter; a contractile vacuole; nucleus oval; diameter about 100m; sapropelic. S. magna Maupas. Spherical; about 50/x in diameter; numerous tentacles of different length; nucleus spheroid; standing fresh water with decaying vegetation. S. stentoris M. Parasitic in Stentor; swarmers ciHated on pos- terior end; the other end with capitate tentacles; nucleus spheroid; 2 contractile vacuoles; about 50/i long. Genus Paracineta Collin. Spherical to ellipsoidal; tentacles distributed ; mostly in salt water, a few in fresh water. P. limhata (Maupas) (Fig. 287, c, d). With or without gelat- inous envelope; 20-50)U in diameter; swarmer with many ciliated bands, contractile; on plants and animals in salt water. Genus Metacineta Biitschli. Lorica funnel-shaped, lower end drawn out for attachment; tentacles grouped at anterior end; nucleus spherical; one contractile vacuole. One species. M. mystacina (Ehrenberg) (Fig. 287, e). Lorica up to 700ai long; in fresh and salt water. Genus Urmula Claparede et Lachmann. Lorica colorless; lower end pointed, attached; aperture narrowed, round or triangular; body more or less filling lorica; 1-2 (up to 5) long active tentacles; nucleus central, oval; one or more contractile vacuoles; fresh water, U. epistylidis C. et L. (Fig. 287,/). Up to 80At long; on EpistyHs, Dendrosoma, etc. Genus Lecanophrya Kahl. Body rounded rectangular in cross- section; anterior region bowl-shaped; somewhat rigid tentacles located on inner surface of bowl; salt water. L. drosera K. (Fig. 287, g). 40-70/^ high; hollow stalk; tentacles in 3-5 indistinct rows; attached to antennae of the copepod, Nitocra typica. Genus Ophryocephalus Wailes. Spheroidal, stalked; a single long mobile, capitate tentacle; multiplication by multiple exog- enous budding from apical region; on Ephelota gemmipara and E. coronata (p. 641); salt water. One species. 634 PROTOZOOLOGY Fig. 287. a, Parapodophrya typha, X270 (Kahl); b, Sphaerophrya soliformis, X200 (Lauterborn); c, d, Paracineta limhata (c, a bud is ready to leave; d, basal part of stalk), X460 (Collin); e, Metacineta niystacina, capturing Halteria, X400 (Collin); f, Urmula epistylidis, Xl40 (Claparede and Lachmann); g, Lecanophrya drosera, X390 (Kahl); h, Ophryocephalus capilatum, X200 (Wailes); i, Acineta lacus- tris, X200 (Stokes). 0. capitatum W. (Fig. 287, h). About 55^1 long; tentacle up to lOOyu by 1.5-5/x; Vancouver. Family 5 Acinetidae Biitschli Genus Acineta Ehrenberg. Lorica more or less flattened; usually with stalk; tentacles in 2 (1 or 3) bundles; body completely SUCTORIA 635 Fig. 288. a, Acineta tuberosa, X670 (Calkins); b, A. cuspidata, X670 (Stokes); c-e, Tokophrya infusionum (c, X400; d, a free-swim- ming bud; e, a j^oung attached form, XSOO) (Collin); f, T. cyclopum, a young individual, X500 (Collin). or partly filling lorica; s warmer with ciliated band or completely ciliated; fresh or salt water. Numerous species. A. tuberosa E. (Fig. 288, a). Lorica 50-100/z high; with stalk; salt and brackish water. A. cuspidata Stokes (Fig. 288, h). Lorica cup-shaped; front 636 PROTOZOOLOGY end with 2 opposing sharp points; lorica 32-42/^ high; on Oedo- gonium in fresh water. A. lacustris S. (Fig. 287, i). Lorica elongate ovoid; flattened; 75-185/z high; on Anacharis in pond. Genus Tokophrya Biitschli. Pyriform or pyramidal; without lorica; tentacles in 1-4 bundles on anterior surface; stalk soft; swarmers oval, with several ciliary bands and long cilia; fresh water. Several species. T. infusionum (Stein) (Fig. 288, c-e). Inverted pyramid; stalk with or without attaching disk; macronucleus oval; 2 contractile vacuoles; about 60/x long. T. cyclopum (Claparede et Lachmann) (Fig. 288, /). Oval or spherical; stalk short; tentacles in 2-5 bundles; macronucleus spherical; 1-2 contractile vacuoles; about 50/^ long; on Cyclops, etc. Genus Thecacineta Collin. Lorica with free margin; body usually attached to bottom of lorica, more or less long; tentacles from anterior end; salt water. Several species. T. cothurnioides C. (Fig. 289, a). Lorica about 50/x high; stalk knobbed; on Cletodes longicaudatus. T. gracilis (Wailes) (Fig. 289, b). Lorica llO/z by 35m; stalk 200^ by ifx] on hydroids. Genus Periacineta Collin. Elongate lorica; attached with its drawn-out posterior end; tentacles from the opposite surface in bundles; fresh water. P. huckei (Kent) (Fig. 289, c). Attached end of lorica with basal plate; 3 contractile vacuoles; up to 125yu long; on Lymnaea stagnalis and Ranatra linearis. Genus Hallezia Sand. Without lorica; with or without a short stalk; tentacles in bundles; fresh water. H. hrachypoda (Stokes) (Fig. 289, d). 34-42/i in diameter; in standing water among leaves. Genus Solenophrya Claparede et Lachmann. Lorica attached directly with its under side; body usually not filhng lorica; tentacles in bundles; fresh water. S. inclusa Stokes (Fig. 289, e). Lorica subspherical; about 44/t in diameter; standing fresh water. *S. pera S. (Fig. 289,/). Lorica satchel-form; about 40-45^ high; body about Sd/x long; standing fresh water. Genus Acinetopsis Robin. Lorica in close contact with body SUCTORIA 037 Fig. 289. a, Thecacineta cothurnioides, X400 (Collin); b, T. gracilis, X270 (Wailes); c, Periacineta buckei, feeding on Chilodonella, X530 (Collin); d, Hallezia brachypoda, X200 (Stokes); e, Solenophrya in- clusa, X230 (Stokes); f, S. pera, X230 (Stokes); g, h, Acinetopsis tentaculata (g, X130; h, X230) (Root); i, j, Tachyblaston ephelotensis (i, a young individual in Ephelota, X260; j, mature form, X500) (Martin); k, Dadylophrya roscovita, X830 (Collin). on sides; stalked; 1-6 large retractile tentacles and numerous small tentacles from apical end; mainly salt water. r,;?S PROTOZOOLOGY A. tentaculata Root (Fig. 289, g, h). Lorica 187ai high; stalk 287/z long; largo tentacles u]) to 500/x long; body about 138/i by 100m; on Ohelia commissuralis and 0. geniculata; Woods Hole. Genus Tachyblaston Martin. Lorica with short stalk; tentacles distributed on anterior surface; nucleus oval; salt water. One species. T. ephelotensis M. (Fig. 289, i,j). Lorica 30-93^ high; stalk 20- 30/1 long; attached to Ephelota gerrmiipara. Genus Dactylophrya Collin. Cup-like lorica, filled with the protoplasmic body; with a short stalk; 12-15 arm-like tentacles from anterior surface; salt water. One species. D. roscovita C. (Fig. 289, k). About 40/i long excluding stalk; on the hydrozoan, Diphasia attenuata. Genus Pseudogemma Collin. Attached with a short stalk to larger suctorians; without tentacles; endogenous budding; swarmer with 4 ciliary bands ; salt water. P. pachystyla C. (Fig. 290, a). About 30/^ long; stalk 3-4/z wide; swarmer 15;u by 9ju; on Acineta tuber osa. Genus Endosphaera Engelmann. Spherical; without lorica; without tentacles; budding endogenous; swarmer with 3 equa- torial ciliary bands; parasitic in Peritricha; fresh and salt water. E. engehnanni Entz (Fig. 290, 6). 15-41)U in diameter; im- bedded in the host's cytoplasm; swarmer 13-1 9/i in diameter; in Opisthoneda henneguyi (p. 618), and other peritrichs. Genus Allantosoma Gassovsky. With neither lorica nor stalk; elongate; one or more tentacles at ends; macronucleus oval or spherical; compact micronucleus; a single contractile vacuole; cytoplasm often filled with small spheroidal bodies; development unknown; in mammalian intestine. A. intestinalis G. (Fig. 290, c). 33-60/x by 18-37^; attached to various ciliates occurring in caecum and colon of horse. A. dicorniger Hsiung (Fig. 290, d). 20-33/i by 10-20ai; un- attached; in colon of horse. A. hrevicorniger H. (Fig. 290, e). 23-36^ by 7-1 l/i; attached to various ciliates of caecum and colon of horse. Family 6 Discophryidae Collin Genus Discophrya Lachmann. Elongate; a short stout pedicel with a plate; tentacles evenly distributed on anterior surface or SUCTORIA 639 Fig. 290. a, Pseudogemma pachystyla, X400 (Collin); b, Endo- sphaera engelnianni, X500 (Lynch and Noble); c, Allantosoma intes- linalis, X1050 (Hsiung); d, A. dicorniger, X1300 (Hsiung); e, A. brevicorniger, X1400 (Hsiung); f, Discophrya elongata, X440 (Collin); g, Thaumatophrya trold, X1150 (Claparede and Lachmann); h, Rhyn- chophrya palpans, X440 (Collin). in bundles; contractile vacuoles, each with canalicule leading to body surface; mainly fresh water. Several species. D. elongata (Claparede et L.) (Fig. 290, /). Cyclindrical; ten- tacles on anterior end and in 2 posterior bundles; stalk striated; about 80/x long; on shell of Pauldina vivipara in fresh water. 640 PROTOZOOLOGY Genus Thaumatophrya Collin. Spherical; long stalk; tentacles distributed, tapering toward distal end; salt water. One species. T. trold (Clapardde et Lachmann) (Fig. 290, g). About 75^ in diameter. Genus Rhynchophrya Collin. Oblong; bilaterally symmetrical; a short striated stalk; 1 main long and a few shorter tentacles; 6-10 contractile vacuoles, each with a canalicule leading to out- side; fresh water. One species. Fig. 291. a, Choanophrya infundihulifera, feeding on disintegrating part of a Cyclops, X400 (Collin); b, c, Rhyncheta cydopum (b, XlOO; c, end of tentacle, X400) (Zenker); d, Ephelota gemmipara, X200 (Hertwig); e, E. coronata, Xl40 (Kent); f, E. plana, front view, with two attached Ophryocephalus, X35 (Wailes); g, Podocyathtis diadema, X200 (Kent). 8UCT0RIA 641 R. palpans C. (Fig. 290, h). S5/j. by SO^u; tentacles retractile, 10-200ai long; stalk 20/x by lO/i; on Hydrophilus piceus. Genus Choanophrya Hartog. Spheroidal to oval; stalked; 10-12 tentacles, tubular, expansible at distal end to engulf voluminous food particles; macronucleus oval to spherical; a micronucleus; fresh water. One species. C. infundibulifera H. (Fig. 291, a). Q5ij. by 60m; fully extended tentacles 200^ long; on Cyclops ornatus. Genus Rhyncheta Zenker. Protoplasmic body attached directly to an aquatic animal; with a long mobile tentacle bearing a sucker at its end. R. cyclopum Z. (Fig. 291, h, c). About 170^ long; on Cyclops. Family 7 Ephelotidae Sand Genus Ephelota Wright. Without lorica; stalk stout, often striated; suctorial and prehensile tentacles distributed; macro- nucleus usually elongate, curved; on hydroids, bryozoans, algae, etc.; salt water. Numerous species. E. gemmipara Hertwig (Fig. 291, d). About 250^ by 220^; stalk up to 1.5 mm. long; on hydroids, bryozoans, etc. E. coronata Kent (Fig. 291, e). Flattened; 90-200^ long; stalk longitudinally striated (Kent); on hydroids, bryozoans, algae, etc. E. plana Wailes (Fig. 291, /). 150-320^ by 100-150/i; stalk 100/i-l mm. long; on bryozoans; Vancouver. Genus Podocyathus Kent. Differ from Ephelota in having con- spicuous lorica; salt water. One species. P. diadema K. (Fig. 291, g). Lorica about 42^ long; on bryo- zoans, hydrozoans, etc. References Collin, B. 1912 Etudes monographique sur les Acinetiens. Arch. zool. exper. et gen.. Vol. 51. Kahl, a. 1934 Sudoria. Grimpe's Die Tierwelt der Nord- und Ost-see. Part 26. Leipzig. Kent, S. 1881-1882 A manual of the Infusoria. Vol. 2. Wailes, G. H. 1928 Dinoflagellates and Protozoa from British Columbia. Vancouver Museum Notes, Vol. 3. Author and Subject Index Numbers in bold-face type indicate pages on which are given the defi- nitions, explanations, and discussions of technical terms; the characteri- zations or differentiations of taxonomic subdivisions; or the descriptions of genera and species. Nu77ibers in italics indicate pages on which appear those illustrations that could not be placed on the same pages as the related text matter. Actinobolinidae, 496, 503 Actinobolus, 503 Actinocephalidae, 392, 403-407 Actinocephalus, 403 acuiispora, 402, 403 Actinocoma, 358 ramosa, 357, 358 Actinocomidae, 358 Actinolophus, 360 pediinculatus, 360, 361 Actinomonas, 42, 237-238 mirahilis, 237, 238 Actinomyxidia, 66, 453, 468-471 Actinophryidae, 358-359 Actinophrys, 41, 86, 131, 358-359 sol, 134, 156, 157, 159, 357, 359 vesiculata, 359 Actinopoda, 289, 356-376 Actinosphaerium, 10, 32, 41, 86, 90, 94, 359 arachnoideum, 359 eichhorni, 36, 43, 156, 357, 359 Actinotricha, 604 Actinozoa, 568 Actipylea, 370-372 Acutispora, 400 macrocephala, 399, 400 Adaptability of Protozoa, 16, 27-28 Adelea, 70, 428 ovata, 135, 146, 428, 429 Adeleidae, 428-431 Adeleidea, 415, 428-433 Adelina, 428 dimidiata, 428, 430 octospora, 428, 430 Adoral membranellae, 48, 54 zone, 48, 49 Aedes aegijpti, 380, 388, 438 albopidus, 388 sollicitans, 438 Aegyria, 523 Aeschna constrida, 407 Aethalium septicum, 91 Agarella, 466 gracilis, 466, 46^ Abiogenesis, 9-10 Acanthociasma, 371 planum, 371 Acanthociasmidae, 371 Acanthocystidae, 358, 362-364 Acanthocystis, 21, 41, 131, 139, 362 aculeata, 22, 125, 362, 363 Acanthodactylus vulgaris, 427 Acanthometrida, 371 Acanthometridae, 371 Acanthometron, 371 elasticum, 52-53, 371 Acanthonia, 371 tetracopa, 371 Acanthoniidae, 371 Acanthophractida, 371 Acanthospora, 402 polymorpha, 402 Acanthosporidae, 392, 401-403 Acartia clausi, 228 Acephahna, 381-391 Achromatic figure, 124, 125, 126, 127, 128, 131 Acidified methjd-green on nucleus, 33 Acineta, 628, 634-635 caspidaia, 635-636 lacustris, 634, 636 papillifera, 566 tuberosa, 635, 638 Acinetaria, 628 Acinetidae, 629, 634-638 Acinetopsis, 636-637 tentaculata, 637, 638 Acis, 401 Acniaea persona, 563 Acnidosporidia, 377, 446-451 Actinelida, 370 Actineliidae, 370 Actinelius, 371 primordialis, 371 Actinia equina, 568 ynesembriianthemum, 568 Actinobolina, 503 borax, 502, 503 043 644 l^ROTOZOOLOGY Aggregata, 70, 126, 138, 418 eberthi, 135, 146, 159, 418, 419 Aggregatidae, 417-420 Agriodrilus, 495 Agriolimax agreslis, 28, 540 Agrion puella, 398 Ahlstrom, 180, 181, 183 Aikenetocystidae, 381, 385 Aikinetocystis, 385 singularis, 385, 386 Akaryomastigont, 274 Alasmidonta undulata, 561 Albertisella, 387 crater, 387, 388 Alexander, 22 Alexeieff, 124, 452 Algae, 24, 90, 92, 171, 174, 290, 292 Allantocystidae, 381, 391 AUantocystis, 391 dasyhelei, 390, 391 Allantosoma, 638 brevicorniger, 638, 639 dicorniger, 638, 639 intestinalis, 638, 639 Allman, 65 AUogromia, 323 Alloiozona, 516 trizona, 515, 516 Allolobophora caliginosa, 493 Allomorphina, 353 trigona, 354 Allosphaerium, 528 caudatum, 528 convexa, 124, 528 granulosum, 528 palustris, 527, 528 sulcatum, 528 Allurus tetraedurus, 493 Aloricata, 616-623 Alveolinella, 350 niello, 349 Alveolinellidae, 350 Amara augustata, 404 Amaroucium, 410-411 Amaurochaete, 300 fuliginosa, 301 Amaurochaetidae, 299 Amaurochaetinea, 299 Amaurosporales, 299 Amberson, 97 Aniby stoma tigrinum, 486 Ameiurus albidus, 505 Amiba, 