Marine Biological Laboratory Library Woods Hole, Mass. I I I I ^^'^*'■^* Presented by Mrs* Harry La Ulanan Jiine 18, 1964 I I I I I I I I E3 3a^B^^^^^^^^^^^SE HANDBOOK OF PROTOZOOLOGY C 2- HANDBOOK OF PROTOZOOLOGY BY Richard Roksabro Kudo, D.Sc. Assistant Professor of Zoology University of Illinois With one hundred and seventy-five illustrations CHARLES C THOMAS • PUBLISHER SPRINGFIELD, ILLINOIS BALTIMORE, MARYLAND 193 I COPYRIGHT 1 93 1 BY CHARLES C THOMAS MANUFACTURED IN THE UNITED STATES The revelatioJis of the microscope are perhaps not ex- celled in itnportance by those of the telescope. While exciting our curiosity^ our wonder and ad?nira- tion^ they have proved of infinite service in advancing our knowledge of things around us.'' Leidy. PREFACE STUDY of Protozoa was formerly considered as belonging ex- clusively to the domain of graduate students in zoology, but as a result of the tremendous advance in our knowledge of protozoan parasites of man and domestic animals in the last fifteen years, a number of universities and colleges have begun to offer courses dealing with both free-living and parasitic Protozoa to advanced students. For some years the author has taught such a course at the University of Illinois. The classes are composed chiefly of advanced students who have had at least one year of zoology and are majoring in zoology, botany, bacteriology, entomology or premedical curriculum. Although some admirable works on {^rotozoology have appeared in recent years, no one of them would afford adequate guidance through- out a course of this kind. Most modern publications on the subject emphasize the parasitic forms and do not give much space to the taxonomy, biology, and orientation of the free-living forms from which the parasitic group undoubtedly evolved. The aim of the present work is, therefore, to provide a handbook of introductory information on the common and representative genera of all the groups of both free-living and parasitic Protozoa. The author claims little originality in the material employed, for it is mainly compiled from data already known. The text is divided into two parts: The first part consists of three chapters giving a general account of the morphology, physiology and reproduction of Protozoa. The treatment here is brief, since there are several excellent treatises on this part of protozoology, such as Calkins' The Biology of the Protozoa. Furthermore, the student has neither time nor need for ex- tended discussion at the beginning of the course. The second part, which is composed of thirty chapters, is concerned with the taxonomy, biology and development of common Protozoa. Differentiation of classes, orders and families is carried on by keys. In some genera which are of common occurrence, such as Amoeba, Entamoeba, Arcella, Euglena, Paramecium, Chilo- don, Vorticella, etc., several species are mentioned. For the convenience of those who wish to study more of the details and particular features of certain forms, there is ap- pended to each chapter a list of important references which will serve as guides to a more comprehensive literature on the subject. Since comprehensive monographs on different groups of Protozoa are widely scattered and often unavailable to the average worker, the author has attempted to gather here as much material from them as could be put together within limited space. This handbook is, therefore, believed to be suit- able for practical use by biology teachers in colleges and uni- versities, field workers in pure and applied biological sciences, veterinarians, physicians, public health workers, and others. To facilitate the use of this handbook, a comparatively large number of illustrations are inserted; for students can comprehend the form, appearance and structure of a micro- scopic organism more thoroughly and satisfactorily by looking at its picture than by reading a lengthy description. All the illustrations have been especially prepared for this work. The majority have been redrawn from illustrations found in earlier works, and in all such cases the indebtedness of the author is indicated by references to the sources. The original illustra- tions are accompanied by scales of magnification only. In order to make the illustrations as useful as possible for practical pur- poses, the magnification in most cases is not more than five hundred times natural size, this being the maximum afforded by microscopes ordinarily used by students. Higher magnifica- tions are used to show very small forms and to bring out some minute protoplasmic structures. The author is indebted to numerous colleagues and investi- gators for their observations which have been included in the present work. Special thanks are due to Mr. H. C. Oesterling, Editor of the Illinois State Natural History Survey, for assis- tance in the revision of the manuscript and the correction of the proof sheets. January, 1931. R. R. K. CONTENTS Preface vii Chapter I Introduction 3 Relationship of Protozoology to Other Bi- ological Sciences 8 The History of Protozoology 13 II Morphology and Physiology of Protozoa. . . 20 The Nucleus 20 The Cytoplasm . 23 III Reproduction in Protozoa 41 Asexual Reproduction 41 Sexual Reproduction 51 IV Outline of the Classification 60 V Subphylum 1 Plasmodroma 82 Class 1 Mastigophora 82 Subclass 1 Phytomastigina 84 Order 1 Chrysomonadida 84 VI Order 2 Cryptomonadida 92 VII Order 3 Dinoflagellida 96 VIII Order 4 Phytomonadida 107 IX Order 5 Euglenoidida 116 Order 6 Chloromonadida 127 X Subclass 2 Zoomastigina 129 Order 1 Pantostomatida 129 XI Order 2 Protomonadida 133 XII Order 3 Polymastigida 155 XIII Order 4 Hypermastigida 167 XIV Class 2 Sarcodina 176 Subclass 1 Rhizopoda 177 Order 1 Proteomyxa 177 J73 ^/ XV Order 2 Mycetozoa 183 XVI Order 3 Foraminifera 192 XVII Order 4 Amoebaea 204 • XVIII Order 5 Testacea 225 XIX Subclass 2 Actinopoda 245 Order 1 Heliozoa 245 XX Order 2 Radiolaria 254 XXI Class 3 Sporozoa 265 Subclass 1 Telosporidia 266 Order 1 Coccidia 267 XXII Order 2 Haemosporidia 284 XXIII Order 3 Gregarinida 291 XXIV Subclass 2 Cnidosporidia 302 Order 1 Myxosporidia 303 Order 2 Actinomyxidia 313 XXV Order 3 Microsporidia 317 Order 4 Helicosporidia .' . 324 XXVI Subclass 3 Acnidosporidia 326 Order 1 Sarcosporidia 326 Order 2 Haplosporidia 328 XXVII Subphylum 2 Ciliophora 333 Class 1 Ciliata 333 Subclass 1 Protociliata 335 XXVIII Subclass 2 Euciliata 339 Order 1 Holotrichida 339 XXIX Order 2 Heterotrichida 371 XXX Order 3 Oligotrichida 381 XXXI Order 4 Hypotrichida 385 XXXII Order 5 Peritrlchlda 392 XXXIII Class 2 Suctoria 399 Appendix Collection, Cultivation, and Observation of Protozoa 411 Index 421 HANDBOOK OF PROTOZOOLOGY CHAPTER I INTRODUCTION PROTOZOA are considered as single-celled organisms; that is to say, the body of a protozoan, no matter how small or large it may be, is morphologically a single cell. Yet Protozoa possess all the characteristics common to living things. The various functions which make up the phenomenon known as life are performed by differentiated parts within the body. These parts, being comparable to the organs of a metazoan which are composed of a large number of cells grouped into tissues, are called organelles, or cell-organs. Thus one sees the one-celled protozoan is a complete organism somewhat unlike the cells making up a metazoan, each of which is dependent on other cells and cannot live independently. From this view- point, certain students maintain that the Protozoa are non- cellular, and not unicellular, organisms. Through the process of organic evolution, the Protozoa have undergone cytological differentiation and the Metazoa histological differentiation. It is beyond the scope of the present work to discuss these view- points in detail. It may, however, be added here that certain cells which compose the body of a metazoan, as for example the leucocyte, spermatozoon, etc., behave as if they were inde- pendent organisms. In being unicellular, the Protozoa and the Protophyta are alike. The majority of the former are quite clearly distinguish- able from the majority of the latter on the basis of nuclear condition, method of division, nutrition, etc. While the major- ity of the Protophyta appear to possess scattered nuclear ma- terial or none at all, the Protozoa contain at least one nucleus. It is generally considered that the binary fission of the Protozoa and the Protophyta is longitudinal and transverse, respectively. A great majority of Ciliata, however, multiply by transverse division. In general the nutrition of Protozoa is holozoic and of Protophyta holophytic. But there are large numbers of Pro- [3] 4 HANDBOOK OF PROTOZOOLOGY tozoa which nourish themselves by holophytic and saprozoic methods. Thus no absolute and clean-cut separation is possible between them. Haeckel, therefore, proposed the term Pro- tistan kingdom 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 plant kingdom. 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 the 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 known as colonial Protozoa, are well represented by the members of Volvocidae, in which the individuals are either joined by cytoplasmic threads or embedded in a common matrix. The majority of these cells are alike both in structure and in function, although in several genera there may be differ- entiation of the individuals into reproductive and \egetative cells. Unlike the cells in a metazoan which form tissues, these vegetative cells of colonial Protozoa, however, are not de- pendent upon other cells; hence they do not form any tissue. The reproductive cells produce zygotes through fusion which subsequently undergo repeated division processes and may pro- duce a stage comparable to the blastula stage of a metazoan, but never reaching the gastrula stage. Thus colonial Protozoa are only cell-aggregates without histological differentiation and may thus be distinguished from the Metazoa. With regard to their habitat, the Protozoa may be divided into free-living forms and those living on or in other organisrns. The vegetative, or trophic, stages of free-living Protozoa have been found in every type of fresh and salt water, in soil and in decaying vegetable matter. While the freshwater inhabiting forms are ordinarily unable to live in salt water, and vice versa, seemingly one and the same species has, in a number of cases, been found in both fresh and salt waters. The factors which influence their presence in a given body of water are temperature, chemical composition, kind and amount of food, etc. Excessive cold seems to be less detrimental INTRODUCTION 5 than excessive heat. In the polar regions or at extremely high altitudes, certain Protozoa occur at times in fairly large num- bers. Although the majority are incapable of living in water containing large quantities of chemical substances, some forms such as the members of Epalcidae are said to live in water rich in sulphurous substances produced by decaying and decompos- ing organic matter. Acid or alkaline contents of the water influence also the distribution of Protozoa in various ways. Numerous species of Protozoa are cosmopolitan in their occurrence, partly because of their early appearance as living organisms. Amoeba proteus, Paramecium caiidatum, etc., have been observed in fresh waters nearly everywhere in the world. The wide distribution of Protozoa is in part to be attributed also to their ability to encyst. With a small number of exceptions, the vast majority of free-living protozoans become more or less rounded and inactive, and differentiate or secrete a resistant envelope around themselves to withstand temporary unfavor- able conditions. The factors involved seem to be low or high temperature, lack of food material, evaporation and chemical changes of the water in which they live. In some cases, the organism encysts temporarily in order to undergo nuclear re- organization and multiplication. Because of this change and also of the failure of causing certain protozoans to encyst under experimental conditions, it is supposed that some internal fac- tors may play as great a part as the environmental conditions in the phenomenon of encystment. Ordinarily a single cyst wall seems to be sufficient to pro- tect the protoplasm against unfavorable external conditions. In some cases, however, there may be a double cyst wall, the inner one usually being more delicate. The cyst wall, as a rule, is composed of homogeneous substance, but it may con- tain calcareous scales, as in Euglypha (Fig. \). While chitin is the usual material of which the cyst wall is composed, cellulose makes up the cyst envelope of numerous Phytomastigina. 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 to 12 centimeters (Sandon). It is said that a very few occur in the subsoil. Here also one notices a very wide geographical dis- 6 HANDBOOK OF PROTOZOOLOGY tribution of apparently one and the same species. For example, Sandon found Amoeba proteiis in samples of soil collected from Greenland, Tristan da Cunha, Gough Island, England, Mauri- tas, Africa, Argentina, and India. This amoeba is known to oc- cur in various parts of Europe, North America, Japan, and Aus- tralia. Most of the Testacea live in moist soil in abundance. Sandon in his survey referred to above found Trinema enchelys (p. 242) in the soils of Spitzbergen, Greenland, England, Japan, Australia, St. Helena, Barbadoes, Mauritus, Africa, and Argen- tina. Fig. 1 Encystment of Euglypha acanthophora. X320 (After Kiihn). Of the Protozoa living in close association with other animals, symbionts, commensals and parasites will here be considered. Certain Protozoa live within the bodies of other animals in a kind of association that is apparently of mutual benefit. They are called symbionts. The relation between ter- mites and some Hypermastigida which inhabit the formers' intestine is a typical example of symbiosis. According to Cleveland, these flagellates digest the cellulose substances which are eaten by termites and transform them into glycogen- ous substances which are used as food by the insects. If de- prived of these flagellates by being subjected to oxygen under pressure, the insects die, and if the wood diet of the termites is stopped, the flagellates die. In this connection, it may be mentioned that no one of the enormous number of species of the Hypermastigida has ever been found in encysted condition. It is presumed that the young termites become the hosts to the flagellates when ' they feed upon freshly voided fecal matter of the older ones already containing the flagellates. INTROD UCTION Commensalism is an association in which one partner, the commensal, is benefited, while the other, the host, is neither injured nor benefited. A number of Protozoa live attached to other Protozoa or other animals. For example, numerous species of Suctoria are attached to the integument of active aquatic animals. Parasitism is a somewhat different type of association. Here a protozoan lives at the expense of another organism. The former is the parasite and the latter the host. The injury to the host varies greatly according to circumstances. Parasitic Protozoa are found to occur in almost every phylum of the animal kingdom, including phylum Protozoa itself. A few forms are parasitic in plants. Some of the Suctoria are parasitic in various Ciliophora. Microsporidia parasitize Myxosporidia and Gregarinida, although they are ordinarily parasites of the Metazoa. / -- Fig. 2 Encystment of Lophomonas hlattarum as seen in stained preparations. XI 150 (After Kudo). A precise distinction between the commensal and the para- site is impossible, since in many cases there is no way to determine the exact effect of the presence of the organism con- cerned upon the host body. In its broad sense, the term para- sitic Protozoa includes the commensals also. The Protozoa inhabiting the digestive tract of the host encyst under certain circumstances (Fig. 2). The cysts are voided in the fecal matter and become the source of new infection. In other gut-inhabiting 8 HANDBOOK OF PROTOZOOLOGY parasites such as Gregarinida, Coccidia, etc., encystment is followed by the production of numerous spores which become the sources of infection when excreted. In the Protozoa which inhabit organs other than those of the digestive tract, the re- sistant spores may or may not be produced. Plasmodium vivax, one of the three species of malarial parasites of man, lives in the circulatory system and is transmitted from man to man by anopheline mosquitoes only. Therefore, it does not produce spores. Cnidosporidia, which are cell or tissue parasites, produce typical resistant spores, which become set free usually through wounds or disintegration of the host body after death and which serve for infection of new host animals. The cysts of both free-living and parasitic Protozoa are carried from place to place by the wind, very often attached to soil particles, decayed leaves, twigs, etc., or by insects, birds, and other animals. When the cysts encounter a proper environment in the water or in a specific host animal, the con- tents germinate and the organisms once more assume their active and trophic phase. Relationship of Protozoology to Other Biological Sciences A brief consideration of the relationship of protozoology to other branches 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 discovering the nature and mechanism of various phenomena, the sum-total of which is known collectively as vitality. Though the investigators generally have been dis- appointed in the results, inasmuch as the assumed simplicity of unicellular organisms has proved to be offset by the com- plexity of their cell-structure, nevertheless any discussion of biological principles today must take into account the informa- tion obtained from studies of Protozoa. It is now commonly recognized that adequate information on various types of Pro- tozoa is prerequisite to a thorough comprehension of biology and a proper application of biological principles. Practically all students agree in holding that the higher types of animals have been derived from organisms which INTRODUCTION 9 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 Protozoa 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 varia- tion among Protozoa. Dimensional variation is encountered commonly in various species, as has been shown by Jennings, Jollos, Dobell, Hegner, and others. Whether the variation is due to germinal or to environmental conditions cannot easily be determined. The interesting case of the double form of Uroleptus mohilis observed by Calkins apparently involved germinal changes, since this form divided true for 367 genera- tions through a period of 405 days. On the other hand, the environmental changes or acquired characteristics are not in- herited. Changes due to differences in temperature or composi- tion of the medium last through numerous generations as long as the differences are maintained, but thereafter the original characteristics reappear. Parasitic Protozoa almost always are limited to one or more specific hosts. By studies of the forms belonging to one and the same genus or species, the phylogenetic relation among the host animals maybe established or verified. The mosquitoes belong- ing to the genera Culex and Anopheles, for instance, are known to transmit Plasmodium praecox and human species of Plas- modium, respectively. They are further infected by specific microsporidian parasites. For instance, Thelohania legeri has been found widely in the many species of anopheline mosquitoes only; T. opacita has, on the other hand, been found in culicine mosquitoes, although the larvae of species belonging to these two genera live frequently in the same body of water. By observing some intestinal Protozoa in certain monkeys, Hegner has recently obtained evidence of the probable phylogenetic relationship between them and other higher mammals. Study of a particular group of parasitic Protozoa and their hosts may throw light on the geographic condition of the earth 10 HANDBOOK OF PROTOZOOLOGY in the remote past. The members of the genus Zelleriella are invariably found in the frogs of the family Leptodactylidae. By an extensive study of these amphibians from South America and Australia, Metcalf has 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 convergent 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 Zelleriella 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 ani- mals. 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 protozoan cells. Through the studies of various investigators in the past thirty 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 widely 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 on the morphology, physiology and reproduction of the parasitic forms has largely been obtained by study of the free-living organisms, a general knowledge of the entire phylum is necessary to an understanding of the parasitic forms. Recent studies have further revealed that almost all domes- tic 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 indis- tinguishable from those in man. Balantidium coli is now gen- erally considered as a parasite of swine, and man is its secondary host. Knowledge of protozoan parasites is useful to medical practioners, just as it is essential to veterinarians inasmuch as certain diseases in animals, such as Texas fever, dourine, nagana, cocciodiosis, blackhead, etc., are caused by protozoans. INTRODUCTION 11 Sanitary betterment and improvement are fundamental re- quirements in the modern civilized world. One of man's neces- sities is safe drinking water. The majority of Protozoa live in water and many of them seem to be responsible, if present in sufficiently large numbers, for giving certain colors or odors to the waters of reservoirs or ponds. For example, according to Whipple, the chrysomonad Synura, which produces an oily substance as a result of metabolic activities, was found to be the cause of "cucumber" odor in several water supplies, and Calkins found that the oil droplets which were developed in a large number of individuals of Uroglenopsis americana be- came the cause of an offensive odor of the water in which they lived. Bursaria, Ceratium, Dinobryon, Mallomonas, etc., if present in large numbers, may give a "fishy" odor. But these Protozoa which are occasionally harmful are com- paratively small in number compared with those which are bene- ficial to man. It is generally understood that bacteria feed on various waste materials present in polluted water, but that upon reaching a certain concentration, they would cease multiplying and would allow the excess organic substances to undergo de- composition. Numerous holozoic Protozoa, however, feed upon the bacteria and prevent them from reaching the saturation population. Protozoa thus help indirectly in the purification of the water. Protozoology therefore must be considered as an important part of modern sanitary science. Young fish feed extensively on small aquatic organisms such 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 Pro- tozoa as food material. On the other hand there are numbers of Protozoa which prey upon fish. The Myxosporidia are almost exclusively parasites of fish and often cause death to large numbers of commercially important fish. Success in fish-cul- ture, therefore, requires among other things a good knowledge of Protozoa. Since Russel and Hutchinson suggested some twenty 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 12 HANDBOOK OF PROTOZOOLOGY the soil by the nitrifying bacteria, several investigators have brought out the fact that in the soils of temperate climates Protozoa are present 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 experiments and observations have already been made. All soil investigators should be acquainted with the biology and taxonomy of free-living Protozoa. 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 dam- ages in the middle of the nineteenth century because of the "pebrine" disease caused by the microsporidian, Nosetna bom- hycis. During the first decade of the present century, another microsporidian, Nosema apis, was found to destroy occasionally 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 Microsporidia are now known to infect certain insects, such as mosquitoes and lepidopterous pests, which, when heavily infected, die sooner or later. Methods of artificial destruction of these insects by means of chemicals are more and more used, but attention should be given to ultilization of the parasitic Protozoa and Protophyta for this purpose. While the majority of Protozoa lack permanent skeletal structures and their fossil forms are unknown, there are two large groups in the Sarcodina which possess conspicuous shells and which are found as fossils. They are Foraminifera and Radiolaria. From early Palaeozoic times down to the present day, the carbonate of lime which makes up the skeletons of Foraminifera has been left embedded in various rock-strata. Although there is no distinctive foraminiferan fauna character- istic 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 foraminiferous rocks is highly useful in checking up logs in well drilling. The skeletons of the Radiolaria are the main con- stituent of the ooze of littoral and deep-sea regions. They have INTROD UCTION 13 been found abundantly in silicious 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 the few large forms, Protozoa 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 the lenses himself, Leeuwen- hoek made more than four hundred microscopes, including one which, it is said, had a magnification of 270 times. Among the many things he discovered were various Protozoa. Between 1673 and 1703 he apparently observed Vorticella, Carchesium, Stylonychia, Volvox, Opalina, Nyctotherus, Polystomella, etc. Thus he was the first to see some of the well-known Protozoa. Leeuwenhoek was followed by Buonanni (1691), who ob- served Colpoda; by Harris (1696), who discovered Euglena; and by an anonymous author (1703), who described Euplotes, Vorticella, and Paramecium. In 1718 there appeared a treatise on microscopic organisms by Joblot, in which the author em- phasized the non-existence of abiogenesis by using boiled hay- infusions in which no Infusoria developed without exposure to the atomosphere. This experiment confirmed that of Redi who, twenty years before, had made his well-known experiments by excluding flies from decomposing meat. Trembly (1745) studied division in some Ciliata, including probably Paramecium. Noctiluca was first described by Baker (1753). Rosel (1755) observed an amoeba, possibly Amoeba proteus or an allied form, which he called "die kleine Proteus," and also Vorticella, Stentor, and Volvox. Ledermiiller is said to have coined the term "Infusoria" in 1763 (Butschli). By using the juice of geranium, Ellis (1770) caused the extrusion of the "fins" (trichocysts) in Paramecium. Eichhorn (1783) observed the heliozoan, 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 unavoid- 14 HANDBOOK OF PROTOZOOLOGY ably some Metazoa and Protophyta in his monographs, some of his descriptions and figures of Ciliata were so well done that they are of value 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 coelen- terates. 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 in 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. He excluded Rotatoria and Cercaria from Infusoria. Through the studies of Ehrenberg the number of known Protozoa increased greatly; he, however, proposed the term "Polygastricha," under which he placed Mastigophora, Rhizopoda, 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 incidentally, together with the then-propounded cell theory and improvements in microscopy, stimulated researches on Protozoa. Dujardin (1835) took pains in studying the protoplasm of various Protozoa and found it alike in all. He named it "sar- code." In 1841 he published an extensive monograph of various Protozoa which came under his observations. The term "Rhi- zopoda" was coined by this investigator. The commonly used term "protoplasm" was coined by Purkinje in 1840. The term 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." This definition is still followed today. Siebold subdivided Protozoa into Infusoria and Rhizopoda. The sharp differentiation of Protozoa as a group certainly inspired numerous microscopists. As a result, various students brought forward group names, such as Radiolaria (J. Muller, 1858), Ciliata (Perty, 1852), Flagellata (Cohn, 1853), Suctoria (Cla- parede and Lachmann, 1858, 1859), Heliozoa, Protista (Haec- INTROD UCTION 15 kel, 1862, 1866), Mastigophora (Diesing, 1865). Of Suctoria, Stein failed to see the real nature (1849), but his two mono- graphs on Ciliata and Mastigophora (1854, 1859-1883) contain concise descriptions and excellent illustrations of numerous species, several of which are inserted in the present work. In- deed, we owe to him much of the classification of the Ciliata which is most commonly adopted at present. Haeckel (1873), who went a step further than Siebold and distinguished between Protozoa and Metazoa, devoted ten years to his study of Radiolaria, especially those of the Chal- lenger 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 forward 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 work was followed by Stokes' "The Fresh-water Infusoria of the United States," which appeared in 1888. Butschli (1880) established 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 painstak- ing researches by Maupas, on the conjugation of ciliates, cor- rected erroneous interpretation of the phenomenon observed by Balbiani some thirty years before and gave impetus to a re- newed cytological 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 immortality of the Protozoa. Schaudinn contributed much toward the cytological and developmental studies of Protozoa. In the first year of the present century. Calkins in the United States and Doflein in Germany wrote modern textbooks on pro- tozoology dealing with the biology as well as the taxonomy. Calkins initiated the so-called isolation pedigree culture of ciliates in order to study the physiology of conjugation and other phenomena connected with the life history of the ciliates. The application of this method has been wide. Today the Protozoa are more and more intensively studied from both the biological and the parasitological sides, and im- 16 HANDBOOK OF PROTOZOOLOGY portant contributions appear continuously. Since all parasitic Protozoa must have originated in free-living forms, the com- prehension of the morphology, physiology and development 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 and large 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 micro- scope and in technique. Here again Leeuwenhoek, in 1681, seems to have been the first to observe a parasitic protozoan, for he found Giardia intestinalis in his own diarrhoeic stools. There is no record of anyone having seen Protozoa living in other organisms until 1828, when Dufour's account of the gregarine from the intestine of coleopterous insects appeared. Some ten years later, Hake observed the oocyst of the coccidian, Eimeria stiedae, of rabbits, without realizing its real nature. A flagellate was observed in the blood of salmon by Valentin in 1841, and the frog trypano- some was discovered by Gluge and Gruby (1842), the latter author creating the genus Trypanosoma for it. The gregarines were a little later given attention by Siebold (1839), KolHker (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 coccidian, Klossia helicina, in the excretary organ of Helix. Eimer (1870) made an extensive study of Coccidia occurring in various animals. Balantidinm coli was discovered by Malmsten in 1856. Lewis in 1870 observed Entamoeba coli in India and Losch in 1875 found Entamoeba histolytica in Russia. At the beginning of the nineteenth century, an epidemic disease, pebrine, of the silkworm appeared in Italy and France, and a number of biologists became engaged in its investigation. Foremost of all, Pasteur (1870) made an extensive report on the nature of the causative organism, now known as Nosema bomby- cis, and also on the method of control and prevention. Perhaps INTRODUCTION 17 this is the first scientific study of a parasitic protozoan to result in an effective practical method of control of its infection. Lewis in 1878 saw an organism which is known since as Try- panosoma lewisi in the blood of rats. In 1879 Leuckart created the term "Sporozoa/' including in it the gregarines and coccidia. Other groups of Sporozoa were soon definitely designated. They are Myxosporidia (Biitschli, 1881), Microsporidia (Bal- biani, 1882) and Sarcosporidia (Balbiani, 1882). Parasitic protozoology received a far-reaching stimulus when Lavern (1880) discovered the malarial parasite in the human blood. Smith and Kilborne (1893; demonstrated that the Babesia 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 between an insect 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 following year he showed by experiments that the tsetse fiy transmits the trypanosome from host to host. Studies of mal- arial diseases continued and several important contributions appeared. Golgi (1886, 1889) studied the schizogony and its re- lation 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 Hae- moproteus of birds. Almost at the same time, Schaudinn and Siedlecki (1897) showed that anisogamy results in the produc- tion of zygotes in Coccidia. The latter author then (1898, 1899) published correct observations upon the life-cycle of Coccidia. Ross (1898) showed how Plasmodium praecox was carried by Culex fatigans and described its life-cycle. Since that time sev- eral investigators have brought to light important observations concerning the biology and development of these organisms and their relation to man. In the present century, Forde and Button (1901) observed that the sleeping sickness in Africa is also 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 advancement in bacteriology, and it was natural, as the number of known parasitic Protozoa rapidly increased, that 18 HANDBOOK OF PROTOZOOLOGY attempts to cultivate them in vitro should be made. Musgrave and Clegg (1904) cultivated, on bouillon-agar, small free-living amoebae 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 culti- vated 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 under- went 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 throughout the tropical, subtropical and temperate zones. Tax- onomic and developmental studies on these forms have, there- fore, 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 Yar- borough (1921) cultivated Balantidium coli and Boeck (1921) also cultivated Chilomastix mesnili. Boeck and Drbohlav (1925) succeeded in cultivating Entamoeba histolytica, and their work was repeated and improved upon by several investigators. While the cultivation has not yet thrown any new light on the life-history of the amoeba, it seems to have some value for diagnosing an infection. Since that time, almost all intestinal Protozoa of both vertebrates and invertebrates have been cultivated in vitro. References BuTSCHLi, O. 1887-1889 Protozoa. Bronn's Klassen und Ordnungen des Thier-reichs. Vol. 1, Part 3. Calkins, G. N. 1926 The biology of the Protozoa. Philadel- phia. Cole, F. J. 1926 The history of protozoology. London. DOBELL, C. 1911 The principles of protistology. Archiv fur Protistenkunde, Vol. 23. INTRODUCTION 19 . 