306 Amitosis, 118-124 Ammodiscidae, 348 Ammodiscus, 348 incertus, 347 Ammonia, 99 Amoeba, 10, 17, 73, 84, 87, 89,90, 91, \m~110, 111, 112, 113, 114, 162, 306 discoides, 100, 306, 307 dojleini, 87 dubia, 43, 87, 91, 100, 306, 307 gorgonia, 308, 309 guttula, 40, 307, 308 limicola, 307, 308 proteus, 10, 21, 40, 43, 51, 69, 70, 71, 85, 87, 88, 98, 100, 102, 103, 104, 105, 112, 136, 137, 138, 306, 307 radiosa, 17, 41, 87, 308, 309 spumosa, 41, 308, 309 striata, 38, 40, 73, 307-308 verrucosa, 17, 20, 38, 85, 99, 100, 102, 114, 306-307 vespertilio, 308, 309 Amoebic dysentery, 315 Amoebidae, 305, 306-312 Amoebina, 87, 148, 289, 304-321 Amoebodiastase, 91 Amoeboid movements, 37, 101-106 Amoebula, 454 Amphacanthus, 591 ovum-rajae, 591 Amphibia, 237, 238, 248, 265, 267, 268, 270, 274, 318, 424, 425, 444, 445, 461, 464, 484, 485, 486, 492, 581, 618, 625, 626 Amphidinium, 223 fusiforvie, 223, 225 lacustre, 19-20, 223, 224 scissum, 223, 224 Amphileptidae, 517-519 Amphileptus, 22, 65, 517 branchiarum, 517, 518 claparedei, 20, 517, 518 meleagris, 517 Amphilonche, 371 hydrortietrica, 371 Amphilonchidae, 371 Amphimonadidae, 239, 253-254 Amphimonas, 253 globosa, 253, 254 Amphimixis, 154 Amphioxus, 548 Amphipoda, 488, 521, 527, 528 Amphisiella, 605 thiophaga, 6O4, 605 Amphisteginidae, 353 Amphitrema, 338 flavum, 337, 338 Amphiura squamata, 570 Amphizonella, 332 violacea, 332, 333 Amphorocephalus, 404 amphorellus, 404, 405 Amphoroides, 403 calverti, 402, 403 AUTHOR AND SUBJECT INDEX 645 AmpuUacula, 516 ampulla, 516 Anabolic products, 94-96 Anal cirri, 48, 49, 50 Anas rubripes trisiis, 442 Anaspides tasmaniae, 391 Ancistrella, 563-564 choanomphali, 564 Ancistrina, 563 ovata, 563, 564 Ancistrospira, 564 veneris, 565 Ancistrum, 562 Ancistruma, 55, 562-563 isseli, 135, 562, 563 mytili, 57, 562, 563 Ancistrumidae, 560, 562-565 Ancyromonas, 243 contorla, 243 Ancyrophora, 403 gracilis, 402, 403 Aneminea, 300 Anemonia sulcata, 568 Angeiocystis, 420 audouiniae, 420 Anguilla vulgaris, 249 Anisogametes, 144, 147 Anisogamy, 144—148 Anisolobus, 396 dacnecola, 396, 397 Anisonema, 212 acinus, 210, 212 emarginatuni, 210, 212 truncatum, 210, 212 Anisonemidae, 212-213 Annelida, 227, 228, 382, 383, 384, 385, 386, 387, 389, 390, 392, 393, 400, 401, 411, 412, 413, 419-420, 421, 426, 428, 429, 450, 451, 469, 471, 477, 488, 490, 491, 493, 494, 495, 618 Annulus, 216 Anodonta catarecta, 556, 561 implicata, 561 marginata, 561 Anomalina, 354 punctulata, 354 Anomalinidae, 354 Anopheles, 6, 434, 435 quadrimaculatus, 436, 475 Anophrys, 543 aglycus, 542, 543 elongata, 542, 543 Anoplophyra, 488 manjlandensis, 488, 489 orchestii, 488, 489 Anoplophryidae, 488-491 Antelope, 592, 594, 595 Anterior body, 277 Anthophysa, 9, 65, 141, 256 vegetans, 133, 255, 256 Anthropoid apes, 575, 597 Anthorhynchus, 404 sophiae, 404, 405 Anura, 23, 483 Anurosporidium, 451 pelseneeri, 451 Aphrydium versatile, 632 Apis mellijlca, 318 Apocynaceae, 250 Apodinium, 227 mycetoides, 226, 227 Apolocystis, 382 gigantea, 382, 383 minuta, 382, 383 Aponiotis cyanellus, 461 Apostomea, 58, 487, 567-572 Arachnida, 404 Arachnula, 292 impatiens, 292, 293 Arboroid colony, 141 Arcella, 20, 38, 42, 137, 327-328 artocrea, 328, 329 catinus, 328, 329 dentata, 165, 328, 329 discoides, 328 mitrata, S^S-329 polypora, 165 vulgaris, 32, 36, 328 var. angidosa, 328 gibbosa, 328 Arcellidae, 323, 327-334 Archotermopsis wroughtoni, 270, 282 Arcichovskij, 37 Arcyria, 302 punicea, 301 Arcyriidae, 302 Arenicola ecaudata, 389 Argentophilous substance, 47 Arndt, 126 Artificial digestion and nucleus, 33, 36 Artodiscus, 325 saltans, 324, 325 Ascartia, 490 Ascidian, 410 Asclepiadaceae, 250 Ascoglena, 209 vaginicola, 208, 209 Asellus, 521 aquaticus, 620, 632 Asexual reproduction, 142-143, 146, 147, 148 Asida, 401 opaca, 401 Askenasia, 501 volvox, 500, 501 Aspidisca, 20, 613 lynceus, 122, 612, 613 polystyla, 612, 613 646 PROTOZOOLOGY Aspidiscidae, tJ03, 613 Asplanchna, 451 Assulina, 341 seminuluin, 341, 3.1,2 Astasia, 9, 38, 46, 70, 211 klehsi, 210, 211 laevis, 131 Astasiidae, 204, 209-212 Asleracanlhion rubens, 490 Asterias gracilis, 565 rubens, 490 Asterigerina, 353 carinata, 352 Asterophora, 403-404 philica, 402, 404 Astomata, 61, 65, 93, 98, 139, 141, 487, 488-495 Astrangia danae, 568 Astrocystella, 385 lobosa, 385, 386 Astrodisculus, 360 radians, 360, 361 Astrophrya, 629 arenaria, 629, 630 Asirophyga magnifica, 543 Astropyle, 367 Astrorhizidae, 347 Astrosiga, 240 Astylozoon, 616-617 fallax, 617 Astylozoonidae, 616-618 Athene noclua, 248 Atopodinium, 602 fibulatum, 601, 602 Atyaephrya desmaresti, 396 Audouinia lamarcki, 392 tentaculata, 420 Auerbach, 471 Aulacantha, 131, 374 scolymantha, 134, 375 Aulacanthidae, 374 Aulosphaera, 375 labradoriensis, 375 Aulosphaeridae, 375 Autogamy, 154 156, 455 Automixis, 154-156 Autotrophic nutrition, 84, 92 Averintzia, 338 cyclostoma, 338 Axial core, 284 fibrils, 41 filament, 44, 45, 48, 86 rod, 41, 43 Axolotles, 238, 268 Axopodia, 41, 42, 43, 86, 124 Axostylar filaments, 61, 67 Axostyle, 61 B Babesia, 13, 442 bigernina, 442-443, 444 bovis, 443-444 canis, 444 Babesiidae, 435, 442-445 Bacillidium, 477 limnodrili, 477, 478 Bacteria and Protozoa, 7, 8, 21, 88 Badhamia, 299 ulricularis, 300 Baetis, 555 Baker, 10 Balanitozoon, 506 gyrans, 506 Balanonema, 551 biceps, 551, 552 Balantidiopsis, 574 Balantidium, 53, 55, 74, 94, 574 coli, 7, 13, 14, 24, 25, 91, 93, 574- 575 duodeni, 576 praenucleatum, 575, 576 suis, 575-576 Balantiodoides, 574 Balantiophorus, 550 Balanus amphitrite, 396 eburneus, 396 Balbiani, 11, 13 Balladina, 609 elongata, 608, 609 Bankia, 565 Baraban, 448 Barbulanympha, 33, 126, 128, 282 laurabuda, 134, 283 uf alula, 134, 282-283 Barbus barbus, 459, 467 fluviatilis, 467, 477 plebejus, 467 Barret, 14 Barrouxia, 427 ornata, 426, 427 Basal granule, 44, 46, 47, 48 49, 50, 52, 58, 59, 67, 71 Basal plate, 48, 49 Bass, 14 Beccaricystis, 387 loriai, 387, 388 Becker, 238, 421, 422, 433, 599 Behrend, 123 Bdaf, 36, 81, 126, 131, 133, 134, 135, 156, 159, 359, 366, 419 Belkin, 91, 115 Beloides, 406 firmus, 405, 406 Benedictia biacalensis, 563 limneoides, 563 Bernstein, 98 Berthold, 101, 115 Bertramia, 451 asperospora, 450, 451 AUTHOR AND SUBJECT INDEX 647 capitellae, 451 euchlanis, 451 Bhatia, 414 Bibio niarci, 405 Bicosoeca, 141, 241 socialis, 241, 24'^ Bicosoecidae, 239, 241-243 Biggar, 543, 576 Biggaria, 543 bermudense, 542, 543 echinometris, 542, 543 Binary fission, 137-138, 139 Biomyxa, 294 cometa, 294 vagans, 293, 294 Biparental inheritance, 165-169 Bird malaria, 436, 437-439 Birds, 238, 248, 422, 424, 425, 436, 437, 438, 439 Bishop, 134 Blackbirds, 425, 437 Blackduck, 442 Black-head of turkey, 238 Blattner, 113 Blastodiniidae, 219, 227-228 Blastodinium, 227 spinulosum, 226, 221 Blastula, 4 Blatta orientalis, 23, 258, 272, 280, 312, 314, 318, 388, 394, 576 Blattella lapponica, 395 Blattidae, 6, 258 Blepharisma, 20, 37, 65, 92, 578 lateritium, 577, 578-579 perisinum, 577, 580 steini, 577, 580 undulans, 22, 70, 580 Blepharoconus, 513 cervicalis, 514 Blepharocoridae, 532, 544-546 Blepharocorys, 545 bovis, 545 equi, 545 uncinata, 545 Blepharoplast, 44, 46, 62, 66, 67, 68, 69, 126, 130, 244 Blepharoprosthium, 78, 513 pireum, 513, 514 Blepharosphaera, 513 intestinalis, 513, 514 Blepharozoum, 515 zonatum, 514, 515 Boaedon lineatus, 425 Boderia, 41, 327 turneri, 326, 327 Bodo, 19, 257 caudatus, 257, 258 edax, 257, 258 uncinatus, 20 Bodonidae, 239, 256-259 Boeck, 14, 134, 321 Boil-disease of fish, 459 Bold, 194, 200, 201 Bolivina, 352 punctata, 352 Bombina bombina, 486 pachypa, 486 Bovibyx mori, 474 Borgert, 131, 134, 376 Bos indicus, 592, 594 Bothriopsis, 406 histrio, 405, 406 Botryoidae, 374 Boughton, 433 Bouonanni, 9 Boveria, 55, 565 teredinidi, 564, 565 Bowling, 159, 160 Boyd, 445 Box boops, 267, 486 Brachiomonas, 189 wesiiana, 190 Brachionus, 451 Brady, 355 Branchioecetes, 521 garnmari, 520, 521 Branchiura coccinea, 495 Brand, 25, 30 Brandt, 89, 367, 376 Brassica, 303 Braun, 27 Bremer, 135 Bresslau, 540 Bresslaua, 540 vorax, 540, 541 Brodsky, 63, 81 Brown, 55, 70, 71, 81, 132 Bruce, 13 Brug, 87, 115 Bryophyllum, 519 vorax, 518, 519 Bryophrya, 540-541 bavariensis, 541 Bryozoa, 474, 632 Buccinum undatum, 419 Budding, 139-140, 221 Buffelus bubalus, 594 Bufo, 464, 484, 626 compactilis, 484 cognatus, 486 inter medicus, 486 lentiginosus, 485 marinus, 486 valliceps, 486 Bugs, 245, 250, 251, 414 Bulbocephalus, 401 elongatus, 401, 402 Buliminidae, 352 BuUington, 611 648 PROTOZOOLOGY Bullinula, 336 indica, 336, 3S7 Bundleia, 514 postciliata, 514 Bunting, 263 Burk, 303 Burnside, 114, 115, 583 Bursaria, 31, 95, 138, 574 truncatella, 574, 575 Bursariidae, 573, 574-576 Bursaridium, 574 difficile, 574, 575 Bursella, 504 spumosa, 504 Biitschli, 10, 11, 13, 15, 94, 101, 106, 183, 486, 538 Butschlia, 513 parva, 513, 514 Butschliella, 490 chaetogastri, 491 opheliae, 489, 490 Butschliidae, 77, 496, 513-516 Buxtonella, 530 sulcata, 529, 530 Cabbage, 303 Caementella, 374 stapedia, 375 Caementellidae, 374 Caenis, 384 Caenomorpha, 576-577 medusula, 20, 577 • Calanus finmarchicus, 226, 228 Calcareous substance, 39, 183 Calcarina, 353 defrancei, 354 Calcarinea, 299 Calcarinidae, 353 Calcium carbonate, 39, 183 phosphate, 99-100 Calkins, 4, 12, 15, 34, 36, 73, 84, 119, 120, 123, 131, 135, 159, 160, 163, 169, 183, 294, 588, 613 Callimastigidae, 260, 265 Callimastix, 265 cyclopis, 265 equi, 265, 266 frontalis, 265, 266 Calliphora, 251 Callipus lactarius, 403 Caloneminea, 302 Calonympha, 274 grassii, 134, 274, 275 Caloscolex, 590 cuspidatus, 590, 591 Calospira, 570 minkiewiczi, 571, 572 Calymma, 367 Calyptotricha, 557 pleuronemoides, 557, 558 Cambarus, 619, 623 Cambell, 55 Camels, 245, 590, 591, 592, 594 Camelus dromedarivs, 590, 591, 592, 594 Camerinidac, 351 Campanelhi, 619 umbellaria, 619, 620 Campascus, 335-336 cornutus, 335, 336 Campbell, 589 Camptonema, 41, 86, 359 natans, 357, 359 Canary, 437, 438 Cannosphaera, 375 Cannosphaeridae, 375 Canthocamptus, 625 minutus, 623 Capillitium, 298 Capitella capitata, 451 Capsa, 565 Capsellina, 333 timida, 333-334 Carabus, 403 auratus, 403 violaceus, 403 Carbohydrate metabolism, 25, 90, 93 Carbon dioxide, 97, 98, 368 Carchesium, 9, 31, 87, 89, 92, 517, 622 granulatum, 38, 622, 623 polypinum, 88, 135, 159, 622 Carcinoectes, 396 hesperus, 396, 397 Cardita calyculata, 408, 565 Cardium edule, 566 Carotin, 79 Carp, 249, 253, 505 Carteria, 194 cordiformis, 194, 195 ellipsoidalis, 194, 195 obtusa, 22 Carteriidae, 188, 194 195 Caryospora, 426 simplex, 426 Caryotropha, 419 mesnili, 419 Cash, 295, 321, 342, 343, 366 Cassidulina, 353 laevigata, 354 Cassidulinidae, 353 Castanellidae, 375 Castanidium, 375 murrarji, 376 Cat, 315, 422, 425 Catabolic products, 98-101 Catbird, 438 AUTHOR AND SUBJECT INDEX 649 Catenoid colony, 140 Catfish, 458, 464, 468, 505 Catostomus, 253 commersonii, 466 Cattle, 245, 247, 265, 270, 317, 421, 422, 442, 443, 444, 513, 530, 544, 590, 591, 592, 593, 594 Caudal cirri, 49 Caulicola, 624 valvata, 624 Caullery, 452, 471 Caulleryella, 412 pipientis, 411, 412 Causey, 70, 71, 81 Cavia aperea, 544, 596 porcella, 544 Cell, 3 Cell-aggregates, Protozoa as, 4 Cell-anus, ,54, 59, 60, 74, 92 Cell-organs, 3, 32-81 Cellobiase, 91 Cellulase, 91 Cellulose, 24, 38, 90, 91, 143, 216 Cenolarus, 373 primordiaUs, 373 Central capsule, 61, 367 motor mass, 55 rod of stalk, 52, 53 Cenirechinus antillarum, 543, 576 Centriole, 67-69, 124, 125, 126, 128, ISO Centrodesmose, 126 Centroplast, 124, 125 Centropyxis, 335 aculeata, 165, 335 Centrosome, 126, 128 Centrosphere, 131 Cepede, 495 Cepedea, 32, 485 cantabrigensis, 484, 485 floridensis, 485 hawaiensis, 485 obovoidea, 485 Cepedella, 491 hepatica, 491 Cephalin, 380 Cephalina, 381, 391-414 Cephaloidophora, 393 nigrofusca, 393 Olivia, 393, 394 Cephaloidophoridae, 391, 393 Cephalothamnium, 256 cyclopum, 255, 256 Ceratiomyxa, 302 fruticulosa, 301 Ceratiomyxidae, 302 Ceratium, 10, 95, 137, 141, 229-230 fusus, 230, 231 hirundinella, 20, 162, 163, 230, 231 longipes, 230, 231 tripos, 230, 231 var. atlantica, 231 Ceratodinium, 225 asymetricum, 224, 225 Ceratomyxa, 459, 461 hopkinsi, 460, 461 mesospora, 460, 461 Ceratomyxidae, 459-461 Ceratophyllus fasciatus, 246, 248 Ceratopogon, 477, 478 solstitialis, 406, 412 Ceratospora, 389 mirabilis, 390 Cercomonas, 19, 259 crassicauda, 19, 44, 258, 259 longicauda, 19, 133, 258, 259 Cerithium rupestre, 409 Certesia, 613 quadrinucleata, 612, 613 Cervus canadensis, 594 Cestracion, 464 zygaena, 461 Cestus veneris, 570 Cetonia, 265 Chaenea, 509-510 limicola, 510 Chaetogaster, 491 Chaetognatha, 321, 490 Chaetospira, 606 mulleri, 606 Chagas, 132 Chagas' disease, 245 Chagasella, 431 hartmanni, 431 Chalkley, 16, 29, 136, 137, 160, 321 Challengeridae, 375 Challengeron, 375 loyvillei, 376 Chaos, 306 Charon, 546 equi, 545, 546 Chatton, 57, 58, 66, 81, 124, 133, 163, 227, 234, 530, 566, 567, 572 Cheissin, 495, 566 Chelydra serpentina, 318 Chemical composition of water on Protozoa, 16, 18-21 Chemical stimuli on Protozoa, 111 Chen, 131, 135, 160, 318 Chicken, 238, 265, 317, 318, 422, 423, 424 Chilodinium, 225 cruciatuni, 224, 225 Chilodochona, 614 quennerstedti, 615 Chilodon, 9, 526 vorax, 523 Chilodonella, 9, 17, 35, 70, 113, 526 650 PROTOZOOLOGY caudata, 526, 527 cucullulus, 20, 62, 99, 118, 120, 121, 526, 527 cyprini, 526, 527 jiuviatilis, 526, 527 hyalina, 527 longipharynx, 527 rotunda, 527 uncinata, 135, 159, ^^4, 526 Chilodontopsis, 523 vorax, 523, 524 Chilomastigidae, 264—265 Chilomastix, 12, 264 bettenco^irti, 265 caprae, 265 cuniculi, 265 gallinarum, 134, 265 intestinalis, 264 mesm'K, 14, 23, 264, :g66 Chilomonas, 65, 70, 88, 114, 131, 185 oblonga, 185 Paramecium, 22, 98, 185, iS6 Chilophrya, 506 labiata, 506, 507 utahensis, 506, 507 Chilostomellidae, 353 Chimpanzee, 575, 599 Chiridota, 389 laevis, 389 Chironomus plumosus, 27 Chitin, 38, 65 Chiton caprearum, 408 Chlamydoblepharis, 193 Chlamydobotrys, 199 stellata, 199-200 Chlamydococcus, 189 Chlamydodon, 55, 525 mnemosyne, 524, 525 Chlamydodontidae, 522, 525-528 Chlamydomonadidae, 188-193 Chalamydomonas, 36, 44, 79, 80, 95, 133, 166, 167, 189 angulosa, 189 botryodes, 167, 168 epiphytica, 189, 190 globosa, 189, 190 gracilis, 189, 190 monadina, 145, 189, 190 paradoxa, 167, 168 Chlamydomyxa, 292 montana, 292, 293 Chlamydophrys, 331-332 stercorea, 19, 332, 333 Chloraster, 196 gyrans, 195, 196 Chlorasteridae, 188, 196 Chlorella, 24, 196 Chlorogonium, 191-192 elongatum, 22, 93 euchlorum, 22, 93, 192 (Jhloromonadina, 79, 173, 213-214 Chloromyxidae, 461, 464 Chloromyxum, 464 leTjdigi, 135, I40, 463, 464 trijugum, 463, 464 Chlorophyll, 78-81 Chloroplast, 78 Choanocystis, 366, 386 lepidula, 365, 366 Choanocystella, 386 ientaculala, 386 Choanocystoides, 387 costaricensis, 386, 387 Choanomphalus, 563 Choanophyra, 86, 641 infundibulifera, 640, 641 Chondriosomes, 71-73 Chondropus, 292, 294 viridis, 294 Chonotricha, 23, 139, 487, 614^615 Chorophilus triseriatus, 484 Christensen, 422, 433 Chromatin, 32, 33-34, 35, 62, 66, 118, 119, 120, 124, 127, 136 Chromatoid body, 315 Chromatophore, 4, 78-81, 92, 173, 203 Chromidia, 35-36, 323 Chromidina, 491 elegans, 491, 492 Chromosomes, 126, 127-129, 131- 137, 157-159, 168, 282, 283 Chromulina, 46, 70, 174, 175 pascheri, 175, 176 Chromulinidae, 174, 175-177 Chrysapsis, 175 sagene, 175, 176 Chrysemys elegans, 318 Chrysidella, 23, 185 schaudinni, 185, 186 Chrysidiastrum, 181-182 catenatum, 182 Chrysocapsa, 183 paludosa, 182, 183 Chrysocapsina, 174, 182-183 Chrysococcus, 175 ornatus, 175, 176 Chrysomonadina, 79, 94, 173-183 Chrysopyxis, 177 cyathus, 176, 177 Chrysosphaerella, 177 longispina, 176, 111 Chytriodinium, 227 parasiticum, 226, 221 Cienkowski, 294 Cilia, 40, 47-48, 50, 59, 64 CiUary field, 47 flagella, 44—46 movement, 47, 48 AUTHOR AND SUBJECT INDEX 651 zone, 47 Ciliata, 10, 11, 17, 19, 20, 57, 481- 627 Cilioflagellata, 217 Ciliophora, 34, 37, 40, 47, 51, 65, 73, 74, 118, 138, 148, 481 641 Ciliophryidae, 358, 359-360 Ciliophrys, 359-360 infusionum, 360, 361 marina, 360 Cinetochilum, 552-553 ■margaritaceum, 20, 552, 553 Cingulum, 229 Circoporidae, 375 Circoporus, 375 odahedrus, 376 Circular cytostomal fibrils, 58, 60 Circum-oesophageal ring, 55, 60 -pharyngeal ring, 54, 60 Cirri, 47-48, 49, 50 Cirrus fiber, 49, 56 Citharichthys xanthostigmus, 461 Cladocera, 623 Cladomonas, 141, 253 fruticulosa, 253, 254 Cladonema radiatum, 568, 569, 570 Cladothrix pelomyxae, 310 Cladotricha, 605 koltzowii, 604, 605 Claparede, 11 Clathrella, 362 foreli, 362, 363 Clathrellidae, 358, 362 Clathrostoma, 536 viminale, 536-537 Clathrostomidae, 531, 536-537 Clathrulina, 42, 364 elegans, 364, 365 Clathrulinidae, 358, 364-366 Clausia, 490 Clausocalanus arcuicornis, 227 furcatus. Til, 571 Qegg, 14 Clelodes longicaudatus, 630, 636 Cleveland, 6, 24, 28, 29, 33, 66, 68, 81, 91, 98, 115, 126, 129, 134, 137, 160, 270, 276, 277, 287, 539 Cliff swallow, 438 Climacostomum, 75, 584 virens, 20, 584, 585 Cliola vigilax, 468 Clitellis arenarius, 471 Clupea pilchardus, 466 Clymenella torquata, 228, 618 Clypeolina, 339 marginata, 337, 339 Cnidosporidia, 63, 93, 377, 453-480 Coccidia, 13, 146, 378, 415-433 Coccidiosis, 412 Coccidium, 421 ovifornie, 421 Coccolithidae, 39, 175, 181 Coccomonas, 191 orbicularis, 191, 192 Coccomyxa, 466 niorovi, 465, 466 Coccomyxidae, 464, 466 Cocconema, 477 Coccospora, 477 slavinae, 477, 478 Coccosporidae, 474, 477 Cochliatoxum, 597 periachtum, 597, 598 Cochliopodium, 137, 332 hilimhosuvi, 332, 333 Cochlodinium, 225 atroviaculatum, 224, 225 Cockroaches, 23, 258, 272, 280, 312, 314, 318, 388, 395, 451, 576, 581 Codonella, 589 cratera, 588, 589 Codonocladium, 240 Codonoeca, 242 indinata, 242-243 Codonosigopsis, 241 Codosiga, 240 disjunda, 240 utriculus, 240 Codosigidae, 239-241 Coelenterata, 66, 227, 253, 321, 490, 551, 558, 568, 569, 570^ 629, 632 Coelodendridae, 376 Coelodendrum, 376 ramosissimum, 376 Coelosporidium, 451 blattellae, 451 periplanetae, 451 Coelozoic Protozoa, 25, 93 Coenobium, 197 Cohn, 11, 161 Cohnilembidae, 547, 558-559 Cohnilembus, 558 caeci, 558, 559 fusiformis, 558, 559 Colacium, 141, 209 vesiculosum, 131, 208, 209 Cole, 15 Coleorhynchus, 406 heros, 405, 406 Colepismatophila, 398 ivatsonae, 397, 398 Colepidae, 496, 501-503 Coleps, 9, 38, 47, 45, 87, 501 bicuspis, 502 elongatus, 502 heter acanthus, 502, 503 hirtus, 502 652 PROTOZOOLOGY ociospinus, 502-503 spiralis, 502, 503 Collared Protozoa, 40, 101 Collecting canals of contractile vacuole, 75-77 Collin, 139, 641 Collinella, 529-530 gundii, 529, 530 Collinia, 488 Collodaria, 372 Collodictyon, 264 triciliaium, 133, 263, 263 Collosphaera, 373 Collosphaeridae, 373 Colonial Protozoa, 4, 31, 140-142 Colony, 4, 31, 140-142 arboroid, 140 catenoid, 140 dendritic, 140 discoid, 140 gregaloid, 140-141 linear, 140 spheroid, 140 Color of Protozoa, 36-37 water due to Protozoa, 175, 186, 218, 225, 232, 501 Colpidium, 17, 22, 97, 124, 549 campylum, 20, 22, 124, 549, 550 colpoda, 47, 48, 86, 124, 549-550 striatum, 22, 91, 550 Colpoda, 9, 35, 540 aspera, 20 californica, 540, 54i cucullus, 20, 22, 540, 541 inflata, 540, 541 steini, 28, 540 Colpodidae, 531, 540-541 Colponema, 259 loxodes, 258, 259 Columba livia, 440 Columbella rustica, 409 Colymbetes, 406 Comatula mediterranea, 565 Cometoides, 403 capitatus, 402, 403 Commensal, 23 Commensalism, 23 Compact nucleus, 38, 34-35 Conchophthiridae, 560-561 Conchophthirus, 55, 74, 560 anodontae, 124, 131, 132, 135, 560 562 caryoclada, 561, 562 curtus, 124, 561 magma, 124, 561 mytili, 65, 123, 124, 135, 561 Concrement vacuole, 77, 78, 109 Concretion vacuole, 109 Condylostoma, 581 patens, 581 vorticella, 581, 582 Condylostomidae, 573, 581 Conjugant, 148 Conjugation, 73, 124, 144, 148-154, 158 Connell, 55, 123, 566 Contractile vacuole, 20, 43, 54, 73-77, 97, 98-99, 100, 104 Conus mediterraneus, 409 Copepoda, 211, 227, 228, 256, 475, 477, 490, 567, 570, 571 Copromastix, 264 protvazeki, 263, 264 Copromonas, 212 subtilis, 144, 145, 212 Coprozoic Protozoa, 19 Coptotermes formosanus, 278, 286 Corbierea, 194 Cordylophora lacustris, 629 Coria, 17, 29 Coronympha, 276 clevelandi, 275, 276 Corycaeus venustus, 228 Corycella, 402 armata, 402-403 Corycia, 331 coronata, 330, 331 Corythion, 341 pulchellum, 340, 341 Costa, 61-62, 260 Costia, 27, 264 necatrix, 24, 263, 264 Cothurina, 623 annulata, 623, 624 canthocampti, 623, 624 Cougourdella, 477 magna, 477, 4'^8 Cowbirds, 437, 439 Crab, 393, 439 Craig, 315, 321 Cranotheridium, 498 taeniatum, 497, 498 Crappie, 26 Craspedotella pileolus, 233 Craspedothorax, 532 Craspidochilus cinereus, 450 Craterocystis, 385 papua, 385-386 Crawley, 452 Crenilabrus melops, 451 ocellatus, 451 paro, 451 Crepidula plana, 586 Cribraria, 300 aurantiaca, 301 Cribrariidae, 300 Crickets, 258 Cristigera, 557 media, 556, 557 phoenix, 556, 557 AUTHOR AND SUBJECT INDE^X 653 Crithidia, i244, 249-250 eunjophthalmi, 250 gerridis, 250 hyalommae, 250 Crobylura, 509 pelagica, 509, 510 Cross-striation in cilia, 47, 48 Crow, 21 Cruciferae, 303 Crumenula, 207 ova, 207, 208 Crustacea, 228, 391, 393, 396 Cruzella, 257 Crvptobia, 252 borreli, 252, 253 cyprini, 252, 253 grobbeni, 253 helicis, 252, 253 Cryptobiidae, 239, 252-253 Cryptocercus punctulatus, 24, 269, 272, 280, 282, 283, 284, 286 Cryptochilidium, 550 echi, 550, 552 Cryptochilum, 553 Cryptochrysis, 184, 186 commutata, 186 Cryptodifflugia, 329 330 oviformis, 330 Cryptoglena, 208-209 pigra, 208, 209 Cryptomonadina, 23, 37, 65, 79, 173, 184-187, 216 Cryptomonadidae, 185-186 Cryptomonas, 95, 114, 131, 184, 185 ovata, 185, 186 Cryptopharynx, 526 setigerus, 526, 527 Cryptops hortensis, 398 Cryptosporidium, 426 muris, 426-427 parvum, 427 Cryptotermes grassii, 274 hermsi, 269, 275 Crystals, 37, 99-101, 306 Ctedoctema, 557 acanthocrypta, 557, 558 Ctenocephalus canis, 250 Ctenodactylus gundi, 529, 530 Ctenophores, 570 Ctenostomata, 19, 573, 600-602 Cucujus, 401 Cucurbitella, 336 mespiliformis, 335, 336 Culex, 6, 435, 437, 475 fatigans, 14 pipiens, 437 quinquefasciatus, 438 salinarius, 437 tarsalis, 438 territans, 437-438 Cunhaia, 596 curvata, 596 Cup, 134 Current and Protozoa, 111 Curtis, 539 Cushman, 39, 81, 346, 355 Cutler, 14 Cyathodiniidae, 532, 544 Cyathodinium, 544 conicum, 544 piriformis, 544, 545 Cyathomonas, 65, 185 truncata, 186 Cyclidium, 20, 557 glaucoma, 48 litomesum, 556, 557 Cyclochaeta, 626-627 domergui, 626, 627 spongillae, 626, 627 Cyclogramma, 63, 523 trichocystis, 523, 524 Cyclonexis, 31, 141, 179 annularis, 179, 180 Cyclonympha, 287 Cycloposthiidae, 587, 596-599 Cycloposthium, 61, 597 bipalmatum, 596, 597 dentiferum, 596, 597 Cyclops, 211, 256, 265, 619, 636, 641 fuscus, 475 minutus, 625 ornatus, 641 Cyclosis, 10, 87 Cyclospora, 425 caryolytica, 425, 4^6 Cyclostoma elegans, 625 Cyclotrichium, 501 meunieri, 92, 500, 501 Cynoscion regalis, 464 Cyphoderia, 20, 340 ampulla, 162, 340 Cyphon pallidulus, 398 Cypridium, 523 Cyprinus, 253, 526 Cypris, 619 Cyrtellaria, 374 Cyrtoidae, 374 Cyrtolophosis, 553 mucicola, 553, 554 Cyrtophora, 177 pedicellaia, 176, 177 Cysts, 16, 142-143, 217, 539 Cystidium, 373 princeps, 374 Cystobia, 390 irregularis, 390 Cystocephalus, 401 algerianus, 401, 402 654 PROTOZOOLOGY Cystodiniidae, 219-220 Cystodinium, 219-220 steini, 218, 220 Oystoflagellata, 217, 233 Cytomere, 418 Cytopharynx, 5J,, 62, 74 Cytoplasm, 36 Cytopyge, 54, 59, 60, 74, 92 Cytosome, 36-37 Cytosomic division, 137-140 binary fission, 137-138, 139 budding, 139-140, 221 multiple division, 138-139 plasmotomy, 140 Cytostome, 48, 54, 63 Cytozoic Protozoa, 24, 93 Czurda, 79 Da Cunha, 580 Dacne rufifrons, 396 Dactylochlamys, 19, 503 pisciformis, 502, 503 Dactylophoridae, 392, 398-401 Dactylophorus, 398 robustus, 398, 399 Dactylophrya, 638 roscovita, 637, 638 Dactylosaccus, 327 vermiformis, 326, 327 Dactylosoma, 444-445 ranarum, 444, 445 Dallasia, 548 Dallinger, 17 Dallingeria, 261 drysdali 261 Dangeard, 133, 201, 215 Daniel, 136, 137, 160, 321 Darby, 22 Darling, 448 Dasyhelea obscura, 391, 480 Dasytricha, 544 ruminantium, 544, 545 Davaine, 12 Davis, 134, 272, 471 Dawson, 91, 115 De Bary, 296, 303 De Garis, 169 Debaisieux, 124, 135, 458, 480 Decapoda, 228, 391, 393, 396, 407, 409, 417, 419, 488, 567, 570, 615, 619 Deer mice, Canadian, 248 Defecation process, 91-92 Deflandre, 343 Degeneration, 37 Dellinger, 102, 115 Deltotrichonympha, 286 operculata, 286 Dembowski, 11, 115 Dendritic colony, 141 Dendrocoelum lacteurn, 555 Dendrocometes, 632 paradoxus, 631, 632 Dendrocometidae, 628, 632 Dendromonas, 256 virgaria, 255, 256 Dendrorhynchus, 400 system, 399, 400 Dendrosoma, 629 radians, 629, 630 Dendrosomidae, 628, 629-632 Dendrosomides, 629 paguri, 630 Dennis, 442, 445 Derepyxis, 178 amphora, 178 ollula, 178 Dermacenter reticulatus, 444 Dermestes lardarius, 405, 406 Desmarella, 241 irregularis, 241 moniliformis, 240, 241 Desmose, 126, 127, 130 Deutomerite, 380 Devescovina, 67, 267 leinniscata, 267, 268 Dexiotricha, 553 Dexiotrichides, 553 centralis, 553, 554 Diadema setosum, 576 Diaphoropodon, 338 mobile, 337, 338 Diapiomus castor, 475 Diastole of contractile vacuole, 73, 75, 76 Dichilum, 551 cuneiforme, 551, 552 Dicnidea, 478 Dicotylus, 555 Dictyophimus, 374 hertwigi, 374 Dictyosteliidae, 302 Didesmis, 513 quadrata, 513, 514 Didiniidafe, 496, 499-501 Didinium, 53, 65, 87, 99, 499-500 balbianii, 500 nasutum, 21, 135, 157, 159, 500 Didymiidae, 299 Didymium, 299 effusum, 300 Didymophyes, 393 gigantea, 393 Didymophyidae, 391, 393-394 Dientamoeba, 319 fragilis, 23, 319 Diesing, 11 Difflugia, 36, 38, 334 arcula, 334, 335 AUTHOR AND SUBJECT INDEX 655 constricta, 334, 335 corona, 165, 335 lobostoma, 334, 335 oblonga, 334, 335 pyriformis, 334 spiralis, 102 urceolata, 334, 335 Difflugiella, 329 apiculata, 329, 330 Digestion, 87-92 Dileptus, 55, 114, 520-521 americanus, 520, 521 anser, 32, 34, 63, 6J^, 118, 520, 521 Diller, 124, 135, 155, 160, 553 Dimastigamoeba, 305 bistadialis, 134, 305, 306 gruberi, 19, 305 Dimastigamoebidae, 50, 304-306 Dimorpha, 131, 238 mutans, 237, 238 Dimorphism, 346 Dinamoeba, 308-309 mirabilis, 309-310 Dinenympha, 70, 131, 269 fimbriata, 134, 268, 269 gracilis, 269 Dinobryon, 46, 95, 141, 177-180, 181 diver gens, 181 sertularia, 180, 181 Dinoflagellata, 37, 46, 66, 79, 80, 93, 137, 141, 162, 173, 216-234 Dinomonas, 254 vorax, 254 Dinophysidae, 229, 233 Dinophysis, 233 acuta, 232, 233 Diophrys, 613 appendiculata, 121-122, 612, 613 Diphasia attenuata, 638 Diphasic amoebae, 305 Diplochlamys, 334 leidyi, 333, 334 Diploconidae, 371 Diploconus, 372 Diplocystidae, 381, 387-388 Diplocystis, 387 Schneider i, 134, 159 Diplodinium, 592 dentatum, 592, 593 ecaudatum, 54, 55 Diplogromia, 323-325 Diploid, 133-135, 158-159 Diplomita, 253 socialis, 254 Diplomonadina, 31, 32, 260, 272- 274 Diplophrys, 326 archeri, 326 Diploplastron, 592 affine, 592, 593 Diplopoda, 397 Diplosiga, 241 francei, 240, 241 socialis, 240, 241 Diplosigopsis, 240 affinis, 242 Diplostauron, 191 pentagoniutn, 190, 191 Diptera, 238, 245, 265, 318, 388, 391, 400, 405, 412, 434, 435, 436, 437, 440, 441, 475, 476, 477, 480 Direct nuclear division, 118-124 Discoid colony, 141 Discoidae, 373 Discolith, 181 Discomorpha, 601-602 pectinata, 601, 602 Discomorphidae, 600, 601-602 Discophrya, 638-639 elongata, 639 Discophryidae, 629, 638-641 Discorhynchus, 404 truncatus, 404, 405 Discos phaer a tubifer, 181, 182 Disematostoma, 75, 548 butschlii, 548, 549 Dissodinium, 233 lunula, 232, 233 Dissosteira Carolina, 395 Distephanus speculum, 181, 182 Distigma, 46, 213 proteus, 210, 213 Ditoxum, 597 funinucleum, 598, 599 Ditrichomonas, 269 Division, 118-140 cytosomic, 119, 137-140 nuclear, 118-137 Dixippus morosus, 28 Dixon, 91 Dobell, 3, 9, 12, 15, 27, 29, 124, 126, 134, 135, 144, 159, 160, 276, 294, 321, 419, 433 Dobellia, 421 binucleata, 421 Dobelliidae, 417, 421 Doflein, 12, 15, 41, 81, 115, 131, 133, 137, 140, 183, 294, 414, 486 Dog, 245, 315, 317, 422, 425 Dogiel, 61, 77, 81, 287, 590, 594, 595, 599 Dogielella, 490 minuta, 489, 490 sphaerii, 489, 490 Virginia, 489, 490 Dogiella, 70 Dolichodinium, 231 lineatum, 231, 232 656 PROTOZOOLOGY Donax, 420 trunculus, 451 Donkey, 245, 247 Donovan, 14 d'Orbigny, 10 Dorisiella, 425 scolelepidis, 426 Dorsal motor strand, 55 Dosinia exoleta, 565 Doudoroff, 17, 29 Dourine, 247 Doyle, 87, 100, 116 Drbohlav, 14 Drehkrankheit, 466 Drepanoceras, 532 Drepanomonas, 532 dentata, 533 Drew, 26 Drimohius hifossatiis, 318 Drosophila, 477 confusa, 251 Drysdale, 17 Duboscq, 66, 70, 81, 126, 135, 269, 295 Duboscqia, 476 legeri, 476 Duboscquella, 227 tintinnicola, 226, 227 Duck, 441 Dufour, 12 Dujardin, 10 Dumatella carolinensis, 438 Dunkerley, 137 Dusi, 22 Dutton, 13 Dysdercus ruficollis, 431 Dysentery amoeba, 314-316 Dysmorphococcus, 197 variabilis, 195, 197 Dysteria, 523-525 calkinsi, 524, 525 Dysteriidae, 522, 523-525 E Earthworm, 159 Ebalia turnefacta, 615 Echinodermata, 389, 390, 490, 535, 542, 543, 550, 559, 565, 570, 576, 586 Echinomera, 398 magalhaesi, 398, 399 Echinometra lucunter, 543 • Echinometris subangularis, 543, 576 Echinospora, 427-428 labbei, 426, 427 Echinus esculentus, 543 Ecology, 16 Ectocommensals, 23, 27 Ectoparasites, 24, 27 Ectoplasm, 37, 47, 