1920 The discovery of the intestinal Protozoa of man. Proc. Roy. Soc. Med., Vol. 13. DOFLEIN, F. and E. Reichenow. 1929 Lehrbuch der Proto- zoenkunde. Jena. NoRDENSKiOLD, E. 1928 The history of biology. New York. Sandon, H. 1927 The composition and distribution of the protozoan fauna of the soil. Edinburgh. Whipple, G. C. (revised by G. M. Fair and M. C. Whipple) 1927 The microscopy of drinking water. Fourth ed. New York. CHAPTER II MORPHOLOGY AND PHYSIOLOGY OF PROTOZOA PROTOZOA range in size from less than 5 microns to more than 1 cm. in diameter. On the whole, however, they are microscopic. The parasitic forms, especially the cytozoic parasites, are generally small, while the free-living forms are of much larger dimensions. Leishmania (Fig. 52) and Plas- modium (Fig. 121) may be taken as examples of minute Proto- zoa. There are numerous species of free-living ciliates which can be seen with the unaided eye, and these are among the larg- est Protozoa. The fundamental components of the protozoan body are the nucleus and the cytoplasm. Not a single protozoan is known which does not possess at least one nucleus. Experimental evi- dence indicates clearly that when a protozoan is deprived of its nucleus it degenerates sooner or later. On the other hand, if the loss is in the cytoplasmic portion, the organism is capable of regenerating its lost part. Thus the nucleus controls both ana- bolic and catabolic activities of the organism. Furthermore, the nucleus contains chromatin substance in which are lodged "genes," or factors, characteristic of each species. The Nucleus The nucleus is of various form, size, and structure. At one extreme there is a small compact nucleus and at the other a large moniliform or elongated one. In between is found every conceivable variety of form. The majority of Protozoa con- tain a single nucleus. During the process of division, however, there may be two or more nuclei. There are, moreover, forms which regularly contain two or more nuclei throughout the greater part of their life-cycle. In several widely scattered spe- cies, each individual possesses two similar nuclei, for example, in Pelomyxa binucleata, Arcella vulgaris (Fig. 4), Giardia intes- tinalis (Fig. 62), Dientamoeha fragilis (Fig. 87), etc. In several [201 MORPHOLOG Y AND PH YSIOLOG Y 2 1 groups of the Ciliata, two different nuclei, a macronucleus and a micronucleus, are normally present. The macronucleus is much the larger and controls the metabolic or trophic activities of the organism, while the micronucleus is very minute and is concerned with the reproductive activity. Some species have two or more nuclei of each kind, but the majority possess only one of each kind. In Mycetozoa (Fig. 69), some other Sarcodina such as Actinosphaerium (Fig. 98), Pelomyxa palustris, Proto- ciliata, and numerous Sporozoa, there occur many nuclei of similar structure. These multinucleate forms result either from repeated divisions of a single nucleus or from fusion of numerous uninucleate individuals. Although protozoan nuclei manifest various structures they may be put under two types: compact, or massive, and vesicu- lar (Fig. 3). The compact nucleus, which is most frequently found in ciliates, is filled more or less compactly with minute Nuclear membrane Endosome Achromatic strand Chromatin granules Fig. 3 a. \'esicular nucleus, b. Compact nucleus. chromatin granules. The macronucleus of Paramecium cauda- tum represents this type (Fig. 16). The vesicular nucleus con- sists of a nuclear membrane, achromatic strands or network, chromatin granules and nuclear sap. Besides there is an intra- nuclear body, which is usually spherical in form, and which ap- pears to be of different make-up, as judged by its staining reac- tion, among different nuclei. In some it seems to be composed almost exclusively of chromatin, while in others it shows vary- ing proportions of chromatin and plastin materials. This chro- matic body is often called the karyosome, but the use of this term has been attended with much confusion. The term endo- some is, therefore, employed in the present work, in agreement with Minchin and Calkins, to designate one or more conspicuous intranuclear bodies. While chromatin granules are usually confined to the intra- 22 HANDBOOK OF PROTOZOOLOGY nuclear space, they are in some cases scattered throughout the cytoplasm either temporarily or permanently. These extranu- clear chromatin granules are known as chromidia. In Testacea, such as Arcella (Fig. 4) and Euglypha (Fig. 1), there are chro- midia surrounding the nuclei. They have been found by some investigators to give rise to secondary nuclei through reorganiza- tion, the original nuclei degenerating in the meantime. Accord- ing to Calkins, in Dileptiis anser (Fig. 4) there occur a large number of small spheroidal chromidia, each of which is com- posed of a plastin core and a chromatin cortex. Contractile vacuoles Cytostome Food vacuoles Nucleus Chromidia Fig. 4 a. A stained Arcella vulgaris showing the two nuclei and chromidia. X350. b. A stained Dilepius anser with s:attered nuclei or chromidia. X about 100 (After Calkins). In Mastigophora or in other groups in which flagellate stages occur, the body possesses a structure which is directly or in- directly connected with the basal portion of the flagellum (Fig. 5). This body has sometimes been called the kinetonucleus, but there is no evidence to indicate that it is a nuclear structure, although in some forms it is connected with the nucleus by a filamentous structure known as the rhizoplast. The term ble- pharoplast, or kinetoplast, is to be used to designate such a struc- MORPHOLOGY AND PHYSIOLOGY 23 ture. Closely related to this is the parabasal body, or apparatus, found in certain Mastigophora, such as Polymastigida and Hy- permastigida. It occurs in a close association with the nucleus. Its function is not well understood, but in some forms it appears to be a cell-organ of protection for the nucleus, while in others it may be a storing organelle of material used by the kinetic cell-organs. The Cytoplasm The bulk of the body of a protozoan is made up of the cyto- plasm, which is almost always colorless. Certain Protozoa encased in a test, or lorica, may show coloration due to the color Flagellum Undulating membrane Nucleus Basal granule Blepharoplast Anterior flagellum Basal granule Blepharoplast Rhizoplast Nucleus Parabasal body Posterior flagellum Diagrams of two flagellates showing their structures. a. Trypanosoma brucei b. Prowazekella lacertae (After Kiihn). of the latter. Chromatophore-bearing forms, of course, appear colored, but the cytoplasm itself is usually colorless. There are, however, a few exceptions. One of them is the heterotrichous ciliate, Blepharisma lateritia (Fig. 160), which is frequently colored pink. Arcichovskij found a special pigment in this protozoan and called it zoopurpurin. The extent and nature of the cytoplasmic dififerentiation differs greatly among various groups. In a number of forms the cytoplasm is differentiated into two parts: ectoplasm and endo- 24 HANDBOOK OF PROTOZOOLOGY plasm. The ectoplasm appears on the periphery as a hyaline and homogeneous zone. The endoplasm is greater in volume and more fluid and may be granulated or alveolated. These two parts, however, are not distinctly separated parts of the cyto- plasm. They are freely interchangeable with each other. A protozoan may show a conspicuous ectoplasmic zone at one time, and may not show it at all at other times. This is true as a rule in Sarcodina. In pellicle-possessing Protozoa, as in the Ciliata, the ectoplasm and the endoplasm appear to be per- manently differentiated during the trophic life of the individual. The majority of Protozoa possess a definite membrane which surrounds the body. This is commonly called the pellicle, or periplast, and fits the body surface more or less closely. The Fig. 6 a. Paramecium caudatum treated with alcohol, showing somewhat distended pellicle with its pores for cilia. X about 150. b-e. Changes in body-form of Euglena viridis. X about 350. presence of a pellicle is easily demonstrated by treating a ciliate with a dehydrating reagent. The protoplasm shrinks and pulls away from the pellicle, and the latter becomes somewhat distended by the accumulation of a watery fluid and to a certain extent by the pressure of the cover glass (Fig. 6). In life the pellicle is elastic and expansible to a considerable extent, as will be noted by examining Euglena viridis (Fig. 6). In some forms, the pellicle is marked by striation as in Phacus .(Fig- 40), by ridges, by furrows, or by nodules arranged in definite rows, as in Euglena spirogyra (Fig. 40). In others, again, the pellicle MORPHOLOGY AND PHYSIOLOGY 25 may be composed of characteristic plates, as in Coleps (Fig. 148). The pellicle, in many cases, may thicken locally and pro- duce spinous projections or hooks which serve as protective or attaching cell-organs. Gelatinous substances are sometimes secreted by Protozoa for protection of the body. Some Protozoa secrete a test, or lorica, which encases the protoplasmic body. The test may be composed of chitin, pseu- dochitin, silicious or calcareous substances. An example of this is the homogeneous chitinous shell of Arcella (Fig. 4). In others the test is made up of scales produced in the cytoplasm and ce- mented together around the body; and again the shell is formed by cementing together foreign materials such as sand grains, sponge skeletons, diatom shells and others. Various Foraminif- era seem to possess a remarkable selective power in the use of foreign materials for the construction of their tests. According to Cushman, Psammosphaera 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 spicule are not found. P. howmanni, on the other hand, uses only mica flakes which are found in a compara- tively small amount, and P. rustica uses acerose sponge spicules for the framework of the test, skilfully fitting smaller broken pieces into polygonal areas. Closely associated with the body surface are the cell-organs of locomotion, the pseudopodia, flagella and cilia. Pseudopodia are usually temporary or semi-permanent cytoplasmic pro- jections which serve for locomotion and food-capturing. Accord- ing to their form and structure, four types are distinguishable: Lobopodia. These are temporary cytoplasmic projections ordinarily composed of both ectoplasm and endoplasm, as in Amoeba proteiis (Fig. 80). They are more or less broad with rounded ends. Filopodia. These are also temporary cytoplasmic projections, but are usually made up of the hyaline ectoplasm only. They are more or less rod-like or filamentous, as in several Testacea (Fig. 93). 26 HANDBOOK OF PROTOZOOLOGY Rhizopodia. These are branching (reticulopodia) or anasto- mosing (myxopodia) temporary cytoplasmic projections. They are commonly found in Foraminifera (Fig, 76) and Testacea (Fig. 94). ^ Axopodia. These are more or less straight, filamentous, and usually radiating, semi-permanent pseudopodia widely present in Heliozoa (Fig. 98) and Radiolaria (Fig. 104). They possess an axial filament which is surrounded by a thin layer of cyto- plasm. The latter undergoes a constant movement. The axial filament may originate in the "central granule," a special basal body, or in the general cytoplasm. Fig. 7 Vahlkampfia Umax, showing different pseudopodia. (After Verworn). a,b, contracted forms; c, individual siiowing typical appearance; d-f, "radiosa" forms, after addition of potassium hydrate solution to the water. While the pseudopodia formed in an individual are usually of characteristic form and appearance, they may show an entirely different appearance under certain 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). In some cases during and after MORPHOLOGY AND PHYSIOLOGY 27 certain internal changes an amoeba may show conspicuous dif- ferences in pseudopodia (Neresheimer). Pseudopodia occur widely in forms which are placed under classes other than Sarcodina during a part of their life-cycle. Care, therefore, should be exercised in using them in taxonomic consideration of the Protozoa. Fiagella are filamentous extensions of the cytoplasm. Or- dinarily they are extremely fine and highly vibratile, so that it is difficult to see them in life under the microscope with a moderate magnification. In a comparatively small number of species the flagellum can be seen distinctly in life as a long filament, as for example in Peranema (Fig. 42). As a rule, the number of fiagella present in a single individual is small, varying from one to Axial filament Fia:. 8 Contractile cytoplasmic sheath Diagrams of fiagella. a, flagellum of Euglena (After Biitschli); b, optical longitudinal; and c, transverse section of flagellum of Tra- chelomonas (After Plenge). eight. In Hypermastigida there are numerous fiagella (Fig. 12) . Instead of being composed of a homogeneous substance, a flagellum appears to be made up of at least two parts (Fig. 8). An axial filament which is highly elastic, takes its origin directly, or indirectly through the basal granule, in the blepharoplast. Surrounding this filament there is a sheath of contractile cyto- plasm which varies in thickness alternately on either side. The flagellum ordinarily tapers toward the free end. 28 HANDBOOK OF PROTOZOOLOGY The flagellum is usually inserted near the anterior end and directed forward. Its movement will pull the organism toward the front. Combined with this there may be a trailing flagellum which, as the name implies, is directed posteriorly. It serves to steer the course of movement or it may push the body forward to a certain extent. In a small number of flagellates, the flagellum is inserted near the posterior end of the body. In such cases its movement will push the body forward. The pulling and pushing flagella were called tractella and pulsella, respec- tively, by Lankester. In some parasitic Mastigophora such as Trypanosoma (Fig. 5), Prowazekella (Fig. 5), Trichomonas (Fig. 61), etc., there is a very delicate membrane along one side of the body and la flagellum makes its outer margin. \\'hen this membrane vi- brates, it presents a characteristic undulating movement, as will easily be seen in Trypanosoma rotatoriiim. This structure is called the undulating membrane. Cilium Pore for cilium '^^(^^«=*'5^j;^^-^ End-view of trichocyst Membranellae Basal line composed of basal granules Peristome fibril Basal lamella End fiber Fig. 9 a. Part of the pellicle of Paramecium caudatum, showing the arrange- ment of cilia. XI 100 (After Schuberg) b. Portion of the adoral zone of Stentor coerideus showing three mem- branellae. (After Dierks). Cilia are the cell-organs of locomotion found chiefly in the Ciliophora. They are fine and short cytoplasmic projections and originate in the ectoplasmic portion of the body (Fig. 13). Ordinarily they are very numerous in holotrichous ciliates and uniform in length, as in Opalina, or they may be longer at the extremities, in the peristome or around the cytostome. They undergo alternate movements of contraction and relaxation. Some investigators believe that there is a layer of contractile element at one side of the axial filament which arises from a minute granule embedded in the ectoplasm, and that its contrac- MORPHOLOGY AND PHYSIOLOGY 29 tion results in bending of the cilium and its relaxation in straight- ening of it. The cilia are generally arranged in longitudinal, oblique or spiral rows. In young Suctoria, the ciliary rows are transverse (Fig. 173, c, d). Although cilia are primarily the cell- organs of locomotion, they serve directly or indirectly for food- capture also. In some ciliates, there are much stouter and considerably longer cytoplasmic projections, known as cirri (Fig. 10). They may occur with the cilia or completely replace them. A cirrus is composed of a number of cilia whose roots produce a basal plate, and from this thick base it tapers gradually to a point. In some cases, the end of a cirrus may show two or more branches (Fig. 167). The cirri usually are confined to the ventral surface of the organism and are called frontal, marginal, ventral, anal, and caudal cirri according to their location (Fig. 10). Unlike cilia, cirri may move in any direction, so that organisms possessing them show various ways of locomotion. In all ciliates except the Holotrichida, there occurs an adoral zone on the left margin of the peristome, which consists of a number of triangular or plate-like membranellae (Fig. 9). Each membranella is composed of numerous cilia which are completely fused into one mass. The adoral zone seems to serve primarily for bringing food particles to the cytostome. Still more common is the undulating membrane which is composed of one or more rows of longitudinally placed cilia (Fig. 10). It is, therefore, different in structure from the so-called undulating membrane found in some Mastigophora mentioned above. The undulating membrane in the cytopharynx of Paramecium and that in the peristome of Pleuronema (Fig. 158) are typical examples. In Suctoria, except one genus, cilia are present only during developmental stages, and as the organisms become mature, tentacles are formed. The latter are either suctorial or prehen- sile in function and are often very long. Each contains a highly contractile axial filament. In a few instances the tentacle is tubular, and this type is interpreted by Collin as possibly de- rived from a cytostome and cytopharynx of the ciliate (Fig. 11). Although the vast majority of Protozoa, possess only one of the three cell-organs of locomotion mentioned above, a proto- 30 HANDBOOK OF PROTOZOOLOGY 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. 10 a. Five anal cirri of Euplotes patella. (After Taylor), b. Schematic ventral view of Stylonychia to show the distribution of cirri. MORPHOLOGY AND PHYSIOLOGY 31 zoan may possess pseudopodia at one phase and flagella at an- other phase during its life-cycle. Among numerous examples, Naegleria (Fig. 79) and Trimastigamoeba (Fig. 79) may be mentioned. Furthermore, pseudopodia and flagella may occur at the same time, as in Dimorpha (Fig. 44), Actinomonas and Ciliophrys (Fig. 44). In other cases such as Monomastix (Fig. 147), a flagellum and cilia are present at the same time. Fig. 11 Diagrams showing possible development of a suctorian tentacle from a cytostome and cytopharynx of a ciliate. (After Collin). Various types of cell-organs are present in the cytoplasm. In Mastigophora, Ciliata and the majority of Sporozoa which possess a definite body form due to the presence of a pellicle, there occur in the cytoplasm highly contractile filaments known as myonemes. In large forms they are noted in life, while in smaller forms staining is required to show their presence. In the hypermastigid Trichonympha, Kofoid and Swezy observed longitudinal and transverse myonemes (Fig. 12). In the Ciliata they are usually arranged parallel to the rows of cilia. In Stentor, which is highly contractile, Schroder found that the myonemes are lodged in canals located just below the alveolar layer. Each myoneme is band-form and is said to be composed of alternating light and dark parts. In some Sporozoa such as the gregarines, the myonemes take chiefly a transverse course, and in the para- sitic Mastigophora such as Trypanosoma, they are usually parallel to the undulating membrane. In numerous ciliates, there occur characteristic structures 32 HANDBOOK OF PROTOZOOLOGY Fig. 12 Schematic drawing of Trichonympha campanula. X450 (After Kofoid and Swezy). a, alveolar layer; af, anterior zone of flagella; bg, basal granules; c, centro- blepharoplast; ec, ectoplasm; en, endoplasm; f, food particles; h, head-organ; If, lateral flagella; Im, longitudinal myonemes; n, nucleus; of, oblique fibers; p, pellicle; pf, posterior flagella; s, surface ridges; tm, transverse myonemes. MORPHOLOGY AND PHYSIOLOGY 33 known as the trichocysts (Fig. 13), which are apparently defen- sive cell-organs. As seen in a living Paramecium, the refractile trichocysts are embedded in the ectoplasm and arranged at right angles to the body surface. Each trichocyst is a spindle-shaped body with a round end which is prolonged into a fine projection facing the body surface. Trichocysts take a nuclear stain in- tensely. Brodsky (1924) believes that they are made up of colloidal excretory substances and are first formed around the Cilia Pellicle Basal granule Ectoplasm Trichocysts Roots of cilia d ^ Trichites Fig. 13 a. Portion of section of Paramecium caudatum showing ectoplasmic structure. X1530. b. Two completely extruded trichocysts of Paramecium caudatum. X1530. c. Spathidium spatula as seen in stained section, showing trichites. X200 (After Woodruff and Spencer). d. Enchelyodon farctus from life. X about 180 (After Blochmann from Doflein). 34 HANDBOOK OF PROTOZOOLOGY macronucleus, becoming fully formed during the course of their migration toward the periphery of the body. The extrusion of trichocysts is easily induced by means of mechanical pressure or chemical stimulation, though the mechanism of the extrusion is not well understood. Brodsky maintains that the fundamen- tal force is not the mechanical pressure, but that the expansion of the colloidal substances results under certain stimuli in the extrusion of the trichocysts through the pellicle. The fully extruded trichocyst is an elongated structure with a drawn-out free end and with a small cap-like structure and a fine filament at its base. The fully extruded trichocysts of Paramecium cauda- tum are as much as 40 microns in length. In certain ciliates there occur rod-like trichites which or- dinarily surround the cytopharynx (Fig. 13). Reserve trichites are scattered throughout the endoplasm. They apparently serve to strengthen the cytostome and cytopharynx and to capture and hold actively motile Protozoa on which the organisms live. In the spores of Cnidosporidia there is a characteristic filament- ous structure known as the polar filament, which is spirally coiled in an envelope, the polar capsule (Fig. 133). Under a suitable stimulation, the filament extrudes and serves probably for temporary anchoring of the spore to the gut-epithelium of the host. A similar structure is also found in some Dinoflagel- lida. In the pellicle-bearing Protozoa there is always a definite cytostome which varies considerably in size, form and location in different forms. In those that feed continuously, such as Para- mecium, the cytostome is permanently open, and in others, it is closed except at the time of food-taking. These forms also have a cytopyge, or cell-anus, through which undigested solid particles or waste bodies are extruded to the exterior. It is usually closed and difficult of observation except during the actual defecation (Fig. 14). The cytostome leads into a tubular widening of the endo- plasm, known as the cytopharynx, or gullet. The cytopharynx may possess an undulating membrane or cilia. It may be sur- rounded by trichites as has been stated. At the end of the cyto- pharynx the food vacuole is first formed. The mode of nutrition is considered as an important means MORPHOLOGY AND PHYSIOLOGY 35 in distinguishing between animals and plants. The Protozoa nourish themselves by various methods as follows: 1. Holozoic (zootrophic, heterotrophic) nutrition. This is the animal-like nutrition. The organism obtains nourishment by taking in other animals or plants and digesting them as does a typical metazoan. 2. Holophytic (autotrophic, phytotrophic) nutrition. The Protozoa possessing chlorophyll or allied substances are capable of obtaining necessary nourishment by using water, carbon dioxide and other inorganic substances. This nutrition is truly plant-like and is common among the Phytomastigina. In a Fig. 14 Outline sketches showing the defecation process in Spirostomum ambiguum. (After Blattner). number of cases, the organism itself is without chromatophores, but is apparently not holozoic because of the presence of chloro- phyll-bearing foreign organisms. For example, in Paulinella (Fig. 96) in which occur no food particles, chromatophores of peculiar shape are always present. They appear to be a species of Alga which holds a symbiotic relationship with this testacean. Perhaps they act as the true chromatophores of Euglenidae. 3. Saprozoic (saprophytic) nutrition. Certain Protozoa are able to derive materials necessary for building up their body from dissolved organic substances in water. The actual ac- quisition is done by osmosis through the body surface. 4. Parasitic nutrition. Many Protozoa living in other ani- mals absorb by osmosis the body fluid, digested food material or cell-substances of the host. This is somewhat similar to the saprozoic nutrition, but substances used here are those which have been produced in the host body. Other parasites, for exam- 36 HANDBOOK OF PROTOZOOLOGY pie Entamoeba histolytica, may be holozoic, since they ingest the host tissue cells. Certain ciliates seem to be able to live in water rich in sulphurous substances produced by putrefying vegetable and animal matter. Lauterborn called them sapropelic forms. Many Protozoa apparently nourish themselves by more than one method at the same or different times. Many chromato- phore-bearing Protozoa are known to nourish themselves by holophytic as well as saprozoic methods under changed en- vironmental conditions. This mode is sometimes known as mixotrophic (Pfeiffer). In the major groups of the Protozoa except the Sporozoa, there occur one or more vacuoles known as contractile, or pulsating, vacuoles. As a rule, the fresh-water inhabiting Pro- tozoa contain contractile vacuoles, and those of the salt water or of parasitic habitat do not, although exceptions are noted here and there. In the Protozoa which do not possess a pellicle, the vacuole is formed by accumulation of watery substance in one or more droplets, which increase in size and unite into one. Thus the vacuole enlarges slowly but continuously, until it reaches a certain size, which may vary even within one indivi- dual, and finally bursts through the thin ectoplasm to the outside. Aside from Protociliata, contractile vacuoles occur gen- erally in the ciliates even among the parasitic forms. They show in many cases a more conspicuous and complicated structure than those found in other groups. In them the vacuoles are more or less definitely located in the superficial portion of the endoplasm, although there is no delimiting membrane around them. In a number of species there are accessory canals known as radiating canals. These canals, which are easily seen in Paramecium, are spaces in the endoplasm through which fluid matter becomes collected and flows toward the central vacuole. When the vacuole is fully formed, its contents are discharged to the exterior through the ectoplasm and pellicle. In forms such as Stentor or Spirostomum, the contractile vacuole is fed by a long longitudinal canal. In some forms there is a definite permanent pore in the pellicle through which the expulsion takes place (Figs. 156 and 160). In many Mastigophora such as Euglena, there occur several MORPHOLOGY AND PHYSIOLOGY 37 minute contractile vacuoles around the reservoir into which their contents are discharged. The reservoir apparently gets rid of the waste matter through a canal, commonly known as the cytopharynx, which leads to the outside. Somewhat similar to this is the contractile vacuole of Vorticellidae. Here a contrac- tile vacuole discharges its contents by a short canal. In Nycto- therus, Balantidium, etc., the contractile vacuole voids its con- tents through a special canal at the posterior end of the body. In the ciliates, the number, appearance and location of the contractile vacuoles are usually constant and highly character- istic, so that they have a taxonomic value. As to the function of the vacuole, it seems probable that it adjusts the water contents of the cytoplasm by throwing out from time to time a certain amount of water from the body, and that in doing so it carries out dissolved waste products. The pulsation of the contractile vacuole is, according to Biit- schli, not due to the active contraction of the cytoplasm, but to the physical attraction of the small droplet of fluid by the water which surrounds the organism. Other cell-organs present in the cytoplasm vary a great deal in different groups. Food vacuoles are conspicuously pres- ent in holozoic Protozoa. These are droplets of fluid, usually water in which are suspended food particles such as Protophyta, other Protozoa or small Metazoa ingested as food. In the amoe- boid Protozoa which do not possess a cytostome, the food par- ticles are of variable dimensions, and when the particles are large it is difficult to make out the thin film of water which sur- rounds them. When minute food-particles are taken in through a cytostome and cytopharynx, the food vacuoles are usually of the same size. In saprozoic Protozoa and the majority of para- sitic forms, in which dissolved food is absorbed by osmosis through the body surface, food vacuoles containing solid particles do not occur. Holophytic Protozoa possess in their endoplasm chromato- phores, or chromoplasts (Fig. 15), which are made up of chloro- phyll. The color of the chromatophores may be yellow, orange, brown, grass-green, blue-green, or even red, due to the pigments which envelop them. Ordinarily they have definite shape, e.g., band-form, stellate, ovoid, ring-form, discoidal, or cup-like; but 38 HANDBOOK OF PROTOZOOLOGY may occasionally occur in an irregularly diffused or reticulate condition. The number of chromatophores present in an indi- vidual varies in different species. In association with the chromatophores are found one or more pyrenoids which are usually embedded in them. A pyre- noid may be naked or covered by amylaceous substance. It Fig. 15 a. Trachelomonas hispida from life. X530. (After Doflein). b,c. Propagative cells of Pleodorina illinoisensis. XIOOO. (After Merton). b, from life; c, from stained preparation, d-f. Terminal cells of Hydrurus foetidus, showing the divi- sion of chromatophore and pyrenoid. (After Geitler). g-i. Chlamydomonas sp., showing the division of pyrenoids. (After Geitler). multiplies during cell-division. As Geitler showed, the pyrenoid in Euglena and allied forms is naked and may or may not be in the chromatophore; while in Volvocidae or Cryptomonadida it is' encased in a starch envelope. The pyrenoid seems to become the center in the formation of paramylum bodies and allied re- serve food materials. MORPHOLOGY AND PHYSIOLOGY 39 Chromatophore-bearing forms usually contain also a red- pigmented spherical, ovoid, or elongated body known as the stigma, or eye-spot (Fig. 15), which is a cell-organ that responds to light stimulation. The stigma is composed of an oily sub- stance (lipochrome) and in a number of cases possesses a second- ary structure made of a paramylum body which seemingly func- tions as a lens system. Oils and fats are widely distributed among various Protozoa. In some cases they serve not only as reserve food material but also for other purposes. Their function may be hydrostatic, as in Radiolaria, or photogenic, as in various Dinoflagellida. In some cases the oil droplets which are liberated into the water by the disintegration of the protozoan body result in an objection- able odor, as was reported by Calkins in the case of Uroglenopsis americana (Fig. 30). Pigments and crystals are also commonly observed in vari- ous Protozoa. These are, as a rule, products of catabolism. Not infrequently a common ciliate such as Paramecium may contain a number of crystals in the endoplasm. According to Schaeffer, these crystals in Amoeba proteus, A. discoides and A. duhia, are characteristic to each species (Fig. 80). In malarial organisms brownish granules, known as melanin pigment, are formed as a result of absorption and digestion by the organisms of the haemoglobin of the erythrocyte. The coloration of Blepharisma lateritia is due to the presence of a specific pigment, as was stated above. Certain groups have an endoskeleton. In Trichomonas and allied Mastigophora, there is a conspicuous rod-like structure which makes the axis of the body. It is commonly known as the axostyle and is understood to serve as a supporting and streng- thening cell-organ of the body (Fig. 61). In other forms a num- ber of filamentous structures known as axial filaments may be present to form an endoskeleton (Fig. 63). These structures are especially noted in the Mastigophora which inhabit the di- gestive tract of animals. References BuLLiNGTON, W. E. 1925 Study of spiral movement in the ciliate Infusoria. Arch. f. Protistenk., Vol. 50. 