64 Edwards, 87 Eel grass, 290 Eels, 249 Effect of parasitism, 24-27 Efimoff, 17, 29, 113 Ehrenberg, 10 Eichhorn, 10 Eimer, 13 Eimeria, 421 acervulina, 423-424 anseris, 424 arloingi, 422 canis, 422, 423 caviae, 422 clupearum, 4^3, 424 cylindrica, 422 debliecki, 422, 423 dispersa, 424 ellipsoidalis, 422 falciformis, 422, 4^ foa Li HBRARV G60 PROTOZOOLOGY intestinalis, 12, 23, (i5, 184, 272, 273 viuris, 134, 272 (Hbbula adarnsoni, 40S divaricaia, 408 rarilineatn, 408 Giese, 37, 81, 580 Gigantochloris, 191 -per maxima, 190, 191 Gigantomonas, 61, 270 herculea, 270, 271 Glaessner, 91 Glaser, 17, 29 Glaucoma, 94, 124, 163, 548 ficaria, 22, 548 frontata, 548 pyriformis, 22, 27, 91, 548, 549 scintillanus, 124 Glenodiniopsis, 220 Glenodinium, 95, 220 cinctuyn, 218, 220 edax, 218, 220 neglectum, 218, 220 ■pulvisculum, 218, 220 uliginosum, 218, 220 Globi^erina, 353 bulloides, 354 Globigerinidae, 353 Globorotalia, 353 Globorotaliidae, 353 Gloeomonas, 191 ovalis, 190, 191 Glossatella, 618 tintinnabulum, 618, 620 Glossina, 245 palpalis, 245 Glossosiphonia complanata, 400 Gluge, 12 Glugea, 475 anomala, 4'^4, 475 hertwigi, 472, 474, 475 mulleri, 475 Glugea cyst, 26, 475 Glycera, 390 Glyco2;enous substance, 24, 36, 61, 90, 94 97 319 Goat, 265, 317', 422, 590, 592 Goldfish, 249, 253 Goldfuss, 10 Golgi, 13, 57 Golgi apparatus, 66, 69-71, 77 Goniodoma, 231 acuminata, 231, 232 Gonium, 31, 141, 199 formosum, 198, 199 pectorale, 198, 199 sociale, 198, 199 Gonocytes, 227 Gonospora, 389 7ninchini, 388, 389, 390 Cionostomum, 605 slrenuum, 604, 605 Gonyaulax, 95, 231 apiculata, 232 poUjedra, 231-232 Gonyostomum, 214 semen, 214 Goose, 424 Gorilla, 599 Goroschankin, 145 Granata, 131, 471 Grasse, 66, 70, 126, 269, 276, 280 Gravity on Protozoa, 111 Gray, 106, 115 Greenwood, 87, 89, 115 Gregaloid colony, 141-142 Gregarina, 53, 70, 394-395 blattarum, 394, 395 locustae, 394, 395 oviceps, 394, 395 Gregarines, 12, 65, 70 Gregarinida, 12, 53, 94, 139, 145, 378-414 Gregarinidae, 391, 394-396 Gregory, 135, 158 Greiner, 135 Gromia, 85, 86, 323, 325 fluvialis, 324, 325 nigricans, 324, 325 ovoidea, 324, 325 Gromiidae, 323-327 Gros, 12, 317 Gross, 222, 234 Grouse, 238 Gruber, 114, 512, 540 Gruberia, 578 calkinsi, 578, 579 Gruby, 12 Gruithuisen, 10 Guinea-pig, 264, 317, 422, 430, 544, 596 Gryllotalpa gryllotalpa, 258 Gryllus abbreviatus, 395, 396 americanus, 395 pennsylvanicus, 396 Gunda segmenlata, 493 Gurleya, 475 richardi, 4'^4, 475 Guttuliniidae, 302 Guyenotia, 471 sphaerulosa, 4'70, 471 Gymnodiniidae, 219, 223-225 Gymnodinioidae, 219-229 Gymnodinioides, 570 calkinsi, 570 Gymnodinium, 79, 95, 223 aeruginosum, 223, 224 agile, 223, 224 palustre, 223, 224 rotundatum, 223, 224 AUTHOR AND SUBJECT INDEX 661 Gyninoii.ympha, 285 Gymnospore, 407 Gymnostomata, 62, 487, 496 530 (lyrinus natator, 403 Gyrocoris, 576 Gyrodinium, 225 biconicum, 224, 225 hyalinum, 224, 225 Gyromonas, 274 ambulans, 273, 274 Haas, 504 Habitats of Protozoa, 18-21, 172, 217 of free-living Protozoa, 18-21 coprozoic, 19 katharobic, 18 mesosaprobic, 19 oligosaprobic, 18-19 polysaprobic, 19 sapropelic, 19 Haeckel, 4, 31, 51, 376 Haecker, 376 Haemaphysalis leachi, 444 Haematochrome, 79, 80, 189 Haenaatococcus, 9, 79, 189 pluvialis, 79, 90, 133, 189, 190 Haemogregarina, 431 stepanowi, 431, 432 Haemogregarinidae, 431-433 Haemoproteidae, 435, 439-442 Haemoproteus, 13, 440 coliunbae, 440 lophortyx, 439, 441 Haemosporidia, 101, 146, 378, 434- 445 Hake, 12 Halberstaedter, 113 Halibut, 462 wormy, 462 Halkyardia, 353 radiata, 354 Halkyardiidae, 353 Hall, R. P., 21, 22, 70, 71, 81, 93. 131, 132, 133, 137, 160,215 Hall, S. R., 81 Hallezia, 636 brachypoda, 636, 637 Halteria, 20, 587 grandinella, 587, 588 var. chlorelligera, 587, 588 cirrifera, 587, 588 Halteriidae, 587-588 Halterium, 440 Hantkenina, 352 alabamensis, 352 Hantkeninidae, 352 Haploid, 133-135, 148, 158-159 Haplosporidia, 446, 448-451 Haplosporidian cysts, 451 liaplosporidium, 449 chitonis, 449-450 heterocirri, 450 limnodrili, 131, 450 nemertis, 450 scolopli, 450 vejdovskii, 450, 451 Haplozoon, 141, 228 clymenellae, 226, 228 Haptophrya, 65, 491 michiganensis, 492 Haptophryidae, 488, 491-493 Harpacticus gracilis, 471 Harpalus pennsylv aniens erylhropus, 395 Harris, 9 Harting, 9 Hartman, E., 445 Hartmann, M., 132, 154, 312 Hartmannella, 126, 311 casiellanii, 311-312 . hyalina, 19, 311 Hartmannula, 525 entzi, 524, 525 Hartog, 91 Hastatella, 617 aesculacantha, 617, 618 Hatt, 407, 414 Hayes, 34, 63, 81, 119 Head-organ, 284 Hedriocystis, 364 reticulata, 365, 366 Hegner, 6, 165, 170, 343, 436, 586 Heidenreich, 495 Heidt, 94, 115 Heleopera, 337 petricola, 337-338 Helicosporidia, 453, 479-480 Helicosporidlum, 480 parasiticum, 479, 480 Helicostoma, 559 buddenbrocki, 558, 559 Heliochona, 614 scheuteni, 614, 615 sessilis, 614, 615 Heliozoa, 11, 19, 31, 37, 39, 40, 41, 73, 86, 101, 124, 356-366 Helix, 13, 253, 428 Helodrilus caliginosus, 384, 488 foetidus, 382, 384 longus, 382, 384 Helops, striatus, 401 Hemicyclostyla, 605 sphagni, 604, 605 Hemidactylium scutatum, 492 Hemidinium, 223 nasutum, 223, 224 Hemiophrys, 517 Hemiptera, 245, 250, 251, 414 662 PROTOZOOLOGY Hemispeira, 565 asteriasi, 564, 565 Hemispeiropsis, 565 comatulae, 565 Hemiluhijex benedii, 471 Hemixis, 157 Henlea leptodera, 387 Henneguy, 583 Henneguya, 468 exilis, 45S, 467, 468 midospora, 468 psorospermica, 467, 468 Henry, 422, 433 Hentschelia, 400 thalassemae, 399, 401 Hepatozoon, 431 muris, 430, 431 Heredity, 32, 162-169 Herfs, 99, 115 Hericia hericia, 480 Herman, 442 Herpetomonas, 244, 251 drosophilae, 250, 251 muscae-domesticae, 251 muscarum, 250, 251 Herpetophrya, 490 astomata, 490 Herpobdella atomaria, 428-429 Herrings, 424, 466 Hertel, 113 Hertwig, 36, 81, 156, 168, 376 Hesse, 414, 480 Heterocirrus viridis, 450 Heterodinium, 231 scrippsi, 230, 231 Heterohelicidae, 352 Heteronema, 212 acus, 19, 210,2X2 mutabilis, 210, 212 Heterophrys, 362 glabrescens, 362 myriopoda, 361, 362 Heterophryidae, 358, 362 Heterotricha, 48, 108, 573-586 Heterotrophic nutrition, 84-92 Hewer, 73 Hewitt, 312 Hexacontium, 373 aster acanthion, 373 Hexaconus, 372 serratus, 371 Hexactinomyxon, 471 psammoryctis, 470, 471 Hexalaspidae, 372 Hexamastix, 266 batrachorum, 266, 267 termopsis, 266 Hexamita, 272 cryptocerci, 272, 273 inflata, 19, 46, 272, 273 iniestinalis, 272, 273 periplanetae, 272 salmonis, 134, 272, 273 Hieronymus, 145 Hill, 10 Hinshaw, 134 Hippocampus, 465 Hirmocystis, 395 harpali, 395, 397 termilis, 395, 397 Hirschler, 70 Histiobalantium, 557 nutans, 557, 558 semisetatum, 557, 558 Histiona, 242 zachariasi, 242 Histological changes in host, 25-27 Histomas, 238 meleagris, 237, 238 History of Protozoology, 9-14 Histozoic Protozoa, 24, 93 Histrio, 603 Hodotermes mossambicus, 270 Hold-fast organellae, 65-66 Holmes, 251, 259 Holomastigotes, 70, 278 elongatum, 278, 279 Holomastigotidae, 277-280 Holomastigotoides, 278 hartmanni, 278, 279 Holophrya, 22, 503-504 simplex, 504, 507 Holophryidae, 496, 503-513 Holophryoides, 514 ovalis, 514, 515 Holophytic nutrition, 84, 92, 93 Holosticha, 609 hymenophora, 608, 609 vernalis, 608, 609 Holothuria, 565 californica, 586 nigra, 390 Holotricha, 47, 48, 108, 487-572 Holozoic nutrition, 84-92, 93 Homalogastra, 555 setosa, 554, 555 Homalozoon, 498 vermiculare, 497, 498 Homarus gammarus, 407 Homotrema, 354 Homotremidae, 354 Honey bees, 8, 318, 475 Hoplonympha, 282 naiator, 282, 283 Hoplonymphidae, 277, 282-284 HopUtophrya, 494 lumbrici, 494 Horning, 71, 72, 82, 83 Horse, 245, 265, 317, 448, 513, 514, AUTHOR AND SUBJECT INDEX 663 515, 516, 544, 545, 546, 597, 638 Hosts for parasitic Protozoa, 24 Howland, 37, 90, 98, 115 Hsiung, 516, 599 Hulpieu, 98, 115 Hutchinson, 8 Huygens, 9 Hyalobryon, 21, 141, 181 ramosum, 180, 181 Hyalodiscus, 294 rubicundus, 293, 294 Hyalogonium, 193 klehsi, 192, 193 Hyaloklossia, 420 pelseneeri, 420 Hyalomma aegyptium, 250 Hyalosphenia, 42, 331 papilio, 330, 331 Hyalospira, 570 Hyalospora, 395 affinis, 395 Hybopsis kentuckiensis, 468 Hybridization, 166-169 Hydaticus, 406 Hydatina, 451 Hydra, 23, 24, 321, 625, 626 Hydractinia echinata, 558 Hydramoeba, 27, 28, 320-321 hydroxena, 24, 134, 320, 321 Hydrogen-ion concentration on Pro- tozoa, 16, 17, 21, 22, 72, 90, 97, 98, 222 Hydrophilus piceus, 406, 641 Hydroporus palustris, 430 Hydrostatic organellae, 53, 95, 368 Hydrous, 403 caraboides, 402 Hydrurus, 141, 182-183 foetidus, 80, 182, 183 Hyla, 484 pickeringi, 484 regilla, 484 versicolor, 151, 484, 581 Hyman, 103, 115 Hymenomonas, 178 roseola, 178 Hymenostomata, 487, 547-559 Hyperammina, 348 subnodosa, 347 Hyperamminidae, 347 Hypermastigina, 24, 44, 61, 86, 91, 98, 126, 139, 235, 277-287 Hypocoma, 566 acinetarum, 564, 566 cardii, 566 patellarum, 564, 566 Hypocomidae, 560, 566 Hypocomides, 566 zyrphaeae, 566 Hypocone, 216 Hypostomata, 496, 522-530 Hypothallus, 298 Hypotheca, 216 Hypotricha, 47, 573, 603-613 Hypotrichidiuna, 605 conicum, 605, 607 Ichthyophthirius, 27, 53, 504 vndtifiliis, 24, 504, 505 Ichthyosporidium, 451 giganteum, 448, 449, 451 hertwigi, 451 Ictalurus furcatus, 464 punctatus, 468 Idiochromatin, 35 Idionympha, 284 perissa, 283, 284 Iduna, 523 Idyaea furcata, 570 Ileonema, 511 ciliata, 511, 512 disper, 511, 512 Indirect nuclear division, 124—137, 139 Infraciliature, 58 Infurosia, 10, 11 Insects, 6, 8, 23, 28, 238, 245, 246 247, 250, 251, 258, 265, 269, 318, 384, 388, 391, 393, 395, 396, 398, 400, 401, 402, 403, 404, 405, 406, 407, 410, 412, 414, 430, 431, 451, 474, 475, 476, 477, 478, 480, 555 Intoshellina, 65, 493 poljanskiji, 492, 493 Intoshellinidae, 488, 493-495 lodamoeba, 94, 318-319 butschlii, 23, 319 suis, 319 williarnsi, 319 lodinophilous vacuole, 94, 454 Irritability, 109-114 Isogametes, 144 Isogamy, 144—145 Isolation pedigree cultures, 12 Isospora, 425 belli, 425 bigemina, 4^3, 425 felis, 425, 4^6 hominis, 423, 425 lacazei, 425 lieberkuhni, 425 rivolta, 423, 425 suis, 425 Isoptera, 6 Isotricha, 544 intestinalis, 53, 544, 545 prostoma, 53, 544, 545 664 PKOTOZOOLOGY Isotrichidae, 531, 544 Isselina, 491 Ivanic, 135 Ixodes ricinus, 444 Jacobson, 58 Jahn, E., 303 Jahn, T. L., 22, 79, 98 Jameson, 134, 135, 159, 160 Janda, 28, 59 Janet, 202 Janicki v., 66, 82, 134, 274, 287 Janus green B., 71 red, 71 Jarrina, 424r-425 paludosa, 423, 425 Jennings, 5, 6, 85, 102, 109, 110, 111, 112, 113, 115, 150, 154, 160, 165, 169 Jensen, 111 Jirovec, 28, 29, 58, 480 Joblot, 9, 10 Joenia, 281 annedens, 281 Joenina, 281-282 pulchella, 282 Joenopsis, 282 polyiricha, 282 Johns, 14 Johnson, 21, 22, 131 JoUos, 36, 163, 164, 170 Jones, 22, 303 Joseph, 113 Joyet-Lavergne, 70, 71, 73 K Kahl, 48, 63, 65, 486, 503, 506, 508, 509, 512, 516, 522, 530, 534, 548, 550, 553, 559, 566, 580, 586, 587, 599, 602, 615, 627, 647 Kahlia, 605 acrobates, 606, 607 Kala azar, 14, 251 Kalmus, 98 Kaloterines brevicollis, 270 clevelandi, 276 dudleyi, 272 flavicollis, 280, 281, 282 hubbardi, 269 insular is, 268 longicollis, 272, 276 minor, 284 nocens, 275 occidentis, 276 perparvus, 267 simplicicornis, 278, 282, 284 Kamm, 414 Karyolysus, 433 lacertarum, 430, 433 Karyomastigont, 274 Karyophores, 53 Karyosome, 32 Katharohic Protozoa, 18 Keilin, 480 Kent, 183, 486, 530, 613, 627, 641 Kentrochona, 614 nebaliae, 614, 615 Kentrochonopsis, 614 Kentrophoros, 519 fasciolatiim, 518, 519 Kephyrion, 175 ovum, 176, 177 Kepner, 85 Kerona, 9, 607 polyporum, 23, 608 Keronopsis, 608 rubra, 608 Keramosphaera, 350 Keramosphaeridae, 350 Keysselitz, 135 Khainsky, 89, 115 Khawkinea, 70, 206 halli, 206 ocellata, 206 Kidder, 55, 58, 65, 74, 82, 123, 124, 131, 135, 160, 488, 553, 560, 563, 666 Kilborne, 13 Kimbell, 6 Kinetonucleus, 69 King, R. L., 75, 82 King, S. D., 70 Kingsbury, 73 Kinoplasm, 51, 52, 53 Kirby, 61, 62, 66, 82, 87, 92, 116, 126, 131, 134, 264, 267, 268, 269, 272, 276, 287, 321, 516, 526, 536, 583, 586 Kite, 37 Klein, 47, 57, 65, 82, 534 Kloss, 12 Klossia, 428 helicina, 13, 428 Klossiella, 429-430 cobayae, 430 muris, 430 Kofoid, 37, 46, 66, 82, 93, 115, 124, 126, 134, 137, 160, 202, 219, 234, 245, 276, 284, 589, 590. 599 Kofoidella, 490 eleutheriae, 489, 490 Kofoidia, 284 loriculata, 284, 285 Kofoidiidae, 277, 284 Kofoidina, 392 ovata, 392 Koidzumi, 287 AUTHOR AND SUBJECT INDEX 665 Kolkwitz, 18, 29 Kolliker, 12 Koltzoff, 52, 82 Korschelt, 115 Korschikoffia, 193 guttula, 192, 193 Kreyella, 533 Krijgsman, 107, 115, 255 Kruger, 63, 65, 82 Krukenberg, 91 Kuczynski, 134 Kudo, 29, 34, 82, 115, 120, 123, 134, 137, 161, 287, 322, 409, 471, 480, 504, 586 Kuhn, 134, 294 Kunstler, 61 Kunze, 135 Kylin, 79 Labbe, 414 Labyrinthomyxa, 290 sauvageaui, 290, 291 Labyrinthula, 289 cienkoivskii, 289, 291 sp. Renn, 290 Labyrinthulidae, 289-290 Lacerta, 257 muralis, 433 Lachmann, 11 Lachmannella, 65, 493 recurva, 492, 493 Lackey, 19, 29, 131, 534, 546 Lacrymaria, 19, 508 coronaia, 509, 510 lagenula, 509, 510 olor, 20, 508-509, 510 Laelaps echidninus, 431 Lagena, 350 striata, 352 Lagenaria cougourda, 477 Lagenidae, 350 Lagenoeca, 243 ovata, 242, 243 Lagenophryidae, 623, 625 Lagenophrys, 625 labiata, 624, 625 patina, 624, 625 vaginicola, 624, 625 Lagynophrya, 504 mutans, 504, 507 Lambert, 452 Lamblia, 272 Lambornella, 548-549 stegomyiae, 549 Laminaria lejolisii, 290 Lampoxanthium, 372 pandora, 372 Lamprodrilus, 494, 495 Lamprosporales, 300 Lampsilis cariosa, 561 radiata, 561 Landacre, 189 Lankester, 37, 46 Lankesterella, 145, 427 minima, 426, 427 Lankestria, 388 culicis, 379, 380-381, 388 Larcoidae, 373 Lasea rubra, 408 Lauterborn, 19, 29 Laveran, 13, 27, 259 Laverania, 436 Lebour, 219, 234 Lecanophrya, 633 drosera, 633, 634 Lechriopyla, 55, 61, 535 nujstax, 535, 536 Lecudina, 392 pellucida, 392, 394 Lecudinidae, 391, 392-393 Lecythion, 401 thalassemae, 399, 401 Lecythium, 41, 326-327 hyalinum, 326, 327 Ledermi'iller, 10 Leeches, 248, 400, 427, 428, 429, 431 Leeuwenhoek, 9, 12 Legendrea, 498 bellerophon, 497, 499 Leger, 135, 414 Legerella, 430 hydropori, 430 Legeria, 406 agilis, 405, 406 Leidy, 11, 295, 322, 343, 366 Leidyana, 396 erraiica, 396, 397 Leidyanidae, 391, 396 Leidyonella, 285 Leidyopsis, 285 Leishman, 14 Leishmania, 7, 14, 24, 31, 244, 251 brasiliensis, 71, 252 donovani, 25, 251, 252 infantum, 251 tropica, 98, 251, 252 Leishmaniosis, 251 Lembadion, 548 bullinum, 548, 549 Lembus, 558 Lemmermann, 215, 238, 259 Lentospora, 466 Lepidosiren paradoxa, 466 Lepismatophila, 398 thermobiae, 397, 398 Lepocinclis, 207 Lepomis, 468 humilis, 461 Leptochlamys, 331 666 PROTOZOOLOGY ampullacea, 331, 333 Leptodactylidae, 6 Leptodiscus medusoides, 233 Leptomonas, 244, 250 ctenocephali, 250 Leptospironympha, 280 eupora, 279, 280 Leptotheca, 461 ohlmacheri, 156, 460, 461 Lepus cuniculus, 248 domesticus, 248 Lernaeophrya, 629 capitata, 629, 630 Lesquereusia, 42, 330 spiralis, 330-331 Leucine, 101 Leuciscus rutilus, 468 Leuckart, 13 Leucocytozoon, 441 anatis, 440, 441 simondi, 441-442 Leucosin, 94-95, 173 Leucotermes flaviceps, 278 Levine, 433 Levinsohn, 90, 117 Lewis, 13, 316 Libinia dubia, 393 Liceidae, 300 Licnophora, 586 conklini, 585, 586 macfarlandi, 585, 586 Licnophoridae, 574, 586 Lieberkiihn, 51 Lieberkuhnia, 41, 84, 86, 325 wagneri, 20, 326 Liesche, 137, 161 Life-cycle of Actipylea, 369-370 Adelea ovata, 429 Aggregata eberthi, 418, 419 Apostomea, 567, 568 Babesia bigemina, 442-443 Chlamydomonas monadina, 145 Chromulina, 174 Chrysomonadina, 174 Coccidia, 415-416, 418-419, 429, 431, 432 Eimeria schubergi, 415-416 Eudorina elegans, 145, 148 Eugregarinina, 379, 380-381 Foraminifera, 345, 346, 351 Gregarinida, 379, 380-381, 407, 409,410 Haemogregarina stepanowi, 431, 432 Haemoproteus Lophortyx, 441 Haemosporidia, 434-435, 440, 441, 442-443 Haplosporidia, 448-449 Helicosporidia, 479 Ichlhyosporidium giganteum, 448- 449 Lankesteria culicis, 379, 380-381 Leucocytozoon anatis, 440, 441 Microsporidia, 143, 473 Mycetozoa, 296-299 Myxosporidia, 456-458 Pandorina morum, 145, 147 Peneroplis pertusus, 351 Phytomonadina, 145, 146, 147, 148 _ Plasmodium vivax, 434-435 Radiolaria, 369-370 Schizocystis gregarinoides, 410 Schizogregarinaria, 409, 410 Sphaeromyxa sabrazesi, 45&-458 Spirophrya subparasitica, 568 Stempellia magna, 473 Stephanosphaera pluvialis, 145, 146 Tetramitus rostratus, 262, 263 Thelohania legeri, 144 Trypanosoma leivisi, 246 Light, 134 Light on Protozoa, 16, 18, 37, 112- 113 Limax amoebae, 27, 43, 44, 102, 103, 113 Limax marginatus, 427 Limnodrilus, 477 arenarius, 493 claparedeanus, 477 hoffmeisteri, 471 udekemianus, 450, 469, 471 Lindner, 539 Linear colony, 141 Lineus bilineatus, 450 Liocephalus liopygus, 389 Lionotus, 20, 70, 517 fasciola, 17, 20, 517, 518 Lipoid substance, 47, 70, 71 Liponyssus saurarum, 433 Lipotropha, 412 macrospora, 412, 413 Lister, 303 Lithobius forficatus, 400, 415, 421, 428 _ _ mutabilis, 428 Lithocircus, 374 maginificus, 374 LithocoUa, 360 globosa, 360, 361 Lithocollidae, 358, 360-362 Lithocystis, 389 brachycercus, 389, 390 Littorina rudis, 491 Litmus, 88, 90 Lituola, 348 nautiloidea, 349 Lituolidae, 348 AUTHOR AND SUBJECT INDEX 667 Lizard, 257 Lobomonas, 190-191 rostrata, 190, 191 Lobopodia, 40-41, 42 Lobster, 407, 417 Locomotor organellae, 40-51 Loefer, 21, 22, 93 Lohner, 97 Losch, 13, 315 Loftusia, 348 Loftusiidae, 348 Loligo, 491 Longitudinal body fibrils, 58, 59, 60 flagellum, 217 Long-lasting modifications, 163, 164 Looper, 24, 321, 359 Lophocephalus, 401 insigrds, 401, Jf02 Lophomonadidae, 277, 280-282 Lophomonas, 61, 265, 280 blattarum, 23, 61, 66, ISO, 134, 142, 265, 280, 281 striata, 23, 134, 137, 280, 281 Lophortyx, 441 Lorica, 38, 40, 65, 101, 141 Loricata, 616, 623-635 Loripes lacteus, 565 Loxocephalus, 123, 551 plagius, 551, 552 Loxodes, 78, 521 magnus, 520, 522 vorax, 520, 521-522 Loxodidae, 77, 517, 521-522 Loxophyllum, 518 rneleagris, 518-519 setigerum, 518, 519 vorax, 519 Lucas, 55, 544, 546 Luce, 100 Lucilia, 251 Lumbricus castaneus, 382, 384 rubellus, 382, 384 terrestris, 382, 384, 488, 494 variegatus, 411, 495 Lund, E. E., 55, 58, 59, 82 Lund, E. J., 97, 138, 161 Lung-fish, 466 Luntz, 113 Lutz, 29 Lwoff, 27, 58, 81, 91, 93, 566, 567, 572 Lycogala, 302 miniatum, 301 Lycogalidae, 301 Lymnaea stagnalis, 636 Lynch, J. E., 55, 58, 61, 82, 535, 546, 618 Lynch, R. S., 154, 161, 167, 168, 170 Lynchia brunea, 440 capensis, 440 hirsuta, 441 lividicolor, 440 maura, 440 Lytechinus variegatus, 543 M MacArthur, 27 MacBride, 73, 303 MacCallum, 13 MacDougall, 55, 113, 135, 159, 164, 170, 525, 526 Machadoella, 413 triatomae, 413, 414 Machilis cylindrica, 395 Mackerel, 424 Mackinnon, 412 MacLennan, 55, 61, 123, 566, 590, 594 Macorna balihica, 562 Macrogamete, 145, 415, 4I6, 429, 434, 435 Macrogametocyte, 415, 4I6, 429, 434, 435 Macrohodotermes mossambicus, 278 Macromastix, 261 lapsa, 261 Macronucleus, 32, 34, 35, 54, 63, 88, 118, 119, 120, 121, 122,482 Macrospironympha, 279-280 xylopletha, 279, 280 Mai de Caderas, 247 Malacophrys, 550 rotans, 549, 550 Malacostraca, 228 Malaria fever, 434, 435-436 Malarial organisms, 13, 435-439 Mallomonas, 46, 95, 175 litomosa, 175, 176 Malmsten, 13 Man as hosts of parasitic Protozoa, 7, 12, 23, 245, 251, 258, 264, 269, 270, 273, 316, 317, 318, 319, 425, 448, 475 Manifold, 448 Manwell, 135, 436, 445, 609 Manz, 448 Margarita, 302 Margaritidae, 302 Margaropus annulaius, 442 Marginal cirri, 49, 56 Marsson, 18, 29 Marsupiogaster, 213 pida, 210,213 striata, 210,213 Martin, 218, 219, 223, 231, 234 Maryna, 65, 532 socialis, 532, 533 Marynidae, 531, 532 668 PROTOZOOLOGY Massive nucleus, 34 Massartia, 225 nievporlentiii^, 22 -'i, 225 Mast, 43, ()5, 80, S2, S7, 100, 105, 112, 110,202 Mastigamoeba, 10, 236 aspera, 236, 237 hylne, 237 longijilum, 236, 237 setosa, 236, 237 Mastigamoebidae, 235, 236 238 Mastigella, 237 vitrea, 236, 237 Mastigina, 236 Mastigophora, 4, 11, 17, 20, 34, 37, 40, 65, 67, 73, 78, 87, 112, 137, 139, 171-287 Mastigasphaera, 201 gobii, 200, 201 Mastotermes dariviniensis, 262, 286 Mattesia, 412 dispora, 412, 413 Maupas, 11, 152, 153, 154 Maupasella, 65, 493 nova, 493, 494 Maurer's dots, 437 McDonald, 55, 586 McNeal, 14 Mechanical stimuli on Protozoa, 109-111 Mediola mediolus, 563 Medusetta, 375 ansata, 376 Medusettidae, 375 Medusochloris, 194 phiale, 194 Megacyclops viridis, 477 Megalospheric generation, 346 proloculum, 346 Meglitsch, 314 Meiosis, 157-159, 419 Melanin, 101, 434 Melanosome, 80, 220 Meldrum, 116 Melolontha, 265, 406 Melophagns ovinus, 247 Membrane, 48 Membranella, 48, 50 basal plate, 48, 56 fiber, 56 fiber plate, 50, 56 Mendelian inheritance, 166, 167, 168, 169 Menoidium, 211 incurvum, 68, 133, 137, 139, 210, 211-212 tortuosum, 212 Menospora, 398 polyacantha, 398, 399 Menosporidae, 391, 398 Mercier, 135, 148,313 Merganser, 442 M erg us scrrator, 442 Merocystis, 419 kathae, 419, 420 Merogregarina, 410 amaroucii, 410 411 Meroselenidium, 413 keilini, 413 Merozoite, 434 Mesenchytraeus flavus, 451 Mesnil, 27, 452,' 471 Mesnilella, 495 clavata, 494, 495 rostrata, 494, 495 Mesodinium, 501 near us, 500, 501 pulex, 20, 500, 501 Mesojoenia, 282 decipiens, 282 Mesosaprobic Protozoa, 19 Mesozoa, 453 Metabolism, 31-32 Metachromatic granules, 95-96 Metacineta, 633 viystacina, 20, 633, 634 Metacystidae, 496, 499 Metacystis, 499 truncata, 499, 500 Metadevescovina, 269 deUlis, 66, 134, 268, 269 Metadinium, 592 medium, 593 Metalnikoff, 89, 116 Metaraera, 400 schubergi, 399, 400 Metaphrya, 488, 490 sagittae, 489, 490 Metazoa, compared with Protozoa, 4 Metcalf, 135, 484, 486 Metopidae, 573, 576-577 Metopus, 55, 65, 576 circumlahens, 576, 577 es, 97, 152, 153, 576, 577 fuscus, 576, 577 striatus, 576, 577 Metridium marginatum, 568 Metschnikoff, 89 Metzner, 113 Meyer, 95 Michelson, 539 Microcometes, 325 paludosa, 324, 325 Microcorycia, 332 flava, 332, 333 Microcyst, 297, 298 Microfolliculina, 584 limnoriae, 584 Microgromia, 325 AUTHOR AND SUBJECT INDEX 669 socialis, 324, 325 Microgamete, 145, 415, 416, 429, 434, 435 Microgametocyte, 415, 416, 4^9, 434, 435 Microjoenia, 282 pyriformis, 281, 282 Microlynchia fusilla, 440 Micron, 31 Micronucleus, 32, 35, 54, 131, 132, 148-152, 482 Micropterus salmoides, 468 Microregma, 509 auduhoni, 509, 510 Microrohopalodina, 275 multinucleata, 275 occidentis, 275-276 Microspheric generation, 346 proloculum, 346 Microspirotrichonympha, 278 ovalis, 278, 279 porteri, 278, 279 Microsporidia, 8, 13, 26, 31, 32, 155, 453, 472 478 Microsporidian cysts, 475 Microsporidiosis, 473-474 Microstomus pacificus, 461 Microtermes hispaniolae, 314 panarnaensis, 314 Microthorax, 533-534 simulans, 533, 534 Microtus, 245 Microvelia, 250 Miescher's tube, 447 Miliolidae, 349, 350 Milk weeds, 251 Miller, 433 Minchin, 33, 68, 259 Minnows, 26, 467, 468 Mites, 431, 433, 480 Mitosis, 124-137, 139 Mitraspora, 461 elongata, 461 Mixotricha, 261-262 paradoxa, 262 Mixotrophic nutrition, 93-94 Mobilia, 616, 625-627 Modifications, long-lasting, 163 Mole, 425 Molgula manhattensis, 629 MoUusca, 252, 253, 310, 401, 407, 408, 409, 419, 420, 427, 428, 450, 451, 490, 491, 513, 540, 556, 561, 562, 563, 564, 565, 566, 586 Monadidae, 239, 255-256 Monas, 20, 46, 107, 255 elongata, 255-256 guttula, 255 socialis, 45, 255, 256 vestita, 255, 256 Monera, 31, 294 Monocercomonas, 268 bufonis, 268 Monochilum, 551 frontatum, 551, 552 Monocnidea, 474-478 Monocystidae, 381-384 Monocystis, 70, 72, 126, 131, 382 lutnbrici, 382, 383 rostrata, 159 ventrosa, 382, 383 Monodinium, 499 Monodontophrya, 493 kijenskiji, 492, 493 Monoductidae, 391, 396-398 Monoductus, 396 lunatus, 396 Monomastix, 511 Monomonadina, 260-272 Monophasic amoebae, 306 Monopylea, 370, 373-374 • Monosiga, 240 ovata, 240, 241 robusta, 240, 241 Monster formation, 169 Moore, 70, 177, 580 Morea, 22 Morphology of Protozoa, 31-81 Morphonemes, 55 Morris, 313, 322 Mosquitoes, 6, 388, 434, 435, 436, 437, 475, 549 Motella, 465 mustela, Til tricirrata, 272 Motorium, 54, 55, 59, 60 Mouse, 245, 248, 265, 272, 317, 422, 426, 427, 430, 448 Mouton, 91, 116 Movement, 101-109 by cilia, 109-109 fiagella, 106-107 myonemes, 109 pseudopodia, 101-106 Moxostoma breviceps, 467 Mrazekia, 477 caudata, 477, 4'^ Mrazekiella, 495 intermedia, 494, 495 Mrazekiidae, 474, 477-478 Mud crabs, 409 Mule, 245 Muller, J., 11, 369 MuUer, O. F., 10 Mailer's law, 369, 370 vesicle, 77, 78, 521, 522 Mulsow, 135, 159 Multicilia, 235 lacustris, 235, 236 670 PROTOZOOLOGY marina, 235, 236 Multiciliidae, 235-236 Multiple division, 138-139 Munia oryzivora, 248 Musca, 251, 477 Musgrave, 14, 412 Muscle fibers, 51 Mussels, 23, 561 Mutations, 113, 163, 164-165 Mya arenaria, 513 Alycetohia pallipes, 480 Mycetozoa, 32, 89, 90, HI, 140, 289,296-303 Mycterothrix, 532 erlangeri, 532, 533 Mylestoma, 602 bipartitum, 601, 602 Mylestomidae, 600, 602 Myonemes, 51-53, 380 Myophrisks, 53 Myriapoda, 393, 398, 400, 403, 404, 415, 421, 428 Myriophryidae, 358, 366 Myriophrys, 366 paradoxa 365, 366 Myriospora, 419 trophoniae, 419-420 Mytilus edulis, 561, 563 galloprovincialis, 408 minimus, 407, 408 Myxamoeba, 296 Myxidiidae, 464-466 Myxidium, 464 immersum, 464, 465 kudoi, 464 lieberkuhni, 135, HO, 464, 465 Myxobolidae, 464, 466-468 Myxobolus, 466 conspicuus, 467 intestinalis, 26, 468 orbiculatus, 467 rfeijferi, 135, 459, 466-467 squamosus, 467, 468 Myxoflagellate, 297, 298 Myxogasteres, 296 Myxomonas, 270 polymorpha, 270 Myxomycetes, 296 Myxophyllum, 561 steenstrupi, 561, 562 Myxoproteus, 461 cordiformis, 461, 463 Myxosoma, 466 catostomi, 124, 154, 455, 466 cerebralis, 459, 466, 467 Myxosomatidae, 464, 466 Myxosporidia, 8, 13, 25, 32, 66, 95, 124, 139, 147, 154, 156, 453, 454-468 Myxosporidian cysts, 455, 458 Myxotheca, 41, 327 arenilega, 326, 327 N Nadinella, 338 tenella, 337, 338 Nagana, 13, 245 Nagler, 312 Naegleria, 305 Nassoidae, 373 Nassoidea, 373 Nassonov, 70, 77, 82 Nassula, 70, 522 aurea, 20, 522, 524 trichocystis, 523 Nassulidae, 522-523 Nasutitermes kirbyi, 265 Navicula, 187 Naville, 126, 135, 147, 159, 412, 414, 419, 458, 471 Nebalia bipes, 228 geoffroyi, 570, 614 Nebela, 34i collaris, 341, 342 Needham, 18, 29 Nelson, 259 Nematocyst, 66 Nematocystis, 382 vermicularis, 382, 383 Nematodinium, 06, 222 partitum, 221, 222 Nematopsis, 407 legeri, 407-409 Nemertinea, 389, 450 Neoactinomyxum, 471 globosum, 470, 471 Neosporidia, 377 Neotermes connexus, 267 simplicornis, 267 Neotoma, 245 Nepa cinerea, 406, 412, 427 Nephroselmidae, 185, 186-187 Nephroselmis, 186-187 olvacea, 186, 187 Nereis beaucourdrayi, 392 cultrifera, 392 Neresheimer, 43, 51 Neuromotor system or apparatus, 55-59, 108 Neurophanes, 51 Neusina, 349 Neusinidae, 348 Newt, 248 Nicollella, 529 ctenodadyli, 529 Nina, 400 gracilis, 135, 399, 400 Nirenstein, 89, 90, 116 Nitocra typica, 633 Nitrogen, 79, 189 AUTHOR AND SUBJECT INDEX 671 Noctiluca, 10, 31, 131, 139, 222 miliaris, 222 scintillans, 71, 95, 221, 222 Noctilucidae, 219, 222-223 Noble, 134, 159, 161, 414, 618 Noland, 29, 97, 116, 161, 501, 506, 516, 519, 523, 556, 559, 576, 613, 621, 627 Noller, 427 Non-celluIar organisms, 3 Nonionidae, 350 Nordenskiold, 15 Nosema, 474 anophelis, 474, 475 apis, 8, 474, 475 bombycis, 8, 13, 474 bryozoides, 474 cyclopis, 474, 475 lophii, 472 Nosema-disease, 474 Nosematidae, 474^477 Notosolenus, 213 apocamptus, 210, 213 sinustus, 210, 213 Notropis blennius, 468 cornutus, 468 gilberti, 467 Novy, 14 Nucleal reaction, Feulgen's, 34, 36, 69, 118, 120,267 Nuclear cleft, 120 Nuclear division, 118-137 direct, 118-124 indirect, 124-137 Nuclear membrane, 32 Nuclearia, 292 delicaiula, 291, 292 simplex, 292 Nucleolus, 33 Nucleoplasm, 32, 33 Nucleus, 32-35, 43, 118-137 compact, 33, 34-35 macro-, 32, 64 micro-, 32, 54 vesicular, 32-34 Nutrition, 84-94 autotrophic, 84, 92 heterotrophic, 84^92 holophytic, 84, 92 holozoic, 84-92 mixotrophic, 93-94 parasitic, 93 phytotrophic, 84, 92 sapropelic, 19 saprophytic, 84, 92-93 saprozoic, 84, 92-93 zootrophic, S4r-92 Nyctobates pennsylvanica, 404 Nyctotherus, 12, 53, 74, 94, 580* 581 cordiformis, 150, 151, 581, 582 ovalis, 23, 34, 35, 53, 120, 581, 582 O Obelia commissuralis, 638 geniculata, 638 Ocellus, 80-81, 109 Ochromonadidae, 174, 179-181 Ochromonas, 171, 179 ludibunda, 179, 180 mutabilis, 179, 180 O'Connor, 321 Octolasium complanatum, 383 Octomitus, 272 Octopus tetracirrhus, 491 Octosporea, 477 muscae-domesticae, 477, 478 Odor of water due to Protozoa, 7, 95, 177, 179 Oesophageal fibers, 54, 55, 59 process, 59, 60 Oikomonadidae, 239, 243-244 Oikomonas, 243 terrno, 243 Oikopleura dioica, 227 Oil 91 94 95 Oligochaetes, 382, 383, 384, 385, 386, 387, 389, 428, 450, 451, 469, 471, 477, 488, 491, 493, 494, 495 Oligosaprobic Protozoa, 18 Oligotricha, 573, 587-599 Onchodactylus, 525 Oncopeltus fasciatus, 251 Onychodromopsis, 611 flexilis, 610, 611 Onychodromus, 611 grandis, 610, 611 Oocyst, 146, 416 Oodinium, 227 poucheti, 226, 227 Ookinete, 146, 434, 442 Oospira, 570 Opalina, 12, 32, 53, 71, 72, 483 carolinensis, 484 chorophili, 484 hylaxena, 484 kennicotti, 484 obtrigonoidea, 484 oregonensis, 484 pickeringii, 484 spiralis, 484 Opalinidae, 483-486 Opalinopsidae, 488, 491 Opalinopsis, 491 sepiolae, 491, 492 Opercular fibers, 54, 55 Opercularia, 619 plicatilis, 620 stenostoma, 620 672 PROTOZOOLOGY Operculina, 352 ammonoides, 351 Ophelia limacina, 490 Ophiothrix frngilis, 570 Ophisthotrichum, 595 janus, 595, f>9(J thomasi, 595 