40 HANDBOOK OF PROTOZOOLOGY Calkins, G. N. 1926 The biology of the Protozoa. Phila- delphia. DiERKS, K. 1926 Untersuchungen iiber die Morphologie und Physiologic der Stentor coerulens mit besonderer Beriick- sichtigung seiner kontraktilen und konduktilen Elemente. Arch. f. Protistenk., Vol. 54. DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- tozoenkunde. Jena. Gray, J. 1928 Ciliary movement. Cambridge. Jennings, H. S. 1906 Behavior of the lower organisms. New York. ScHAEFFER, A. A. 1920 Amoeboid movement. Princeton. CHAPTER III REPRODUCTION IN PROTOZOA THE MODE of reproduction in the Protozoa is highly vari- able among different groups, and even in the same group it varies with differences in habitat. It will here be briefly considered under asexual and sexual reproduction. Asexual Reproduction Nuclear Division Between a simple direct division on the one hand and a complicated indirect division which is comparable to the mitosis of a typical metazoan cell on the other hand, all kinds of nuclear division are to be encountered. Direct nuclear division. While not so widely found as was thought in former years, amitosis occurs without doubt in the macronuclear division of the Ciliophora and in the nuclear divi- sion of several Cnidosporidia and others. The macronucleus elongates itself without any noticeable changes in internal structure and becomes constricted through the middle, resulting in the formation of two daughter nuclei, A typical example is the division of the macronucleus as observed in Paramecium caudatum (Fig. 16). When the macronucleus is an elongated beaded form, as in Spirostomum amhiguum, the whole becomes condensed into a rounded mass prior to the division. In Urolep- tus mobilis, which contains normally eight or more nuclei, the macronuclei, according to Calkins, after throwing off fine granules and losing the nuclear cleft, fuse into one, preparatory to a direct division (Fig. 17). The nucleus then divides twice or three times before the cytoplasmic division occurs; the fourth nuclear division appears after the daughter cells have become separated completely. In Dileptus anser (Fig. 4), with scattered nuclei or chromidia. Calkins has shown that the individual gran- ules become elongated and divide where they happen to lie. In Endamoeba hlattae, the nucleus of the trophozoite divides [411 42 HANDBOOK OF PROTOZOOLOGY amitotically (Fig. 18). In Cnidosporidia the minute nucleus fre- quently undergoes a division which could be considered only as amitosis (Fig. 18). In the case of external budding in the Fig. 16 Macronuclear, and subsequent cytoplasmic, division in Paramecium caudatum as seen in stained specimens. Cytoplasmic cell-organs are entirely omitted. X260. Suctoria, as for instance, Ephelota, the macronucleus branches out a small portion of its body into each of the developing buds, and nuclear constrictions result in the forming of many young individuals (Fig. 18). REPROD UCTION 43 Indirect nuclear division. The indirect division which occurs in Protozoa is of manifold types as compared with the mitosis in the cells of Metazoa, in which, aside from minor variations, the change is of a uniform pattern. There are, however, in- stances of indirect nuclear division in Protozoa which are similar to the typical mitosis of multicellular animals. Chatton, Alexei- eff and others have proposed several terms to designate the various types of indirect nuclear division, but no one of these Fig. 17 Stages in macronuclear division in Uroleptus mohilis. X300. (After Calkins). a. A stage in the fusion of the macronuclei; the micronuclei in mitosis. b. A much later stage in the macronuclear fusion. c. The stage in which the macronuclei became fused into one mass prior to amitosis. d. A stage in the amitosis of the macronuclear material. types is sharply defined, since there are intermediate forms be- tween any two of them. For our purpose, mention of the chief types will suffice. A veritable mitosis was noted by Dobell in the heliozoan Oxnerella maritima (Fig. 19), which possesses an eccentrically located nucleus containing a large endosome and a central granule ("centroplast") from which radiate many axopodia {a). The first sign of the nuclear division is the slight enlargement, 44 HANDBOOK OF PROTOZOOLOGY and migration toward the central granule, of the nucleus. The granule first divides into two {c, d) and the nucleus becomes h 1 Fig. 18 a-f. Amitosis in Endamoeba blattae as seen in life. X665. (After Kudo), g. Budding in Ephelota biitschliana. (After Calkins). h-1. Amitosis in trophozoite of M^i-vojowa ca/o5/om. X1500. (After Kudo). located between the two granules (e). Presently spindle fibers are formed and the nuclear membrane disappears (/, g). After REPROD UCTION 45 passing through an equatorial-plate stage, the two groups of chromosomes move toward the opposite granules (g-i). As the spindle fibers become indistinct, radiation around the central Fig. 19 Oxnerella maritima and stages of mitosis. X about 1000. (After Dobell). a, a living individual; b, a stained specimen; c-g, prophases; h, metaphase; i, anaphase; j, k, telophase; 1, complete division of the body into two daughter individuals. granules becomes conspicuous and the two daughter nuclei are completely reconstructed to assume the resting phase (J-l). In the asexual, or schizogonic, reproduction of the coccidian. 46 HANDBOOK OF PROTOZOOLOGY Eimeria schubergi (Fig.20),Schaudinn observed a division which is a good example of the type commonly called promitosis. In this the endosome becomes elongated and then divided into two masses ; the chromatin granules are assembled in two groups Fig. 20 a. Nuclear division o{ schizont of Eimeria schubergi. X1500. (After Schaudinn). b. Nuclear division of Chilomonas Paramecium. X1500. (After Doflein). c. Nuclear division in sporont of Thelohania legeri. X2100. (After Kudo). with spindle fibers. In the nucleus of Chilomonas Paramecium (Fig. 20), the nuclear elongation takes place at right angles to the axis of the body. The endosome breaks up and the chroma- tin granules become collected into larger rounded chromosomes which are then arranged in the equatorial plane. At about this REPRODUCTION 47 time, fibers become distinct; two groups of chromosomes move toward the opposite ends and finally divide into two daughter nuclei. In these two cases the nuclear membrane persists. In the microsporidian, Thelohania legeri (Fig. 20), the spor- ont nucleus divides mitotically. Formation of spireme and spindle fibers and disappearance of the nuclear membrane are distinctly observable, although whether the chromosomes split Fig. 21 Nuclear division in Menoidium incurvum. X about 1400. (After Hall), a, resting phase; b, c, prophase; d, "equatorial plate;" e, f, anaphase; g, telophase. or not cannot be made out. In Mastigophora, which possess, as a rule, a blepharoplast from which a flagellum arises and which behaves in a manner somewhat comparable to that of the central granule of Oxnerella or of the centrosome in a metazoan mitosis, the blepharoplast divides and produces a strand between the divided parts in close association with the nucleus. This strand is known as the paradesmose, or centrodesmose (Figs. 21, 22). In several Mastigophora, a clear picture of the metaphase has been observed by numerous investigators. 48 HANDBOOK OF PROTOZOOLOGY Fig. 22 a-j. Nuclear division in Trichonympha campanula. X400. (After Kofoid and Swezy). a, beginning of division of the centroblepharo- plast, the nucleus in prophase; b, nucleus in prophase; c, two cen- troblepharoplasts and the paradesmose between them; d, close association of the nucleus and paradesmose; e, formation of spindle fibers; f, metaphase, the paradesmose is on the opposite side of the nucleus; g, anaphase; h-j, telophase, k-u. Nuclear division in Lophomonas blattarum. X1150. (After Kudo), k, resting nucleus; 1, m, prophase, n, metaphase; o-r, ana- phase; s-u, telophase. REPROD UCTION 49 Cytoplasmic Division Binary fission. As in metazoan cells, binary fission occurs very widely among the Protozoa. It is the division of the body into two nearly equal daughter cells. In the Amoebaea the body divides simply into two daughter individuals. In Testacea, as a rule, one of the daughter individuals occupies the old test, while the other moves out and forms a new one, as in Arcella and Euglypha. However, in some forms, such as Cochliopodium and Pseudodifflugia, the division is longitudinal, the test dividing also into two parts. In the majority of the Mastigophora, the division is longi- tudinal (Fig. 21). The nucleus and the blepharoplast divide first. The old flagellum may or may not be absorbed during the division. The new flagellum or flagella develop from the blepharoplasts. In a few forms, such as Oxyrrhis marina and Lophomonas striata, the cytoplasmic division is transverse. In the latter species the second daughter individual develops its anterior end directed posteriorly. The two almost completely divided daughter individuals may remain together for some time, being connected by a filamentous strand. In the Ciliophora the division is usually transverse (Fig. 16). The macro- and micro-nucleus each divide into two, and then the cytoplasmic organelles, such as the cytostome, contractile vacuoles, etc., are regenerated before the body divides into two. Incomplete division of the stalk results in producing arboroid colonies in many Peritrichida. Budding. Multiplication by budding, which is less fre- quently found in Protozoa than binary fission, is the formation of one or more smaller individuals from the large parent organism. It is either endogenous or exogenous, depending upon the loca- tion of the developing bud. Exogenous budding is noted in Noc- tiluca (Fig. 35), Myxosporidia (Fig. 23), Telosporidia, Suctoria (Fig. 18), etc. Endogenous budding is found in certain Suctoria (Fig. 173), although it does not seem to occur either in the Ciliata or in the Mastigophora. In Testacea such as Arcella, endogenous budding is said to take place. It occurs quite commonly in numerous members of the Sporozoa. Multiple division. In multiple division the body divides into a number of daughter individuals completely, with or without 50 HANDBOOK OF PROTOZOOLOGY degenerating remains of the parent body. In this process the nucleus may undergo either simultaneous multiple division, as in Aggregata, or more commonly, repeated binary fission, as in Plasmodium, to produce large numbers of daughter nuclei. The number of daughter individuals varies, not only among the ■.■■-.fi^a;'.?;*- 'iJVIt-' • /mi Fig. 23 Asexual reproduction in Myxosporidia. (From Kudo after several authors), a, trophozoite of Myxidium Ueberkiihni; b, budding in the same myxo- sporidian; c, d, plasmotomy of trophozoite of Chloromyxum leydigi; e, plas- motomy of a trophozoite of Sphaeromyxa balbianii. different groups, but also within one and the same species. Multiple division occurs commonly in Foraminifera, Radiolaria, Sporozoa, etc. Asexual multiple division, which is called schizog- ony, takes place widely in Sporozoa. In Mastigophora it is not of common occurrence but has been noted in cultures of Try- panosoma lewisi, T. cruzi, Lophomonas blattarum, etc. REPRODUCTION 51 Plasmotomy. In certain Myxosporidia which inhabit organ- cavities of the host fish, the multinucleate trophozoite has been found to divide into two or more smaller, still multinucleate bodies (Fig. 23). Doflein called this process plasmotomy. A similar division is also noted in some Mycetozoa and occasion- ally in Protociliata. Colony formation. When the division is repeated without complete separation of the daughter individuals, various types of colonies are produced. Based upon the arrangement of the component individuals, these are usually placed under three types: catenoid, arboroid, and spheroid. Catenoid (linear) colony. The daughter individuals are attached endwise, forming a chain of several individuals. Examples: the astomous ciliate, Haptophrya, and the dino- flagellate, Ceratium. Arboroid (dendritic) colony. The daughter individuals re- main connected with one another through attachment to stalks or tests, producing a tree-like appearance. Examples: Dino- bryon, Hyalobryon, Hydrurus (Fig. 31), Phalansterium (Fig. 45), Anthophysa (Fig. 55), Epistylis (Fig. 170), Carchesium (Fig. 169), etc. Spheroid colony. The individuals are embedded in a gelatin- ous matrix which is more or less rounded. Examples: Volvox, Eudorina, Pleodorlna (Fig. 39), Syncrypta, Uroglena, Uro- glenopsis (Fig. 30). Some are rosette-form, as in Gonium (Fig. 38) ; others are plate-form, as in Platydorina (Fig. 38). The gregaloid colony, which also is sometimes spoken of is a group of individuals of one and the same species, usually of Sarcodina, which become attached to one another by means of pseudopodia. Such a colony can hardly be said to be due to incomplete division of the parent body. Sexual Reproduction Some Protozoa reproduce themselves in a manner compar- able to the sexual reproduction which occurs universally in the Metazoa. Complete fusion of two gametes is here called copula- tion and is to be seen in various groups. A temporary union of two individuals for the exchange of nuclear material is desig- nated as conjugation and is common among the Ciliophora. 52 HANDBOOK OF PROTOZOOLOGY Copulation In the process of copulation two gametes take part. If the two gametes are morphologically alike, they are called isoga- metes; and if unlike, anisogametes. Isogamy, or hologamy, is typically represented by the flagellate Copromonas subtilis (Fig. 24), in which there occurs, Fig. 24 Copulation in Copromonas subtilis. X1300. (After Dobell). according to Dobell, complete nuclear and cytoplasmic fusion between two individuals. Each nucleus, after casting off a portion of its nuclear material, fuses with the other nucleus. The process is comparable to fertilization among the Metazoa. The zygote thus formed encysts instead of carrying on an active trophic life. Among the Sporozoa, isogamy is commonly found in the gregarines such as Lankesterella (Fig. 123), Schizocystis (Fig. 126), etc. It is also quite common in the Foraminifera Fig. 25 Macrogamete and microgamete of Volvox aureus. XIOOO. (After Klein). (Figs. 73, 76). It perhaps occurs in the Radiolaria, although positive evidence is yet to be presented (Fig. 102). Anisogamy seems to be more widely distributed. On the whole the differences between the microgametes and macroga- metes are comparable to those which exist between the sperma- REPROD UCTION 53 tozoa and ova of the Metazoa. The microgametes are actively motile, relatively small and numerous, while the macrogametes are non-motile as a rule, much larger but fewer (Fig. 25). In Chlamydomonas (Fig. 37), according to Goroschankin, the two gametes begin to fuse at their anterior ends. The flagella are lost and the cytoplasmic and nuclear fusions take place. A new body wall is secreted around the whole. In Volvox, the two gametes may be produced in the same colony, as in Volvox glo- bator, or in different colonies, as in V. aureus and V. perglohator. The union of gametes results in the formation of a zygote. Pan- dorina and Eudorina show similar changes. In the Sporozoa, anisogamy has been observed in numerous species of Eimeria (Fig. 109), Plasmodium (Fig. 120), etc. In the Cnidosporidia, some cases of anisogamy have been reported by certain investi- gators, while others report negative findings. Anisogamy has been suggested to occur in some Amoebaea, particularly in En- damoeba blattae, by Mercier, but this awaits confirmation. Conjugation Conjugation is a temporary fusion of two individuals of one and the same species for the purpose of nuclear exchanges. This process is found almost exclusively in the Ciliophora. The two individuals may be similar or dissimilar morphologically. The former case is called isogamous conjugation, and the latter anisogamous conjugation. The former appears to occur more commonly than the latter. In Paramecium caudatum (Fig. 26) two individuals come in contact on their oral surfaces. The micronucleus in each conju- gant divides twice (b-e), forming four micronuclei, three of which degenerate and do not take active part during further changes (f-h). The remaining micronucleus divides once more, producing a wandering nucleus and a stationary nucleus (/, g). The wandering nucleus in each of the conjugants enters the other conjugant and fuses with its stationary nucleus {h, r). The two zygotes thus formed become separated from each other and are called exconjugants. In each of them, the micronucleus divides three times in succession {i-m) and produces eight nuclei (w), four of which remain as micronuclei, while the other four develop into macronuclei (o). Cytoplasmic fission follows then, Fig. 26 Diagrammatic representation of conjugation in Paramecium cau- datum. X about 130. (After Calkins), a-f, micronuclear divisions; g, exchange of micronuclear material; h, fer- tilization; i-n, stages in three successive divisions of the nucleus; o, differentia- tion of four macronuclei and micronuclei; p, one of the products of the first cytoplasmic division, containing two macronuclei and two micronuclei; q, the products of the second and last cytoplasmic division, each possessing one mac- ronucleus and one micronucleus; r, nuclear fusion such as shown in h, under higher magnification (X1200 after Dehorne). [541 REPROD UCTION 55 producing, first, two with four nuclei {p) and, 'then, four small individuals, each containing a macronucleus and a micronucleus Anisogamous conjugation is essentially the same except that the conjugants are dissimilar in size and in some cases in struc- ture. In Chilodon (Fig. 27), the conjugants are unequal in size. According to Dogiel, in Cycloposthium hipalmatum (Fig. 27) Fig. 27 a. Anisogamous conjugation in Chilodon cucullulus. X140. (After Engelmann). b. Anisogamous conjugation in Cycloposthium bipal- matum. X245 (After Dogiel). conjugation takes place between two similar individuals or between two unequal ones. A sexual process which is somewhat intermediate between copulation and conjugation is noted in certain ciliates. Accord- ing to Maupas' classical work on Vorticella nehulifera, the ordinary trophic individual divides twice, forming four small in- dividuals, which become detached from one another and swim about independently. Sooner or later each of these small or- ganisms attaches itself to one side of an ordinary stalked in- dividual. In it the micronucleus divides three times and 56 HANDBOOK OF PROTOZOOLOGY produces eight nuclei, of which seven degenerate and the re- maining one divides once more. In the stalked individual 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 fuses completely. The wandering nucleus of the smaller conjugant unites with the stationary nucleus of the larger conjugant, the other nuclei degenerating. The single nucleus thus produced divides several times to form a number of nuclei, from some of which macro- nuclei are differentiated. Later the organism undergoes divi- sion. Meiotic Division In the foregoing paragraphs, references have been made to the divisions which the nuclei undergo prior to fusion. In all Metazoa, during the development of the gametes, the gameto- cyte nuclei undergo a reduction division, or meiosis, by which the number of chromosomes is halved; that is, each fully formed gamete possesses one-half the number of chromosomes typical to the species. The zygote stage restores the number. In the Protozoa, meiotic division takes place presumably prior to or during sexual reproduction, but the process is under- stood only in a few species. Among the ciliates in which con- jugation is common, meiosis seems to take place in the second micronuclear division, although in a few forms, for example, Oxytricha fallax, according to Gregory, the actual reduction takes place during the first division. Prandtl (1906) was the first to note the reduction in number of chromosomes in the Protozoa. In Didinium nasutum, he observed sixteen chromo- somes in each of the daughter nuclei during the first division, but only eight in the second division. Since then, the fact that the reduction is accomplished at the time of the second micro- nuclear division has been confirmed in Chilodon uncinatus (four to two chromosomes) by Enriques in 1908 and by MacDougall in 1925; in Carchesium polypinum (sixteen to eight; Popofif, 1908); Uroleptus mohilis (eight to four; Calkins, 1919). In various species of Paramecium and other ciliates, the number of chromosomes is so large, possibly more than one hundred, that it has been impossible to observe the stage of actual reduction. REPROD UCTION 57 In Monocystis rostrata, a parasite of the earthworm, Muslow noted that the nuclei of the two gregarines which encyst to- gether, multiply by a mitosis in which eight chromosomes are constantly present, but in the last division of gametic differen- tiation each daughter cell receives four chromosomes. In another species of Monocystis of the same host, Calkins and Bowling found that the normal number of chromosomes is ten, and that it is halved in the last gametic division. It will be seen from these that the zygote will contain the normal number of chromosomes. On the other hand, in the coccidian, Aggregata eberthi (Dobell, 1925; Belaf, 1926), and in the gregarine, Diplocystis schneideri (Jameson, 1920), there is no reduction in the number of chromosomes during the gamete-formation and, therefore, the resulting zygote contains twice the typical number of chro- mosomes. The first zygotic nuclear division was found to be meiotic, thus restoring the number of chromosomes in each nucleus. Paedogamy In a few forms, it has been observed that the organism di- vides into two uninucleate individuals, and that the two bodies fuse completely into one after a reduction division of the nuclei. This process has been named paedogamy. Perhaps the classical example is that which was found by Hertwig (1898) in Actino- sphaerium eichhorni. The organism encysts within a capsule, and the body divides into numerous uninucleate secondary cysts. The protoplasm of each of the latter divides into two cells and remains within a common cyst-wall. Their nuclei divide twice, and all the division products in each cell degenerate except one. Nuclear and cytoplasmic union between the two occurs, and a zygote is thus formed. Autogamy In some instances, the nucleus or nuclei divide once or twice without any division of the cytoplasm. The nuclei then fuse in pairs with one another after throwing off a certain portion of the chromatin material. This has been called autogamy. Un- doubtedly several cases of so-called autogamy were due to mis- interpretation, but in some Microsporidia, such a process has 58 HANDBOOK OF PROTOZOOLOGY been recognized by several investigators (Fig. 136). In Myxo- sporidia the spore possesses a binucleate sporoplasm. Most observers agree that, prior to germination of the sporoplasm, the two nuclei undergo fusion (Fig. 28). Endomixis By pedigree culture methods. Woodruff and Erdmann have found that Paramecium aurelia undergoes, at an interval of thirty days, a complete nuclear reorganization without cell fusion. The macronucleus breaks up into a number of fragments, which become completely absorbed by the cytoplasm later. Each of the two micronuclei divides twice, some of the products forming a new macronucleus and others forming two new micro- nuclei. This nuclear reorganization which takes place period- Fig. 28 Stained spores of Myxosoma catostomi, showing two nuclei in the sporoplasm (a), which later fuse into one (b). X2600. ically was termed endomixis by the above-mentioned authors. The process has further been found to occur in Paramecium caudatum, in which the micronucleus divides three times. Here four of the division products form new macronuclei, two degen- erate, and two persist as new micronuclei. Endomixis has been found in several other ciliates. As to the significance of the fertilization and endomixis, the generally accepted theory is that these processes probably re- store the "vitality" of the individual in which they occur. References Belar, K. 1926 Der Formwechsel der Protistenkerne. Eine vergleichend-morphologische Studie. Ergebnisse und Fort- schritte der Zoologie. Vol. 6. REPROD UCTION 59 Calkins, G. N. 1919 Uroleptus mohilis. 1. History of the nuclei during division and conjugation. Jour. Exper. Zool., Vol. 27. . 1926 The biology of the Protozoa. Philadelphia. Calkins, G. N. and S. W. Cull. 1907 The conjugation of Paramecuim caudatum. Arch. f. Protistenk., Vol. 10. DoFLEiN, F. AND E. Reichenow. 1929 Die Lehrbuch der Protozoenkunde. Jena. Erdmann, Rhoda and L. L. Woodruff. 1916 Periodic re- organization process in Paramecium caudatum. Jour. Exper. Zool., Vol. 20. Gregory, L. H. 1923 The conjugation of Oxytricha fallax. Jour. Morph., Vol. 37. Kudo, R. 1924 A biologic and taxonomic study of the Micro- sporidia. Illinois Biological Monogr., Vol. 9. MacDougall, M. S. 1925 Cytological observation on gymno- stomous ciliates, with a description of the maturation phenomena in diploid and tetraploid forms of Chilodon uncinatus. Quart. Jour. Micr. Sci., Vol. 69. Woodruff, L. L. and Rhoda Erdmann. 1914 A normal periodic reorganization process without cell fusion in Para- mecium. Jour. Exper. Zool., Vol. 17. CHAPTER IV OUTLINE OF THE CLASSIFICATION THE SYSTEM of classification adopted here was formulated largely by Biitschli and has been modified from time to time by other protozoologists. In this system the Protozoa are divided into two subphyla: Plasmodroma and Ciliophora. The Plasmodroma include three classes: (1) the Mastigo- phora, which have flagella; (2) the Sarcodina, which form pseudopodia; and (3) the Sporozoa, which possess no locomotor cell-organs. The Ciliophora include two classes: (1) the Ciliata, which have cilia throughout their life-cycle; and (2) the Suc- toria, which show cilia only in the immature stage. In the Plasmodroma the nuclei are of a single type, but in the Cilio- phora there are two types of nuclei. A synopsis of all classes will be given here for the convenience of the reader. PHYLUM PROTOZOA Page Subphyhim 1 Plasmodroma 82 Class 1 Mastigophora 82 Subclass 1 Phytomastigina 84 Order 1 Chrysomonadida 84 Suborder 1 Euchrysomonadina 86 Family 1 Chromulinidae 86 Genus Chrysapsis 86 Chromulina 86 Chrysococcus 86 Mallomonas 86 Family 2 Isochrysidae 87 Genus Synura 87 Syncrypta 88 Family 3 Ochromonadidae 88 Genus Ochromonas 88 Uroglena 88 Uroglenopsis 88 Cyclonexis 89 Dinobryon 89 Hyalobryon 89 Stylopyxis 89 [60] OUTLINE OF CLASSIFICATION 61 Family 4 Coccolithophoridae 89 Pontosphaera 89 Discosphaera 89 Family 5 Silicoflagellidae 90 Distephanus 90 Suborder 2 Rhizochrysidina 90 Genus Rhizochrysis 91 Suborder 3 Chrysocapsina 91 Genus Hydrurus 91 Order 2 Cryptomonadida 92 Suborder 1 Eucryptomonadina 93 Family 1 Cryptomonadidae 93 Genus Cryptomonas 93 Chrysidella 93 Chilomonas 94 Cyathomonas 94 Cryptochrysis 94 Family 2 Nephroselmidae 94 Genus Protochrysis 94 Nephroselmis 94 Suborder 2 Phaeocapsina 95 Genus Phaeothamnion 95 Order 3 Dinoflagellida 96 Suborder 1 Adinida 98 Genus Exuviaella 98 Prorocentrum 98 Suborder 2 Dinifera 98 Tribe 1 Peridinioidae 98 Family 1 Peridiniidae 99 Genus Peridinium 100 Ceratium 100 Goniodoma 100 Family 2 Dinophysidae 100 Genus Dinophysis 101 Amphisolenia 101 Oxyphysis 101 Family 3 Phytodiniidae 101 Genus Phytodinium 101 Stylodinium 101 Tribe 2 Gymnodinioidae 101 Family 1 Glenodiniidae 102 Genus Glenodinium 102 Family 2 Pronoctilucidae 102 Genus Pronoctiluca 102 Oxyrrhis 102 Family 3 Pouchetiidae 102 Genus Pouchetia 102 62 HANDBOOK OF PROTOZOOLOGY Family 4 Noctllucidae 104 Genus Noctiluca 104 Family 5 Gymnodiniidae 104 Genus Gymnodinium 104 Hemidinium 104 Amphidinium 104 Family 6 Blastodiniidae 105 Genus Blastodinium 105 Chytriodinium 105 Oodinium 105 Apodinium 105 Haplozoon 105 Family 7 Polykrikidae 105 Genus Polykrikos 105 Suborder 3 Cystoflagellata 106 Genus Leptodiscus 106 Craspedotella 106 Order 4 Phytomonadida 107 Family 1 Polyblepharidae 108 Genus Pyramimonas 108 Polytomella 108 Collodictyon 109 Medusochloris 109 Family 2 Chlamydomonadidae 109 Genus Chlamydomonas 109 Haematococcus 109 Brachiomonas 109 Lobomonas 110 Chlorogonium 110 Carteria 110 Family 3 Volvocidae 110 Genus Gonium 110 Platydorina Ill Spondylomorum Ill Stephanosphaera . Ill Pandorina 112 Eudorina 112 Pleodorina 112 Volvox 113 Family 4 Polytomidae 114 Genus Polytoma 114 Parapolytoma 114 Family 5 Phacotidae 114 Genus Phacotus 115 Pteromonas 115 Coccomonas 115 OUTLINE OF CLASSIFICATION 63 Order 5 Euglenoidida 116 Family 1 Euglenidae 117 Genus Euglena 117 Phacus 120 Lepocinclis 120 Trachelomonas 121 Cryptoglena 121 Ascoglena 121 Colacium 122 Eutreptia 123 Euglenamorpha 123 Family 2 Astasiidae 123 Genus Astasia 123 Urceolus 123 Peranema 124 Petalomonas 124 Menoidium 124 Scytomonas 124 Copromonas 124 Family 3 Heteronemidae 124 Genus Heteronema 125 Distigma 126 Entosiphon 126 Anisonema 126 Notosolenus 126 Order 6 Chloromonadida 127 Genus Gonyostomum 127 Vacuolaria 127 Trentonia 127 Thaumatomastix 128 Subclass 2 Zoomastigina 129 Order 1 Pantostomatida 129 Family 1 Holomastigidae 129 Genus Multicilia 129 Family 2 Rhizomastigidae 130 Genus Mastigamoeba 130 Mastigina 130 Mastigella 130 Actinomonas 132 Dimorpha 132 Pteridomonas 132 Ciliophrys 132 Order 2 Protomonadida 133 Family 1 Phalansteriidae 133 Genus Phalansterium 133 Family 2 Choanoflagellidae 134 64 HANDBOOK OF PROTOZOOLOGY Genus Monosiga 134 Codonosiga 134 Desmarella 134 Proterospongia 135 Sphaeroeca 135 Salpingoeca 135 Family 3 Bicosoecidae 135 Genus Bicosoeca 135 Poteriodendron 135 Family 4 Trypanosomatidae 136 Genus Trypanosoma 136 Crithidia '. 