Ophiurespira, 570 iveilli, 570, 577 Ophrydiidae, GIG, 618 Ophrydium, 31, 618 sessile, 617, 618 vernalis, 617, 618 Ophryocephalus, 633 capitatum, 634 Ophryocystidae, 409-411 Ophryocystis, 409-410 mesnili, 410, 411 Ophryodendridae, 628, 632 Ophryodendron, 632 helgicum, 631, 632 porcellanum, 631, 632 Ophryoglena, 555 collini, 554, 555 intestinalis, 554, 555 parasitica, 555 pyriformis, 554, 555 Ophryoglenidae, 547, 555 Ophryoscolecidae, 61, 74, 90, 94, 587, 590 Ophryoscolecin, 61 Ophryoscolex, 590 bicoronatus, 590, 591 caudatus, 590, 591 quadricoronatus, 590, 591 Ophthalmidiidae, 350 Opisthodon, 518 Opisthonecta, 618 henneguyi, 617, 618, 638 Opisthostyla, 619 annulata, 619, 620 Opisthotricha, 603 Opsaus tau, 463 Oral basket, 62 Orbitoides, 354 Orbitoididae, 354 Orbitolinidae, 349 Orbulina universa, 162 Orcadella, 300 operculata, 301 Orcheobius, 428 herpobdellae, 135, 428-429, 430 Orchestia agilis, 488, 527, 528 palustris, 527, 528 Orchitophrya, 490 stellarum, 489, 490 Organella, 3, 32-81 Oriental sore, 251 Origin of parasitism, 27-29 O'Roke, 441, 445 Orthognathotermes wheeleri, 270 Orosphaera, 372 Orosphaeridae, 372 Orthodon, 523 hamatus, 523, 5i^4 Orthomorpha graclis, 393 Oryctes, 265, 393 nasicornis, 393 Osmerus, 475 Osmiophile structures, 69- TT^ Ostracodinium, 594 dentatum, 594, 595 Ostrea virginica, 310, 409 Ovis orientalis cycloceros, 590 Oxidation, 96-98 Oxygen on Protozoa, 97-98 Oxymonas, 267 dimorpha, 267 projector, 266, 267 Oxnerella, 359 maritima, 124^125, 134, 359 Oxyphysis, 233 oxytoxoides, 232, 233 Oxyrrhis, 137, 220 marina, 131, 220, 221 Oxytricha, 19, 47, 55, 603 bijaria, 603, 604 fallax, 17, 135, 150, 158, 603, 604 ludibunda, 603, 604 setigera, 604 Oxytrichidae, 603-611 Oyster, 310, 409 Pachygrapsus crassipes, 396 Pack, 506 Paedogamy, 154, 156, 157, 455 Palaemonetes, 570 Palatinella, 177 cyrtophora, 176, 177 Palm, 303 Palmella stage, 171, 174, 184 Pamphagus, 41, 131, 331 arniatus, 19 mutabilis, 330, 331 Pandorina, 80, 95, 141, 201 morum, 145, U7, 200, 201 Panopeus herbsti, 409 Pansporoblast, 454 Pantin, 103, 116 Panzer, 95, 116 Parabasal apparatus, 62, 66-67 body, 46, 66 thread, 66 Parablepharisma, 580 pellitum, 579, 580 Paracalanus, 490 parvus. Til, 228, 571 'Parachaenia, 513 myae, 512, 513 AUTHOR AND SUBJECT INDEX 673 Paracineta, 033 limbata, 033, 6.)4 Paradesmose, 126 Paradevescovina, 269 * Paradileptus, 521 conicus, 520, 521 robustus, 520, 521 Paradinium, 228 poucheti, 226, 228 Paraellobiopsis, 228 coutieri, 226, 228 ParafoUiculina, 584 violacea, 584, 585 Paraglaucoma, 550 rostraia, 51^9, 550 Paraglycogen, 94, 97, 380 Paraholosticha, 609 herbicola, 608, 609 Paraisotricha, 543-544 beckeri, 544, 545 colpoidea, 544, 545 Paraisotrichidae, 77, 531, 543-544 Paraisotrichopsis, 515 composita, 515 Parajoenia, 61, 267 grassii, 266, 267 Parajulus venustus, 393 Paramaecium, 537 Parameciidae, 531, 537-540 Paramecium, 9, 10, 17, 18, 20, 21, 22, 55, 63, 65, 70, 71, 73, 75, 85, 87, 88, 94, 97, 99, 110, 111, 112, 113, 118, 159, 164, 165, 500, 537 aurelia, 5, 22, 135, 150, 154, 155, 156, 157, 158, 167, 169, 537, 538 bursaria, 6, 22, 24, 154, 169, 537, 538, 539 calkinsi, 20, 34, 537, 538 caudatum, 16, 17, 20, 22, 34, 63, 64, 89, 90, 98, 99, 100, 111, 119, 148, 149, 150, 152, 156, 169, 537, 5SS, 539 colpoda, 549 rnultimicronucleata, 17, 22, 58, 59, 60, 75, 76, 98, 537, 538 polycaryum, 537, 538 putrinum, 537, 538, 539 trichium, 537, 538 woodruffi, 74, 537, 538 Paramoeba, 321 pigmentifera, 320, 321 schaudinni, 321 Paramoebidae, 305, 321 Paramylon, 94, 95 Paranassula, 522 microstoma, 522-523, 524 Paraoesophageal fibrils, 59, 60 Parapodophrya, 632 typha, 86, 633, 634 Parapolj'toma, 193 satura, 192, 193 Parasite, 24, 93 Parasitic nutrition, 93 Parasitic Protozoa, 6, 7, 8, 23-29, 31 Parasitism, 24 Origin of, 27-29 Paraspathidium, 496-497 trichostomum, 497 Paravorticella, 618 clymenellae, 617, 618 Pareuglypha, 339 Parmulina, 332 cyathus, 332-333 Parophrys vetulus, 461 Pascher, 133, 167, 170, 183, 187, 202,215 Pasteur, 13 Patella caerulea, 566 Pathological changes in host, 24—27 Pauldina vivipara, 639 Paulinella, 92, 339 chromatophora, 340 Pavillardia, 222-223 tentaculifera, 223 Pavonina, 352 flabelliformis, 352 Pearson, 504 Pebrine, 8, 13 Pecten maxirnus, 419 Pectinellae, 47, 499 Pedigree culture, 12 Pelamphora, 499 butschlii, 499 Pelatractus, 499 grandis, 499, 500 Pellicle, 38, 59, 63 Pelodinium, 600 reniforme, 600, 601 Pelomyxa, 90, 91, 94, 310 binucleata, 32 palustris, 19, 91, 310, 311 villosa, 310, 311 Penard, 65, 77, 83, 114, 343, 366, 509, 516, 519, 627 Penardia, 294, 322 mutabilis, 293, 294 Penardiella, 498 crassa, 497, 498 Peneroplis, 41, 350 pertusus, 39, 185, 344, 351 Peneroplidae, 350 Penniculus, 59, 60 Pentatrichomonas, 271 scroa, 271, 272 Pepsin, 91, 296 674 PROTOZOOLOGY Peranema, 38, 44, 70, lOG, 211 granulifera, 2 11 Irichophorum, 71, 211 P^rard, 530 Perca, 468 jluviatilis, 249 Perezella, G5, 490 pelagica, 489, 490 Perezia, 475 ■mesnili, ^74, 475 Periacineta, 636 huckei, 636, 637 Pericaryon, 570 cesticola, 570, 571 Peridiniidae, 229-233 Peridiniinea, 217, 219-233 Peridinin, 79 Peridinioidae, 219, 229-233 Peridinium, 95, 229 divergens, 229, 230 tabulatum, 229, 230 Perioral membrane, 50 Periplaneta americana, 388 Peripylea, 370, 372-373 Perispira, 498 strepliosoma, 497, 498 Ppnsf omp 47 Peritricha,' 23, 38, 52, 75, 141, 487, 616-627 Peritromidae, 574, 584-586 Peritromus, 584 californicus, 584-586 emniae, 586 Peromyscus inaniculatus, 248 Perty, 11 Petalomonas, 211 mediocanellata, 210, 211 Petalostoma minutum, 421, 469 Petrocheliden lunifrons lunifrons, 438-439 Pfeiffer, 93 Pfeifferinella, 427 ellipsoides, 426, 427 impudica, 426, 427 Phacodinium, 580 metschnicoffi, 577, 580 Phacotidae, 188, 196-197 Phacotus, 196 lenticularis, 195, 196 Phacus, 20, 46, 112, 206 acuminata, 207, 208 anacoelus, 207, 208 longicaudus, 206-207, 208 pleuronectes, 206, 208 pyrum, 133, 207, 208 triqiieter, 207, 208 Phaeocalpia, 375 Phaeocapsina, 184, 187 Phaeoconchia, 376 Phaeocystina, 374 Phaeodium, 367 Phaeogromia, 375 Phaeosphaera, 183 gelatinosa* 182, 183 Phaeosphaeria, 374 P haeothamnion confervicoluin, 186, 187 Phalangium cornutum, 404 crassum, 404 opilio, 404 Phalansteriidae, 239 Phalansterium, 239 digitatum, 239, 240 Pharyngeal basket, 62 Phascolodon, 525-526 vorticella, 524, 526 Phelps, 22 Pheretima, 385 barbadensis, 382, 385, 386 beaufortii, 385 haivayana, 385 heterochaeta, 387 rodericensis, 385 sermowaiana, 387 wendessiana, 386 Phesant, 424 Phialoides, 406 ornata, 405, 406 Phialonema, 211 Philaster, 559 armata, 558, 559 digitiformis, 558, 559 Philasteridae, 547, 559 Philasterides, 559 Phorcus richardi, 408 Phoretrophrya, 570 nebaliae, 569, 570 Phormia, 251 Phormobothrys, 374 Phoront, 567 Phosphorescence, 95, 222 Phosphorus, 79, 96, 189 Photosynthesis, 18, 79, 92 Phryganella, 336 acropodia, 336, 337 Phtorophrya, 570 insidiosa, 570, 571 Phycochrisin, 79 Phycocyanin, 79 Phyllognathus, 393 Phyllomitus. 258 undulans, 258, 259 Phyllomonas, 192 phacoides, 192 Phyloxanthin, 79 Physalophrya, 539-540 spumosa, 536, 540 Physaridae, 299 Physematiidae, 372 Physiology of Protozoa, 84-114 AUTHOR AND SUBJECT INDEX 675 Physomonas, 255 Physophaga, 570 Phytodiniidae, 229, 233 Phytodinium, 233 simplex, 232, 233 Phytomastigina, 4, 17, 18, 19, 21, 38, 51, 74, 78, 92, 143, 173-233 Phytomonadina, 79, 173, 178, 188- 201 Phytomonas, 244, 250-251 davidi, 251 elmassiani, 250, 251 Phytomyxinae, 302-303 Phytotrophic nutrition, 84, 92 Pickard, 55 Pieris brassicae, 475 Pig, 245, 317, 319, 422, 425, 448, 575, 576 Pigeon, 424, 440 Pigments, 25, 37, 65, 79, 80, 184 Pileocephalus, 380, 404 striatus, 402, 404 Pimelia, 401 Pimephales notatus, 468 Pinaciophora, 364 fluviatilis, 363, 364 Piney, 83 Pipetta, 373 tuba, 373 Pisania maculosa, 408 Pithiscus, 194 Pithothorax, 510 ovatus, 510 Placobdella catenigera, 431 marginata, 248, 400, 427 Placocista, 341 spinosa, 341, 342 Placopsilina, 349 cenomana, 349 Placopsilinidae, 349 Placus, 508 socialis, 507, 508 Plagiocampa, 506 marina, 506, 507 Plagiophrys, 41, 331 parvipunctata, 330, 331 Plagiopyla, 22, 534-535 viinuta, 535, 536 nasuta, 535, 536 Plagiopylidae, 531, 534-536 Plagiopyxis, 336 callida, 336, 337 Plagiospira, 565 crinita, 564, 565 Plagiotricha, 605 Planaria limacina, 493 torva, 493 ulvae, 493 Planorbis cornua, 427 Planorbulina, 354 Planorbulinidae, 354 Plants, 250, 251, 290, 303 Plasma-membrane, 37 Plasmodia, 296 Plasmodiidae, 435-439 Plasmodiophora, 302-303 brassicae, 303 Plasmodium, 6, 7, 14, 24, 31, 113, 138, 435 cathemerium, 437-438 circumflexum., 439 elongatum, 438 falciparum, 25, 436, 437 malariae, 436, 437 nucleophilum, 438 polare, 438-439 praecox, 13, 437, 438 vaughni, 438 vivax, 146, 435-436, 437 Plasmodroma, 171-480 Plasmogamy, 458 Plasmosome, 33 Plasmotomv, 140 Plastin, 32,' 33 Platycola, 625 longicollis, 624, 625 Platydorina, 141, 199 caudata, 199, 200 Platyhelminthes, 451, 490, 493, 555 Platynematum, 551 sociale, 20, 551, 552 Platyophrya, 506 lata, 506, 507 Platysporea, 459, 464-468 Platytheca, 243 microspora, 243, 244 Plectellaria, 373 Plectoidae, 373 Pleodorina, 201 californica, 201 illinoisensis, 80, 200, 201 Pleurocoptes, 558 hydractiniae, 558 Pleurocystis, 384 cuenoti, 38^385, 386 Pleuromonas, 257 jaculans, 20, 257, 258 Pleuronema, 555-556 anodontae, 556 coronatum,, 20, 556 crassum,, 556 marinum, 556 setigerum, 556 Pleuronematidae, 547, 555-558 Pleurostomata, 496, 517-522 Pleurotricha, 609 lanceolata, 135, 608, 609 Plistophora, 476 longifilis, 472, 476, 477 simulii, 477 676 PROTOZOOLOGY Plodia inter punctella, 412 Plumatella fungosa, 474 repens, 474 Pocillomonas, 196 flos aquae, 195, 196 Podocyathus, 641 diadema, 640, 641 Podophrya, 632 collini, 632 elongata, 631, 632 fixa, 631, 632 gracilis, 631, 632 Podophryidae, 628, 632-634 Pohl, 100 Polar capsule, 63, 66, 453, 454, 472 filament, 66, 144, 453, 454, 472 Polyblepharides, 196 singularis, 195, 196 Polyhlepharididae, 188, 196 Polychaetes, 392, 412, 413, 419, 426, 450, 451, 488 Polycyttaria, 373 Polydora caeca, 488 flava, 488 Polygastricha, 10 Polykrikidae, 219, 228-229 Polykrikos, 66, 141, 228 barnegatensis, 228-229 kofoidi, 228, 230 Polymastigidae, 260, 265-269 Polymastigina, 61, 91, 235, 260-276 Polymastix, 265 melolonthae, 265, !266 Polymnia, 490 nebulosa, 419 Polymonadina, 260, 274-276 Polymorpha, 514 ampulla, 514, 515 Polymorphina, 350 Polymorphinidae, 350 Polyplastron, 593-594 multivesiculatum, 61, 594, 595 Polyrhabdina, 392 spionis, 392, 394 Polysaprobic Protozoa, 19, 96-97 Polyspira, 570 delagei, 570, 573 Polystomella, 351 Polytoma, 9, 193 uvella, 44, 45, 93, 193, 193 Polytomella, 114, 194 agilis, 96, 133, 194, 195 Pomoxis sparoides, 26, 464 Pompholyxophrys, 362 punicea, 362-363 Pontigulasia, 336 vas, 336, 337 Pontosphaera haeckeli, 181, 182 Popoff, 135, 159, 163 Porcellana platycheles, 632 Porifera, 627 Porospora, 407 galloprovincialis, 407 gigantea, 407, 408 Porosporidae, 392, 407-409 Porotermes adamsoni, 111, 278, 282 grandis, 272 Portunus, 418 depurator, 419, 570, 615 Posterior neuromotor chain, 59, 60 Postoesophageal fibrils, 59, 60 Potamilla reniforinis, 412, 413 Poteriodendron, 141, 242 petiolatuia, 242 Pouchetia, 220 fusus, 220, 221 maxima, 220, 221 Pouchetiidae, 219, 220-222 Powell, 132 Powers, 92, 116, 501, 543, 546, 576, 586 Prandtl, 135, 158, 161 Pratje, 95, 116 Precystic stage, 142 Prehensile tentacle, 50, 86 Primite, 380 Pringsheim, 21, 79, 83, 93, 116, 145 Prismatospora, 403 evansi, 402, 403 Proboscidiella, 275 Procavia brucei, 528 capensis, 528 Proceros, 493 Proloculum, 345 megalospheric, 346 microspheric, 346 Prolophomonas, 280 tocopola, 280, 281 Pronoctiluca, 220 tentaculatum, 220, 221 Pronoctilucidae, 219, 220 Prorocentridae, 218 Prorocentrinea, 217, 218-219 Prorocentrum, 218 micans, 218 Iriangulatum, 218 Prorodon, 63, 65, 508 discolor, 20, 507, 508 griseus, 508 utahensis, 506 Prorodonopsis, 515 coli, 515 Prostomata, 496-516 Protanoplophrya, 491 sto?nata, 491, 492 Protective organellae, 59-65 Protein, 47, 70, 71, 91, 97 Proteomyxa, 289-292 Proteromonas, 257 lacertae, 46, 257, 258 AUTHOR AND SUBJECT INDEX 677 Proterythropsis, 222 crassicaudala, 221, 222 Proteus, 10, 306 Protista, 4, 11 Protochrysis, 187 phaeophycearum, 186, 187 Protociliata, 23, 47, 93, 95, 108, 140, 318,483-486 Protocruzia, 580 pigerrima, 577, 580 Protomagalhaesia, 395 serpentula, 394, 395 Protomerite, 380 Protomite, 567 Protomonadina, 235, 239-259 Protomonas, 290 atnyli, 290 Protomont, 567 Protoopalina, 32, 486 intestinalis, 135, Jt85, 486 mitotica, 485, 486 saturnalis, 485, 486 Protophrya, 491 ovicola, 489, 491 Protophyta, compared with Pro- tozoa, 3-4, 171 Protoplasm, 31 Protoplasmic movements, 101-109 Protopsis, 220 ochrea, 221, 222 Protoradiophrya, 141, 495 Jissispiculata, 494, 495 Protospongia, 141, 241 haeckeli, 240, 241 Protozoa as non-cellular organisms, 3 as unicellular organisms, 3 classification of, 4 colonial, 4 definition of, 3, 11, distinguished from Protopyta, 3- 4, 171 Metazoa, 3 ecology of, 16-29 fossil, 8-9, geographical distribution of, 16 in faeces, 19 fresh and salt water, 16-23 thermal waters, 17, 162 parasitic in Algae, 290, 292 Amphibia, 237, 238, 248, 265, 267, 268, 270, 274, 318, 424, 425, 444, 445, 461, 464, 484, 485, 486, 492, 581, 618, 625, 626 Annelida, 227, 228, 382, 383, 384, 385, 386, 387, 389, 390, 392, 393, 400, 401, 411, 412, 413, 419, 420, 421, 426, 428, 429, 450, 451, 469, 471, 477, 488, 490, 491, 493, 494, 495, 618 Arachnida, 404 birds, 238, 248, 422, 424, 425, 436, 437, 438, 439 Bryozoa, 474, 632 cat, 315, 422, 425 cattle, 245, 247, 265, 270, 317, 421, 422, 442, 443, 444, 513, 530, 544, 545, 590, 591, 592, 593, 594 Chaetognatha, 321, 490 chicken, 238, 265, 317, 318, 422, 423, 424 cockroaches, 23, 258, 272, 280, 312, 314, 318, 388, 395, 451, 576, 581 Coelenterata, 227, 253, 321, 490, 551, 558, 568, 569, 570, 629, 632 Copepoda, 211, 227, 228, 475, 477, 490, 567, 570. 571 Decapoda, 228, 391, 393, 396, 407, 409, 417, 419, 448, 567, 570, 615, 619 Diptera, 238, 245, 265, 318, 400, 405, 412, 434, 435, 436, 437, 440, 441, 475, 476, 477, 480 dogs, 245, 315, 317, 422, 425 donkeys, 245, 247 Echinodermata, 389, 390, 490, 535, 542, 543, 550, 559, 565, 570, 576, 586 fishes, 8, 248, 249, 252, 253, 267, 272, 320, 424, 431, 451, 461, 462, 463, 464, 465, 466, 467, 468, 475, 477, 483, 486, 504, 526, 627 fowls, 238, 265, 317, 318, 422, 423, 424, 441 frogs, 6, 12, 23, 27, 237, 248, 265, 268, 270, 318, 424, 425, 427, 431, 445, 461, 464, 484, 485, 486, 517, 576, 581 goat, 265, 317, 422, 590, 592 guinea-pig, 264, 317, 422, 430, 544, 596 horses, 245, 265, 317, 448, 513, 514, 515, 516, 544, 545, 546, 597, 638 Hydra, 23, 24, 321, 625 Insecta, 6, 8, 23, 238, 245, 246, 247, 250, 251, 258, 265, 269, 318, 384, 388, 391, 393, 395, 396, 398, 400, 678 PROTOZOOLOGY 401, 402, 403, 404, 405, 406, 407, 410, 412, 414, 430, 431, 451, 474, 475, 476, 477, 478, 480, 555 leeches, 248 man, 7, 12, 23, 245, 251, 258, 264, 269, 270, 273, 316, 317, 318, 319, 425, 448, 475 Mollusca, 252, 253, 310, 401, 407, 408, 409, 419, 420, 427, 428, 450, 451, 490, 491, 513, 540, 556, 561, 562, 563, 564, 565, 566, 586 mosquitoes, 6, 388, 434, 435, 436, 437, 475. 549 Mouse, 245, 248, 265, 272, 315, 317, 422, 426, 427, 430, 448 Myria'poda, 393, 398, 400, 403, 404, 415, 421, 428 newt, 248 pigs, 245, 317, 319, 422, 425, 448, 575, 576 plants, 250, 251, 290, 303 Platyhelminthes, 451, 490, 493, 555 Porifera, 627 Protozoa, 227, 290, 318, 570, 618, 633 rabbits, 12, 248, 265, 317, 421 rats, 245, 246, 265, 272, 317, 422, 431, 448 Reptilia, 248, 257, 426, 427, 433, 444 Rotifera, 451 sheep, 265, 317, 422, 448, 544, 590, 591, 592, 594 Sipunculoidea, 421, 469 snake, 248, 265, 318, 425 termites, 6, 262, 265, 266, 267, 268, 269, 270, 272, 274, 275, 276, 278, 279, 280, 281, 282, 284, 285, 286, 287, 314, 392, 395, 476 ticks, 247, 250 toads, 268. 461, 464, 484, 486 Tunicata, 227, 410, 629 turkeys, 238, 424 turtles, 248, 317, 318, 431 wood-roach, 269, 272, 280, 282, 283, 284, 286 physiology of, 84—114 reproduction of, 114, 118-159 size of, 31 Protozoology and biology, 5 cytology, 6 economic entomology, 8 evolution, 5 genetics, 5 geography, 6 geology, 8-9 medicine, 7 phylogeny, 6 pisciculture, 7-8 sanitary science, 7 soil biology, 8 veterinary science, 7 zoogeography, 6 Protrichocysts, 65, 185 Protrichomonas, 267 legeri, 266, 267 Prowazek, 113, 135, 539 Prowazekella, 257 Prowazekia, 257 Prunoidae, 373 Pruthi, 22 Psammodromus hispanicus, 427 Psammoryctes barbatus, 471 Psammosphaera bowmanni, 39 fusca, 39 parva, 39 rustica, 39 Pseudoblepharisma, 580 tenuis, 579, 580 Pseudocalanus elongatus, 228 Pseudodevescovina, 267-268 uniflagellata, 268 Pseudochitinous substance, 38, 52 Pseudochlamys, 329 patella, 329, 330 Pseudochromosomes, 133 Pseudodifflugia, 137, 338 gracilis, 337, 338 Pseudofolliculina, 584 arctica, 584, 585 Pseudogemma, 638 pachystyla, 638, 639 Pseudoklossia, 419 pectinis, 419, 420 Pseudomallomonas, 175 Pseudomicrothorax, 532 agilis, 532, 533 Pseudopodia, 40-43, U, 50, 51, 84- 86, 137 Pseudoprorodon, 508 farctus, 507, 508 Pseudospora, 290 eudorini, 290 parasitica, 290 volvocis, 290, 291 Pseudosporidae, 289, 290 Pseudotrichonympha, 286 grassii, 286 Pseudotrypanosoma, 62, 272 giganteum, 271, 272 Psilotricha, 605 acuminata, 605, 607 AUTHOR AND SUBJECT INDEX 679 Pteridomonas, 238 pulex, 237, 238 Pteromonas, 196 angulosa, 195, 190-197 Pterospora, 389 maldaneorum, 389, 390 Ptychoptera contaminata, 404 Pulsating vacuole, 73-77 Pulsella, 46 Purkinje, 11 Pusule, 93, 172, 217 Putter, 97, 98, 116 Pycnothricidae, 522, 528-530 Pycnothrix, 528 monocystoides, 528, 529 Pyorrhoea alveolaris, 317 Pyramidochrysis, 175 modesta, 175, 176 Pyramidomonas, 194 Pyramimonas, 194 montana, 194 . tetrarhynchus, 194, 195 Pyrenoids, 79, 80, 92 Pyrocystis, 233 Pyrotheca, 477 incurvata, 477, 4'^8 Pyrsonympha, 70, 268-269 vertens, 268, 269 Python, 265 Pyxicola, 624-625 affinis, 624, 625 socialis, 624, 625 Pyxidicula, 137, 329 operculata, 41, 329, 330 Pyxidium, 619 urceolatum, 619, 620 vernale, 619, 620 Pyxinia, 405 bulbifera, 405 Pyxinoides, 396 balani, 396 Quadrula, 342 symmetrica, 342 Quail, 238, 422, 423, 424, 441 Querquedula crecca, 442 discolor, 442 Rabbit, 12, 248, 265, 317, 421 Radial cytostomal fibrils, 59, 60 Radiating canals, 75 Radiolaria, 9, 11, 24, 31, 37, 40, 41 52, 61, 95, 101, 139, 145, 185, 356, 367-376 Radiophrya, 141, 494 hoplites, 494 Radium rays on Protozoa. 113 Rainey's corpuscles, 446 Raja, 249, 464 oxyrhynchus, 249 Rana, 484 areolata, 484 cantabrigensis, 484 catesbeiana, 485 fusca, 265 pipiens, 464 var. sphenocephala, 484 Ranatra linearis, 636 Raphidocystis, 364 tubifera, 363, 364 Raphidiophrys, 364 pallida, 363, 364 Rats, 247, 248, 265, 272, 317, 422, 431, 448 Reaction of Protozoa to chemical stimuli, 111 current. 111 electrical stimuli, 113-114 gravity. 111 light stimuli, 112-113 mechanical stimuli, 109-111 radium rays, 113 Rontgen ray, 113 temperature, 113 ultraviolet rays, 112-113 Reconstruction bands, 120 Red snow, 17 Red water, 218, 225, 235, 501 Red-water fever, 442 Red-winged blackbirds, 437, 439 Redi, 10 Reduction division in Protozoa, 157-159 Reduviid bug, 245 Rees, 55, 276 Regeneration, 31, 114 Reichenow, 15, 36, 79, 83, 96, 118, 120, 161, 189, 234, 486, 599 Reindeer, 592, 594 Relation between neuromotor and silverline sys- tems, 58-59 nucleus and cytosome, 31, 137 Remanella, 63, 78, 522 rugosa, 520, 522 Renn, 290 Reophacidae, 348 Reophax, 348 nodulosus, 347 Reorganization band, 120, 121, 122, 123 Reproduction in Protozoa, 114, 118-159 asexual, 142-143 sexual, 143-159 Reptiles, 248, 257, 426, 427, 433, 434 Reserve food matter, 94-96 oso PROTOZOOLOGY Respiration, 78, <)(> 9S Reticulariii, 301 bjcoperdon, 301 Reticulariidae, 301 Reliculitermea jlaviceps, 2()S, 28(1 flavipes, 27S, 2S() hageni, 278, 2S2 hesperus, 269, 278, 282, 280 lucifugus, 269, 278, 286, 476 speratus, 278, 286, 287 tibialis, 286 Retortamonas, 257 blattae, 258 gryllotalpae, 258 intestinalis, 258 Reynolds, 24, 28, 29, 134, 165, 170, 256, 259, 321, 540 Rhabdammina, 347 abyssorum, 347 Rhabdocystis, 382-383 claviformis, 383 Rhabdophrya, 630 trimorpha, 630, 631 Rhabdostyla, 619 vernalis, 619, 620 Rhagadostoma, 508 Rhaphiceros, 594, 595 Rhaphidomonas, 214 Rhipicephalus evertsi, 444 sanguineus, 444 Rhipidodendron, 253 sjdendidum, 253, 254 Rhithrogena semicolorata, 476 Rhizammina, 347 algaeformis, 347 Rhizamminidae, 347 Rhizobium, 312 Rhizocaryum, 65, 488 concavum, 488, 4-89 Rhizochrysidina, 174, 181-182 Rhizochrysis, 131, 181 scherffeli, 133, 181, 182 Rhizomastigina, 51, 235-238, 304 Rhizomastix, 238 gracilis, 237, 238 Rhizoplasma, 292 kaiseri, 292, 293 Rhizoplast, 46, 68 Rhizopoda, 11, 289-354 Rhizopodia, 41, 42, 85 Rhizotrogus, 265, 406 Rhodes, 264 Rhodomonas, 186 lens, 186 Rhopalonia, 399 hispida, 399-400 Rhopalophrya, 511 salina, 87, 511, 512 Rhumbler, 84, 91, 101, 103, 112, 117, 162,355 Rhyncheta, 641 cyclopum, 640, 641 Rhynchobolus americanus, 393 Rhynchocystidae, 381, 384 Rhynchocystis, 384 pilosa, 384, 386 porreda, 384, 386 Rhynchogromia, 323 Rhynchomonas, 257 marina, 257 nasuta, 19, 257, 258 Rhynchonympha, 283-284 tarda, 134, 284, 285 Rhynchophrya, 640 palpans, 639, 641 Richardson, 72, 83 Robertson, 55 Robins, 438 Rontgen rays, 113 Rose!, 10 Root, 165, 170 Root-hernia, 303 Roskin, 41, 51, 83, 86, 90, 117, 295 Ross, 13, 445 Rossbach, 99 Rostellum, 267 Rotalia, 353 beccarii, 352 Rotaliidae, 353 Rotifera, 451 Roux, 516, 613 Ruminants, 61, 91 Rumjantzew, 36, 83, 94 Rupertia, 354 stabilis, 354 Rupertiidae, 354 Ruppia, 303 Russel, 8 Saccammina, 347 sphaerica, 347 Saccamminidae, 347 Saccinobaculus, 269 amploaxostylus, 268, 269 Sagartia leucolena, 568 parasitica, 551 Sagenocene, 374 Sagitta, 490 claparedei, 321 Sagosphaeridae, 374 St. Remy, 448 Salamander, 486, 492 Salinity and Protozoa, 19-21 Salmon, 272, 466 Salpa, 227 Salpingoeca, 241 fusiformis, 242 Sanders, 81 Sandon, 21, 30 AUTHOR AND SUBJECT INDEX 681 Sapotaceae, 250 Sappinia, 312 diploidea, 312 Saprodinium, 600 dentatum, 600, 6U1 putrinum, 600, 601 Sapropelic Protozoa, 19, 600 Saprophilus, 552 agitatus, 552 viuscorum, 552 Saprophj'tic nutrition, 92 Saprozoic nutrition, 78, 84, 92-93 Sarcina flava, 96 Sarcocystine, 27, 447 Sarcocystis, 447 berirami, 448 lindemanni, 447-448 miescheriana, 446, 448 muris, 448 tenella, 446, 447, 448 Sarcode, 10 Sarcodina, 8, 11, 20, 34, 36, 37, 40, 65, 73, 78, 84, 142, 181, 288-376 Sarcophaga, 251 Sarcosporidia, 13, 27, 446-448 Sarcosporidiotoxin, 27, 447 Sardine, 424 Sassuchin, 96, 117 Satellite, 380 Saunders, 22, 89 Scaphiopus albus, 485 solitarius, 486 Schaeffer, 85, 100, 103, 117, 306, 322 Schaudinn, 11, 13, 86, 91, 125, 131, 377, 415, 433 Schaudinnella, 387 henleae, 387, S88 Schaudinnellidae, 381, 387 Schellackia, 427 holivari, 427 Schewiakoff, 99, 117, 548, 553 Schiller, 219 Schilling, 234 Schizamoeba, 28, 319-320 salmonis, 320 Schizocystidae, 409, 411-414 Schizocystis, 145, 411-412 gregarinoides, 410, 412 Schizogony, 142, 377 Schizogregarinaria, 409-414 Schizonts, 142, 377, 454, 473 Schizotrypanum, 245 Schneideria, 405 mucronata, 405 Schrader, 480 Schroder, 51, S3 Schuberg, 53, 83 Schubotz, 100 Schuffner's dots, 437 Schultzella, 327 dilfluens, 324, 327 SchultzelUna, 493 mucronata, 493, 4^-'f Schumacher, 96 Sciadiophora, 404 phalangii, 404, 405 Sciadostoma, 534 Sclerotia, 296 Scololepis fuliginosa, 426 Scolopendra, 398, 400 cingulata, 400, 428 heros, 404 Scoloplos mulleri, 450 Scourfieldia, 191 complanata, 190, 191 Scutigera, 400 Scyphidia, 618 constricta, 617, 618 Scyphydiidae, 616, 618-619 Scytomonas, 212 pusilla, 19, 310, 212 Secondary nucleus, 305 Secretion, 65, 66, 67, 70, 71, 73, 88, 98-101 Selective power of Protozoa, 38-39 Selenidium, 410, 412 potamillae, 412, 413 Selenococcidiidae, 417 Selenococcidium, 417 intermedium, 417 Sensomotor apparatus, 59 Sepia elegans, 491 officinalis, 418, 419 Sepiola rondeletii, 491 Sericostoma, 404 Serinus canaria, 437 Sessilia, 616-625 Seticephalus, 400 elegans, 399, 400 Sewage organisms, 19 Sex reaction types, 154, 169 Sexual fusion, 14-1^148 Sexual reproduction, 143-159 autogamy, 154-156 automixis, 154-156 conjugation, 73, 124, 144, 148- 154, 158 endomixis, 156-157 paedogamy, 154, 156, 159 sexual fusion, 144-148, 159 Shapiro, 90, 117 Sharp, 55, 83, 590 Shaw, 202 Sheep, 262, 317, 422, 448, 544, 590 591 592 594 Shell, 8,'38, 61, 80, 101, 162, 344 Siebold, 11, 12 Sieboldiellina, 493 planariarum, 492, 493 682 PROTOZOOLOGY Siedlecki, 13 Silica, 39, 181 Silicina, 348 limitata, 347 Silicinidae, 348 Silicious tests, 181 Silicoflagellidae, 175, 181 Siliqua patula, 561 Silkworm, 8, 474 Silpha laevigata, 403 thoracica, 403 Silver line, 57 Silverline system, 57-59 Simulium, 477 venustum, 441 Sinuolinea, 464 dimorpha, 463, 464 Siphonophora, 227, 253 Siphostoma, 465 Sipunculoidea, 421, 469 Sipunculus, 389 Size of Protozoa, 31 Skeleton, 8, 39, 40, 54, 61, 368 Slavina appendiculata, 428, 477 Sleeping sickness, 14, 25, 245 Slime molds, 296-303 Smith, G. M., 183, 194, 202, 215 Smith, T., 13 Snails, 15, 253, 427 Snake, 248, 265, 318, 425 Snyderella, 276 tobogae, 275, 276 Sodium chloride on nucleus, 33 on Protozoa, 19-21, 99 Soil Protozoa, 21-23, 91 Sokoloff, 114, 117 Solenophyra, 636 inclusa, 636, 637 pera, 636, 637 Sonderia, 535 pharyngea, 535, 536 vorax, 536 Sonneborn, 5, 154, 156, 161, 167, 168, 170 Sorophora, 299, 302 Sorosphaera, 303 Soule, 97, 117 Spadella bipundata, 321 inflata, 321 serratodentata, 321 Sparrows, 425, 437, 438 Spasmostoma, 504-505 viride, 505, 507 Spathidiella, 497 Spathidiidae, 496-499 Spathidioides, 497 sulcata, 497-498 Spathidiopsis, 508 Spathidium, 496 spathula, 62, 157, 496, 497 Specht, 97 Spencer, 62, 83, 406 Spermatozopsis, 195 exultans, 195 Sphaenochloris, 192 printzi, 192 Sphaenophyra, 565 dosiniae, 505 Sphaenophryidae, 560, 565 Sphaeractinomyxon, 469-470 gigas, 470, 471 stolci, 470, 571 Sphaerastrum, 41, 360 fockei, 361, 362 Sphaerella, 189 Sphaerellaria, 372 Sphaerellopsis, 189 fluviatilis, 189, 190 Sphaerium, 556 corneum, 490, 491 Sphaerita, 36 Sphaerocapsa, 371 Sphaerocapsidae, 371 Sphaerocystis, 397 simplex, 398 Sphaeroeca, 241 volvox, 240, 241 Sphaeroidae, 372 Sphaeromyxa, 464 balbianii, 135, 140, 465 sabrazesi, 135, 148, 154, 456, 457, 465 Sphaerophyra, 633 magna, 633 soliforniis, 633, 634 stentoris, 633 Sphaerorhynchus, 401 ophioides, 401 Sphaerospora, 462 polyniorpha, 463 tincae, 463 Sphaerosporea, 459, 461-464 Sphaerosporidae, 461, 462-464 Sphaerozoidae, 373 Sphaerozoum, 373 ovodimare, 373 Sphaleromantis, 175 ochracea, 175, 176 Sphenoderia, 342 lenta, 342 Spheroid colony, 141 Spindle fibers, 124, 125, 126, 127, 128, 131 Spionidae, 392 Spiraulax, 232 jolliffei, 232, 233 Spireme ball, 151, 152 Spirillum volutans, 95, 96 Spirobolus spinigerus, 393 AUTHOR AND SUBJECT INDEX 683 Spirochona, 614 gemrnipara, 614, 615 Spirochonidae, 614—615 Spirocystis, 411 nidula, 411 Spirodinium, 597 equi, 596, 597 Spiroglugea, 477 odospora, 477, 478 Spirogonium, 194-195 chlorogonioides, 195 Spirogyra, 90, 290 Spiroloculina, 350 limhata, 349 Spiromonas, 253 augusta, 253, 254 Spironympha, 278 Spirophyra, 568-569 sub parasitica, 568, 569-570 Spirorhynchus, 576 verrucosus, 576, 577 Spirostomidae, 573, 578-581 Spirostomum, 22, 51, 75, 92, 97, 98, 99 113 114 118 578 amhiguurn, 20-21, 22, 92, 578, 579 filuvi, 578, 579 intermedium, 578, 579 loxodes, 578, 579 minus, 20, 578, 579 teres, 20, 578, 579 Spirotricha, 487, 573-613 Spirotrichonympha, 278 bispira, 137 leidyi, 278, 279 polygyra, 129, 134, 278 pulchella, 278, 279 Spirotrichonymphella, 278 pudibunda, 278 Spirotrichosoma, 278-279 capitata, 279 Spirozona, 534 caudata, 533, 534 Spirozonidae, 531, 534 Spleen index, 25 Splitting of chromosomes in Proto- zoa, 131-132 Spondylomorum, 199 quaternarium, 199, 200 Sponge, 627 Spongilla fluviatilis, 627 Spongomonas, 141, 253 uvella, 253, 25/+ Sporadin, 379, 380 Sporangium, 297 Spore, 143, 298, 381, 416, 450, 453, 472 acnidosporidian, 447, 450 actinomyxidian, 468, 470 haplosporidian, 450 microsporidian, 472, 476 mycetozoan, 298 myxosporidian, 156, 453, 455, 467 telesporidian, 381, 416 Spore-membrane, 454, 472 Sporoblast, 416 Sporocytes, 458 Sporogony, 377, 455 Sporokinete, 433, 442 Sporont, 377, 442, 454, 473 monosporoblastic, 454 disporoblastic, 454 Sporophore, 298 Sporoplasm, 156, 453, 454, 472 Sporozoa, 13, 23, 24, 37, 40, 73, 139, 142, 145, 377-480 Sporozoite, 416, 434 Sprats, 424 Stabler, 134, 318 Stalk, 52, 53, 65, 101, 141 Starch, 79, 90, 92, 93, 94 Stasziecella, 220 Statocyst, 77, 78, 109 StatoHths, 77, 78 Staurocyclia, 373 phacostaurus, 373 Staurojoenina, 284 assimilis, 134, 283, 284 Staurojoeninidae, 277, 284 Staurophrya, 631 elegans, 631 Siegom,yia scutellaris, 549 Stein, 11, 12, 183, 486, 530, 613 Steinecke, 79 Steinella, 65, 492-493 uncinata, 493 Steinia, 603 Steinina, 404 rotunda, 402, 404 Stemonitidae, 299 Stemonitis, 299 splendens, 300 Stempellia, 475 magna, 472, 473, 475 Stenophagous Protozoa, 21 Stenophora, 393 larvata, 393, 394 robusta, 393, 394 Stenophoridae, 391, 393 Stenostomum leucops, 490 Stentor, 10, 31, 40, 47, 51, 65, 75, 114, 118, 162, 581, 633 amethystinus, 24, 582, 583 coeruleus, 37, 52, 112, 114, 135, 581 igneus, 582, 583 mulleri, 582, 583 multiformis, 583 niger, 583 polymorphus, 582, 583 pyriformis, 583 684 PROTOZOOLOGY roeseli, 582, 583 strialus, 583 Stentoridae, 573, 581-584 Stentorin, 37 Stephanonympha, 274 nelumbiu7n, 275 Stephanoon, 141, 199 askenasii, 199, 200 Stephanopogon, 507 colpoda, 507 Stephanosphaera, 200 pluvialis, 145, 146, 200 Stephoidae, 374 Stern, 22, 125, 131 Stevens, 566, 586 Stichotricha, 606 secunda, 606, 607 Sticklebacks, 475 Stictospora, 406 provincinlis, 405, 406 Stigma, 79-80, 109 Stigmatogaster gracilis, 400 Stiies, 321 Stokes, 11, 486, 516, 530, 613, 627 Stokesia, 555 vernalis, 554, 555 Stokesiella, 256 dissimilis, 255, 256 leptostoma, 255, 256 Stole, 90, 91, 114, 117 Stolotermes victor iensis, 279 Stomatophora, 385 coronata, 385, 386 Stomatophoridae, 381, 385-387 Stomatostyle, 543 Streblomastix, 267 strix, 124, 137, 266, 267 Strehlow, 167, 170 Strelkow, 61, 83 Streptomonas, 254 cordata, 254 Stripe band, 535 Strobilidiidae, 587, 589 Strobilidium, 589 gyrans, 588, 589 Strombidinopsis, 589 gyrans, 588, 589 Strombidium, 587 calkinsi, 587 Strongylidium, 606 calif or nicum, 606, 607 Strongylocentrotus franciscanus, 535 droebachiensis, 535, 543 purpuratus, 535, 542 Stylobryon, 141, 256 abbotti, 255, 256 Stylocephalidae, 392, 401 Stylocephalus, 401 giganleus, 401, 402 Stylochona, 614 coronata, 614, 615 Stylochrysalis, 178 parasita, 178 Stylocometes, 632 digitatus, 632 Stylocystis, 404 praecox, 402, 404 Stylonychia, 9, 19, 20, 35, 47, 49, 609-610 mytilus, 610 notophora, 610, 611 pustulata, 22, 90, 99, 122, 135, 150, 610 putrina, 610, 611 Stylopyxis, 181 mucicola, 180, 181 Styloscolex, 494, 495 Succinia, 428 putris, 561 Suctoria, 11, 20, 23, 32, 35, 50, 51, 78, 86, 131, 139, 148, 628-641 Suctorial tentacle, 50 Sulcoarcus, 515-516 pellucidulus, 515, 516 Sulcus, 216 Summers, 121. 