142 Leptomonas 143 Phytomonas 144 Herpetomonas 144 Leishmania 144 Oikomonas 145 Histomonas 146 Rhizomastix 146 Family 5 Cryptobiidae 146 Genus Cryptobia 147 Family 6 Amphimonadidae 147 Genus Amphimonas 147 Spongomonas 147 Cladomonas 147 Rhipidodendron 147 Spiromonas 148 Diplomita 148 Family 7 Monadidae 148 Genus Monas 149 Stokesiella 149 Dendromonas 149 Cephalothamnium 150 Anthophysa 150 Physomonas 150 Family 8 Bodonidae 150 Genus Bodo 150 Rhynchomonas 150 Prowazekella 151 Embadomonas 151 Phyllomitus 152 Colponema 152 Cercomonas 152 Family 9 Trimastigidae 152 Genus Trimastix 152 Dallingeria 153 Family 10 Costiidae 153 Genus Costia 153 OUTLINE OF CLASSIFICATION 65 Order 3 Poly mast igida 155 Tribe 1 Monozoa 155 Group 1 Genus Enteromonas 156 Tricercomonas 156 Tetramitus 156 Copromastix 156 Streblomastix 156 Group 2 Genus Devescovina 157 Paradevescovina 157 Metadevescovina 158 Foaina 158 Dinenympha 158 Pyrsonympha 158 Monocercomonas 158 Group 3 Genus Eutrichomastix 158 Retortamonas 159 Hexamastix 159 Protrichomonas 159 Polymastix 159 Group 4 Genus Chilomastix 160 Group 5 Genus Trichomonas 160 Ditrichomonas 161 Giantomonas 161 Myxomonas 161 Tribe 2 Diplozoa 161 Genus Hexamitus 161 Octomitus 162 Giardia 162 Trepomonas 163 Gyromonas 163 Trigonomonas 163 Urophagus 163 Tribe 3 Polyzoa 163 Genus Oxymonas 164 Proboscidiella 165 Calonympha 165 Stephanonympha 165 Snyderella 165 Coronympha 165 Order 4 Hypermastigida 167 Family 1 Holomastigotidae 167 Genus Holomastigotes 168 Holomastigotoides 168 Spirotrichonympha 168 Spirotrichonymphella 168 Microspirotrichonympha 168 66 HANDBOOK OF PROTOZOOLOGY Family 2 Lophomonadidae 168 Genus Lophomonas 169 Eulophomonai 170 Family 3 Joenidae 170 Genus Joenia 170 Joenina 170 Parajoenia 170 Joenopsis 171 Microjoenia 171 Mesojoenia 172 Family 4 Hoplonymphidae 172 Genus Hoplonympha 172 Family 5 Staurojoeniidae 172 Genus Staurojoenia 172 Family 6 Kofoidiidae 172 Genus Kofoidia 172 Family 7 Trichonymphidae 172 Genus Trichonympha 173 Pseudotrichonympha 174 Gymnonympha 174 Leydyopsis 174 Leydyonella 174 Family 8 Cyclonymphidae 174 Genus Cyclonympha 174 Class 2 Sarcodina 176 Sublclass 1 Rhizopoda 177 Order 1 Proteomyxa 177 Family 1 Labyrinthulidae 178 Genus Labyrinthula 178 Labyrinthomyxa 178 Family 2 Zoosporidae 178 Genus Pseudospora 178 Protomonas 179 Family 3 Vampyrellidae 179 Genus Vampyrella 180 Nuclearia 180 Arachnula 181 Chlamydomyxa 181 Rhizoplasma 181 Dictomyxa 181 Order 2 Mycetozoa 183 Suborder 1 Euplasmodia 187 Tribe 1 Endosporeae 187 Legion 1 Amaurosporales 187 Sublegion 1 Calcarinea 187 Family 1 Physaridae 187 Genus Badhamia 187 Fuligo 187 OUTLINE OF CLASSIFICATION 67 Family 2 Didymiidae 187 Gefiiis Didymium 187 Sublegion 2 Amaurochaetinea 187 Family 1 Stemonitidae 187 Genus Stemonitis 187 Family 2 Amaurochaetidae 188 Genus Amaurochaete 188 Legion 2 Lamprosporales 187 Sublegion 1 Aneminea 187 Family 1 Cribrariidae 188 Genus Cribraria 188 Family 2 Liceidae 188 Genus Orcadella 188 Family 3 Tubulinidae 188 Genus Tubulina 188 Family 4 Reticu'ariidae 189 Genus Reticularia 189 Family 5 Lycogalidae 189 Genus Lycogala 189 Sublegion 2 Caloneminea 187 Family 1 Trichiidae 190 Genus Trichia 190 Family 2 Arcyriidae 190 Genus Arcyria 190 Family 3 Margaritidae 190 Genus Margarita 190 Tribe 2 Exosporeae 187 Family 1 Ceratiomyxidae 190 Genus Ceratiomyxa 190 Suborder 2 Sorophora 190 Family 1 Guttuliniidae 190 Family 2 Dictyosteliidae 190 Appendix Phytomyxinae 190 Genus Plasmodiophora 190 Order 3 Foraminifera 192 Family 1 Astrorhizidae 196 Genus Rhabdammina 196 Family 2 Rhizamminidae 196 Genus Rhizammina 196 Family 3 Saccamminidae 196 Genus Saccammina 196 Family 4 Hyperamminidae 196 Genus Hyperammina 196 Family 5 Ammodiscidae 196 Genus Ammodiscus 196 Family 6 Silicinidae 196 Genus Silicina 196 68 HANDBOOK OF PROTOZOOLOGY Family 7 Reophacidae 196 Genus Reophax 196 Family 8 Lituolidae 196 Genus Lituola 196 Family 9 Fusulinidae 196 Genus Fusulina 196 Family 10 Loftusiidae 196 Genus Loftusia 196 Family 11 Textulariidae 196 Genus Textularia 197 Family 12 Verneuilinidae 197 Genus Verneuilina 197 Family 13 Valvulinidae 197 Genus Valvulina 197 Family 14 Neusinidae 197 Genus Neusina 198 Family 15 Trochamminidae 198 Genus Trochamniina 198 Family 16 Placopsilinidae 198 Genus Placopsilina 198 Family 17 Orbitolinidae 198 Genus Tetrataxis 198 Family 18 Miliolidae 198 Genus Spiroloculina 198 Triloculina 198 Family 19 Fischerinidae 198 Genus Fischerina 198 Family 20 Ophthalmidiidae 198 Genus Vertebralina 198 Family 21 Peneroplidae 198 Genus Peneroplis 198 Family 22 Alveolinellidae 198 Genus Alveolinella 198 Family 23 Keramosphaeridae 198 Genus Keramosphaera 198 Family 24 Lagenidae 199 Genus Lagena 199 Family 25 Polymorphinidae 199 Genus Polymorphina 200 Family 26 Nonionidae 200 Genus Elphidium 200 Family 27 Camerinidae 200 Genus Operculina 200 Family 28 Heterohelicidae 200 Genus Pavonina 200 Family 29 Hantkeninidae 200 Genus Hantkenina 201 OUTLINE OF CLASSIFICATION 69 Family 30 Buliminidae 201 Genus Bolivina 201 Family 31 Ellipsoidinidae 201 Genus Ellipsoidina 201 Family 32 Rotaliidae 201 Genus Rotalia 201 Family 33 Amphisteginidae 201 Genus Asterigerina 201 Family 34 Calcarinidae 201 Genus Calcarina 201 Family 35 Halkyardiidae 201 Genus Halkyardia 201 Family 36 Cassidulinidae 201 Genus Cassidulina 201 Family 37 Chilostomellidae 201 Genus Allomorphina 201 Family 38 Globigerinidae 202 Genus Globigerina 202 Family 39 Globorotaliidae 202 Genus Globorotalia 202 Family 40 Anomalinidae 202 Genus Anomalina 202 Family 41 Planorbulinidae 202 Genus Planorbulina 202 Family 42 Rupertiidae 202 Genus Rupertia 203 Family 43 Homotremidae 203 Genus Homotrema 203 Family 44 Orbitoididae 203 Genus Orbitoides 203 Order 4 Amoebaea 204 Family 1 Bistadiidae 205 Genus Naegleria 205 Trimastigamoeba 206 Family 2 Amoebidae 206 Genus Amoeba 206 Pelomyxa 208 Vahlkampfia 210 Hartmannella 210 Sappinia 211 Family 3 Endamoebidae 211 Genus Endamoeba 211 Entamoeba 213 Endolimax 220 lodamoeba 220 Dientamoeba 221 Schizamoeba 221 Hydramoeba 222 70 HANDBOOK OF PROTOZOOLOGY Family 4 Paramoebidae 223 Genus Paramoeba 223 Order 5 Testacea 225 Family 1 Arcellidae 226 Genus Arcella 226 Pyxidicula 226 Pseudochlamys 227 Difflugiella 227 Cryptodifflugia 227 Lesquereusia 228 Hyalosphenia 228 Leptochlamys 229 Chlamydophrys 229 Cochliopodium 230 Amphizonella 230 Zonomyxa 230 Microcorycia 230 Parmulina 231 Capsellina 231 Diplochlamys 231 Family 2 Allogromiidae 232 Genus Allogromia 232 Microgromia 232 Lieberkiihnia 232 Rhynchogromia 234 Diplophrys 234 Amphitrema 234 Lecythium 234 Pseudodifflugia 234 Diaphoropodon 235 Clypeolina 236 Family 3 Difflugiidae 236 Genus Dififlugia 236 Centropyxis 238 Cucurbitella 238 Plagiopyxis 238 Pontigulasia 238 Phryganella 238 Bullinula 239 Heleopera 239 Averintzia 239 Family 4 Euglyphidae 239 Genus Euglypha 239 Paulinella 240 Cyphoderia 240 Campascus 241 OUTLINE OF CLASSIFICATION 71 Trinema 241 Corythion 242 Placocista 242 Assulina 243 Nebela 243 Quadrula 243 Subclass 2 Actinopoda 245 Order 1 Heliozoa 245 Suborder 1 Aphrothoraca 247 Genus Actinophrys 247 Actinosphaerium 247 Camptonema 248 Oxnerella 248 Suborder 2 Chlamydophora 248 Genus Astrodisculus 248 Actinolophus 248 Heterophrys 248 Elaeorhanis 250 Lithocolla 250 Sphaerastrum 250 Suborder 3 Chalarothoraca 250 Genus Pompholyxophrys 250 Acanthocystis 251 Raphidiophrys 251 Raphidiocystis 252 Wagnerella 252 Pinaciophora 252 Suborder 4 Desmothoraca 252 Genus Clathrulina 252 Hedriocystis 252 ' Choanocystis 253 Order 2 Radiolaria 254 Suborder 1 Actipylea 258 Legion 1 Actinelida 258 Family 1 Actineliidae 258 Genus Actinelius 258 Family 2 Acanthociasmidae 258 Genus Acanthociasma 258 Legion 2 Acanthometrida 258 Family 1 Acanthometridae 259 Genus Acanthometron 259 Family 2 Acanthoniidae 259 Genus Acanthonia 259 Family 3 Amphilonchidae 259 Genus Amphilonche 259 Legion 3 Acanthophractida 259 Family 1 Sphaerocapsidae 259 Genus Sphaerocapsa 259 72 HANDBOOK OF PROTOZOOLOGY Family 2 Diploconidae 259 Genus Diploconus 259 Family 3 Hexalaspidae 259 Genus Hexaconus 259 Suborder 2 Peripylea 259 Legion 1 CoUodaria 259 Family 1 Physematiidae 259 Genus Lampoxanthium 259 Family 2 Thalassicollidae 259 Genus Thalassicolla 259 Family 3 Thalassophysidae 259 Genus Thalassophysa 259 Family 4 Thalassothamnidae 259 Genus Thalassothamnus 259 Family 5 Orosphaeridae 259 Genus Orosphaera 260 Legion 2 Sphaerellaria 260 Family 1 Sphaeroidae 260 Genus Hexacontium 260 Family 2 Prunoidae 260 Genus Pipetta 260 Family 3 Discoidae 260 Genus Staurocyclia 261 Family Larcoidae 261 Genus Cenolarus 261 Legion 3 Polycyttaria 261 Family 1 Sphaerozoidae 261 Genus Sphaerozoum 261 Family 2 Collosphaeridae 261 Genus Collosphaera 261 Suborder 3 Monopylea 261 Legion 1 Nassoidea 261 Family 1 Nassoidae 261 Genus Cystidium 261 Legion 2 Plectellaria 261 Family 1 Plectoidae 261 Genus Triplagia 261 Family 2 Stephoidae 261 Genus Lithocircus 261 Legion 3 Cyrtellaria 261 Family 1 Cyrtoidae 261 Genus Dictyophimus 261 Family 2 Botryoidae 261 Genus Phormobothrys 261 Suborder 4 Tripylea 262 Legion 1 Phaeocystina 262 OUTLINE OF CLASSIFICATION 73 Family 1 Aulacanthidae 262 Genus Aulacantha 262 Family 2 Caementellidae 262 Genus Caementella 262 Legion 2 Phaeosphaeria 262 Family 1 Sagosphaeridae 262 Genus Sagenoscene 262 Family 2 Aulosphaeridae 262 Genus Aulosphaera 262 Family 3 Cannosphaeridae 262 Genus Cannosphaera 262 Legion 3 Phaeogromia 262 Family 1 Challengeridae 262 Genus Challengeron 262 Family 2 Medusettidae 262 Genus Medusetta 262 Legion 4 Phaeocalpia 263 Family 1 Castanellidae 263 Genus Castanidium 263 Family 2 Circoporidae 263 Genus Circoporus 263 Family 3 Tuscaroridae 263 Genus Tuscarora 263 Legion 5 Phaeoconchia 263 Family Coelodendrldae 263 Genus Coelodendrum 263 Class 3 Sporozoa 265 Subclass 1 Telosporidia 266 Order 1 Coccidia 267 Suborder 1 Eimeridea 267 Family 1 Selenococcidiidae 269 Genus Selenococcidium 269 Family 2 Aggregatidae 270 Genus Aggregata 270 Caryotropha 270 Angeiocystis 271 Family 3 Dobelliidae 271 Genus Dobellia 271 Family 4 Eimeriidae 271 Genus Eimeria 271 Jarrina 274 Isospora 274 Cyclospora 275 Caryospora 275 Pfeifferinella 275 Barrouxia 276 Lankesterella 276 Cryptosporidium 276 74 HANDBOOK OF PROTOZOOLOGY Suborder 2 Adeleidea 276 Family 1 Adeleidae 278 Genus Adelea 278 Adelina 278 Klossia 278 Orcheobius 279 Klossiella 279 Legerella 279 Family 2 Haemogregarinidae 279 Genus Haemogregarina 279 Hepatozoon 281 Karyolysus 282 Order 2 Haemosporidia 284 Family 1 Plasmodiidae 286 Genus Plasmodium 286 Family 2 Haemoproteidae 287 Genus Haemoproteus 288 Leucocytozoon 288 Family 3 Babesiidae 289 Genus Babesia 289 Theileria 289 Cytamoeba 289 Order 3 Gregarinida 291 Suborder 1 Eugregarinina 291 Legion 1 Acephala 293 Genus Monocystis 293 Zygocystis 293 Pleurocystis 293 Pterospora 294 Cystobia 294 Lithocystis 295 Urospora 295 Gonospora 295 Lankesteria 295 Nematocystis 295 Rhynchocystis 296 Allantocystis 296 Legion 2 Cephalina 296 Genus Gregarina 296 Hirmocystis 296 Leidyana 296 Stenophora 297 Acutispora 297 Nina 298 Asterophora 298 Amphoroides 298 OUTLINE OF CLASSIFICATION 75 Steinina 298 Stylocephalus 298 Porospora 298 Dendrorhynchus 299 Suborder 2 Schizogregarinaria 299 Genus Schizocystis 299 Ophryocystis 300 Lipotropha 301 Caulleryella 301 Subclass Z Cnidosporidia 302 Order 1 Myxosporidia 303 Suborder 1 Eurysporea 306 Family Ceratoniyxidae 306 Genus Ceratomyxa 306 Leptotheca 306 Myxoproteus 306 Wardia 307 Mitraspora 307 Suborder 2 Sphaerosporea 308 Family 1 Chloromyxidae 308 Genus Chloromyxum 308 Family 2 Sphaerosporidae 308 Genus Sphaerospora 308 Sinuolinea 309 Unicapsula 309 Suborder 3 Platysporea 309 Family 1 Myxidiidae 309 Genus Myxidium 309 Sphaeromyxa 309 Zschokkella 310 Family 2 Coccomyxidae 310 Genus Coccomyxa 310 Family 3 Myxosomatidae 311 Genus Myxosoma 311 Lentospora 311 Agarella 311 Family 4 Myxobolidae 312 Genus Myxobolus 312 Henneguya 312 Order 2 Actinomyxidia 313 Family I Tetractinomyxidae 313 Genus Tetractinomyxon 313 Family 2 Triactinomyxidae 314 Genus Triactinomyxon 314 Sphaeractinomyxon 315 Hexactinomyxon 315 Synactinomyxon 315 Neoactinomyxum 315 76 HA NDBOOK OF PRO TOZOOLOG Y Order 3 Microsporidia 317 Suborder 1 Monocnidea 320 Family 1 Nosematidae . 32Q Genus Nosema 32D Glugea 320 Perezia 320 Gurleya 321 Thelohania 321 Stempellia 321 Duboscqia 321 Plistophora 321 Family 2 Coccosporidae 323 Genus Coccospora 323 Family 3 Mrazekiidae 323 Genus Mrazekia 323 Octosporea 323 Spiroglugea 323 Toxoglugea 323 Suborder 2 Dicnidea 323 Family Telomyxidae 323 Genus Telomyxa 323 Order 4 Helicosporidia 324 Genus Helicosporidium 325 Subclass 3 Acnidosporidia 326 Order 1 Sarcosporidia 326, Genus Sarcocystis 328 Order 2 Haplosporidia 328 Genus Haplosporidium 329 Urosporidium 331 Anurosporidium 331 Bertramia 331 Ichthyosporidium 331 Coelosporidium 331 Subphylum 2 Ciliophora 333 Class 1 Ciliata 333 Subclass 1 Protociliata 335 Family Opalinidae 336 Genus Protoopalina 336 Zelleriella 337 Cepedia 337 Opalina 338 Subclass 2 Euciliata 339 Order 1 Holotrichida 339 Suborder 1 Astomina 339 Genus Rhizocaryum 339 Biitschliella 340 OUTLINE OF CLASSIFICATION 77 Anoplophrya 341 Mesnilella 341 Hoplitophrya 341 Maupasella 341 Schultzellina 341 Kofoidella 341 Intoshellina 341 Haptophrya 342 Sieboldiellina 342 Lachmannella 342 Steinella 342 Lada 342 Cepedella 342 Herpetophrya 342 Perezella 343 Collinia 344 Protophrya 344 Isselina 344 Orchitophrya 344 Monomastix . 344 Suborder 2 Gymnostomina 344 Family 1 NicollelHdae 345 Genus Nicollella 345 CoUinella 345 Pycnothrix 345 Family 2 Holophryidae 346 Genus Holophrya 346 Balanitozoon 346 Urotricha 346 Actinobolus 346 Coleps 346 Tiarina 347 Plagiopogon 347 Metacystis 347 Trachelocerca 347 Trachelophyllum 347 Lacrymaria 347 Chaenia 347 Prorodon 348 Ichthyophthirius 349 Enchelys 350 Enchelyodon 350 Lagynus 350 Spathidium 350 Didinium 350 Monodinium 352 Mesodinium 352 Dinophrya 352 78 HANDBOOK OF PROTOZOOLOGY Family 3 Tracheliidae 352 Genus Trachelius 352 Dileptus 352 Lionotus 353 Loxodes 353 Loxophyllum 354 Amphileptus 354 Family 4 Chilodontidae 354 Genus Chilodon 354 Nassula 355 Opisthodon 355 Orthodon 355 Dysteria 357 Phascolodon 357 Scaphidiodon 357 Trochilia 357 Aegyria 357 Suborder 3 Trichostomina 358 Family 1 Urocentridae 358 Genus Urocentrum 358 Family 2 Ophryoglenidae 358 Genus Ophryoglena 359 Cyrtolophosis 359 Loxocephalus 359 Uronema 359 Dallasia 359 Frontonia 360 Glaucoma 360 Colpoda 361 Colpidium 361 Lambornella 361 Entorhipidium 362 Family 3 Microthoracidae 363 Genus Microthorax 363 Cinetochilum 363 Family 4 Parameciidae 363 Genus Paramecium 363 Family 5 Pleuronematidae 366 Genus Pleuronema 366 Cyclidium 367 Lembadion 367 Lembus 368 Pleurocoptes 368 Calyptotricha 368 Family 6 Isotrichidae 368 OUTLINE OF CLASSIFICATION 79 Genus Isotricha 368 Dasytricha 369 Conchophthirus 369 Buxtonella 369 Order Z Heterotrichida 371 Suborder 1 Gymnoheterotrichina 371 Family 1 Plagiotomidae 371 Genus Plagiotoma 371 Nyctotherus 372 Blepharisma 372 Spirostomum 372 Metopus 373 Family 2 Bursariidae 374 Genus Bursaria 374 Balantidiuni 374 Balantidiopsis 374 Condylostoma 375 Family 3 Stentoridae 375 Genus Stentor 375 Folliculina 377 Cllmacostomum 377 Family 4 Boveriidae 377 Genus Boveria 377 Family 5 Caenomorphidae 378 Genus Caenomorpha 378 Family 6 Epalcidae 378 Genus Epalxis 378 Pelodinium 379 Discomorpha 379 Saprodinium 379 Suborder 3 Tintinnoinea 379 Genus Tintinnidium 379 Order 3 Oligotrichida 381 Family 1 Halteriidae 381 Genus Halteria 381 Strombidium 381 Family 2 Ophryoscolecidae 381 Genus Ophryoscolex 381 Entodinium 382 Diplodinium 382 Spirodinium 382 Triadinium 382 Cycloposthium 382 Tripalmaria 382 Tetratoxum 384 Cochliatoxum 384 Ditoxum 384 80 HANDBOOK OF PROTOZOOLOGY Order 4 Hypotrichida 385 Family 1 Peritromidae 385 Genus Peritromus 385 Family 2 Oxytrichidae 385 Genus Oxytricha 385 Stylonychia 386 Urostyla 386 Kerona 386 Epiclintes 386 Amphisia 386 Holosticha 388 Stichotricha 388 Uroleptus 389 Pleurotricha 389 Gastrostyla 389 Onychodromus 389 Actinotricha 389 Family 3 Euplotidae 389 Genus Euplotes 389 Uronychia 390 Diophrys 390 Family 4 Aspidiscidae 390 Genus Aspidisca 390 Family 5 Psilotrichidae 391 Genus Psilotricha 391 Balladina 391 Order 5 Peritrichida 392 Family 1 Trichodinidae 392 Genus Trichodina 392 Cyclochaeta 392 Trichodinopsis 394 Family 2 Vorticellidae 394 Genus Vorticella 394 Carchesium 394 Zoothamnium 395 Epistylis 395 Ophrydium 395 Opercularia 395 Gerda 397 Scyphidia 397 Glossatella 397 Rhabdostyla 397 Astylozoon 397 Hastatella 397 Cothurnia 397 Vaginicola 398 Lagenophrys 398 OUTLINE OF CLASSIFICATION 81 Family 3 Licnophoridae 398 Genus Licnophora 398 Family 4 Spirochonidae 398 Genus Spirochona 398 Class Z Suctoria 399 Family 1 Dendrosomidae 400 Genus Trichophrya 400 Astrophrya 400 Lernaeophrya 400 Dendrosoma 400 Dendrosomides 401 Rhabdophrya 402 Family 2 Ophryodendridae 402 Genus Ophryodendron 402 Family 3 Dendrocometidae 402 Genus Dendrocometes 402 Stylocometes 402 Family 4 Podophryidae 402 Genus Podophrya 402 Sphaerophrya 402 Paracineta 404 Metacineta 404 Urnula 404 Family 5 Acinetidae 404 Genus Acineta 404 Tokophrya 404 Thecacineta 404 Periacineta 404 Hallezia 406 Solenophrya 406 Acinetopsis 406 Tachyblaston 406 Dactylophrya 406 Pseudogemma 406 Endosphaera 406 Family 6 Discophryidae 408 Genus Discophrya 408 Thaumatophrya 408 Rhynchophrya 408 Choanophrya 408 Rhyncheta 408 Family 7 Ephelotidae 408 Genus Ephelota 408 Podocyathus 408 Family 8 Hypocomidae 410 Genus Hypocoma 410 CHAPTER V SUBPHYLUM 1 PLASMODROMA DOFLEIN CLASS 1 MASTIGOPHORA DIESING THE CLASS Mastigophora includes those Protozoa which possess one or more flagella. Aside from this common characteristic, the members of this class make a very heterogene- ous assemblage. Since it includes a large number of chlorophyll- bearing organisms, it seems to stand in the way of a sharp distinction between the Protozoa and the Protophyta. Many of its members have been, and still are, classified with the Proto- phyta by botanists. In the majority of the Mastigophora, each individual pos- sesses one to four flagella during the entire life-cycle except in the encysted or palmella stage. In some forms there occur six or eight flagella, and in Hypermastigida an enormous number of flagella are usually found. The palmella stage (Fig. 29) is con - mon among the Phytomastigina and, unlike the encysted stage, is capable not only of metabolic activity and growth but also of reproduction. Thus these forms show undoubtedly a close relationship to the algae. All four types of nutrition, carried on separately or in combination, are to be found among the members of the Mastigophora. In holophytic forms, the chlorophyll is contained in the chromatophores, which are of various forms among difi'erent species (Fig. 15) and vary in color, being green, blue- green, yellow, brown, reddish-brown, red, etc. The difference in color is mainly due to the pigments which envelop the chlorophyll. Many forms adapt their mode of nutrition to changed environmental conditions, for instance, from holophy- tic to saprozoic in absence of sunlight. Holozoic, saprozoic and holophytic nutrition seem to be combined in Ochromonas. The chromatophore frequently contains a refractile granule or body, the pyrenoid (Fig. 15), which becomes the center of the forma- tion of the paramylum body. Besides the latter, reserve food 182 1 PLASMODROMA, MASTIGOPHORA, CHRYSOMONADIDA 83 materials consisting of oil and carbohydrates are occasionally found. In the less complicated forms, the body is naked except for a slight cortical differentiation of the ectoplasm to delimit the body surface. Such forms are capable of pseudopodial for- mation. In others there occurs a thin expansible pellicle secreted by the ectoplasm, which covers the body surface closely. These forms are often plastic and change their form in a peculiar fashion (Fig. 6). In still others the body is constant, being en- cased in a shell, test, lorica, or plate, which is composed of chitin, pseudochitin, or cellulose. Not infrequently a gelatinous secre- tion envelops the body. In one group, Choanoflagellidae, there is a collar-like structure located at the anterior end surrounding the flagellum. The great majority of the Mastigophora possess a single nucleus, and only a few are multinucleated. The nucleus is usually of vesicular type with a conspicuous endosome. Con- tractile vacuoles are always present in the forms inhabiting fresh water. In the 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 Dinoflagellida, there are apparently no contractile vacuoles, but non-contractile pusules, which seem to have hydrostatic function, are present in the cytoplasm. In forms with chromatophores, there occurs usually a reddish or brownish, rounded or elongated body, the stigma, which is situated near the base of the fiagellum. It seems to be the center of phototropic activity of the organism which possesses it. A number of Mastigophora are capable of forming pseudopodia of various types which serve for food-capturing and locomotion. Asexual reproduction of the Mastigophora is, as a rule, by longitudinal fission, but in some forms multiple fission also oc- curs under certain circumstances, and in others budding may take place. Colony-formation, due to incomplete separation of the daughter individuals, is widely found among the group. Sexual reproduction has been noted in a number of species. The development varies among different groups and will be briefly taken up for individual orders. 84 HANDBOOK OF PROTOZOOLOGY The class Mastigophora includes free-living as well as para- sitic forms. Its members are found in fresh and salt waters of much wider range than are other groups, because of their holo- phytic nutrition. Many are free-swimming, others creep over the surface of submerged objects, and still others are sessile. Together with the algae, the Mastigophora compose a major portion of plankton life, which is the basis for the existence of all higher forms of aquatic animals. The parasitic forms are ectoparasitic or endoparasitic. The latter live either in the di- gestive tract or in the circulatory system of the host. Trypan- osoma, a representative genus of the latter type, includes impor- tant disease-causing parasites of man and of domestic animals According to Doflein, the Mastigophora are divided into two subclasses: Phytomastigina and Zoomastigina. SUBCLASS I PHYTOMASTIGINA DOFLEIN Most of the Phytomastigina possess chromatophores, and their usual method of nutrition is therefore holophytic, though a few are mixotrophic. The majority are conspicuously colored. vSome that lack chromatophores are included in this group, since their morphology and development resemble closely those of typical Phytomastigina. According to Calkins, the subclass is divided into six orders, as follows: With cellulose shell composed of plates; two flagella, one of which is transverse Order 3 Dinoflagellida Without cellulose shell composed of plates; no transverse flagellum Chromatophores yellow or brown; contractile vacuoles simple Cytopharynx absent; body not flattened Order 1 Chrysomonadida Cytopharynx present; body flattened Order 2 Cryptomonadida Chromatophores green; contractile vacuoles simple or complex Without cytopharynx; vacuole simple Order 4 Phytomonadida With cytopharynx; vacuole complex Metabolic products paramylum Order 5 Euglenoidida Metabolic products oil Order 6 Chloromonadida ORDER I CHRYSOMONADIDA STEIN Most of the Chrysomonadida are minute. They show vari- ous body organizations. Chromatophores are yellow to brown PLASMODROMA, MASTIGOPHORA, CHRYSOMONADIDA 85 (rarely green or bluish) and usually discoid, though sometimes reticulated. The products of metabolism are refractile bodies, known collectively as leucosin (probably carbohydrates), fats and oils. Starches have never been found in them. The flagella, usually one or two in number, are planted at or near the anterior end of the body, with a stigma near the insertion point, as a rule, when there is but one flagellum. Many Chrysomonadida are able to form pseudopodia for ob- taining food materials, which vary among different species. Nutrition, though chiefly holophytic, is often holozoic or sapro- zoic also. Contractile vacuoles are invariably found in fresh- Fig. 29 Diagram showing the development of Chromulina. X about 200. (After Kuhn, modified), a, encystment; b, fission; c, colony for- mation; d, palmella formation. water forms. They are ordinarily of simple structure, although a few of them have rather complicated systems. Under conditions not fully understood, the Chrysomonadida transform themselves into a rounded stage known as the pal- mella phase and undertake metabolic activities as well as multiplication (Fig. 29). Asexual reproduction is usually by longitudinal division during either the motile or the palmella stage. Incomplete separation of the daughter individuals fol- lowed by repeated fission, results in numerous colonial forms of all three types mentioned elsewhere (p. 51). Some resemble higher algae very closely. Sexual reproduction is entirely unknown in this group. Encystment occurs commonly among the chryso- 86 HANDBOOK OF PROTOZOOLOGY monads. In this the flagellum is lost and a silicious wall is secreted around the cyst. There is usually an opening with a plug. This group is divided into the following three suborders: Motile stage dominant Suborder 1 Euchrysomonadina Palmella stage dominant Sarcodina-like; flagellate stage unknown Suborder 2 Rhizochrysidina Palmella phase dominant Suborder 3 Chrysocapsina Suborder 1 Euchrysomonadina Pascher With one anterior flagellum Family 1 Chromulinidae With two equal flagella Family 2 Isochrysidae With two unequal flagella Family 3 Ochromonadidae With calcareous discs and rods Family 4 Coccolithophoridae With simple skeleton Family 5 Silicoflagellidae Family 1 Chromulinidae Senn Minute forms, naked or with sculptured shell; with a single flagellum; often with rhizopodia; a few colonial. Free-swim- ming or attached. Some fifteen genera. Genus Chrysapsis Pascher. Chromatophores diffused or in a network. With stigma; amoeboid locomotion. Chrysapsis sagene Pascher (Fig. 30, a). Body about 10 mi- crons long; flagellum about 30 microns long. Fresh water. Genus Chromulina Cienkowski. Body minute, ovoid. With one or two chromatophores. A single flagellum. Cysts possess a plug. Several species in clean fresh water. The presence of a large number of organisms sometimes gives a golden-brown color to the surface of the water. Chromulina pascheri Hofeneder (Fig. 30, b-d). Body diam- eter about 15 to 20 microns. Genus Chrysococcus Klebs. Shell spheroidal or ovoidal, smooth or sculptured and often brown-colored. Through an opening a flagellum protrudes. One or two chromatophores. One of the daughter individuals formed by binary fission leaves the parent shell and forms a new one. Chrysococcus ornatus Pascher (Fig. 30, e). In fresh water. About 15 microns long. Genus Mallomonas Perty. Body elongated; with silicious PLASMODROMA, MASTIGOPHQRA, CHRYSOMONADIDA 87 scales and often spines. Two chromatophores, rod-shaped. Several species. Mallomonas ploesslii Perty (Fig. 30,/). Body about 25 to 30 microns long. Fresh water. Fig. 30 a. Chrysapsis sagene. X750 (After Pascher). b-d. Chromiilina pascheri. X 500 (After Hofeneder). b, an individual from a colony; c, d, cysts. e. Chrysococcus ornatus. X450 (After Pascher). f. Mallomonas ploesslii. X400 (After Klebs). g. Synura uvella. X380 (After Stein). h. Syncrypta volvox. X325 (After Stein). i. Ochromonas mutabilis. X500 (After Senn). j. O. ludibunda. X400 (After Pascher). k. Uroglena volvox. X325 (After Stein, modified). 1. Uroglenopsis americana. X350 (After Pascher). m. Cyclonexis annularis. X390 (After Stokes). Family 2 Isochrysidae Pascher Solitary or colonial chrysomonads with two equal flagella; with or without a pellicle (when present, often sculptured) ; some possess a stalk. Several genera. Genus Synura Ehrenberg. Spherical colony composed of 88 HANDBOOK OF PROTOZOOLOGY two to fifty ovoid individuals arranged radially. Body usually covered by short bristles. Two chromatophores lateral; no stigma. Asexual reproduction of individuals is by longitudinal division; that of a colony by bipartition. Cysts are spherical. Synura uvella Ehrenberg (Fig. 30, g). Fresh water. If present in large numbers, the organism is said to be responsible for an odor of the water resembling that of ripe cucumber (Moore). Genus Syncrypta Ehrenberg. Spherical colonies; individ- uals with two lateral chromatophores, are embedded in a gela- tinous mass. Cysts unknown. Syncrypta volvox Ehrenberg (Fig. 30, h). In standing water. Family 3 Ochromonadidae Pascher With two unequal flagella. The body has no pellicle and is therefore changeable. Contractile vacuoles are simple; with or without delicate test. Solitary or colonial. Free-swimming or attached. Genus Ochromonas Wysotzki. Solitary or colonial. Body surface is delicate; posterior end is often drawn out for attach- ment. One or two chromatophores; usually with a stigma. Encystment. Ochromonas mutahilis Klebs (Fig. 30, i). About 15 microns in diameter. Ochromonas liidibunda Pascher (Fig. 30, j). Body about 15 microns long. Genus Uroglena Ehrenberg. Spherical or ovoidal colonies, composed of ovoid or ellipsoidal individuals arranged along the periphery of a spherical gelatinous mass. All individuals are connected with one another by gelatinous processes running inward and meeting in a point. With a stigma and a plate-like chromatophore. Asexual reproduction of individuals by longi- tudinal fission; that of a colony by bipartition. Spherical cysts with spinous projections, and a long tubular process. Uroglena volvox Ehrenberg (Fig. 30, k). In standing water. Genus Uroglenopsis Lemmermann. Similar to Uroglena, but individuals without inner connecting processes. Uroglenopsis americana (Calkins) (Fig. 30, 1). When present PLASMODROMA, MASTIGOPHORA, CHRYSOMONADIDA 89 abundantly in a water reservoir, the organism gives an offensive odor to the water (Calkins). Genus Cyclonexis Stokes. Wheel-like colonial forms com- posed of ten to twenty wedge-shaped individuals. Young colo- nies are funnel-shaped. With two lateral chromatophores; no stigma; reproduction and encystment unknown. Cyclonexis annularis Stokes (Fig. 30, m). Colony about 25 to 30 microns in diameter. In marshy water with Sphagnum. Genus Dinobryon Ehrenberg. Solitary or colonial. Individ- uals with vase-like, hyaline, but sometimes, yellowish cellulose test which is drawn out at its base. The delicate body is elon- gated and attached to the base of the test with its attenuated posterior tip. One or two lateral chromatophores; usually with a stigma. Asexual reproduction by binary fission; one of the daughter individuals leaving the test as a swarmer, to form a new one. In colonial forms the daughter individuals remain attached to the inner margin of the opening of the parent tests and there secrete new tests. Encystment common ; the spherical cysts possess a short process. Dinobryon sertularia Ehrenberg (Fig. 31, a). Fresh water. Genus Hyalobryon Lauterborn. Solitary or colonial. In- dividual body structure is similar to that of Dinobryon. The test in some cases, is tubular, and those of young individuals are attached to the exterior of the parent tests. Hyalobryon ramosum Lauterborn (Fig. 31, b). Fresh water. Genus Stylopyxis Balachonzeff . Solitary. The body is lo- cated at the bottom of a delicate stalked test with a wide aper- ture. Two lateral chromatophores. Family 4 Coccolithophoridae Lohmann The members of this family, with a few exceptions, occur in salt water only. With perforate (tremalith) or imperforate (dis- colith) discs, composed of calcium carbonate. One or two fla- gella; two yellowish chromatophores; a single nucleus; oil drops and leucosin. Nutrition holophytic. Examples: Pontosphaera haeckeli Lohmann (Fig. 31, c). Discosphaera tubifer Murray and Blackman (Fig. 31, d). 90 HANDBOOK OF PROTOZOOLOGY Family 5 Silicoflagellidae Borgert Exclusively marine planktons. With silicious skeleton which envelops the body. Example: Distephanus speculum (Miiller) (Fig. 31, g). Fig. 31 a. Dinobryon sertularia. X500 (After Scherffel and Senn). b. Hyalobryott ramosum. X400 (After Lauterborn). c. Pontosphaera haeckeli. X800 (After Kiihn). d. Discosphaera tubifer. X500 (After Kiihn). e. Distephanus speculum. X400 (After Kiihn). f. Rhizochrysis scherffeli. X500 (After Doflein). g-i. Hydrurus foetidus. g, an entire colony (after Berthold); h, a portion (X250 after Klebs); i, cyst (X600 after Klebs). Suborder 2 Rhizochrysidina Pascher No flagellate stage is known 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 or- ganisms resemble some members of the Sarcodina. Several genera. PLASMODROMA, MASTIGOPHORA, CHRYSOMONADIDA 91 Genus Rhizochrysis Pascher. Body naked and amoeboid; with one or two chromatophores. Rhizochrysis scherffeli Pascher (Fig. 31,/). Suborder 3 Chrysocapsina Pascher Palmeila stage is prominent. Flagellate forms are transient. Colonial; individuals are enclosed in a gelatinous mass. One or two flagella, one chromatophore, and a contractile vacuole are typically present in each individual. One group of relatively minute forms and the other of large organisms. Among the latter, Ilydrurus foetidus Kirchner (Figs. 15, d-f; 31, g-i) is conspicuous in having a large palmeila stage, which may be cylindrical or dendritic, and which may grow from one to thirty centimeters long. Individuals are arranged loosely in the gelat- inous matrix. Apical growth resembles much higher algae. Multiplication of individuals results in formation of pyramidal forms with a flagellum, a chromatophore, and a leucosin mass. The encysted stage may show a wing-like rim. References Calkins, G. N. 1926 The biology of the Protozoa. Phila- delphia. DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- tozoenkunde. Jena. KtJHN, A. 1921 Morphologie der Tiere in Bildern. I. H.; I Teil. Berlin. 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. Geitler, L. 1926 Zur Morphologie und Entwickelungs- geschichte der Pyrenoide. Arch f. Protistenk., Vol. 56. LoHMANN, H. 1913 Ueber Coccolithophoriden. Verb. Deutsch. Zool. Ges., Bremen. Pascher, A. 1913 Chrysomonadinae. Susswasserflora Deutsch- lands, etc. Jena. West, G. S. and F. E. Fritsch. 1927 A treatise on the British freshwater algae. Cambridge. CHAPTER VI ORDER 2 CRYPTOMONADIDA STEIN THE CRYPTOMONADIDA differ from the Chrysomonadida in having a constant body form. Pseudopodia are very rarely formed, as the body surface is covered by a pellicle. The majority show dorso-ventral differentiation, with an oblique longitudinal furrow. One or two unequal flagella arise from the furrow or from the cytopharynx. In case two flagella are present, both may be directed anteriorly or one posteriorly. These organisms are free-swimming or creeping. One or two chromatophores are usually present. They are discoid or band-form, and may be green, bluish green, blue, yellow, brown, reddish brown, or red. The nature of the color- ing matter is not well understood, but it is said to be similar to that which is found in the Dinoflagellida and diatoms. One or more spherical pyrenoids which are enclosed within an en- velope of amyloid substance are present. Nutrition is mostly holophytic; a few saprozoic or holozoic. Assimilation products are amyloid substances; fat and oil are produced in holozoic forms which feed upon bacteria and small Protozoa. The stigma is usually associated with the insertion point of the flagella. Contractile vacuoles, one or 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 members form palmella stages and others gelatinous aggregates. In the suborder Phaeocapsina, the palmella stage is permanent. Cysts are spherical, and the cyst wall is composed of cellulose. The Cryptomonadida abound in sea water, living also often as symbionts in marine organisms. A comparatively few forms are found in fresh water. According to Pascher, they are divided into two suborders: Motile flagellate forms predominant Suborder 1 Eucryptomonadina Palmella stage permanent Suborder 2 Phaeocapsina [92]] CR YP TO MONAD ID A 93 Suborder 1 Eucryptomonadina Pascher Anterior end truncate; two anterior flagella; with an oblique furrow near anterior end Family 1 Cryptomonadidae Reniform; with two lateral flagella; furrow equatorial Family 2 Nephroselmidae Family 1 Cryptomonadidae Stein Genus Cryptomonas Ehrenberg. Body elliptical with a firm pellicle. Anterior end truncate. Longitudinal furrow large, extending to the middle of the body, through which two equally long flagella arise. Two lateral chromatophores vary in color from green to blue green, brown, or rarely red. Holophytic; paramylum bodies. Fresh and salt waters. ©®^% Fig. 32 a. Cryptomonas ovata. X500 (After Doflein, modified), b, c. Chrysidella schaudinni. X 1000 (After Winter). d. Chilomonas Paramecium. X500 (After Doflein, modified). e. Cyathomonas truncata. X500 (After Doflein, modified). f. Cryptochrysis commuta. X500 (After Pascher). g. Protochrysis phaeophycearum. X600 (After Pascher). h. Nephroselmis olivacea. X500 (After Pascher). i,j. Phaeothamnion confervicolum. X450 (After Kiihn). Cryptomonas ovata Ehrenberg (Fig. 32, a). Length about 30 to 40 microns. Widely distributed among vegetation in fresh water. Genus Chrysidella Pascher. Somewhat similar to Cryp- tomonas, but much smaller. Chromatophores much shorter. Those occurring in Foraminifera or Radiolaria as symbionts are known as Zooxanthellae. Several species. Chrysidella schaudinni (Winter) (Fig. 32, b, c). Body less 94 HANDBOOK OF PROTOZOOLOGY than 10 microns long. In the foraminiferan, Peneroplis per- tusus. Genus Chilomonas Ehrenberg. Similar to Cryptomonas in general body form and structure, but colorless because of the absence of chromatophores. With numerous assimilation pro- ducts, amyloid bodies. Saprozoic. Chilomonas Paramecium Ehrenberg (Fig. 32, d). Length 30 to 50 microns. Very common in stagnant water and also in hay infusion. Widely distributed. Genus Cyathomonas Fromentel. Body small, somewhat oval, much flattened. Anterior end obliquely truncate. W'ith two equal or subequal anterior flagella. Colorless. The nucleus central ; contractile vacuole usually anterior. A row of refractile granules close and parallel to the anterior margin of the body. Asexual reproduction by longitudinal fission. In stagnant water and infusion, Cyathomonas truncata Ehrenberg (Fig. 32, e). Length about 20 microns. Often in infusion. Genus Cryptochrysis Pascher. Furrow indistinct. Chroma- tophore brownish or olive-green. Some lose flagella and may assume amoeboid form. Two equal flagella. Cryptochrysis commutata Pascher (Fig. 32, /). About 20 microns long. Fresh water. Family 2 Nephroselmidae Pascher Body reniform; with lateral equatorial furrow. Two flagella arising from the furrow, one directed anteriorly and the other posteriorly. Several genera. Genus Protochrysis Pascher. Body with a distinct furrow, but without cytopharynx. A stigma at the base of the flagella. One or two chromatophores, brownish yellow. Pyrenoid cen- tral; two contractile vacuoles. Fission seems to take place during the resting stage. Protochrysis phaeophycearum Pascher (Fig. 32, g). Body about 17 to 20 microns long. Genus Nephroselmis Stein. Furrow indistinct; no stigma; cytopharynx distinct. Chromatophores discoid, brownish green in color. A central pyrenoid; with reddish globules. CR YP TO MO N A DID A 95 Nephroselmis olivacea Stein (Fig. 32, h). 20 to 25 microns long. Suborder 2 Phaeocapsina Pascher Palmella stage predominant. These organisms are perhaps the border-line forms between brown algae and Cryptomona- dida. Example: Phaeothamnion confervicolum Lagerheim (Fig. 32, 7', j)which is less than 10 microns long. References Pascher, A. 1913 Cryptomonadinae. Siisswasserflora Deutsch- lands, etc. H. 2. West, G. S. and F. E. Fritsch. 1927 A treatise on the British freshwater algae. Cambridge. CHAPTER VII ORDER 3 DINOFLAGELLIDA BUTSCHLI THE DINOFLAGELLIDA form One of the most distinct groups of the Mastigophora, inhabiting mostly marine water, and to a lesser extent fresh water. The modern tendency is to hold this group as an order of the Phytomastigina. In the general ap- pearance, the arrangement of the two flagella, the characteristic furrows, and possession of brown chromatophores, the Dino- flagellida are closely related to the Cryptomonadida. The body is covered by an envelope composed of cellulose. It may be simple smooth membrane, or it may be composed of two valves or of numerous plates, which are variously sculp- tured and possess manifold projections. Differences in the posi- tion and course of the furrow and in the projections of the envelope produce 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 some- Anterior flagellar pore Annulus or girdle Hypocone Longitudinal flagellum Epicone Transverse flagellum Sulcus Posterior flagellar pore Fig. 33 Diagram of typical naked dinoflagellate. (After Lebour). times spiral. While the majority show a single transverse fur- row, 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 envelope is not developed, the terms epicone and hypocone are used (Fig, 33). The sulcus 96 DINOFLAGELLIDA 97 may run from end to end or from one end to the annulus. The two flagella arise typically from the annulus, one being trans- verse and the other longitudinal. The transverse flagellum which is often band-form, en- circles the body and undergoes undulating movements, which in former years were looked upon as ciliary movements (hence the discarded name Cilioflagellata). In the suborder Adinida, this flagellum vibrates freely in a circle near the anterior end. The longitudinal flagellum often projects beyond the body and vibrates. Combination of the movements of these flagella pro- duces whirling movements characteristic of the organisms. The majority of Dinoflagellida possess a single somewhat massive nucleus with achromatic network, evenly scattered chromatin, and usually several endosomes. There are two kinds of vacuoles. One is often surrounded by a ring of smaller vacu- oles and the other is large and opens to the exterior by a canal. The latter is known as the pusule, and its function is supposed to be hydrostatic. In many forms a stigma is present, and in some it is provided with an amylaceous lens and a dark pig- ment-ball. The majority of planktonic forms possess a large number of small chromatophores which are usually brownish or often slightly greenish and are located in the periphery of the body. Bottom-dwelling and parasitic forms are often colorless, because of absence of chromatophores. A few contain haemato- chrome. The method of nutrition is holophytic, holozoic, sapro- zoic, or mixotrophic. In holophytic forms, starch and fats are widely distributed. Asexual reproduction is by binary or multiple fission in either the active or the resting stage. The mode of division dif- fers among different groups. Encystment is of common occur- rence. In some forms the cyst wall is formed within the test. The cysts remain alive for many years. In one instance, Ceratium cysts were found to retain their vitality after six and one-half years. Conjugation and copulation have been reported in certain forms, but definite knowledge on sexual reproduction awaits further investigation. The Dinoflagellida 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 98 HANDBOOK OF PROTOZOOLOGY include various diatoms, copepods and several pelagic animals. The group is divided into three suborders as follows: Naked or with bivalve shell; without annulus or sulcus. .Suborder 1 Adinida Naked or with test; annulus and sulcus present at some stage Suborder 2 Dinifera Naked without annulus or sulcus; without transverse flagellum Suborder 3 Cystoflagellata Suborder 1 Adinida Bergh Test bivalve; without any groove; with yellow chromato- phores. Two flagella arise from the anterior end; one directed anteriorly, the other vibrates in a circle. Fresh and salt waters. Several genera. Genus Exuviaella Cienkowski. Subspherical or oval. No anterior projection, except two flagella. Two lateral chromato- phores, large brown, each with a pyrenoid and an amylum body. Nucleus posterior. Marine. Several species. Exuviaella marina Cienkowski (Fig. 34, a, b). About 80 microns long. Genus Prorocentrum Ehrenberg. Elongated oval; anterior end is bluntly pointed, with a spinous projection at the end. Chromatophores small, yellowish brown. Marine. Prorocentrum micans Ehrenberg (Fig. 34, c). About 50 mi- crons long. The cause of "red water." Suborder 2 Dinifera Bergh Typical Dinoflagellida with one to many transverse annuli and a sulcus. There are two flagella, one of which undergoes a typical undulating movement, while the other is usually directed posteriorly. According to Kofoid and Swezy, this suborder is divided into two tribes. Body covered by a thick shell . Tribe 1 Peridinioidae Body naked or covered by a thin shell Tribe 2 Gymnodinioidae Tribe 1 Peridinioidae Kofoid and Swezy The shell is composed of epitheca, girdle, and hypotheca, which may be divided into numerous plates. Body form various. With annulus and sulcus Shell composed of plates; but no suture Family 1 Peridiniidae Breast plate divided by sagittal suture Family 2 Dinophysidae Without annulus or sulcus Family 3 Phytodiniidae DINOFLAGELLIDA 99 Family 1 Peridiniidae Bergh The shell is composed of numerous plates. The annulus is usually at the equator and covered by a plate known as the cingulum. The plates which are variously sculptured and finely perforated vary in shape and number among different species. Fig. 34 a, b. Exuviaella marina. X250 (After Schiitt). c. Prorocentrum micans. X250 (After Schiitt). d. Peridinium tabulatm. X500 (After Stein). e. P. diver gens. X500 (After Calicins). f. Ceratium hirundinella. X400 (After Stein). g. Goniodoma acuminatum. X325 (After Stein), h. Dinophysis acuta. X430 (After Schutt). i. Oxyphysis oxytoxoides. X580 (After Kofoid). j. Phytodinium simplex. X250 (After Klebs). k. Stylodinium globosum. X225 (After Doflein). 100 HANDBOOK OF PROTOZOOLOGY In many species, some of the plates are drawn out into various processes, varying greatly in different seasons and localities even among one and the same species. These processes seem to retard the descending movement of the organisms from the upper to the lower level in the ocean when the flagellar activity ceases. The chromatophores are in the form of numerous small platelets and yellow or green in color. In some deep-sea forms, chromatophores do not occur. Chain formation by multiplica- tion through fission occurs in some forms. Surface and pelagic forms inhabiting fresh and salt waters. Several genera. Genus Peridinium Ehrenberg. Subspherical to ovoid; end- view reniform. Annulus slightly spiral with projecting rims. Often hypotheca with short horns and epitheca drawn out. Colorless, green or brown ; stigma usually present. Cysts spherical. Salt or fresh water. Numerous species. Peridinium tahulatum Claparede and Lachmann (Fig. 34, d). Fresh water form. Diameter about 45 microns. Peridinium divergens (Ehrenberg) (Fig. 34, e). Salt water. Color yellow. Diameter about 45 microns. Genus Ceratium Schrank. Body somewhat compressed; with one anterior and one to four posterior horn-like processes. Often large. Chromatophores are yellow, brown or greenish; color variation is conspicuous even among the one and the same species. Fission is said to take place at night and in the early morning. Numerous species. Specific identification is difficult due to a great variation. Fresh or salt water. Ceratium hirundinella Miiller (Fig. 34,/). Spinous projec- tions on the shell. Seasonal and geographical variations. Chain- formation frequent. Length 150 to 250 microns and breadth 40 to 80 microns. Fresh water. Genus Goniodoma Stein. Body polyhedral with a deep annulus. Epitheca and hypotheca slightly unequal in size, com- posed or regularly arranged armored plates. Chromatophores small brown platelets. Marine. Goniodoma acuminatum (Ehrenberg) (Fig. 34, g). About 50 microns long. Family 2 Dinophysidae Stein and Bergh The epitheca is flattened and smaller than the hypotheca. DINOFLAGELLIDA 101 The annulus possesses elevated rims. Marine. Several genera. Genus Dinophysis Ehrenberg. Body compressed. Chroma- tophores yellow. Marine. Dinophysis acuta Ehrenberg (Fig. 34, h). Length about 45 microns. Widely distributed. Genus Amphisolenia Stein. Epitheca is very small and com- posed of two plates; the large hypotheca, composed also of two elongated plates. Chromatophore unknown. In warm sea water. Amphisolenia clavipes Kofoid. Genus Oxyphysis Kofoid. Epitheca well developed; sulcus short; sulcal lists feebly developed. Annulus impressed. Pelagic in the sea. Oxyphysis oxytoxoides Kofoid (Fig. 34, i). Family 3 Phytodiniidae Klebs Without grooves or flagella. Chromatophores yellow-brown. A very ill-defined group containing no definite characters of the order. Several genera in fresh or salt water. Genus Phytodinium Klebs. Body spherical or ellipsoidal; chromatophores discoidal. Phytodinium simplex Klebs (Fig. 34,7). Iri fresh water. Genus Stylodinium Klebs. Body ovoidal with a stalk. Stylodinitim globosum Klebs (Fig. 34, k). About 40 microns long. Fresh water. Tribe 2 Gymnodinioidae Poche Naked or covered by a single piece cellulose membrane with the longitudinal and transverse furrows, and two flagella. Chromatophores which are mostly abundantly present are yellow or greenish platelets or bands. Stigma is sometimes pres- ent. Asexual reproduction in the active phase is binary fission, while that in the encysted condition is either binary or multiple division. Nutrition is holophytic, holozoic, saprozoic, or para- sitic. The majority are deep-sea forms; a few coastal or fresh water forms also occur. This tribe is divided into the following families: With a cellulose membrane Family 1 Glenodiniidae Without shell 102 HANDBOOK OF PROTOZOOLOGY Furrows rudimentary Family 2 Pronoctilucidae Annulus and sulcus distinct Solitary With ocellus Family 3 Pouchetiidae Without ocellus With tentacles Family 4 Noctilucidae Without tentacles Free-living F"amily 5 Gymnodiniidae Parasitic Family 6 Blastodiniidae Permanently colonial Family 7 Polykrikidae Family 1 Glenodiniidae Lebour Shell composed of epitheca, annulus, and hypotheca; not divided into plates nor marked by sutures. Chiefly freshwater forms. One genus. Genus Glenodinium Ehrenberg. Body spherical; ellipsoidal or reniform in end-view; several discoidal yellow to brown chromatophores. Horseshoe- or rod-shaped stigma. Glenodinium uliginosum Schilling (Fig. 35, a). 36 to 43 microns long. Fresh water. Family 2 Pronoctilucidae Lebour ( = Protodiniferidae Kofoid and Swezy) Genus Pronoctiluca Fabre-Domergue. Body with an an- terior tentacular process and sulcus; annulus poorly marked. Marine. Pronoctiluca tentaculatum (Kofoid and Swezy) (Fig. 35, b). About 54 microns long. Marine. Genus Oxyrrhis Dujardin. Body oval, asymmetrical pos- teriorly. Girdle incomplete. Marine. Oxyrrhis marina Dujardin (Fig. 35, c). Body 22 to 32 mi- crons long. Family 3 Pouchetiidae Kofoid and Swezy Ocellus consists of lens and melanosome (pigment mass). Sulcus and annulus somewhat twisted. Pusules usually present. Pelagic. Several genera. Genus Pouchetia Schiitt. Nucleus anterior to ocellus. Cyto- plasm is colored. Holozoic. Cyst frequent. Pelagic. Pouchetia fusus Schiitt (Fig. 2>S,d). About 100 microns long. DINOFLAGELLIDA 103 F"ig. 35 a. Glenodinium uliginosiim. X250 (After West). b. Pronoctiluca tentaculatiim. X550 (After Kofoid and Swezy). c. Oxyrrhis marina. X625 (After Senn). d. Pouchetia ftisus. X250 (After Schiitt from Kofoid and Swezy). e. f. Noctilnca scintillans. e, profile (X60 after Allman from Kofoid and Swezy); f, exogenous budding (XlOO after Robin) g. Gymnodinium agile. X550 (After Kofoid and Swezy). h. He?nidinium nasutum. X500 (After Stein). i. Amphidinium scissum. X660 (After Kofoid and Swezy). j. Blastodinium spinulosum. X180 (After Chatton). k. Chytriodinium parasiticum in a copepod egg. (After Dogiel). I. Apodinium mycetoides. X475 (After Chatton). m. Polykrikos kofoidi. X250 (After Kofoid). 104 HA NDBOOK 0 F PRO TOZOOLOG Y Family 4 Noctilucidae Kent The somewhat contractile tentacle arises from the sulcal area and extends posteriorly. Formerly this group had been included in the Cystoflagellata. Studies by recent investigators, particularly Kofoid, show their affinities with the present sub- order. Holozoic. Marine. Genus Noctiluca Suriray. Body spherical, bilaterally sym- metrical. Peristome marks the median line of the body. A cytostome at the bottom of peristome. With a distinct tentacle. The cytoplasm is much vacuolated, and cytoplasmic strands connect the central mass with the periphery. Colorless or blue- green, sometimes tinged with yellow coloration in the center. Swarmers are formed by budding, and each possesses one flagellum, girdle, and tentacle. Widely distributed in salt water. One species. Noctiluca scintillans (Macartney) (= N. miliaris Suriray) (Fig. 35, e,f). Usually 500 to 1000 microns in diameter, with the extremes of 200 microns and 2mm. Family 5 Gymnodiniidae Kofoid Naked form with simple but distinct furrows. Several genera in fresh or marine water Genus Gymnodinium Stein. Ordinarily naked, subcircular; numerous discoid chromatophores vari-colored (yellow to deep brown, green, or blue) or sometimes absent. Stigma occasionally present. Longitudinal fission in active form; cyst with a mu- cilaginous or firm envelope. Marine, brackish, or fresh water. Gymnodinium agile Kofoid and Swezy (Fig. 35, g). About 28 microns long. In sandy beaches. Genus Hemidinium Stein. Body oval; girdle about half a turn. Hemidinium nasutum Stein (Fig. 35, h). Oval, assy metri- cal. Sulcus on hypocone. Chromatophores yellow or brown. Nucleus posterior. Transverse fission. 24 to 28 microns long. Fresh or brackish water. Genus Amphidinium Claparede and Lachmann. Variable form ; epicone small, girdle near the anterior end ; sulcus straight on hypocone or also on part of epicone. With or without DINOFLAGELLIDA 105 chromatophores Mainly holophytic, some holozoic Coastal or fresh water. Numerous species. Amphidinium scissum Kofoid and Swezy (Fig. 35, i). Length 50 to 60 microns. In sandy shore. Family 6 Blastodiniidae Kofoid and Swezy All parasitic in or on plants and animals. Numerous genera. Genus Blastodinium Chatton. Parasitic in the alimentary canal of Copepoda. Spindle-shaped, binucleated. The envelope which is not of cellulose nature often with two spirally arranged bristles. Spiral furrows. Chromatophores are often in yellowish brown network. Blastodinium spinulosum Chatton (Fig. 35, j). In copepods of the genera Paracalanus and Clausocalanus. Genus Chytriodinium Chatton. Parasitic in eggs of plankton copepods. Young individuals grow at the expense of host's egg and when fully formed, the body divides into numerous parts, each producing four swarmers. Chytriodinium parasiticum (Dogiel) (Fig. 35, k). In copepod egg- Genus Oodinium Chatton. Ovoid or spherical body with a short stalk. Ectoparasitic on Salpa, Annelida, Siphonophora, etc. Genus Apodinium Chatton. With a much longer filiform stalk and with two nuclei (Fig. 35, /). Ectoparasitic. Genus Haplozoon Dogiel. Parasitic in the intestine of poly- chaetes. Haplozoon clymenellae (Calkins) in Clymenella torquata. Family 7 Polykrikidae Kofoid and Swezy Two, four, or eight individuals permanently jointed. Each individual has a structure similar to Gymnodinium, the sulcus however extending the entire length. Color greenish to pink. Nuclei about one-half the number of individuals. Holozoic. Genus Polykrikos Biitschli. With the above-mentioned characters Polykrikos kofoidi (Chatton) (Fig. 35, m). Body greenish grey to rose in color. Composed of two, four, eight, or sixteen individuals. The cytoplasm contains nematocysts. Each nema- tocyst possesses presumably a hollow thread, and is discharged 106 HANDBOOK OF PROTOZOOLOGY under suitable stimulation. A binucleate colony composed of four individuals measures about 110 microns long. Marine. Suborder 3 Cystoflagellata Haeckel Since Noctiluca which has been for many years placed in this suborder, is removed, according to Kofoid, into the second suborder, the Cystoflagellata become a highly ill-defined group. It includes two peculiar marine forms: Leptodiscus medusoides Fig. 36 a. Leptodiscus medusoides, profile. X50 (After Hertwig). b. Cr as pedotella pil coins. X 110 (After Kofoid). Hertwig (Fig. 36, a), and Craspedotella pileolus Kofoid (Fig. 36, h), both of which are medusoid in general body form. References Chatton, E. 1920 Les Peridiniens parasites; morphologic, reproduction, ethologie. Arch. Zool. Exper., T. 59. Kofoid, C. A. 1906 On the significance of the asymmetry of the Dinoflagellata. University of California Publ. Zool., Vol. 3. . 1920 A new morphological interpretation of Noctiluca and its bearing on the status of Cystoflagellata. Ibid., Vol. 19. Kofoid, C. A. and Olive Swezy. 1921 The free-living un- armored dinoflagellata. Mem. Uni. California, Vol. 5. Lebour, Marie V. 1925 The dinoflagellates of northern seas. London. Pratje, a. 1921 Noctiluca miliaris Sur. Arch. f. Protistenk., Vol., 42. Schilling, A. 1913 Dinoflagellatae (Peridineae). Siisswas- serflora Deutschlands. etc. H. 3. CHAPTER VIII ORDER 4 PHYTOMONADIDA BLOCHMANN THE PHYTOMONADIDA are small, more or less rounded, green flagellates with a close resemblance to the algae. All of them have a definite body form, and most of them are sur- rounded by a cellulose membrane, which is thick in some and thin in others. There is a definite opening in the membrane at the anterior end, through which one or two (or seldom four 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 holophytic or mixotrophic; some colorless forms are, however, saprozoic. The metabolic products are usually amyloid substances. Some Phytomonadida are stained red, owing to the presence of haematochrome, or carotin. The contractile vacuoles may be located in the anterior part or scattered throughout the body. The nucleus is ordinarily centrally located. The nuclear division seems to be mitotic, and chromosomes have 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. Isogamy or anisogamy takes place with various gradations. Colony formation also occurs, especially in the family Volvocidae. Encystment and formation of the palmella stage are common among many forms. The Phytomonadida are divided into five families: Without cellulose membrane; four or more flagella Family 1 Polyblepharidae With cellulose membrane Membrane a single piece With chromatophores Two or four flagella; solitary Family 2 Chlamydomonadidae Two flagella; colonial Family 3 Volvocidae Without chromatophores Family 4 Polytomidae Membrane composed of two vahes Family 5 Phacotidae [ 107 1 ids HANDBOOK OF PROTOZOOLOGY Family 1 Polyblepharidae Dangeard Flagella are four or more in number. Lacking a cellulose membrane, the body form changes to a certain extent. Found mostly in salt water. Common genera are as follows: Genus Pyramimonas Schmarda ( = Pyramidomonas Stein). Small pyramidal or heart-shaped body; with bluntly drawn-out posterior end. There are usually four ridges in the anterior region. Four 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. Fig. 37 a. Pyramimonas tetrarhynchus. X300 (After Dill), b, c. Polytomella agilis. X750 (After Doflein). d. Collodictyon triciliatum. X300 (After Carter), e-g. Chlamydomonas monadina. X350 (After Goroschankin). f, copulation; g, palmella phase, h. C. angulosa. X350 (After Dili), i. Haematococcus laaistris. X325 (After Stein). j. Brachiomonas submarina. X720 (After West), k. Lobomonas pentagonia. X830 (After Hazen). 1. Chlorogonium euchlorum. X320 (After Jacobsen). m. Carteria cordiformis. X325 (After Stein). Pyramimonas tetrarhynchus Schmarda (Fig. 37, a). Up to 40 microns in length. Genus Polytomella Aragao. Body colorless, rounded with a small papilla at the anterior end, where four equally long flagella arise. Starch; with or without stigma. Encystment. PHYTOMONADIDA 109 Polytomella agilis Aragao (Fig. 37, h, c). With stigma and numerous starch grains. Fresh water. Genus CoUodictyon Carter. Colorless. With pseudopodia. Holozoic. CoUodictyon triciliatum Carter (Fig. 37, d). About 35 microns long. Fresh water. Genus Medusochloris Pascher. With four flagella; medusoid in form and movement. Medusochloris phiale Pascher. Family 2 Chlamydomonadidae Biitschli Solitary; spheroid, oval, or ellipsoid in form; with a cellulose membrane. Two or rarely four flagella. Chromatophores, stigma, and pyrenoids are usually present. Genus Chlamydomonas Ehrenberg. Spherical, ovoid or elongated; sometimes flattened. Two flagella. The membrane is often thickened at the anterior end. Usually a large chromato- phore, containing one or more pyrenoids. Stigma. A single nucleus. Contractile vacuoles two in number at the anterior end. Asexual reproduction and palmella formation are known. Sexual reproduction is isogamy. Enormous number of species. Chlamydomonas monadina Stein (Fig. 37, e-g). Body about 20 microns long. Fresh water. Landacre noted that the or- ganisms obstructed the sand filters used in connection with a septic tank, together with the diatom Navicula. Chlamydomonas angulosa Dill (Fig. 37, h). Body about 15 to 20 microns. Fresh water. Genus Haematococcus Agardh ( = Sphaerella Sommerfeldt). Spheroidal or ovoid with a gelatinous envelope. Chromato- phores peripheral and reticulate, with two to eight scattered pyrenoids. Several contractile vacuoles. Haematochrome is frequently abundant both in motile and in encysted stages. Asexual reproduction in motile form; sexual reproduction is isogamy. Haematococcus lacustris (Girod) (Fig. 37, i). Body small, 8 to 30 microns long. Brick red; cysts are similarly colored. The cause of "red snow" or "red rain." Genus Brachiomonas Bohlin. Lobate; with horn-like pro- cesses, all directed posteriorly; no contractile vacuoles. Ill- no HANDBOOK OF PROTOZOOLOGY defined chromatophores parietal; with pyrenoids. Sexual and asexual reproduction. Brachiomonas siihmarina Bohlin (Fig. 37, j). Body 15 to 24 microns long. Fresh water. Genus Lobomonas Dangeard. Ovoid or angular with a thick wall and a number of processes. Chromatophores cup- shaped; one pyrenoid. Asexual and sexual reproduction. Lobomonas pentagonia Hazen (Fig. 37, k). About 20 microns long. In fresh or brackish water. Genus Chlorogonium Ehrenberg. Fusiform. Membrane thin and adheres closely to the protoplasmic body. Plate-like chromatophores usually present, sometimes ill-contoured. Four pyrenoids. Numerous scattered contractile vacuoles. A stigma; a central nucleus. Asexual reproduction by two successive transverse fissions during motile phase. Anisogamy reported. Chlorogonium euchlorum Ehrenberg (Fig. 37, /). Length up to 50 microns. In stagnant water. Genus Carteria Diesing. With the characteristics of Chlamydomonas, but with four fiagella. Fresh water. Carteria cordiformis (Carter) (Fig. 37, m). Body somewhat heart-shaped, length 10 to 20 microns. Family 3 Volvocidae Ehrenberg An interesting group of colonial flagellates. The individual is similar on the whole to that of Chlamydomonadidae, with two equally long fiagella (four in Spondylomorum), green chromatophores, pyrenoids, stigma, and contractile vacuoles. The body is covered by a cellulose membrane and not plastic. The colony or coenobium is discoid or spherical. Exclusively freshwater inhabitants. Genus Gonium Miiller. Four or sixteen individuals arranged in one plane. Each cell ovoid or slightly polygonal, possesses two fiagella which are arranged in the plane of the coenobium, and may or may not be covered by a gelatinous envelope. Protoplasmic connections among individuals occur frequently. Asexual reproduction through simultaneous divisions of the component cells. Sexual reproduction is isogamy and the zy- gotes are reddish in color. Gonium sociale (Dujardin) (Fig. 38, a, b). Four individuals. PHYTOMONADIDA 111 10 to 20 microns long, form a colony. In open water of ponds and lakes. Gonium pectorale Miiller (Fig. 38, c). Sixteen individuals form a colony; four individuals in the center; twelve peripheral. Individuals 7 to 11 microns long. In stagnant water of ponds and ditches. Genus Platydorina Kofoid. Cells arranged in a slightly twisted plane. Flagella directed alternately to both sides. Fig. 38 a, b. Gonium sociale. X320 (After Fritsch). c. G. pectorale. X240 (After Stein). d. Platydorina caudata. X about 210 (After Kofoid). e. Spondylomorum quaternarium. X250 (After Stein). f. Stephanosphaera pluvialis. X190 (After Hieronymus). g, h. Pandorina morum. X200 (After Pringsheim). h, a stage in asexual reproduction. Platydorina caudata Kofoid (Fig. 38, d). Found in rivers and lakes. About 150 microns long by 130 microns wide. Genus Spondylomorum Ehrenberg. Individuals similar to Carteria, but colonial. Sixteen individuals all directed an- teriorly and arranged in four transverse rings. Asexual repro- duction by simultaneous divisions of the component cells. Sexual reproduction unknown. Fresh water. Spondylomorum quaternarium Ehrenberg (Fig. 38, e). About 45 microns long. In fresh water and soil. Genus Stephanosphaera Cohn. Spherical colony, with 112 HANDBOOK OF PROTOZOOLOGY eight individuals arranged in a ring. Flagella upon one face only. Individuals are pyriform with several processes. Asexual reproduction and isogamy. Fresh water. Stephana sphaer a pluvialis Cohn (Fig. 38, /). Diameter 30 to 60 microns. Fresh water. Genus Pandorina Bory. Spherical or subspherical colony of usually sixteen (sometimes eight or thirty-two) biflagellate individuals which are closely packed within a gelatinous, but firm and thick matrix. Individuals are often angular. With stigma and chromatophores. Asexual reproduction through simultaneous division of each of the individuals. Anisogamy is preceded by division of each cell into 16 to 32 gametes. The zygotes are colored and covered by a smooth wall. Pandorina morum (Miiller) (Fig. 38, g, h). Individuals 8 to 15 microns long. Colony 20 to 40 microns in diameter. Common in ponds and ditches. Genus Eudorina Ehrenberg. Spherical or ellipsoidal colony of usually 32 or sometimes 16 spherical cells. The cells are widely separated from one another and arranged along the periphery. Four at each pole and three groups of eight in be- tween. Each cell is similar to that of Chlamydomonas. Asexual reproduction is similar to that of Pandorina. Isogamy. Macro- gametes green spherical bodies, 32 to 64 in number; microga- metes are numerous and occur in bundles. The reddish zygote possesses a smooth wall. Eudorina elegans Ehrenberg (Fig. 39, a). In ponds, ditches and lakes. Genus Pleodorina Shaw. Somewhat similar to Eudorina, being composed of 32, 64 or 128 ovoid or spherical cells. The cells are of two types: small somatic and large generative, and are located within a gelatinous matrix. Pleodorina illinoisensis Kofoid (Fig. 39, h). Thirty-two cells: 4 vegetative and 28 reproductive individuals. They are arranged in five circles: 4 in each polar circle, 8 at the equator and 8 on either side of the equator. Four small vegetative cells are at the anterior pole. Colony 100 to 140 microns long by 84 to 102 microns wide. Pleodorina calif ornica Shaw. 64 or 128 cells, of which from one-half to two-thirds are reproductive cells. PH YTOMONADIDA 113 Genus Volvox Linne. Often large spherical or subspherical colonies, consisting of a large number of cells which are dif- ferentiated into somatic and reproductive cells. The former are numerous and embedded in the gelatinous matrix of colony. The somatic cell contains a chromatophore, one or more pyre- noids, a stigma and several contractile vacuoles. In some there I V V ,v „ . Fig. 39 a. Eudorina elegans. X235 (After Goebel). b. Pleodoritia illinoisensis. X150 (After Kofoid). c. Volvox globator. X about 150 (After Janet). d. V. aureus. X80 (After Klein). e. Polytoma uvella X250 (After France). f. Parapolytoma satura X600 (After Jameson), g, h. Phacotus lenticularis. X325 (After Stein). i. Pteromonas angidosa. X500 (After West). are protoplasmic connections between two neighboring somatic cells, in others such connections apparently do not exist. The generative cells are few and large. Both mono- and bi-sexual reproductions occur. The monosexual gametes are usually fewer and larger in size than the bisexual gametes, and each produces a young colony by repeated division. Bisexual 114 HANDBOOK OF PROTOZOOLOGY reproduction is anisogamy. The zygotes are usually brownish red in color and their outer coverings may be smooth or spinous. Volvox glohator Leeuwenhoek (Fig. 39, c). Monoecious. About 700 microns in diameter. Common in European waters. Volvox perglohator Powers. Dioecious. Diameter up to 1 mm. Common in American waters. Volvox aureus Ehrenberg (Figs. 25; 39, d). Dioecious. Cy- toplasmic threads are relatively thin. Diameter 200 to 800 microns. Volvox spermatosphara Powers. Monoecious. Without any cytoplasmic connections between the cells. Diameter up to 600 microns. Volvox tertiiis Meyer. Dioecious. Without cytoplasmic connections in mature state. Family 4 Polytomidae Poche These are colorless saprozoic Phytomonadida. Reserve amyloid material may occur. With two flagella located at the anterior end. Body form resembles in general way that of Chlamydomonas. Genus Polytoma Ehrenberg. Body ovoid ; colorless. Stigma if present red or pale-colored. Saprozoic, but numerous starch bodies are present in the posterior half of the body. Asexual reproduction in the motile stage. Sexual reproduction is isogamy. Zygotes are spherical, with a smooth wall. In in- fusion or stagnant water. Polytoma uvella Ehrenberg (Fig. 39, e). Body oval to pyri- form. Stigma may be absent. Widely distributed in water containing decaying organic substances. Genus Parapolytoma Jameson. Anterior margin obliquely truncated, resembling a cryptomonad, but colorless. Stigma and starch absent. Division into four individuals within the envelope occurs. Parapolytoma satura Jameson (Fig. 39,/). In fresh water. About 15 microns long. Family 5 Phacotidae Poche The thick shell is typically composed of two valves. Two flagella protrude from the anterior end. Stigma and chromato- PHYTOMONADIDA 115 phores are present. Asexual reproduction takes place within the shell; the valves may become separated from each other owing to an increase in the gelatinous contents. Genus Phacotus Perty. The valves are distinct. Body form circular in front view and lenticular in profile. The proto- plasmic body does not fill the dark-colored shell completely. The flagella protrude through a foramina. Asexual reproduction into 2 to 8 individuals. Phacotus lenticularis (Ehrenberg) (Fig. 39, g, h). In stagnant water. Body about 10 to 15 microns in diameter. Genus Pteromonas Seligo. The body is broadly winged in the plane of the junction of the two valves. Protoplasmic body fills the shell. The chromatophore is cup-shaped and contains 1 to 6 pyrenoids. Asexual reproduction into 2 to 4 individuals. Sexual reproduction by isogamy. Zygotes are usually brown colored. Pteromonas angidosa (Carter) (Fig. 39, i). With a rounded wing and four protoplasmic projections in profile. About 16 microns in diameter. Fresh water. Genus Coccomonas Stein. The envelope is somewhat rect- angular and shows a single opening at the anterior end for the flagella. Inner wall distinct. The protoplasm does not fill the space formed by the envelope. Asexual reproduction into four individuals. Coccomonas orbicularis Stein. In ditches and ponds. References Crow, W. B. 1918 The classification of some colonial chlamy- domonads. New Phytologist, Vol. 17. Dangeard, p. 1900 Obsei\'ations sur la structure et le de- veloppement du Pandorina moriim. Le Botaniste, T. 7. Entz, G. Jr. 1913 Cytologische Beobachtungen an Polytoma uvella. Verb. Deutsch. Zool. Ges. Ver., 23. 