124, 160, 161, 488, 610, 613 Supportive organellae, 59-65, 67, 543 Surface tension and amoeboid movement, 101-103 Surra, 247 Sutherland, 276, 287 Sutural plane, 454 Suture on ciliates, 58, 60 Swarczewsky, 452, 614 S warmers, 145, 146, 845 Swezey, 599 Swezy, 37, 46, 66, 82 Sycia, 392 inspinata, 392, 394 Syllis gracilis, 451 Symbiont, 23-24, 92, 185, 274 Symbiosis, 23-24, 92, 185, 274, 277 Symmetry, 31 bilateral, 31 radial, 31 universal, 31 Sympetrum rubicunduluyn, 403 Synactinomyxon, 471 lubificis, 470, 471 Synapta, 389 Synchaeta, 451 Syncrypta, 177 volvox, 177, 178 Syncryptidae, 174, 177-178 AUTHOR AND SUBJECT INDEX 685 Syncystis, 412 niirahilis, 412, 413 Syndinium, 228 iurho, 133, 226, 228 Synophrya, 570 hypertrophica, 569, 570 Synura, 46, 95, 177 adamsi, 178 uvella, 177, 178 Systenus, 400, 412 Systole, 73, 75, 76 Syzygy, 380 Tabanid flies, 247 Tachyblaston, 638 epheloiensis, 637, 638 Tachysoma, 604 parvistyla, 604 Tactile organellae, 47 Taeniocj'stis, 406 mira, -'^05, 406 Talbott, 599 Taliaferro, 30, 170 Talorchestia longicornis, 527, 528 Tanabe, 134 Tanypus, 404 Tarentola, 257 Taylor, 47, 55, 56, 83, 99, 109, 611 Teal, 442 Teal duck, 442 Tectin, 38 Teichmann, 27, 452 Teleuscolex, 494, 495 Tellina, 420, 565 balthica, 562 Telomyxa, 478 glugeiformis, 478 Telomyxidae, 478 Telosporidia, 377-445 Telotrochs, 616, 621 Temperature and Protozoa, 16-18, 113, 162 ten Kate, 53, 55, 59, 83 Tenebrio violilor, 410 Tentacles of Protozoa, 50, 51, 86, 628 Tentaculifera, 521, 628 Teredo, 565 navalis, 565 Termite Protozoa, 6, 262, 265, 266, 267, 268, 269, 270, 272, 274, 275, 276, 278, 279, 280, 281, 282, 284, 285, 286, 287, 314, 392, 395, 476 Terrapene Carolina, 317 Test, 38, 344 Testacea, 18, 21, 38, 39, 41, 73, 85, 92, 111, 139, 289, 323-342 Testudo argentina, 317 calcarala, 317 graeca, 317 Tetractinomyxidae, 469 Tetractinomyxon, 469 intermedium, 469, 470 Tetrablepharis, 195 multifilis, 195 Tetramastix, 194 Tetramitidae, 260, 263-264 Tetramitus, 263 pyriformis, 263 ro^tratus, 17, 50, 362, 263 salinus, 263-264 Tetramvxa, 303 Tetrataxis, 349 palaeotrochus, 349 Tetratonympha, 287 mirabilis, 283, 287 Tetratonymphidae, 277, 287 Tetratoxum, 597 escavatum, 597 parvuni, 597 unifasciculatum, 596, 597 Teuthophrys, 499 trisula, 499, 500 Texas fever, 13, 442 Textularia, 348 agglutinans, 349 Textulariidae, 348 Thalassema neptuni, 401 Thalassicolla, 372 nucleata, 134, 372 Thalassicollidae, 372 Thalassophysa, 372 Thalassophysidae, 372 Thalassothamnidae, 372 Thalassothamnus, 372 Thaumatomastix, 214 setifera, 214 Thaumatophyra, 640 trold, 639, 640 Thecacineta, 636 cothurnioides, 636, 637 gracilis, 636, 637 Thecamoeba, 323 Thecoplasm, 52, 53 Theileria, 444 parva, 444 Thelohanellus, 468 notatus, 26, 124, 467, 468 Thelohania, 475 legeri, 6, lU, 155, 475, 476 multispora, 472 opacita, 6, 472, 475, 476 Theobaldia annulata, 27, 439 melaneura, 439 Thermal waters and Protozoa, 17, 162 Thermobia domestica, 398 686 PROTOZOOLOGY Thigmophyra, 561 macomae, 561-562 Thigmophryidae, 560, 561-562 Thigmotricha, 23, 487, 560-566 Thomson, 259 Thoracophrya, 508 Thorakomonas, 191 sabulosa, 190, 191 Thuricola, 623 folUculata, 20, 624 Thuricolopsis, 624 kellicottiana, 624 Thylacidium, 574 truncatum, 574, 575 Thylacomonas, 243 compressa, 243 Tiarella, 565 Tiarina, 503 fuscus, 502, 503 Ticks, 247, 250, 442, 444 Tillina, 75, 540 campijlum, 550 helia, 549 magna, 19, 540, 541 Tinea tinea, 463 Tintinnidiidae, 40, 227, 587, 589 Tintinnidium, 589 fluvialile, 588, 589 semiciliatum, 588, 589 Tintinnopsis, 55, 589 eylindrata, 588, 589 illinoisensis, 588, 589 Tipula, 238, 265, 318 Toads, 268, 461, 464, 484, 486 Tokophrya, 636 cyclopum, 139-140, 635, 636 infusionum, 635, 636 Tomite, 567 Tomont. 567 Tonniges, 63, 83 Tontonia, 588 gracillima, 588 Torpedo, 464 Torquenympha, 282 octoplus, 281, 282 Toxicyst, 63 Toxin, 27, 64, 65, 86, 447 Toxoglugea, 478 vibrio, 478 Tracheliidae, 517, 519-521 Trachelius, 519 ovum, 519, 520 Trachelocerca, 51, 511-512 phoenicopterus, 512 subviridis, 512-513 Trachelomonas, 45, 46, 80, 207 hispida, 80, 207, 208 piscatoris, 207, 208 vermiculosa, 208 verrueosa, 208 urceolata, 207, 208 Trachelophyllum, 511 clavatuni, 510, 511 Tractella, 46 Tramea laeerala, 403 Transverse fiVjrils, 59 fiagellum, 216-217 Traumatiophtora, 572 punctata, 572 Treillard, 27 Tremalith, 181 Trentonia, 214 flagellata, 214 Trepomonas, 273-274 agilis, 19, 46, 273, 274 rotans, 46, 273, 274 Triactinomyxidae, 469-471 Triactinomyxon, 469 dubium, 469 ignotuni, 469, 470 legeri, 469 magnum, 469 mrazeki, 469 Triadinium, 597 caudatum, 596, 597 galea, 597 minimum, 596, 597 Triatoma dimidiata, 414 megista, 245 protracta, 245 Tricercomitus, 270 termopsidis, 270, 271 Tricercomonas, 264 intestinalis, 263, 264 Trichia, 302 affinis, 301 Trichiidae, 302 Trichites, 62-63 Trichlorididae, 188, 193 Trichloris, 193 paradoxa, 192, 193 Trichocera annulata, 318 hiemalis, 318 Trichocysts, 10, 59, 62, 63-64, 185, 214, 225, 570 Trichodina, 135, 625 pedieulus, 625-626 urinicola, 626 sp. Diller, 626 Trichoduboscqia, 476 epeori, 476 Trichomastix, 265 Trichomonadidae, 260, 269-272 Trichomonas, 12, 46, 61, 62, 269 augusta, 134, 270 batrachorum., 134, 270 buccalis, 270 elongata, 134, 270, 271 homonis, 269, 271 linearis, 270, 271 AUTHOR AND SUBJECT INDEX 687 iermitis, 270, 271 termopsidis, 61 vaginalis, 270, 271 Trichonympha, 285-286 agilis, 134, 285, 286 campanula, 126, 127, 285, 286 grandis, 134, 286 Trichonymphidae, 277, 284-286 Trichopelma, 532 sphagnefrum, 532, 533 Trichopelmidae, 531, 532-534 Trichophrya, 629 columbiae, 629, 630 epistylidis, 629, 630 salparum, 629, 630 sinuosa, 629 Trichorhynchus, 400, 532 pulcher, 399, 400 Trichospira, 634 inversa, 533, 534 Trichospiridae, 531, 534 Trichostomata, 487, 531-546 Trichotaxis, 609 stagnatilis, 608, 609 Trigonomonas, 274 compressa, 273, 274 Triloculina, 350 trigonuln, 349 Trimastigamoeba, 306 philippinensis, 305, 306 Trimastigidae, 260-262 Trimastix, 261 marina, 261 Trimyema, 534 compressum, 20, 533, 534 Trimyemidae, 531, 534 Trinema, 340-341 enchelys, 22, 341, 3^2 Tripalmaria, 597 dogieli, 597, 598 Triplagia, 374 primordialis, 374 Tripneustes esculentus, 543, 559 Tripylea, 370, 374-376 Triton, 268, 618 taeniatus, 267 Tritrichomonas, 270 brevicollis, 270, 271 fecalis, 28, 270 foetus, 270 Triturus viridescens, 248, 626 Trochammina, 349 inflata, 349 Trochamminidae, 349 Trochilia, 525 palustris, 524, 525 Trochilioides, 525 recta, 20, 524, 525 Trochocochlea articulata, 408 mutabilis, 407, 408 turbinata, 408 Trochodinium, 225 prisjnaticum, 224, 225 Trodinium, 225 robustum, 224, 225 Troglodytella, 55, 599 abrassarti, 598, 599 var. acuminata, 599 gorillae, 599 Troisi, 414 Trophochromatin, 35 Trophocyte, 227 Trophonia plumosa, 419-420 Trophont, 567 Trophozoite, 142 Tropidoscyphus, 213 octocostatus, 210, 213 Trout, 272 Trypanodinium, 227 ovicola, 226, 227 Trypanoplasma, 252 Trypanosoma, 7, 12, 14, 46, 95, 113, 244-245 americanum,, 247 brucei, 13, 46, 245 cruH, 25, 139, 245 danilewskyi, 249 diemyctyli, 248, ^45 duttoni, 248 equinum, 247 equiperdum, 247 evansi, 247 gaynbiense, 14, 24, 25, 245 giganteum, 249 granulosum, 249 inopinatum, 248, ^4^ Zeii'm, 13, 98, 139, ^4^, 247-248 melophagium, 247 nabiasi, 248 noctuae, 248 paddae, 248 percae, 249 peromysci, 248 rajae, 249 remaki, 249 rotatorium, 46, 248, ^4P theileri, 247 Trypanosomatidae, 93, 239, 24^ 252 Trypanosomiasis, 245 Truttafario, 272 Tschenzoff, 131 Tsetse flies, 245 Tubiflex, 389, 477 inilatus, 493 tubifex, 469, 471 Tubulina, 301 fragiformis, 301 688 PKOTOZUOLOGY Tubulinidae, 300 Tunicata, 227, 410, 629 Turbellaria, 555 Turdus migratorius migratorius, 438 Turkey, 238, 424 Turner, 56, 58, 83, 120, 135, 161, 611 Turtles, 248, 317, 318, 431 Tuscarora, 376 murrayi, 376 Tuscaroridae, 375 Tussetia, 193 Twist disease, 459, 466 Tyzzer, 238, 316, 422, 423, 433 U Uca pugilalor, 393 pugnax, 393 Ulivina, 392 _ rhynchoboli, 393 Ultraviolet rays on Protozoa, 112- 113 Undulating membrane of Ciliata, 48, 49, 50 Mastigophora, 46 Unicapsula, 461-462 musciilaris, 156, 459, 462 Unicapsulidae, 461-462 Unicellular organisms, 3 Uniparental inheritance, 165 Uradiophora, 395 cuenoti, 396 Urceolaria, 625 77iitra, 625, 626 paradoxa, 625, 626 Urceolus, 46, 211 cyclostomus, 45, 210, 211 sabulosus, 210, 211 Urea, 98, 99 Urechis caupo, 392 Uribe, 134 Uric acid, 99 Urinympha, 284 talea, 134, 283, 284 Urnula, 633 epistylidis, 633, 634 Urocentrum, 553 turbo, 124, 553, 554 Urodeles, 483, 618 Uroglena, 46, 141, 179 volvox, 179, 180 Ureglenopsis, 95, 141, 179 americana, 179, 180 europaea, 179 Uroleptopsis, 606 citrina, 606, 607 Uroleptus, 73, 606 dispar, 606, 607 halseyi, 123. 135, 159, 606, 610 limnetis, 606, 607 longicaudatus, 606, 607 mobilis, 150, 157, 163 Uronema, 553-554 marina, 20, 554 pluricaudatuni, 554r-555 Uronychia, 613 setigera, 612, 613 Urophagus, 274 rostratus, 46, 273, 274 Urosoma, 604 caudata, 604, 605 Urospora, 389 chiridotae, 388, 389 Urosporidae, 381, 389-390 Urosporidium, 451 fuliginosum, 450, 451 Urostyla, 35, 606 caudata, 607, 608 grandis, 108, 607 trichogaster, 607 Urotricha, 506 agilis, 506, 507 far cat a, 506, 507 labiata, 506 parvula, 506 Urozona, 553 butschlii, 553, 554 Utricaceae, 250 Uyemura, 17, 162 Vacuolaria, 214 virescens, 133, 214 Vaginicola, 623 annulata, 623, 624 leptostoma, 623, 624 Vaginicolidae, 623-625 Vahlkampfia, 28, 310 Umax, 4:1, 310, 311 patuxent, 310-311 Valentin, 12 Valvulina, 348 triangularis, 349 Valvulinidae, 348 Vampvrella, 90, 291 lateritia, 291-292 Vampyrellidae, 289, 290-294 Vampyrophyra, 571 pelagica, 571, 572 Variation in Protozoa, 5, 162-169, 180, 181 Vasicola, 499 ciliata, 499, 500 Vaucheria, 290 Vegetative form or stage, 142 Ventral cirri, 48, 49, 56 Ventral motor strand, 55 Venus fasciata, 565 Verneuilina, 348 propinqua, 349 AUTHOR AND SUBJECT INDEX 689 Verneuilinidae, 348 Veronica, 303 Vertebralina, 350 striata, 349 Verworn, 31, 43, S3, 85, 106, 112, 113, 114, 117 Vesicular nucleus, 32-34 Viper a as pis, 426 Visscher, 55, 63, 83 Vitrina, 428 Xiviparus j a ponicus, 491 malleatus, 491 Vlk, 44, 83 Volk, 433 Volutin, 36, 95-96 Volvocidae, 38, 188, 197-201, 290 Volvox, 10, 31, 95, 113, 141, 290 aureus, 147, 197, 198 globator, 197, 198 perglobator, 197 spermatosphaera, 197 tertius, 199 Vorticella, 9, 10, 19, 51, 70, 90, 94, 621 campanula, 621, 622 convallaria, 621, 622 microstoma, 621, 622 monilata, 38, 621, 622 nebulifera, 152 picia, 621, 622 Vorticellidae, 616, 621-623 W Wagnerella, 364 borealis, 363, 364 Wailes, 231, 233, 234, 343, 366, 641 Wardia, 461 ovinocua, 461, 463 Wardiidae, 459, 461 Watson, 414 Weatherby, 99 Weismann, 11, 154 Weissenberg, 265, 452 Wenrich, 215, 503, 516, 530, 546, 559 Wenyon, 30, 259, 276, 322, 380, 414, 433, 445 Wenyonella, 425 africa7ia, 423, 425 Wermel, 22, 36, 94. 321 West, 183, 187, 202, 215 Whip-flagellum, 44r-46 Whipple, 95, 117 Wichterman, 150, 161, 581 Wolf son, 18, 30 Woodcock, 68 Woodroach, 6, 24, 91, 269, 280, 282, 283, 284, 286 Woodruff, 10, 15, 62, 83, 150, 153, 156, 161, 496 Woodruffia, 541 metabolica, 541 rostrata, 541 Wormy halibut, 459, 462 X Xanthophyll, 79 Xenotis megalotis, 464 Yarborough, 14 Yocom, 20, 30, 55, 56, 83, 135, 611 Zelleriella, 6, 32, 486 antilliensis, 135, 486 hirsuta, 486 intermedia, 131, 133, 135, 486 scaphiopodos, 484, 486 Zonomyxa, 332 violacea, 332, 333 Zooamylum, 94, 380, 384 Zoochlorellae, 24, 548, 557, 583, 584, 588 Zoomastigina, 19, 74. 93, 173, 235- 287 Zoopurpurin, 37 Zoospores, t66, 167 Zootermopsis angusticollis, 266, 267, 270, 286, 392, 395 laticeps, 270, 286 nevadensis, 266, 270, 286, 392. 395 Zoothamnium, 31, 53, 517, 623 adamsi, 622, 623 arbuscula, 622, 623 Zootrophic nutrition, 84-92 Zooxanthellae, 23, 185, 368, 537 Zopf, 295 Zostera marina, 290 Zschokkella, 465 hildae, 465, 466 Zuelzer, 36, 99, 113, 117 Zuluta, 53 Zumstein, 93, 117 Zweibaum, 73 Zygocystidae, 381, 384-385 Zygocystis, 384 wenrichi, 384, 386 Zygosoma, 392 globosum, 134. 159, 392, 394 Zygote, 72, 145, 146, 158, 167 Zyrphaea crispata, 566 THIS BOOK PROTOZOOLOGY Second Edition Bj/ Richard R. Kudo, D.Sc. was set, printed and hound by The Collegiate Press of Menasha, Wisconsin. The typeface is Monotype 8 A, set 10 point on 12 point. The type page is 24 x 42 picas. The text paper is 50-lh. Lexington English Finish. The binding is DuPont PX30, Color 6010 Linen, Embossed satin 1 . The jacket is True-Colour, Light Blue, Wove, Antique. With THOMAS BOOKS careful attention is given to all details of manufacturing and design. It is the publisher's desire to present books that are satisfactory as to their physical qualities and artistic possibilities and appropriate for their particular use. THOMAS BOOKS will be true to those laws of quality that assure a good name and good will.