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 unicellular and colonial organisms. Arch. f. Protistenk., Vol. 60. Pascher, a. 1927 Volvocales — Phytomonodinae. Siisswasser- flora Deutschlands, etc., H.4. CHAPTER IX ORDER 5 EUGLENOIDIDA BLOCHMANN THE EUGLENOIDIDA include many of the large flagellates of common occurrence. Some are plastic, but others have a definite body form with a well-developed, striated or variously sculptured pellicle. The body is usually elongated. At the anterior end, there is an opening through which a flagellum protrudes. In holophytic forms the so-called cytostome and the cytopharynx, if present, are apparently not concerned with food-taking, but seem to give a passage-way for the flagellum and also to excrete the waste fluid matters which become col- lected in the contractile vacuoles located around the reservoir. In holozoic forms, a well-developed cytostome and cyto- pharynx are present. The contractile vacuoles form a complex structure and are highly characteristic of the group. There are several minute contractile vacuoles arranged around a reservoir which receives their contents, and discharges through the so- called cytopharynx. Ordinarily there is only one flagellum, but two or three are present in a few forms. Chromatophores are present only in Euglenidae and absent in the other two families. They are green and of various shapes, such as spheroidal, band-form, cup-form, discoid, or stellate. They usually con- tain pyrenoids. Some forms may contain haematochrome. A small but conspicuous stigma is invariably present near the anterior end of the body in chromatophore-bearing forms. Reserve food material is the paramylum, the presence of which depends naturally on the metabolic condition of the or- ganism. The paramylum body assumes diverse forms in differ- ent species, but is constant in each species, and this facilitates identification to a certain extent. Nutrition is holophytic in chromatophore-possessing forms, which, however, may be sap- rozoic, depending on the organic substances present in the water. The holozoic forms feed upon bacteria, algae and smaller Pro- tozoa. 1116] EUGLENOIDIDA, CHLOROMONADIDA 117 The nucleus, as a rule, is large and distinct and contains al- most always a large endosome. Asexual reproduction is by longitudinal fission; sexual reproduction has been observed in a few species. Encystment is wide-spread. Most members of the group inhabit fresh water, but some live in brackish or salt water, and a few are parasitic in animals. Following Calkins, the order is here divided into three families: With chromatophores and stigma Family 1 Euglenidae Without chromatophores or stigma With one flagellum Family 2 Astasiidae With two flagella .Family 3 Heteronemidae Family 1 Euglenidae Stein Body plastic ("euglenoid"), but, as a rule, more or less spindle-shaped during movement. The majority possess a single flagellum (with the exception of Eutreptia and Euglena- morpha) which arises in an opening at the anterior end. Green (sometimes red) chromatophores and stigma occur, though in some cases absent. Metabolic products are oil and paramylum. Asexual reproduction by longitudinal fission in either the active or the resting stage. Mostly freshwater inhabitants, but some marine. Genus Euglena Ehrenberg. Body short or elongated spindle, cylindrical, or band-form. The pellicle is marked in some forms by longitudinal or spiral striations. In forms in which the pellicle is not well developed, the body is highly plastic. Ac- tively moving individuals are ordinarily spindle-shaped, while those remaining in one place may show considerable changes of form. Some species are regularly spirally twisted. Stigma is usually located near the anterior end. Chromatophores are numerous and discoidal, bandform, or stellate. Pyrenoids are sometimes present; they may or may not be surrounded by amyloid sheath. Metabolic products are paramylum bodies which may be two in number, one being located on either side of the nucleus, and rod-like to ovoid in shape; numerous and small ovoidal; or discoidal and scattered throughout. The con- tractile vacuoles are very small and arranged around the reser- voir located near the anterior end. 118 HANDBOOK OF PROTOZOOLOGY Asexual reproduction is by longitudinal fission; sexual repro- duction has been reported in Euglena sanguinea. Encystment common. The members of this genus are 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 the pond or pool. Numerous species in fresh water. Euglena pisciformis Klebs (Fig. 40, a). Body about 25 to 30 microns long by 7 to 10 microns broad. Spindle in form, with bluntly pointed anterior and sharply attenuated posterior end. Highly active. Paramylum indistinct; chromatophores small and discoidal. Flagellum is fairly long. Common. Euglena viridis Ehrenberg (Figs. 6; 40, b). Body 50 to 120 microns in length. Anterior end rounded, posterior end pointed. Spindle-shaped during motion; highly plastic when stationary. Pellicle smooth and obliquely striated. Chromatophores are more or less band-form and arranged in a stellate form. Nutri- tion is holophytic, but the organism is also able to carry on sap- rozoic nutrition, during which period the chromatophores are said to degenerate. vSolitary and common. Euglena acus Ehrenberg (Fig. 40, c). Body 100 to 200 mi- crons long; narrow spindle-form; posterior end sharply pointed. Spiral striation on the pellicle is very delicate. Paramylum bodies are short rod-form. Nucleus central; stigma distinct; flagellum short. Movement sluggish. Solitary. Euglena spirogyra Ehrenberg (Fig. 40, d). Body 150 to 260 microns long. With spirally arranged striations, consisting of small knobs on the pellicle. Two ovoidal paramylum bodies, one on either side of the nucleus which is located in the ap- proximate center of the body. Movement sluggish. Flagellum short; stigma prominent. Solitary among algae. Euglena oxyuris Schmarda (Fig. 40, e). Almost always spirally twisted; pellicle with spirally arranged striations. Two paramylum bodies are ovoid and conspicuously observable on either side of the nucleus. Body large, 250 to 400 microns long. Solitary. Euglena sanguinea Ehrenberg (Fig. 40,/). Body about 55 to 120 microns long. With haematochrome. Often found in E UGLENOIDIDA , CHLOROMONA DID A 119 Fig. 40 a. Euglena pisciformis. X200 (After Klebs). E. viridis. X325 (After Doflein, modified). E. acus. X325 (After Stein). E. spirogyra. X325 (After Stein). E. oxyuris. X325 (After Stein). E. sanguinea. XlOO (After Klebs). E. deses. X325 (After Stein). E. gracilis. X200 (After Klebs). Phacus pleuronectes. X325 (After Stein). P. longicaudus. X325 (After Stein) P. pyrurn. X325 (After Stein). P. triqueler. X325 (After Stein). b. c. d. e. f. g- h. i. J- k. 120 HANDBOOK OF PROTOZOOLOGY crust on the surface or on the half-dry bed of a pool. It is con- sidered, by some investigators, as a variety of E. viridis. Euglena deses Ehrenberg (Fig. 40, g). Body about 100 to 150 microns in length. Elongated, highly plastic; stigma dis- tinct at the anterior end which is sometimes attenuated. Nu- cleus central; chromatophores hemi-lenticular; numerous small paramylum bodies scattered. Flagellum short. Euglena gracilis Klebs (Fig. 40, h). Body about 40 to 45 microns long. Cylindrical to elongated oval ; flagellum less than the body length; chromatophores numerous and discoid; nucleus central. Genus Phacus Nitzsch. Body greatly flattened; asymmet- rical; body-form constant. Pellicle often with prominent longitudinal or oblique striations. Body structure is similar to that of Euglena. A single flagellum and a stigma. The nucleus is usually located near the posterior extremity. A short cytopharynx; green chromatophores, rounded discoid; paramylum body very conspicuous. Numerous species in fresh water, occur with Euglena. Phacus pleuronectes (Ehrenberg) (Fig. 40, i). Short posterior elongation is slightly curved. A prominent fold on the convex side, extending to the middle of the body ;longitudinally striated. One or more circular paramylum bodies. Colorless forms sometimes appear. Body up to 75 microns in length. Phacus longicaudus {T>u]a.r6\n) (Fig. 40,7). Body about 85 to 100 microns long. Usually twisted with a long caudal pro- longation. Stigma prominent. A large discoidal paramylum body in the center of the body. Pellicle longitudinally striated. Phacus pyrum (Ehrenberg) (Fig. 40, k). Length about 40 microns. Pyriform with a straight caudal prolongation. Pel- licle with oblique striations. Phacus triqueter (Ehrenberg) (Fig. 40, /). Body about 40 to 45 microns long. Ovate; with a longitudinal ridge; caudal prolongation is acuminate. Oblique striation distinct. Genus Lepocinclis Perty. Body more or less ovo-cylindrical ; rigid with a usually spirally striated pellicle. Often with a short posterior spinous projection; stigma sometimes present. Numerous discoidal chromatophores marginal; paramylum bodies usually large and ring-shaped, laterally disposed. EUGLENOIDIDA, CHLOROMONADIDA 121 Pyrenoids absent. Longitudinal fission. Occur with Euglena and Phacus. Several species are known. Lepocinclis ovum (Ehrenberg) (Fig. 41, a). About 20 to 40 microns long. Genus Trachelomonas Ehrenberg. With a simple test which often possesses numerous spinous projections. Sometimes yel- lowish to dark brown in color. A single flagellum protrudes from the anterior aperture, the rim of which is frequently thick- ened to form a collar. Chromatophores are either two curved plates or numerous discs. Paramylum bodies, if present, are in the form of small grains. Stigma and pyrenoids are often present. Multiplication by longitudinal fission; one daughter individual retains the test and the flagellum, while the other escapes through the flagellar aperture, forms a new flagellum and secretes a test. Cysts common. Among algae. Specific differentiation is based upon the test. Numerous species. Trachelomonas hispida (Perty) (Fig. 41, h). Ellipsoidal; about 35 microns long. Test with numerous minute spines. Aperture with or without a short neck. Brownish in color. Trachelomonas cylindrica Ehrenberg (Fig. 41, c). About 25 microns long. Test elongate, without spines. Trachelomonas armata Ehrenberg (Fig. 41, d). Body about 40 microns long. Subspherical; test surface finely punctate and brown in color. Numerous short spines surround the aperture; often with long spines along the posterior margin. Genus Cryptoglena Ehrenberg. Body rigid, flattened. Two lateral band-form chromatophores; a single flagellum; nucleus posterior. Among algae. Cryptoglena pigra Ehrenberg (Fig. 41, e). Body ovoid, pointed posteriorly. Flagellum short; stigma prominent. About 12 microns long. Genus Ascoglena Stein. Encased in a flexible colorless to brown test which is attached with its base to foreign object. Solitary and without stalk. Body ovoidal, plastic; attached to the test with its posterior end. A single flagellum protrudes from the aperture end of the test. A stigma; numerous chroma- tophores discoid; with or without pyrenoids. Reproduction as in Trachelomonas. Cysts unknown. 122 HANDBOOK OF PROTOZOOLOGY Ascoglena vaginicola Stein (Fig. 41,/). Test about 50 mic- rons high. Continental Europe. Genus Colacium Ehrenberg. Stalked individuals form Fig. 41 a. Lepocinclis ovum. X650 (After Stein). b. Trachelomonas hispida. X650 (After Stein). c. T. cylindrica. X650 (After Stein). d. T. armata. X650 (After Stein). e. Cryptoglena pigra. X 650 (After Stein). f. Ascoglena vaginicola. X.'580 (After Stein). g. Colacium vesiculosum. X580 (After Stein). h. Eutreptia viridis. X400 (After Klebs). i. Euglenamorpha hegneri. XllOO (After Wenrich). EUGLENOIDIDA, CHLOROMONADIDA 123 colony; frequently attached to plankton organisms, particularly copepods, rotifers, etc. Stalk is mucilaginous; individual cells pyriform, ellipsoidal or cylindrical. Without flagellum. Dis- coidal chromatophores numerous; with pyrenoids. Multiplica- tion by longitudinal fission ; also by swarmers, possessing a single flagellum and a stigma. Several species. Colacium vesiculosum Ehrenberg (Fig. 41, g). Attached to freshwater copepods. Colony of 2 to 8 individuals; also solitary. Body about 30 microns long. Genus Eutreptia Perty. With two flagella at the anterior end; pellicle distinctly striated. Body plastic; spindle-shaped during movement. Stigma; numerous discoid chromatophores; pyrenoids absent ; paramylum bodies spherical or subcylindrical. Multiplication as in Euglena. Cyst with a thick stratified wall. Eutreptia viridis Perty (Fig. 41, h). About 90 microns long. Fresh or salt water. Genus Euglenamorpha Wenrich. Body form and structure similar to those of Euglena, but with three flagella and inhabit- ing the intestine of frog tadpoles. One species. Euglenamorpha hegneri Wenrich (Fig. 41, i). Body 40 to 50 microns long. Family 2 Astasiidae Biitschli Similar to Euglenidae in body form and general structure, but without chromatophores. A single flagellum is present. Body is usually plastic, although it assumes an elongated form. There is a cytopharynx and cytostome, the former being as- sociated with the reservoir of the contractile vacuoles. Stigma is absent, except in Astasia ocellata. The flagellum is usually straight and its free end vibrates in a characteristic manner. Asexual reproduction by longitudinal fission. Genus Astasia Dujardin. Body metabolic, although usually elongate; stigma absent except in one species. Fresh or salt water. Astasia margaritifera Schmarda (Fig. 42, a). Body spindle- form when in motion. Pellicle indistinctly spirally marked. Numerous paramylum bodies small. Body about 60 microns long. Genus Urceolus Mereschkowsky ( = Phialonema Stein). 124 HANDBOOK OF PROTOZOOLOGY Body colorless, flask-shaped; a funnel-like neck; posterior region stout. A single flagellum protrudes from the funnel and reaches inward the posterior third of the body. Salt or fresh water. Urceolus cyclostomus (Stein) (Fig. 42, b). Body about 50 microns long. Fresh water. Genus Peranema Dujardin. Body oblong, with a broad, rounded or truncate posterior end during locomotion; highly changeable when stationary. The delicate pellicle shows a fine striation. The long flagellum tapers toward the free end and vibrates. Nucleus central; several contractile vacuoles. Sapro- zoic. In stagnant water; often in hay infusion. Peranema trichophorum (Ehrenberg) (Fig. 42, c). Body 60 to 70 microns long. In stagnant water, infusion, etc. Common. Genus Petalomonas Stein. Colorless body constant in form ; pellicle often with longitudinal keels on one side. A single flagellum. Holozoic or saprozoic. Cytostome at the anterior end; cytopharynx fairly deep. Fresh water. Petalomonas ervilia Stein (Fig. 42, d). Body about 45 mi- crons long. Genus Menoidium Perty. Body curved in a crescent or S-form. With a definite pellicle and a single flagellum. Menoidium incurvum (Fresenius) (Fig. 42, e). About 15 to 25 microns long. Fresh water. Genus Scytomonas Stein. Body oval or pyriform, with a delicate pellicle; a single flagellum. A contractile vacuole with a reservoir. Holozoic on bacteria. Longitudinal fission in motile stage. Coprozoic. Scytomonas pusilla Stein (Fig. 42,/). About 15 microns long. Genus Copromonas Dobell. Body elongated ovoid, with a single flagellum. A small cytostome at the anterior end. Holozoic on bacteria. Copulation is followed by an encyst- ment (p. 52). Coprozoic in fecal matters of frog, toad, and man. Several authors hold that this genus is probably identical with Scytomonas which was indistinctly described by Stein. Copromonas suhtilis Dobell (Fig. 24, a). Body 7 to 20 microns long. Family 3 Heteronemidae Calkins Colorless body may be plastic or rigid with a variously marked pellicle. Flagella two in number, one directed an- E UGLENOIDIDA , CHLOROMONADIDA 125 teriorly and the other usually posteriorly. Contractile vacuoles and reservoir. Stigma usually absent. Paramylum bodies are, as a rule, also present. Free-swimming or creeping. Genus Heteronema Dujardin. Body plastic, rounded or elongated. Two flagella arise from the anterior end, one directed forward and the other trailing. The cytostome near the base of the flagella. Holozoic. Fig. 42 a. Astasia margaritijera. X410 (After Senn). b. Urceolus cyclostomus. X325 (After Stein). c. Peranema trichophoruni. X400. d. Petalomonas ervilia. X325 (After Stein). e. Menoidium incurvum. X 1050 (After Hall). f. Scytomonas pusilla. X325 (After Stein). g. Heteronema acus. X325 (After Stein), h. Distigma proteus. X325 (After Stein). i. Entosiphon sulcatum. X325 (After Stein). j. Anisonema acinus. X300 (After Klebs). k. A. truncatum. X325 (After Stein). 1. A. emarginata. X400 (After Stokes.) m. Notosolenus apocamptus. X900 (After Stokes). n. N. sinuatus. X450 (After Stokes). 126 HANDBOOK OF PROTOZOOLOGY Heteronema acus (Ehrenberg) (Fig. 42, g). Extended body tapers towards both ends. Anterior flagellum as long as the body, the trailing one about one-half. Contractile vacuole near the anterior end ; nucleus central. About 30 to 80 microns long. Fresh water and soil. Genus Distigma Ehrenberg. Plastic; elongated when ex- tended. Body surface without any marking. Two flagella unequal in length, directed forward. Cytostome and cyto- pharynx located at the anterior end. Endoplasm transparent. Holozoic. Fresh water; especially stagnant water, infusion, etc. Distigma proteus (Stein) (Fig. 42, h). Longer flagellum about as long as the body, the other about one-half. Nucleus central; contractile vacuole anterior. When extended, about 100 microns long. Genus Entosiphon Stein. Body more or less rigid; oval, flattened. Flagella arise from a cytostome at the anterior end. One flagellum trailing. The protrusible cytopharynx is a long conical tubule almost reaching the posterior end. The nucleus central and toward one side. Entosiphon sulcatum (Dujardin) (Fig. 42, i). Body about 20 microns long. Fresh water and infusion. Genus Anisonema Dujardin. Body as a rule oval, more or less flattened and asymmetrical. A slit-like ventral furrow. The flagellum arises from the anterior end. Cytopharynx long; contractile vacuole anterior; nucleus posterior. Fresh water. Anisonema acinus Dujardin (Fig. 42, /). Body about 55 microns long. Anisonema truncatum Stein (Fig. 42, k). Body about 40 to 45 microns long. Anisonema emarginata Stokes (Fig. 42, /). Body about 15 microns long. Genus Notosolenus Stokes. Free-swimming; rigid; oval. Ventral surface convex, dorsal surface with a broad longitud- inal groove. Two flagella arise from the anterior end; one long, directed anteriorly and vibratile; the other shorter and trail- ing. Colorless. Notosolenus apocamptus Stokes (Fig. 42, m). Body up to 10 microns in length. E UGLENOIDIDA , CHLOROMONA DID A 127 Notosolemis sinuatus Stokes (Fig. 42, n). microns long. Both in standing water. Body about 20 ORDER 6 CHLOROMONADIDA KLEBS The Phytomastigina placed in this order are of rare occur- rence and consequently not well known. The majority possess small discoidal grass-green chromatophores which on addition of an acid become blue-green. The metabolic products are fatty oil. Starch or allied carbohydrates are absent. Stigma is also not present. Fig. 43 a. Gonyostomum semen. X325 (After Stein). b. Vaciiolaria virescens. yillS (After Senn). c. Trentonia flagellata. X 200 (After Stokes). d. Thaumatomastix setifera. X500 (After Lauterborn). Genus Gonyostomum Diesing. With grass-green chromato- phores. There are highly refractile trichocyst-like structures in the cytoplasm. Gonyostomum semen Diesing (Fig. 43, a). Sluggish animal. Body about 45 to 60 microns long. In marshy water among decaying vegetation. Genus Vacuolaria Cienkowski. Body grass-green, without trichocyst-like structures. Anterior end narrow. With two fla- gella. Cysts with a gelatinous envelope. Vacuolaria virescens Cienkowski (Fig. 43, b). Body about 75 to 100 microns long. Fresh water. Genus Trentonia Stokes. Bi-fiagellate as in the last genus, but anterior margin is slightly bilobed. Trentonia flagellata Stokes (Fig. 43, c). Slow-moving or- 128 HANDBOOK OF PROTOZOOLOGY ganism. Encystment is followed by binary fission. Body about 60 microns long. Fresh water. Genus Thaumatomastix Lauterborn. Body colorless; pseu- dopodia formed. Two fiagella; one extended anteriorly, the other trailing. Holozoic. Perhaps a transitional form between the Mastigophora and the Sarcodina. Thaumatomastix setifera Lauterborn (Fig. 43, d). Body about 30 to 35 microns long. References Dangeard, p. 1901 Recherches sur les Eugleniens. Le Botaniste. P. 97. DoBELL, C. 1908 The structure and life-history of Copro- monas siihtilis nov. gen. et nov. spec: A contribution to our knowledge of the Flagellata. Quart. Jour. Micr. Sci., (2) Vol. 52. Lemmermann, E. 1913 Eugleninae. Siisswasserfl. Deutsch- lands, etc. H. 2. Pascher.A. 1913 Chloromonadinae. Ibid. H. 2. 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. i CHAPTER X SUBCLASS 2 ZOOMASTIGINA DOFLEIN THE ZOOMASTIGINA laclc both chromatophorcs and par- amylum bodies. The body organization varies greatly from a simple to a very complex type. The majority possess a single nucleus which is, as a rule, vesicular in structure. In numerous forms a parabasal body is present (p. 23). Myonemes are pres- ent in several parasitic forms. Nutrition is holozoic, saprozoic, or parasitic. Asexual reproduction is by longitudinal fission; sexual reproduction is unknown. Encystment occurs widely. The Zoomastigina are free-living or parasitic in various animals. According to Calkins, they are divided into four orders: With pseudopodia besides flagella Order 1 Pantostomatida Without pseudopodia, but with flagella With one or two flagella Order 2 Protomonadida With two to eight flagella Order 3 Polymastigida With more than eight flagella Order 4 Hypermastigida ORDER 1 PANTOSTOMATIDA SENN The group contains those Zoomastigina which possess both pseudopodia and flagella. Flagella vary in number from one to several. Pseudopodia vary also greatly in form and in number. The order is subdivided into two families as follows: With numerous flagella Family 1 Holomastigidae With one to three, rarely four, flagella Family 2 Rhizomastigidae Family 1 Holomastigidae Senn Genus Multicilia Cienkowski. Body spheroidal, but amoe- boid. Flagella numerous, being 40 to 50 in number, long and evenly distributed. One or more nuclei. Holozoic. Food is ob- tained by means of pseudopodia. Contractile vacuoles are nu- merous. Multiplication by fission. Diameter of body less than 50 microns. Fresh or salt water. [129 1 130 HANDBOOK OF PROTOZOOLOGY MuUicilia marina Cienkowski (Fig. 44, a). With a single nucleus. About 20 to 30 microns in diameter. Marine. MuUicilia lacustris Lauterborn (Fig. 44, h). Multinucleate. Body diameter 30 to 40 microns. Fresh water. MuUicilia paliistris Penard. Fresh water. Family 2 Rhizomastigidae Biitschli The members of this family possess one to three, rarely four flagella and also axopodia or lobopodia. Thus they com- bine the chief characteristics of the Mastigophora and Sarco- dina. Because of the constant presence of the flagella, they are ordinarily considered as belonging to the Mastigophora. There is a single nucleus. The flagellum arises from a basal granule which is often connected with the nucleus by a rhizoplast. Asexual reproduction is binary fission which takes place both in trophic and encysted stages. Sexual reproduction has been reported in one species. Method of nutrition is either holozoic or parasitic. Free-living and a few parasitic forms. Genus Mastigamoeba Schulze. Monomastigote, uninu- cleate, with finger-like pseudopodia. Flagellum long and arises from the nucleus. Fresh water and soil. Mastigamoeba aspera Schulze (Fig. 44, c). Large form. 150 microns in diameter. Genus Mastigina Frenzel. With a single flagellum which arises from the nucleus located at one end. Body surface is tough, being frequently covered by ciliary projections, and shows a little tendency toward pseudopodial formation. Roll- ing movement. Fresh water, soil, or parasitic. Mastigina setosa Goldschmidt (Fig. 44, d). Body length up to 140 microns. Mastigina hylae Frenzel (Fig. 44, e). In the large intestine of many species of frog. Body about 100 microns long. Genus Mastigella Frenzel. With a flagellum which is not connected with the nucleus. Pseudopodia numerous, digitate. Body-form changes actively and constantly. Contractile vacuole. Mastigella vitrea Goldschmidt (Fig. 44, /). 150 microns long. Sexual reproduction has been reported to occur by Goldschmidt. PA NTOSTOMA TIDA 131 Fig. 44 a. Multicilia marina. X300 (After Cienkowski). b. M. lacustris. X300 (After Lauberborn) c. Mastigamoeha aspera. X 150 (After Schulze) d. Mastigina setosa. X275 (After Goldschmidt). e. M. hylae. X515 (After Becker). f. Mastigella vitrea. X275 (After Goldschmidt) g. Actinomonas mirabilis. X850 (After Griessmann from Doflein). h. Dimorpha miitans. X700 (After Blochmann). i. Pteridomonas pulex. X400 (After Penard). j, k. Ciliophrys infusionum. X400 (After Biitschli). 132 HANDBOOK OF PROTOZOOLOGY Genus Actinomonas Kent. Body generally spheroidal, with a single flagellum and radiating axopodia or filopodia. Ordi- narily attached with a cytoplasmic process to foreign object, but undergoes free-swimming movement by withdrawing it. A single nucleus central; several contractile vacuoles. Holozoic. Actinomonas mirahilis Kent (Fig. 44, g). Diameter about 10 microns; flagellum 20 microns long. Fresh water. Genus Dimorpha Gruber. Ovoid or subspherical; with two flagella and radiating axopodia, all arising from an eccentric granule. The nucleus is also eccentric. Pseudopodia are some- times withdrawn. In fresh water. Dimorpha ?nutans Gruber (Fig. 44, h). Diameter up to 15 microns. Genus Pteridomonas Penard. Body small, heart-shaped, usually attached with a long cytoplasmic process. From the opposite pole, there arises a single flagellum, around which occurs a ring of extremely fine filopodia or flagella. The nu- cleus central; a contractile vacuole. Holozoic. Fresh water. Pteridomonas pulex Penard (Fig. 44, i). About 20 microns wide. Genus CiliophrysCienkowski. Body spherical with extremely fine radiating filopodia, giving the appearance of a helio- zoan, with perhaps 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. Ciliophrys infusionum Cienkowski (Fig. 44, j,k). Flagel- lated stage 25 to 30 microns long. Fresh water infusion. Ciliophrys mariria Caullery. Diameter about 10 microns. Salt water. References Becker, E. R. 1925 The morphology of Mastigina hylae (Frenzel) from the intestine of the tadpole. Jour. Paras., Vol. 11. Lemmermann, E. 1914 Pantostomatineae. Siisswasserflora Deutschlands, etc. H. 1. CHAPTER XI ORDER 2 PROTOMONADIDA BLOCHMANN THIS ORDER contains small Zoomastigina with one, two, or sometimes three flagella. The body is in many cases plas- tic, having no definite pellicle, and in some cases it is amoeboid. The method of nutrition is holozoic, saprozoic, or parasitic. The order includes a heterogeneous lot of Protozoa, mostly parasitic, whose affinities to one another are very incompletely known. Reproduction is, as a rule, by longitudinal fission, al- though budding or multiple fission has also been known to occur. Sexual reproduction, though reported in some forms, has not been confirmed. In dividing the Protomonadida into ten families. Calkins' scheme has been chiefly followed : With one flagellum Protoplasmic collar present Collar entirely enclosed in jelly Family 1 Phalansteriidae Collar not enclosed in jelly Without any lorica Family 2 Choanoflagellidae With lorica Family 3 Bicosoecidae Protoplasmic collar absent Family 4 Trypanosomatidae With two flagella Undulating membrane present; parasitic Family 5 Cryptobiidae Undulating membrane absent Flagella of equal length Family 6 Amphimonadidae Flagella of unequal length One primary flagellum, the other secondary Family 7 Monadidae One primary flagellum, the other trailing Family 8 Bodonidae With three flagella; one primary, two trailing Family 9 Trimastigidae With four flagella; two long, two short Family 10 Costiidae Family 1 Phalansteriidae Kent Genus Phalansterium Cienkowski. Body small and ovoid; with a flagellum and a narrow collar. Numerous individuals are embedded in gelatinous substance which assumes a dendritic form. The flagella protrude. Fresh water. [ 133 ] 134 HANDBOOK OF PROTOZOOLOGY Phalansterium digitatum Stein (Fig. 45, a) 17 microns long. The body about Family 2 Choanoflagellidae Stein Small flagellates, sometimes with the second flagellum which serves for fixation of the body. A delicate collar surrounds the flagellum. Ordinarily sedentary forms. If temporarily freed, the organisms swim with the flagellum directed backward. Often colonial. Free-living in fresh water. Holozoic on bacteria or saprozoic. Fig. 45 a. Phalansterium digitatum. X400 (After Stein). b. Monosiga ovata. X600 (After Kent). c. M. robusta. X575 (After Stokes). d. Codosiga utriculus. X 1000 (After Stokes). Genus Monosiga Kent. Solitary; with a cytoplasmic collar. Apparently without a shell. With or without stalk. Attached to fresh or salt water vegetation. Several species. Monosiga ovata Kent (Fig. 45, b). About 10 to 15 microns long. Salt water. Monosiga robusta Stokes (Fig. 45, c). About 13 microns long. Fresh water. Genus Codonosiga Kent. Similar to Monosiga, but in- dividuals are in a cluster-form at the end of a stalk which may have branches. Fresh water. Codonosiga utriculus Stokes (Fig. 45, d). Attached to fresh water plants. Body about 11 microns in length. Some of the other genera of the family are: Genus Desmarella Kent. Band-form colonies; simple or branched. PROTOMONADIDA 135 Genus Proterospongia Kent. Stalkless individuals embedded irregularly in a jelly mass, with the collars protruding. Genus Sphaeroeca Lauterborn. Similar to the last genus, but individuals with stalks and radiating. Genus Salpingoeca Clark. With a vase-like lorica to which the stalked or stalkless organism is attached. Family 3 Bicosoecidae Poche Small monomastigote forms. With test. Solitary or colonial. Collar rudimentary or developed. Holozoic. Fresh water. Fig. 46 a. Bicosoeca socialis. X555 (After Lauterborn). b. Fart oi a co\ony oi Poteriodendron petiolatum. X435 (After Stein). Genus Bicosoeca James-Clark. Test vase-like; body small, ovoid with rudimentary collar, a flagellum extending through it. The protoplasmic body is anchored to the base by a cyto- plasmic process (flagellum?). A nucleus and a contractile vacu- ole attached or free-swimming. Bicosoeca socialis Lauterborn (Fig. 46, a). Free-swimming in fresh water. Lorica 23 microns by 12 microns; body about 10 microns long. Genus Poteriodendron Stein. Colonial; test is vase-shaped and possesses a prolonged stalk. 136 HANDBOOK OF PROTOZOOLOGY Poteriodendron petiolatum (Ehrenberg) (Fig. 46, b). Test about 30 to 50 microns high. Fresh water. Family 4 Trypanosomatidae Doflein Body characteristically leaf-like, although changeable to a certain extent. A single nucleus and a blepharoplast. A single flagellum arises from a basal granule which may be independent from, or united with, the blepharoplast (Figs. 5 and 47). The 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. 47 Diagrams showing the structural differences among the genera of Trypanosomatidae. (After Wenyon). basal portion of the flagellum forms the outer boundary of the undulating membrane which extends along the side of the body. Exclusively parasitic. This family contains a number of parasites which are responsible for serious diseases of man and domestic animals in various parts of the world. Genus Trypanosoma Gruby. Parasitic in the circulatory system of vertebrates. The body is leaf-like, pointed at the flagellate end, and bluntly rounded, or rarely pointed, at the other. Polymorphism which seems to be due to differences in development, is common. The nucleus is located centrally. PROTOMONADIDA 137 Near the bluntly rounded end, there is a blepharoplast and usually a basal granule from which the flagellum arises and runs toward the other end, marking the outer margin of the undulating membrane. In most cases the flagellum extends Fig. 48 The life cycle of Trypanosoma melophagium in the blood of sheep and in Melophagus ovinus. (After Hoare). a, trypanosome as ingested by Melophagus with the sheep's blood; b-e, crithidia formation through division; f-h, large transitional crithidia in the hind-gut which by division are transformed into smaller forms; i-k, formation of metacyclic trypanosomes; 1-m, formation of pyriform crithidia; n, leish- mania forms. freely beyond the body. Myonemes are common. Asexual re- production is binary or rarely multiple fission. The organism is carried from host to host by blood-sucking invertebrates and undergoes definite changes in the alimentary canal of the latter (Fig. 48). Sexual reproduction is not known. A number of forms are pathogenic to their hosts and the diseased condi- tion is termed trypanosomiasis in general. 138 HANDBOOK OF PROTOZOOLOGY A. Trypanosoma in Man Trypanosoma gamhiense Dutton (Fig. 49, a). Parasitic in the blood and lymph of man in certain regions of Africa; trans- mitted by the tsetse fly, Glossina palpalis. Reservoir hosts are domestic and wild animals. Body 15 to 30 microns long. Mature forms are slender and long, and shows a long flagellum; individuals formed by longitudinal fission are short and broad with no projecting flagellum. Half-grown forms are inter- mediate in size and structure. The organism is responsible for the "sleeping sickness" of man in Africa. Fig. 49 Mammalian trypanosomes as seen in stained smears. XlOOO. (After various authors). a, five individuals of Trypanosoma gamhiense and an erythrocyte of man; b, T. cruzi; c, T. brucei; d, T. theileri; e, T. melophagium ; f, T. evansi; g, T. equinum; h, T. equiperdum; i, T. lewisi. Trypanosoma cruzi (Chagas) ( = Schizotrypanum cruzi Cha- gas) (Fig. 49, h). Parasitic in children in South America (Bra- zil, Peru, Venezuela, etc.). The trypanosome is a small curved form, measuring about 20 microns in total length. With a centrally located nucleus. A large blepharoplast is located close to the sharply pointed non-flagellate end. Multiplication takes place in the cells of nearly every organ of the host body. Upon entering a host cell, the trypanosome loses its flagellum and undulating membrane, and assumes a leishmania form which measures 2 to 5 microns in diameter. This form under- goes repeated binary fission, and a large number of daughter PROTOMONADIDA 139 individuals are produced. They develop sooner or later into trypanosomes which, upon rupture of the host cell, become liberated into the blood stream. This trypanosome is trans- mitted by the reduviid bug, Triatoma megista and allied species. The diseased condition is known as "Chagas' disease." B. Trypanosoma in Domestic Animals Trypanosoma hrucei Plimmer and Bradford (Fig. 49, c). Polymorphic. Body varies from 15 to 30 microns in length (average 20 microns). Transmitted by various species of tsetse flies, Glossina. The trypanosome is the most virulent of all. It causes the fatal disease known as "nagana" among mules, donkeys, horses, camels, cattle, swine, dogs, etc., which ter- minates in 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. Trypanosoma theileri Laveran (Fig. 49, d). Non-pathogenic large trypanosome which occurs in the blood of cattle. Cosmo- politan. The extremities of the body are sharply pointed; length 60 to 70 microns. Myonemes are well developed. Trypanosoma americanum Crawley. This trypanosome was noted in American cattle and is probably identical with T. theileri. It is transmitted from cattle to cattle by tabanid flies. Trypanosoma melophagium (Flu) (Fig. 49, e). Non-patho- genic trypanosome of the sheep. 50 to 60 microns long with attenuated ends. The development of the organism in Melo- phagus ovinus is illustrated in Fig. 48. Trypanosoma evansi (Steel) (Fig. 49,/). In horses, mules, donkeys, cattle, dogs, camels, elephants, etc. The infection in horses seems to be usually fatal and known under the name of "surra." The trypanosome measures about 25 microns long and is monomorphic. Transmitted by tabanid flies. Widely distributed. Trypanosoma equinum Vages (Fig. 49, g). In horses in South America, causing an acute disease known as "mal de Caderas." Other domestic animals do not suffer as much as do the horses. Length 20 to 25 microns. The trypanosome is peculiar in that it does not show any blepharoplast by ordinary staining. 140 HANDBOOK OF PROTOZOOLOGY Trypanosoma equiperdum Doflein (Fig. 49, h). In horses and donkeys. The cause of a chronic disease known as "dourine." Widely distributed. Length 25 to 30 microns. No intermediate host; transmission takes place directly from host to host during sexual act. C. Trypanosoma in Other Mammals Trypanosoma lewisi (Kent) (Fig. 49, i). In the blood of various species of the rat, Rattus. Cosmopolitan. Under ordinary conditions, the trypanosome is not pathogenic to the host. The organism which measures about 25 microns long, is very active. It is slender and possesses a long flagellum. Transmission by the flea, Ceratophyllus fasciatus, in the diges- tive tract of which the parasite undergoes asexual reproduction. When the infected fleas are eaten by a rat, the latter becomes the victim of a new infection. Trypanosoma duttoni Thiroux. In the species of the mouse, Mus. Similar to T. lewisi, but rats are not susceptible, hence considered as a distinct species. Transmission by fleas. Trypanosoma peromysci Watson. Similar to T. lewisi. In Canadian deer mice, Peromyscus maniculatus and others. Trypanosoma nabiasi Railliet. Similar to T. lewisi. In rab- bits, Lepus domesticus and L. cnniculiis. D. Trypanosoma in Birds and Reptiles Trypanosoma paddae Laveran and Mesnil. In Java spar- row, Munia oryzivora. Trypanosoma 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. E. Trypanosoma in Amphibians Trypanosoma rotatorium (Meyer) (Fig. 50, a). In tadpoles and adults of various species of the frog. Between a slender form with a long projecting flagellum measuring about 35 microns long and a very broad one without free portion of the flagellum, various intermediate forms are to be noted in a single P ROTO MO NAD ID A 141 host. The blood vessels of internal organs, such as kidneys, contain more individuals than the peripheral vessels. A cen- trally located nucleus and a small blepharoplast. Undulating membrane is highly developed. Myonemes prominent. Mul- tiplication by longitudinal fission. The leech, Hemiclepsis marginata, has been found to be the transmitter in some lo- calities. Fig. 50 a. Trypanosoma rotatorium. X750. b. T. inopuiatum. X1175. c. T. diemyctyli. X800 (After Hegner). d. T. giganteum. X500 (After Neumann). e. T. granulosum. XlOOO (After Minchin). i.T.remaki. X 1650 (After Kudo). g. T. percae. XlOOO (After Minchin). h. T. danilewskyi. XlOOO (After Laveran and Mesnil). i. T.rajae. XI 600 (After Kudo). Trypanosoma inopinatum Sergent and Sergent (Fig. 50, b). In the blood of various frogs. The trypanosome is almost always slender in form and measures 12 to 20 microns in length. Larger forms 30 to 35 microns, are also noted. In both forms, blepharoplast is comparatively large. Leeches transmit the organism from host to host. Numerous species of Trypanosoma have been reported from 142 HANDBOOK OF PROTOZOOLOGY the frog, but specific identification is indistinct. It is better and safer to hold that they belong to one of the two species men- tioned above, until their development and transmission be- come known. Trypanosoma diemyctyli Tobey (Fig. 50, c). In the blood of the newt, Diemyctylus viridescens. A comparatively large form. Body slender and measures about 50 microns long by 2 to 5 microns broad, the flagellum 20 to 25 microns long. Undulating membrane is well developed. F. Trypanosoma in Fish Both fresh and salt water fish are hosts to different species of trypanosomes. What effects these parasites exercise upon the host fish are not understood. Ordinarily only a few in- dividuals are found in a host fish. Trypanosoma granulosum Laveran and Mesnil (Fig. 50, e). In the eel, Anguilla vulgaris. Total length 70 to 80 microns. Trypanosoma giganteum Neumann (Fig. 50, d). In Raja oxyrhynchus. Total length 125 to 130 microns. Trypanosoma remaki Laveran and Mesnil (Fig. 50, /). In Lucius lucius, L. reticulatus and probably other species. Di- morphic. Total length 24 to 33 microns. Trypanosoma percae Brumpt (Fig. 50, g). In Perca fluvia- tilis. Total length 45 to 50 microns. Trypanosoma danilewskyi Laveran and Mesnil (Fig. 50, h). In the carp and goldfish. Widely distributed. About 40 mi- crons long. Trypanosoma rajae Laveran and Mesnil (Fig. 50, i). In various species of Raja. Length 30 to 35 microns. Genus Crithidia Leger. Parasitic in arthropods and other invertebrates. The blepharoplast is located between the cen- trally located nucleus and the end from which the flagellum pro- jects (Fig. 47). The undulating membrane is thus not so well developed as in Trypanosoma. The organism may lose the flagellum and form a leptomonas or rounded leishmania stage which leaves the host intestine with fecal matter and becomes the source of infection in other host animals. Crithidia euryophthalmi McCulloch (Fig. 51, a-c). In the gut of the bug, Euryophthalmus convivus which feeds on Lupinus PROTOMONADIDA 143 arboreus in the sand dunes on California coast. Multiple division and endogenous budding characterize this species, Crithidia gerridis Patton (Fig. 51, d). In the gut of several species of water bugs belonging to the genera Gerris and Micro- velia. Total length 22 to 45 microns. Fig. 51 a-c. Crithidia euryophthalmi. X 875 (After McCulloch). a, b, from the mid-gut; c, from the rectum. C. gerridis. X1070 (After Becker). C. hyalommae. XIOOO (After O'Farrell). Leptomonas ctenocephali. XIOOO (After Wenyon). Phytomonas elmassiani. X1500 (After Holmes), i, from milkweed, Asclepias sp.; j, from the gut of a suspected transmitter, the bug, Oncopeltus fasciatus. Herpetomonas muscarum. X1070 (After Becker). \'arious phases of H. drosophilae. XIOOO (After Chatton and Leger). d. e,f. g.h. i. J- k. 1-n. Crithidia hyalommae O'Farrell (Fig. 51, e,/). In the body cavity of the tick {Hyalomma aegyptium) of the cattle 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. Genus Leptomonas Kent. Exclusively parasitic in inver- tebrates. The blepharoplast is very close to the end beyond which the fiagellum projects, and therefore there is no undulat- ing membrane (Fig. 47). Non-flagellate phase resembles Leish- mania. 144 HANDBOOK OF PROTOZOOLOGY Leptomonas ctenocephali Fantham (Fig. 51, g, h). In the hindgut of the dog flea, Ctenocephalns canis. Widely distri- buted. Genus Phytomonas Donovan. Morphologically similar to Leptomonas (Fig. 47), but it occurs in both plants and inver- tebrates. In the latex of the plants belonging to the families: Euphorbiaceae, Asclepiadaceae, Apocynaceae, Sapotaceae and Utricaceae. Transmitted by hemipterous insects. The organ- ism is often found in enormous numbers in localized areas in the host plant. The infection spreads from part to part. The in- fected latex is a clear fluid, owing to the absence of starch grains and other particles, and this results in the degeneration of the infected part of the plant. Several species. Phytomonas davidi (Lafront). Body about 15 to 20 microns long by about 1.5 microns broad. The posterior portion of the body is often twisted two or three times. Multiplication by longitudinal fission. Widely distributed. In various species of Euphorbia. Phytomonas elmassiani (Migone) (Fig. 51, i,j). In various species of milkweeds. Length 9 to 20 microns. Suspected trans- mitter, Oncopeltus fasciatns, according to Holmes. In South and North America. Genus Herpetomonas Kent. Ill-defined genus (Fig. 47). Exclusively invertebrate parasites. Trypanosoma, Crithidia, Leptomonas and Leishmania forms occur during development. Several species. Herpetomonas muscanun (Leidy) (= H. muscae-domesticae (Burnett)) (Fig. 51, k). In the gut of flies, belonging to the genera Musca, Calliphora, Sarcophaga, Lucilia, Phormia, etc. Herpetomonas drosophilae (Chatton and Alilaire) (Fig. 51, l-n). In the intestine of Drosophila confusa. Genus Leishmania Ross. All parasitic in vertebrate and invertebrate hosts, the latter not having been actually demon- strated, but suspected. Non-flagellate and flagellate forms occur (Fig. 47). Body very minute. In the vertebrate host the organism is not flagellated. Body spherical or ovoid, with a definite pellicle. With an eccentric nucleus and a blepharo- plast. The body measures from 2 to 5 microns in diameter. The organism attacks endothelial cells of blood capillaries and P ROTO MONAD ID A 145 mucosae; the spleen becomes highly enlarged. The transmitting agent is believed to be blood-sucking arthropods. In culture, the organism develops into leptomonad forms. This genus in- cludes three "species" occurring in man, all of which are prac- tically indistinguishable morphologically from one another, and, two of which are considered as identical. Leishmania donovani (Laveran and Mesnil) ( = L. infantum Nicolle) (Fig. 52, a-/). The organism attacks the endothelium and macrophage of man, causing the disease known as "kala azar." It occurs in India, China, west to southern Russia, and shores of the Mediterranean Sea. fe Fig. 52 a-f. Leishmania donovUni. X2000. (After Wenyon; Thomson and Robertson), a, three individuals from lymph smear of a kala azar patient; b, from a spleen smear; c-f, cultural forms. g, h. L. tropica. X2000 (After Wenyon ; Thomson and Robertson). g, from an Oriental sore; n, the parasites in a polymorphonuclear cell from a sore. Leishmania tropica (Wright) (Fig. 52, g, h). The organism infects the skin of the exposed part and rarely the mucous lining of the mouth, pharynx and nose of man. The resulting disease is usually called "Oriental sore." Distribution is similar to the above-mentioned species. Leishmania brasiliensis Vianna. The organism occurs in South and Central America. Some authors consider this spec- ies as identical with L. tropica. Although morphologically identical, these species show specific serum reactions. Genus Oikomonas Kent. A monofllagellate rounded or- ganism, living in stagnant water, soil and exposed fecal matter. Uninucleate. Encystment common. 146 HANDBOOK OF PROTOZOOLOGY Oikomonas termo (Ehrenberg) (Fig. 53, a, h). About 4 to 5 microns long. Stagnant water and soil. Genus Histomonas Tyzzer. Parasitic in domestic fowls. Body amoeboid with usually one flagellum which is connected with a blepharoplast. Histomonas meleagris (Smith) (Fig. 53, c). Length 12 to 15 microns. Supposed to be the cause of the "black-head" of turkeys and chicken. Fig. 53 a, b. Oikomonas termo. a, a stained trophozoite (XIOOO after Martin); b, living cyst (X1250 after Sandon). c. Histomonas meleagris. X700 (After Tyzzer). d. Rhizomastix gracilis. XIOOO (After Mackinnon). e. Cryptobia helicis. X 1 900 (After Beiaf). f. C. borreli. X650 (After Mavor). g. h. C. cyprini. X 665 (After Plehn). Genus Rhizomastix Alexeieff. Body rounded with a central nucleus. A blepharoplast is located between the nucleus and the posterior end of the body. A long fiber runs from it to the anterior end and continues into the flagellum. In the spherical cyst, the nucelus undergoes division. Rhizomastix gracilis Alexeieflt (Fig. 53, d). Body about 13 microns long, flagellum 20 microns long. In the intestine of axolotlesand tipulid larvae. Family 5 Cryptobiidae Poche Biflagellate trypanosome-like Protomonadida. One fla- gellum free, the other marks the outer margin of an undulating membrane. Blepharoplast is an elongated rod-like structure, often referred to as the parabasal body. All parasitic. PROTOMONADIDA 147 Genus Cryptobia Leidy (=Trypanoplasma Laveran and Mesnil). Parasitic in the reproductive organs of molluscs and other invertebrates and in blood and intestines of fish. Cryptobia helicis Leidy (Fig. 53, e). In the reproductive organs of various species of Helix of America and Europe. Length 6 to 20 microns. Asexual reproduction through binary fission is known. Cryptobia borreli (Laveran and Mesnil) (Fig. 53, /). In the blood of various freshwater fish such as Catostomus, Cy- prinus, etc. Body 20 to 25 microns long. Cryptobia cyprini (Plehn) (Fig. 53, g, h). In the blood of carp and goldfish. Comparatively rare. Body 10 to 30 microns long. Cryptobia grobbeni (Keysselitz). In the gastrovascular cavi- ty of Siphonophora. Size about 65 microns by 4 microns. Family 6 Amphimonadidae Kent Body naked or with a gelatinous envelope. With two equally long anterior flagella. Often colonial. Free-swimming or at- tached. One or two contractile vacuoles. Mainly fresh water. Genus Amphimonas Dujardin. Small oval or rounded amoe- boid form. Flagella at anterior end. Free-swimming or attached by an elongated stalk-like posterior process. Fresh or salt water. Amphimonas globosa Kent (Fig. 54, a). Diameter of body about 23 microns. Fresh water. Genus Spongomonas Stein. Individuals in granulated gela- tinous masses. Colony reaches often several centimeters in height. In motile stage pointed pseudopodia are produced. Fresh water. Spongomonas uvella Stein (Fig. 54, b). Body about 2X mi- crons long. Colony about 50 microns high. Fresh water. Genus Cladomonas Stein. Individuals are embedded in dichotomous dendritic gelatinous tubes which are united later- ally. Fresh water. Cladomonas fruticulosa Stein (Fig. 54, c). Body about 8 microns long. The whole colony reaches 85 microns in height. Genus Rhipidodendron Stein. Similar to Cladomonas, but the tubes are fused lengthwise. Fresh water. Rhipidodendron splendidum Stein (Fig. 54, d, e). Body 148 HANDBOOK OF PROTOZOOLOGY about 13 microns long. Fully grown colony 350 microns high. Genus Spiromonas Perty. Body elongated; without gela- tinous covering and spirally twisted; two flagella from the anterior end. Solitary in fresh water. Spiromonas augusta (Dujardin) (Fig. 54, /). Body about 10 microns long. Stagnant water. Fig. 54 a. Amphimonas globosa. X400 (After Kent). b. Spongomonas tivella. X325 (After Stein). c. Cladomonas fruticulosa. X325 (After Stein). d, e. Rhipidodendron splendidum. (After Stein), d, a young colony (X325); e, a free-swimming individual (X575). f. Spiromonas augusta. X750 (After Kent). g. Diplomita socialis. X750 (After Kent). Genus Diplomita Kent. With transparent lori-ca; body at- tached to the bottom of the lorica by a retractile filamentous process. A rudimentary stigma (?). Freshwater. Diplomita socialis Kent (Fig. 54, g). Pond water. Pale brown or yellow. Lorica 15 microns long. Family 7 Monadidae Stein Two flagella unequal in length : one primary and the other secondary. Motile or attached. One or two contractile vacuoles. Colony formation frequent. Free-living. PROTOMONADIDA 149 Genus Monas Ehrenberg. Known for a long time, but still very incompletely. Body not longer than 20 microns, plastic and actively motile ("dancing movement"). It attaches itself often to foreign objects. Monas vulgaris (Cienkowski) (Fig. 55, a). Oval; with a single nucleus. About 15 microns long. In stagnant water and infusion. • Fig. 55 a. Monas vulgaris. X 750 (After Doflein). b. Slokesiella dissimilis. X375 (After Stokes). c. 5. leptostoma. X630 (After Stokes). d. A young colony of Dendromonas virgaria. X500 (After Stein). e. Cephalothamnium cyclopum. X325 (After Stein). f, g. Anthophysa vegetans. (After Stein), f, a colony (X170); g, a single individual (X575). h. Physomonas socialis. X500 (After Kent). Genus Stokesiella Lemmermann. Body is attached by a fine cytoplasmic thread to a delicate and stalked vase-like test. Fresh water. Stokesiella dissimilis (Stokes) (Fig. 55, h). Fresh water. Solitary. Lorica about 28 microns long. Stokesiella leptostoma (Stokes) (Fig. 55, c). Fresh water. Often in groups. Lorica about 16 microns long. Genus Dendromonas Stein. Colonial. Individuals without 150 HANDBOOK OF PROTOZOOLOGY lorica, located at the end of the branched stalks. Fresh water. Dendromonas virgaria (Weisse) (Fig. 55, d). Pond water. Body about 8 microns long; height of colony 200 microns. Genus Cephalothamnium Stein. Colonial without test, but individuals are clustered at the end of a stalk which is colorless and rigid. Fresh water. Cephalothamnium cyclopum Stein (Fig. 55, e). Body about 10 microns long. Attached to the body of Cyclops. Genus Anthophysa Bory. Colonial forms, somewhat similar to Cephalothamnium. Stalks yellow or brownish and usually bent. Detached individuals are amoeboid with pointed pseu- dopodia. Anthophysa vegetans (Miiller) (Fig. 55, /, g). Common in stagnant water and infusion. Body about 5 or 6 microns long. Genus Physomonas Kent. Solitary. Usually attached by a filiform flexible pedicel; anterior end obliquely truncate. No cytostome. Fresh or salt water. Some authors place this genus with Monas. Physomonas socialis Kent (Fig. 55, A). Fresh water among decaying vegetation. Body 5 to 10 microns long. Family 8 Bodonidae Biitschli With two flagella; one is directed anteriorly and the other posteriorly and trailing. Flagella arise from the anterior end which is drawn out to a varying degree. One or several con- tractile vacuoles. Nutrition is holozoic or parasitic. Asexual reproduction is by binary fission. Genus Bodo Ehrenberg ( = Prowazekia Hartmann and Cha- gas). Small Protomonadida; ovoid, but plastic. Cytostome anterior; a single nucleus central or anterior. Flagella are con- nected with two blepharoplasts, near which is found a rounded parabasal body. Encystment common. Very common in stagnant water and infusion. Also frequently coprozoic. Bodo caudatus (Dujardin) (Fig. 56, a-i). Body about 10 to 20 microns long. Bodo edax Klebs (Fig. 56, j, k). About 10 to 15 microns long. Genus Rhynchomonas Klebs. Similar to Bodo, but there is an anterior extension of the body, in which one of the flagella P ROTO MO NAD ID A 151 is embedded, while the other flagellum trails. A single nucleus. Minute forms. Rhynchomonas nasuta (Stokes) (Fig. 56, /, m). In fresh water and also coprozoic. Genus Prowazekella Alexeiefif. Elongated pyriform. Two flagella from the anterior end; one is directed anteriorly, and the other posteriorly. A single nucleus anterior. The encysted Fig. 56 a-i. Bodo caudatus. X 750 (After Sinton). a-d, feeding on a Bacillus; e-i, excystation in culture, j, k. B. edax. X700 (After Kiihn). 1, m. Rhynchomonas nasuta. X900 (After Parisi). n. Prowazekella lacertae. X 1250 (After Kiihn). o-q. Embadomonas intestinalis. X1900 (After Jepps). r. Phyllomitus undulans. X500 (After Stein), s. Colponema loxodes. X325 (After Stein), t, u. Cercomonas longicauda. X 1000 (After Wenyon). V. C. crassicauda. X 1000 (After Dobell). stage is remarkable in that it is capable of increasing in size to a marked degree. Exclusively parasitic; in the intestine of various species of the lizard. Prowazekella lacertae (Grassi) (Fig. 56, n). In the intestine of lizards belonging to the genera Lacerta, Tarentola, etc. Genus Embadomonas Mackinnon. Body small, ovoid or 152 HANDBOOK OF PROTOZOOLOGY pyriform. In the intestine of mammals and insects, Cytostome comparatively large. Nucleus anterior. Cysts are pyriform or ovoidal. Embadomonas intestinalis (Wenyon and O'Connor) (Fig. 56, o~q). In man. Embadomonas agilis Mackinnon. In the gut of trichopteran and tipulid larvae. Genus Phyllomitus Stein. Body oval, cytostome large and conspicuous, with two unequal flagella which are united by a membrane. Fresh water and coprozoic. Phyllomitus undulans Stein (Fig. 56, r). Body small 5 to 21 microns long. Genus Colponema Stein. Body small, less than 30 microns long. Constant in form; ventral furrow conspicuous and widens at the anterior end. One flagellum arises from the anterior end and the other from the middle of body. One or two con- tractile vacuoles. Fresh water. Colponema loxodes Stein (Fig. 56, s). Body up to 30 microns long. Genus Cercomonas Dujardin. Biflagellate, both flagella arising from the anterior end of body. One directed anteriorly and the other runs backward over the body surface, becoming a trailing flagellum. Nucleus pyriform in shape and connected with the basal granules of the flagella. Spherical cysts uni- nucleate. Fresh water and coprozoic. Cercomonas longicauda Dujardin (Fig. 56, /, ii). Body pyri- form and 5 to 20 microns long. Multiplication by binary fission. Fresh water. Often coprozoic. Cercomonas crassicauda Dujardin (Fig. 56, v). Body about 10 to 14 microns long. Habitat similar to the last mentioned species. Family 9 Trimastigidae Senn Incompletely known forms with three flagella, of which one is directed anteriorly and the other two posteriorly. Body bilaterally symmetrical. No cytostome. Other structures un- known. Free-living in fresh water. Genus Trimastix Kent. Ovate or pyriform. Contractile vacuole conspicuous. PROTOMONADIDA 153 Trimastix marina Kent (Fig. 57, a). About 18 microns long. Marine. Genus Dallingeria Kent. Small; with drawn-out anterior end. Dallingeria drysdali Kent (Fig. 57, b). Small fresh water form. Body length is less than 6 microns. Fig. 57 a. Trimastix marina. X625 (After Kent). b. Dallingeria drysdali. XIOOO (After Kent). c-h. Costia necatrix. c, d, (X 600 after Weltner); e, f, (X1050 after Moroff); g, cyst (X1050 after Moroff); h, two individuals attached to the host fish integument (X375). Family 10 Costiidae With four flagella; two equally long and the other two equally short. Genus Costia Leclerq. Body oval in front view; pyriform in profile. Along one side, there is a funnel-like depression, from the bottom of which the flagella arise. Ectoparasitic on fish. Costia necatrix (Henneguy) (Fig. 57, c-h). Body 10 to 20 microns long by 5 to 10 microns broad. A single compact nucleus central; a contractile vacuole. Asexual reproduction is by longitudinal fission. Spherical uninucleate cysts measure 7 to 10 microns. When present in large numbers, the skin of fish appears to be covered with a whitish coat, and it is thought that the organisms are responsible for the death of young fish. References Christophers, S. R., H. E. Shortt and P. J. Barraud. 1926 The morphology and life-cycle of the parasite of Indian kala azar in culture. Indian Med. Res. Mem. 154 HANDBOOK OF PROTOZOOLOGY HoARE, C. A. 1923 An experimental study of the sheep- trypanosome {T. melophagium Flu, 1908), and its trans- mission by the sheep-ked {Melophagus ovinus h.). Parasit., Vol. 15. 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 Try- panosomiases. Second edition. Paris. Lemmermann, E. 1914 Protomastiginae. Susswasserfl. Deut- schlands, etc., H. 1. MiNCHiN, E. A. AND J. D. Thomson, 1915 The rat trypano- some, Trypanosoma lewisi, in its relation to the rat flea, Ceratophyllus 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. Wenyon, C. M. 1926 Protozoology. Vol. 1. London. CHAPTER Xn ORDER 3 POLYMASTIGIDA BLOCHMANN THE zooMASTiGiNA grouped here possess three to eight flagella and, generally speaking, are minute forms with varied characters and structures. The majority inhabit the digestive tract of animals. Many possess a cytostome. One to many nuclei occur. The body is usually covered by a thin pellicle and, therefore, is somewhat plastic, although each species shows a more or less typical form. The cytoplasm does not show any special cortical differentiation. In many, there is an axial structure known as the axostyle or axial filament (p. 39). Parabasal body is invariably present and shows various forms. Contractile vacuole is generally absent. Nutrition is holozoic, saprozoic, or parasitic. Asexual reproduction is by longitudinal fission, sometimes multiple. Encystment is common, and the cyst is responsible for infection of new hosts through the mouth. Sexual reproduc- tion has not been definitely established. Some of the Poly- mastigida have recently been studied rather extensively by numerous investigators, but it is, as Calkins set forth clearly, impossible to place them in definite genetically related groups. Calkins' scheme is adopted in subdividing them into the follow- ing three tribes: With one cytostome and kinetic element Tribe 1 Monozoa With two cytostomes and kinetic elements Tribe 2 Diplozoa With numerous nuclei and kinetic elements Tribe 3 Polyzoa Tribe 1 Monozoa Calkins Without cytostome and undulating membrane Without axostyle Group 1 With axostyle Group 2 With cytostome Without undulating membrane; with axostyle Group 3 With undulating membrane Without axostyle Group 4 With axostyle Group 5 [155] 156 HANDBOOK OF PROTOZOOLOGY Group 1 Genus Enteromonas da Fonseca. Body globular. Two an- terior flagella and one trailing flagellum. Enteromonas hominis da Fonseca (Fig. 58, a). Body small, 5 to 6 microns in diameter. In human feces. Genus Tricercomonas Wenyon and O'Connor. Body similar to that of Cercomonas, but with three anterior flagella and a posterior flagellum. Parasitic. Oblong cyst with four nuclei when mature. Fig. 58 a. Enteromonas hominis. XlOOO (After da Fonseca). b. Tricercomonas intestinalis. X1300 (After Wenyon and O'Connor). c. Tetramitus rostratus. X500 (After Klebs). d. T. pyrijormis. X500 (After Klebs). e. Copromastix prowazeki. X800 (After Aragao). f. Streblomastix strix. X800 (After Kidder). Tricercomonas intestinalis Wenyon and O'Connor (Fig. 58, b) In human intestine. Body 4 to 8 microns long. Rare, but widely distributed. Genus Tetramitus Perty. Body ellipsoidal or pyriform. Four anterior flagella, unequal in length, one may be a trailing flagellum. Cystome distinct. Contractile vacuole. Holozoic. Fresh or salt water. Tetramitus rostratus Perty (Fig. 58, c). Form variable; about 25 to 28 microns long. In stagnant water. Tetramitus pyriformis Klebs (Fig. 58, d). About 18 microns long. In infusion. Genus Copromastix Aragao. Four anterior flagella equally long. Body triangular or pyramidal. Coprozoic. Copromastix prowazeki Aragao (Fig. 58, e). In human and rat feces. About 16 to 18 microns long. Genus Streblomastix Kofoid and Swezy. Body elongated; POLYMASTIGIDA 157 anterior flagella four in number. Nucleus an elongated spindle. With spirally arranged myonemes. Parasitic. Streblomastix strix Kofoid and Swezy (Fig. 58, /). In the intestine of the termite, Termopsis aiigiisticollis . Group 2 Genus Devescovina Foa. Body oblong, axostyle is rigid and ends at the posterior end of the body. Three anterior flagella and one long trailing flagellum. Parabasal body wounds around the axostyle. Parasitic. Devescovina lemniscata Kirby (Fig. 59, a). In the intestine of the termite, Cryptotermis hermsi. About 20 to 30 microns long. Genus Paradevescovina Kirby. Minute; structure similar to that of Devescovina. The parabasal body is a curved rod Fig. 59 a. Devescovina lemniscata. X750 (After Kirby). b. Paradevescovina nana. X1250 (After Kirby) . c. Metadevescovina debilis. X850 (After Light). d. Foaina gracilis. X900 (After Janicki). e. Dinenympha fimbriata. X625 (After Kirby). f. Monocercomonas bufonis. X 1250 (After Alexeieff). 158 HANDBOOK OF PROTOZOOLOGY stretched between the blepharoplast and a point on the side of body. With a stout axostyle. Paradevescovina nana Kirby (Fig. 59, b). In the termite, Kalotermes hermsi. Body length 10 to 15 microns. Genus Metadevescovina Light. Body spindle to elongated oval in form; circular in cross-section. Body surface smooth, but often with attached bacteria. Nucleus anterior. Axostyle not protruding beyond the posterior end of body. The parabasal body is a spiral rod around the axostyle. Three sets of flagella. A single primary flagellum, three long secondary flagella and several tertiary flagella, all of which emerge from the region anterior to the nucleus. Feeding on bits of wood. Metadevescovina dehilis Light (Fig. 59, c). In the intestine of the termite, Kalotermes hubbardi. Body 35 to 40 microns long. Genus Foaina Janicki. Body ellipsoidal; rigid axostyle pro- trudes a little. Flagella similar to those of Devescovina in num- ber and appearance. Blepharoplast is somewhat back of the anterior tip. Parabasal body is composed of two curved rods. Foaina gracilis Janicki (Fig. 59, d). In the gut of termites. Body about 25 to 30 microns long. Genus Dinenympha Leidy. Four to eight posterior flagella arranged in spiral form. Axostyle free at the posterior end. Dinenympha jimbriata Kirby (Fig. 59, e). In the intestine of the termite, Reticulotermes hesperus. Body 60 to 70 microns long. Genus Pyrsonympha Leidy. Body ovoid; plastic. Axostyle is divided into two parts at its posterior margin and the whole vibrates in life. 4 to 8 posterior flagella. Several species in termites. Pyrsonympha vertens Leidy. In Termes flavipes. Genus Monocercomonas Grassi. Body small. Four flagella inserted in pairs in two places. Two flagella directed anteriorly, and two posteriorly. Axostyle filamentous. Monocercomonas bufonis Dobell (Fig. 59,/). In frogs and toads. Body small, about 13 microns long. Group 3 Genus Eutrichomastix Kofoid and Swezy ( = Trichomastix Blochmann). Body pyriform; anterior end rounded. Cyto- POLYMASTIGIDA 159 stome and nucleus anterior. Three flagella of equal length arise from the anterior end, the fourth trailing. Axostyle pro- jects beyond the posterior end of body. All parasitic. Eutrichomastix serpentis (Dobell) (Fig. 60, a). In the large intestine of several species of the snake belonging to the genera: Pituophis, Eutaenia and Python. Body about 10 to 25 microns long. Genus Retortamonas Grassi. Similar to Eutrichomastix in possessing four flagella, one of which trails. Cytostome (?). Axostyle indistinguishable; but a deeply staining axial filament is noted in numerous specimens, although some lack it entirely. Parasitic in the intestine of various insects. Fig. 60 a. Eutrichomastix serpentis. X1085 (After Kofoid and Swezy). b. Retortamonas orthopterorum. X 1 850 (After B6laf). c. Protrichomonas legeri. X750 (After Alexeleff). d. Polymastix melolonthae. X400 (After Hamburger). Retortamonas orthopterorum (Parisi) (Fig. 60, b). In cock- roaches. Body very minute, 3 to 6 microns long. Genus Hexamastix Alexeieff. Body similar to Eutricho- mastix, but there are six flagella, of which one trails. Axostyle conspicuous and parabasal body prominent. Hexamastix hatrachorum Alexeieff. In amphibians. Genus Protrichomonas Alexeiefif. Three anterior flagella of equal length, arising from a blepharoplast located at the ante- rior tip. Parasitic, Protrichomonas legeri Alexeieff (Fig. 60, c). In the oeso- phagus of the marine fish. Box hoops. Genus Polymastix Biitschli. Body pyriform. Four flagella arise from two blepharoplasts located at the anterior end. Cytostome and axostyle inconspicuous, but present. Ecto- 160 HANDBOOK OF PROTOZOOLOGY plasm is covered by longitudinally placed ridges. Parasitic in insects. Polymastix melolonthae (Grassi) (Fig. 60, d). In the gut of the larvae of the cockchafer. Group 4 Genus Chilomastix Alexeieff. Body pyriform, with a large cytostopial cleft at the anterior end. Nucleus anterior. Three anteriorly directed flagella and fourth flagellum undulates within the cleft. Cysts are common. In the intestine of verte- brates. Fig. 61 a-c. Chilomastix mesnili. X800. a, living individual; b, a stained specimen; c, a stained cyst. d. Trichomo7ias hominis. X800. e. T. elongata. X800. f. T. vaginalis. X650 (After Wenyon). g. Ditrichomonas termitis. X470 (After Cutler), h. Giantomonas herculea. X400 (After Dogiel). i. Myxomonas polymorpha. X300 (After Dogiel). Chilotnaslix mesnili (Wenyon) (Fig. 61, a-c). In the human intestine; held to be a commensal, although often found in abundance in diarrhoeic stools. Length 10 to 15 microns long. Cysts measure 5 to 10 microns in length. Group 5 Genus Trichomonas Donne. Body pyriform. Anterior Hagella 3 or 4 in number; another flagellum runs along the outer POLY MAS TIG ID A 1 6 1 margin of the undulating membrane, on the base of which there is an axoneme. The axostyle projects beyond the posterior end of body. Cysts have been noted in forms inhabiting animal intestines, but not in the species occurring in man. All para- sitic in the intestine. Trichomonas Jiominis (Davaine) (Fig. ()\,d). In the human gut. 5 to 18 microns long. Trichomonas elongata Steinberg ( = T. biiccalis Goodey and VVellings) (Fig. 61, e). In the human mouth; about 10 to 20 mi- crons long. Trichomonas vaginalis Donne (Fig. 61, /). In the human vagina. Body 10 to 25 microns long. Genus Ditrichomonas Cutler. Similar to Trichomonas, but with two anterior flagella. Parasitic. Ditrichomonas termitis Cutler (Fig. 61, g). In the gut of the termite, Archotermopsis wroughtoni. Genus Giantomonas Dogiel. Somewhat similar to Tricho- monas, but much larger. Three short flagella and a very long flagellum. Axostyle is large and the undulating membrane is well developed. Parasitic. Giantomonas herculea Dogiel (Fig. 61, h). In the intestine of the termite, Hodotermes mossamhicus. Body 60 to 75 mi- crons long by 30 to 35 microns broad. Genus Myxomonas Dogiel. Body highly amoeboid, with- out any flagella, but with an undulating membrane and a primi- tive axostyle. It is considered as a Trichomonas which lost its flagella and which became amoeboid. Parasitic. Myxomonas polymorpha Dogiel (Fig. 61, ^'). In the intestine of the termite, Hodotermes mossamhicus. Reaches 100 microns in length. Tribe 2 Diplozoa Calkins Genus Hexamitus Dujardin. Body small, more or less pyriform. Two nuclei near the anterior end. Six anterior and two posterior flagella. Cytostome indistinct. Encystment. Free-living. Several species. Hexamitus inflatus Dujardin (Fig. 62, a). 15 to 25 microns long. Stagnant water and infusion. 162 HANDBOOK OF PROTOZOOLOGY Genus Octomitus Prowazek. Similar to Hexamitus, but parasitic. Body plastic; no cytostome; nutrition parasitic. Octomitus intestinalis (Dujardin) (Fig. 62, h, c). About 10 to 16 microns long. In the intestine of the frog, also in midgut of Trutta fario and in the rectum of Motella tricirrata and M. mustela in European waters. Moore noted a similar form in young salmon and trout in North America, and named it Octomitus salmonis. Octomitus periplanetae Belaf. In the gut of the cockroach. Fig. 62 a. Hexamitus inflatus. X520 (After Klebs). b, c. Octomitus intestinalis. X 1200 (After Alexeieff). d-f. Giardia intestinalis. X800 (After Kofoid and Swezy). d, front view; e, profile; f, cyst, g. Trepomonas agilis. X800 (After Klebs). h. Gyromonas ambulans. X400 (After Seligo). i. Trigonomonas compressa, feeding on a Bacillus. X370 (After Klebs). j. Urophagus rostratus. X600 (After Klebs). Genus Giardia Klinstler ( = Lamblia Blanchard). Pyriform; bilaterally symmetrical. In profile, dorsal side convex; the ventral side possesses a single sucking disc at the anterior re- gion. Eight fiagella: four from the margin of the sucking disc; POL YMASTIGIDA 163 two from the middle and two from the posterior end of body. Parasites in the intestine of various vertebrates. Several species. Giardia intestinalis (Lambl) (Fig. 62, d-f). Body 12 to 18 microns long by 6 microns broad. Commensal in the human intestine. Genus Trepomonas Dujardin. Body flattened and more or less rounded. Two cytostomal grooves on the posterior half, one on each side. Eight flagella (one long and three short flagella on each side) arise from the anterior margin of the groove. At the anterior end there occurs a horseshoe-like structure, in which two nuclei are located. Marine, parasitic, or coprozoic. Trepomonas agilis Dujardin (Fig. 62, g). About 15 microns long. In infusion made from the sea water and once coprozoic(?) . Genus Gyromonas Seligo. Body small, constant, flattened; slightly spirally coiled. Four flagella from the anterior end. Cytostome not observed. Fresh water. Gyromonas amhulans Seligo (Fig. 62, h). About 15 microns long. Genus Trigonomonas Klebs. Body pyriform, but plastic. Cytostome on either side, from the anterior margin of which arise three flagella. Flagella are six in all. The two nuclei are situated near the anterior end. Rotation movement. Holozoic. Fresh water. Trigonomonas compressa Klebs (Fig. 62, i). Length about 35 microns. Fresh water. Genus Urophagus Klebs. Body somewhat resembles that of Hexamitus, but difl^ers from the latter by the presence of a single cytostome, located at the posterior end of the body, where two short processes occur. Holozoic. Urophagus rostratus Klebs (Fig. 62, j). About 20 microns long. Free-living. Tribe 3 Polyzoa Calkins This group includes those Polymatigida which inhabit the intestine of various species of termites, 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 karyomasti- 164 HANDBOOK OF PROTOZOOLOGY gont. In some forms the nucleus is not in the complex and this is called akaryomastigont. Genus Oxymonas Janicki. Perhaps the most primitive of the group. A single nucleus and two groups of flagella. With an axostyle. ,Q <^- ©i !^^l Fig. 63 a. Oxymonas projector. X945 (After Kofoid and Swezy). b. Proboscidiella muUinucleata. X435 (After Kofoid and Swezy). c. Calonympha grassii. X900 (After Janicki). d. Coronympha clevelandi. X 1000 (After Kirby). Oxymonas projector Kofoid and Swezy (Fig, 63, a). In the termite, Kalotermes perparvum. POL YMASTIGIDA 165 Genus Proboscidiella Kofoid and Swezy. One to many nuclei, each with a karyomastigont. A single extensile and retractile proboscis. Binary fission. In the intestine of termites. Proboscidiella multinucleata Kofoid and Swezy (Fig. 63, b). In the intestine of the termite, Planocryptotermes nocens. Genus Calonympha Foa. Body rounded and quite large. Numerous long flagella arise from the anterior region, and numerous nuclei are arranged near the insertion points of the flagella. Thus numerous karyomastigonts occur. In some forms akaryomastigonts are present. Axial filaments form a bundle. Calonympha grassii Foa (Fig. 63, c). In the termite, Crypto- termis grassii. Genus Stephanonympha Janicki. Oval, but plastic. Pellicle sculptured with foreign bodies. Numerous nuclei are spirally arranged around the anterior end, each forming a karyomas- tigont. Stephanonympha nelumbium Kirby. Size 45 microns by 27 microns. In the termite, Cryptotermes hermsi. Genus Snyderella Kirby. Numerous nuclei scattered in the cytoplasm. Akaryomastigonts are close together and extend through the greater part of the peripheral region of the cyto- plasm. The axial filaments are collected into a bundle. Snyderella tabogae Kirby. In the termite, Kalotermes longi- collis. Genus Coronympha Kirby. Body pyriform with 16 nuclei which are arranged in a single circle in the anterior region of the body. Each nucleus is the center of a karyomastigont. Parasitic. Coronympha clevelandi Kirby (Fig. 63, d). In the intestine of Kalotermes clevelandi. References DoBELL, C. AND F. W. O'CoNNOR. 1921 The intestinal Pro- tozoa of man. London. Grasse, p. p. 1926 Contribution a I'etude des Flagelles parasites. Arch. zool. exper., T. 65. Kofoid, C. A. and Olive Swezy. 1915 Mitosis and multiple 166 HANDBOOK OF PROTOZOOLOGY fission in trichomonad flagellates. Proc. Amer. Acad. Arts and Sci., Vol. 51. 1920 On the morphology and mitosis of Chilomastix mesnili (Wenyon) , a common flagellate of the human intes- tine. University of California Publ. in Zool., Vol. 20. . 1922 Mitosis and fission in the active and encysted phases of Giardia enterica etc. Ibid., Vol. 20. Wenyon, C. M. 1926 Protozoology. Vol. 1. London. CHAPTER XIII ORDER 4 HYPERMASTIGIDA GRASSI /iLL THE members of this order are inhabitants of the ali- J~\ mentary canal of the termite and other insects. The body organization is of extreme complexity, although there is only a single nucleus. Flagella are numerous and have their origin in blepharoplasts, 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 protozoans (p. 6). Method of nutrition is either holozoic or parasitic. No cystostome has been detected. Bits of wood, starch grains, and other food materials, are taken in by means of pseudopodia. Asexual reproduction is by longitudinal fission; multiple division has also been noted in some species under certain condi- tions. Sexual reproduction has so far not been observed. En- cystment occurs only in Lophomonadidae. Because of the peculiarity and complexity of their structures and also of their common occurrence in termites, the Hypermastigida have in recent years been frequently studied. This order is divided into the following eight families: Body without segmented appearance Flagella arranged in spiral rows Family 1 Holomastigotidae Flagella not placed in spiral rows Flagella in one or more tufts One anterior tuft of flagella Flagella directed anteriorly Family 2 Lophomonadidae Some directed posteriorly Family 3 Joenidae Two anterior tufts of flagella Family 4 Hoplonymphidae Four anterior tufts of flagella Family 5 Staurojoenidae Several anterior tufts (loriculae) Family 6 Kofoidiidae Flagella not in tufts Family 7 Trichonymphidae Body with segmented appearance Family 8 Cyclonymphidae Family 1 Holomastigotidae Janicki Flagella are arranged in spiral rows. A part of the posterior region may be free from flagella. The "anterior body" sur- ["167 1 168 HANDBOOK OF PROTOZOOLOGY rounds, or occurs near, the nucleus. Asexual reproduction by longitudinal division. Inhabitants in the intestine of termite. Genus Holomastigotes Grassi. Body small and spindle- shaped. Few spiral rows reach from the anterior to the pos- terior end. The nucleus is located near the anterior end and is surrounded by a mass of dense cytoplasm. Nutrition by ab- sorption of fluid material. Several species. Holomastigotes elongatiim Grassi (Fig. 64, a). In the intes- tine of termites. Widely distributed. Several subspecies. Genus Holomastigotoides Grassi. Body large and spindle- shaped. Spiral rows of flagella as in the last genus, but more numerous (12 to 40 in number). A mass of dense cytoplasm surrounds the nucleus. Nucleus ovoid. Four species. Holomastigotoides hartmanni Koidzumi (Fig. 64, h). Body 50 to 140 microns long. In Coptotermes formosanus. Genus Spirotrichonympha Grassi. Body moderately large; elongated pyriform. The flagella are more deeply embedded in the cytoplasm in the anterior region of the body. The mass of dense cytoplasm is conical in form and its base indistinct. Spherical nucleus. Spirotrichonympha leidyi Koidzumi (Fig. 64, c). In the ter- mite, Coptotermes formosanus. Genus Spirotrichonymphella Grassi. Body small and with- out spiral ridges. Posterior flagella longer. Not wood-feeding. Spirotrichonymphella pudibunda Grassi. In an Australian termite, Porotermes adamsoni. Genus Microspirotrichonympha Koidzumi. Body small, sur- face not ridged. Spiral rows of flagella only on the anterior half. Between the nucleus and the anterior extremity, there is a tubu- lar structure. A mass of dense cytoplasm surrounds the nucleus. Axial rod may or may not occur. Microspirotrichonympha porteri Koidzumi (Fig. 64, d). In the termite, Leucotermes flaviceps. Family 2 Lophomonadidae Grassi Numerous flagella arise from the anterior end in a tuft. Each flagellum originates in a blepharoplast from which extends inward an axial filament. A single nucleus is located near the anterior end and surrounded by a funnel-shaped space formed HYPERMASTIGIDA 169 by the axial filaments. No cytostome. Parabasal body. Nutri- tion holozoic or parasitic. Asexual reproduction by binary or multiple fission. Encystment common. Sexual reproduction un- known. Parasites of cockroaches and termites. Genus Lophomonas Stein. Body rounded or elongated. Fig. 64 a. Holomastigotes elongatum. X700 (After Koidzumi). b. Holomastigotoides hartmanni. X250 (After Koidzumi). c. Spirotrichonympha leidyi. X400 (After Koidzumi). d. Microspirotrichonympha porteri. X250 (After Koidzumi). e-i. Lophomonas blattarum. (After Kudo), e, f, living trophozoites (X320); g, a stained specimen (X1150); h, highly spread individ- ual containing the dividing nucleus (X1150); i, cyst (X1150). j-1. L. striata. (After Kudo), j, a living trophozoite (X320); k a dividing form; 1, a cyst (X1150). 170 HANDBOOK OF PROTOZOOLOGY Small. A single vesicular nucleus near the anterior end. Para- sitic in the colon of the cockroach. Cysts common. Lophomonas hlaUarum Stein (Figs. 2; 64, e-i). Body small, pyriform, but plastic. Axostyle may project beyond the pos- terior margin of the body. Active swimming movements. Holozoic in the colon of the cockroach. Binary or multiple fission. Body length 25 to 30 microns. Widely distributed. Lophomottas striata Biitschli (Fig. 64, j-l). Body elongated spindle in form. Body surface with obliquely arranged needle- like structures which some investigators believe to be Proto- phyta (to which Grasse gave the name, Fusiformis lophomona- dis). Axostyle is short, never protruding. Movement sluggish. Cyst spherical with the needle-like structures. In the same habi- tat as the last species. Genus Eulophomonas Grassi. Similar to Lophomonas, but the flagella vary from 5 to 15 or a little more in number. Eulophomonas calotermitis Grassi. In the termite, Kalotermes flavicollis. Family 3 Joenidae Grassi The flagella are confined mostly to the anterior end, but some of them are directed posteriorly. A conspicuous axostyle is always present. Parasites of termites. Genus Joenia Grassi. Body ellipsoidal. Anterior portion is capable of forming pseudopodia. Flagellar tufts are in part di- rected anteriorly. Body surface is covered by numerous immo- bile short filamentous processes, which some authors hold to be symbiotic bacteria. The spherical nucleus at the anterior end; posterior to the nucleus, there is a conspicuous axostyle com- posed of numerous axial filaments. A parabasal apparatus sur- rounds it. Bits of wood used as food. Joenia annectens Grassi (Fig. 65, a). In the termite, Kalo- termes flavicollis. Genus Joenina Grassi. The structure is more complicated than that of Joenia. Flagella are inserted at the anterior end in a semi-circle. Parabasal bodies are two elongated curved rods. Feeding on wood fragments. Joenina piilchella Grassi. In the termite, Porotermes adamsoni. Genus Parajoenia Janicki. Body oval and medium large. H YPER MA S TIG ID A 171 Long flagella are arranged at the anterior end in two semi- circular areas. There is a trailing flagellum. The posterior half of the body is covered by ciliary structure (symbiotic bacteria?). Nucleus large. Conspicuous axostyle runs backward from the nucleus. Two curved parabasal bodies. Parajoenia grassii Janicki (Fig. 65, h). In the termite Kaloternies castaneus. Genus Joenopsis Cutler. Body oval and large. There is a horseshoe-shaped pillar at the anterior end. Flagella arise from 81 -vJ- 1 \ Fig. 65 a. Joe7iia anneclens. (After Grassi and Foa). b. Parajoenia grassii. X940 (After Janicki). c. Cyclonympha strobila. X285 (After Dogiel). the structure; some directed anteriorly, others posteriorly. Parabasal bodies long rods. A strong axostyle. Feeding on bits of wood. Joenopsis polytricha Cutler. In the termite, Archotermopsis wroughtoni. Genus Microjoenia Grassi. Body small, pyriform; anterior end flattened. The flagella are arranged in longitudinal rows. Axostyle. Parabasal body simple. Microjoenia axostylis Cutler. In the termite, Archotermopsis wroughtoni. 172 HANDBOOK OF PROTOZOOLOGY GenusMesojoeniaGrassi. Body large. Flagellar tuft is spread over a wide area. Distinct axostyle, bent at the posterior end. Parabasal bodies two in number. Mesojoenia decipiens Grassi. In the termite, Kalotermes. Family 4 Hoplonymphidae Light Two flagellar tufts; each arises from a plate near the an- terior end of the slender body which is protected by a highly developed pellicular armor. Genus Hoplonympha Light. Body slender fusiform, covered with thick, rigid pellicular armor. Each tuft of flagella arises from a plate connected with blepharoplasts at the anterior end. Nucleus near the anterior extremity, more or less triangular in form. Hoplonympha natator Light (Fig. 66, a, b). In the intestine of the termite, Kalotermes simplicicornis. Family 5 Staurojoeniidae Grassi Four flagellar tufts arise from the anterior end. Genus Staurojoenia Grassi. Body pyriform. Spherical nucleus central. Four flagellar tufts from the anterior end. In- gest wood fragments. Staurojoenia assimilis Kirby (Fig. 66, c). In the intestine of the termite, Kalotermes minor. Family 6 Kofoidiidae Light Flagellar tufts are composed of several loriculae (per- manently fused bundles). No axostyle, no parabasal body. Genus Kofoidia Light. Body spherical. Between the oval nucleus and the bases of the flagellar tufts, there occurs a chro- matic collar. Wood fragments as food. Kofoidia loriculata Light (Fig. 66, d, e). In the termite, Kalotermes simplicicornis. Family 7 Trichonymphidae Kent The body is divisible into two regions: anterior and poste- rior. The surface of the anterior portion is differentiated into one or two thick ectoplasmic layers, densely traversed by numerous flagella. There is an "axial core" or "head organ" at HYPERMASTIGIDA 173 the anterior tip. No cytostome. A single nucleus. Flagella numerous and long. They are arranged in longitudinal rows in the anterior third. Multiplication by simple longitudinal fission. Parasites of termites. Fig. 66 a, b. Hoplonympha natato>'. X450 (After Light), c. Staurojoenia assimilis. X200 (After Kirby). d, e. Kofoidia loriculata, (After Light), d, from life (X175); e, a stained specimen (X300). f. Trichonympha campanula. X150 (After Kofoid and Swezy). g. Leidyopsis sphaerica. X150 (After Kofoid and Swezy). Genus Trichonympha Leidy. Anterior portion consists of the nipple and the bell, both of which are composed of two layers. A distinct axial core. Nucleus central. Flagella located in longitudinal rows on the bell. Several species. Trichonympha campanula Kofoid and Swezy (Figs. 12; 66, /). In the intestine of the termite, Termopsis augusticollis. 174 HANDBOOK OF PROTOZOOLOGY Genus Pseudotrichonympha Grassi. Two parts in the an- terior end as in Trichonympha. The head organ with a spherical body at its tip and is surrounded by a single layer of ectoplasm; the bell is covered by two layers of ectoplasm. The nucleus lies freely. Body covered by spiral rows of short flagella. Pseudotrichonympha grassii Koidzumi. In the termite, Cop- totermes formosanus. Genus Gymnonympha Dobell. Body oval or pyriform, but plastic. A spherical body at the anterior end, around the base of which is a ring of flagella. Flagella about half as long as the body. Posterior one-third shows longitudinally striated pellicle. Nucleus near the anterior end. Gymnonympha zeylanica Dobell. In the termite, Kalotermes militaris. Genus Leidyopsis Kofoid and Swezy. Ectoplasmic differen- tiation only in the anterior third, the remaining part is covered by a thin .pellicle. The axial core bears a hemispherical tip. Nucleus anterior. Long flagella arise from the anterior third of the body. Very similar to Gymnonympha. Leidyopsis sphaerica Kofoid and Swezy (Fig. 66, g). In the termite, Termopsis augusticollis . Genus Leidyonella Frenzel. Body large Anterior end is pointed. Flagella as long as the body. Pellicle with longitudinal striation. Leidyonella cordubensis Frenzel. In an Argentine termite, Eutermes inquilinus. Family 8 Cyclonymphidae Reichenow ( = Tetratonymphidae Koidzumi) Body large and elongated. It is transversely ridged, and presents a metameric appearance. Each ridge with a single row of flagella. No cytostome. The anterior end is complex, contain- ing a nucleus. Asexual reproduction by longitudinal fission. Genus Cyclonympha Dogiel ( = Tetratonympha Koidzumi). With the characters of the family. Cyclonympha strohila Dogiel ( = Tetratonympha mirahilis Koidzumi) (Fig. 65, c). In the termites of Japan. Body 110 to 170 microns long. HYPERMASTIGIDA 175 References Cleveland, L. R. 1925 The effects of oxygenation and starvation on the symbiosis between the termite, Termop- sis, and its intestinal flagellates. Biol. Bull., Vol. 48. DoGiEL, V. 1922 Untersuchungen an parasitischen Pro- tozoen aus dem Darmkanal der Termiten. III. Trichonym- phidae. Arch. Soc. Russe Protist., Vol. 1. Janicki, C. v. 1910, 1915 Untersuchungen an parasitischen Flagellaten. I, II. Zeitschr. wiss. Zool., Vols. 95, 112. KoFOiD, C. A. AND Olive Swezy. 1919, 1926 Studies on the parasites of termites. Univ. California Publ. Zool., 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 blattarum, a flagellate inhabiting the colon of the cockroach, Blatta orientalis. Arch. f. Protistenk., Vol. 53. CHAPTER XIV CLASS 2 SARCODINA BUTSCHLI THE MEMBERS of this class do not possess any definite pellicle and, therefore, are capable of changing the body form and forming pseudopodia. The term "amoeboid" is often used to describe their appearance. The pseudopodia serve for both loco- motion and food-capturing. The peripheral portion of the body shows no structural differentiation in Amoebaea, Proteomyxa, and Mycetozoa. Internal or external skeletal sturctures are variously developed in other orders. Thus in Testacea and Foraminifera, there is a well-developed test, or shell that usu- ally has an aperture, through w^hich the pseudopodia are ex- truded. In Heliozoa and Radiolaria, endoskeletons of various forms and materials are developed. Unlike the Mastigophora or the Ciliata, the Sarcodina lack permanent cell-organs for capturing and ingesting the food mat- ter, although some of them possess semi-permanent axopodia. The cytoplasm, as a rule, is differentiated into the ectoplasm and the endoplasm, but this differentiation is not constant. In Radiolaria, there is a perforated membranous "central cap- sule" between the ectoplasm and endoplasm. The endoplasm contains the nuclei, food vacuoles, various granules, and con- tractile vacuoles. The majority of the Sarcodina are uni- nucleate, but numerous species of Foraminifera and Mycetozoa are multinucleate. In one group (Paramoebidae), there is a peculiar "secondary nucleus." The Sarcodina are typically holozoic, but in a few cases holo- phytic. The food consists of Protozoa, small Metazoa, and Protophyta, which present themselves conspicuously in the cytoplasm. One or more contractile vacuoles are invariably present in forms inhabiting fresh water, but absent, as a rule, in parasitic forms or in those which live in salt water The Sarcodina vary in size from a few microns up to several milli- [176] SARCODINA, PROTEOMYXA 177 meters. Colonial Sarcodina, especially plasmodium-forming Mycetozoa, reach a considerable size. Asexual reproduction is usually by binary (or rarely by mul- tiple) fission, budding, or plasmotomy. Definite proof of sexual reproduction has been given in a comparatively small number. Encystment is common in the majority of both free-living and parasitic Sarcodina, but it is unknown in certain groups. The life-cycle has been worked out in a few forms. It seems to vary in different groups. The youngest 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 adult trophic stage may show an amoeboid or flagellate phase owing to differences in environmental conditions (p. 205). These points support strongly the view that both classes have descended from a common ancestor and have undergone evolu- tionary changes in two different directions. The Sarcodina are divided into two subclasses, as follows : With lobopodia, myxopodia, or filopodia Subclass 1 Rhizopoda With axopodia (usually radiating) Subclass 2 Actinopoda SUBCLASS 1 RHIZOPODA SIEBOLD The term Rhizopoda is often used to designate the class but is used here for one of the subclasses. These Sarcodina possess pseudopodia which are not axopodia. The subclass is divided into five orders as follows: Without test With radiating pseudopodia Order 1 Proteomyxa With rhizopodia; forming plasmodium Order 2 Mycetozoa With lobopodia Order 3 Amoebaea With test Test single-chambered; chitinous Order 4 Testacea Test one to many chambers; calcareous Order 5 Foraminifera ORDER 1 PROTEOMYXA LANKESTER A number of incompletely known Rhizopoda are placed in this group. They possess few common characteristics. The pseudopodia are filopodia which often branch or anastomose with one another. In this respect the Proteomyxa show affinity 178 HANDBOOK OF PROTOZOOLOGY to the Mycetozoa. Without any skeletons. Their hfe history is not well known. Flagellate swarmers and encysted stages occur commonly. The majority of the Proteomyxa lead parasitic life in fresh-water algae or green plants. Three families and several genera are usually distinguished in this order. Individuals often fused into pseudoplasmodium Family 1 Labyrinthulidae Solitary and Heliozoa-like With flagellated swarmers Family 2 Zoosporidae Without flagellated swarmers Family 3 Vampyrellidae Family 1 Labyrinthulidae Haeckel The body is a small fusiform protoplasmic mass. Several individuals are grouped in a network of sparingly branched and anastomosing filopodia. Multiplication by fission. Under un- favorable conditions individuals encyst independently. Flagel- lated stage may or may not be present. Two genera. Genus Labyrinthula Cienkowski. Minute forms feeding on various species of algae of both fresh and salt waters. Often brightly colored due to the chlorophyll bodies taken in as food. Labyrinthula cienkowskii Zopf (Fig. 67, a). Attacks the fresh-water alga, Vaucheria. Genus Labyrinthomyxa Duboscq. Body fusiform, amoeboid and flagellate phases variable in size. The flagellated stage pene- trates through the host cell membrane. Labyrinthomyxa sauvagea lit Duboscq (Fig. 67, 6-e). Fusiform bodies 7 to 11 microns long. Pseudoplasmodium formed. Amoeboid stage measures 2.5 to 14 microns; flagellate stage 7 to 18 microns long. Parasitic in Laminaria lejolisii at RoscofT, France. Family 2 Zoosporidae Zopf-Delage Body form irregular, but with radiating filopodia. The general appearance is somewhat like a heliozoan. Swarmers. Genus Pseudospora Cienkowski. Body minute. Parasitic in algae and Mastigophora (including Volvocidae). The organism nourishes itself on the protoplasm of the host, grows, and multi- plies into a number of smaller individuals by repeated division. SA R CO DIN A , PRO TEO M YXA 179 The latter are biflagellated, seek a new host, and transform them- selves into amoeboid stages. Encystment common. Pseudospora volvocis Cienkowski (Fig. 67,/, g). Parasitic in species of Volvox. Body diameter about 12 to 30 microns. Pseudospora parasitica Cienkowski. Attacks Spirogyra and allied algae. Pseudospora eudorini Roskin. Parasitic in Eiidorina elegans. Genus Protomonas Cienkowski. Body irregularly rounded with radiating filopodia. Food consists of starch grains. Divi- sion into biflagellate swarmers which become amoeboid and unite to form pseudoplasmodium. Fresh or salt water, Protomonas amyli Cienkowski (Fig. 67, h-j). In fresh water. Fig. 67 a. Lahyrinthula cienkowskii. X about 150 (After Doflein). b-e. Labyrinthomyxa sauvageaid. (After Duboscq). b, c, small and large flagellated forms inlife (X750); d,e,pseudoplasmodia formed by fusiform bodies and large amoebae (stained, X375). f, g. Pseudospora volvocis. X500 (After Robertson). h-j. Protomonas amyli. (After Zopf). h, amoeba; i, flagellate phase; j, cyst. Family 3 Vampyrellidae Doflein Filopodia radiate from all sides or formed from a limited area of the body. Flagellate swarmers absent. The organisms are able to bore through, by secreting probably a specific enzyme, the cellulose membrane of various algae and engulf the proto- plasmic contents. The metabolic products of chlorophyll substance appear as carotin, a reddish substance, in the form of 180 HANDBOOK OF PROTOZOOLOGY an irregular mass in the cytoplasm. The organism is as a rule multinucleate, but divides in the encysted stage into daughter individuals with one or many nuclei. The multinucleate cysts are often reddish, owing to the presence of the carotin. Genus Vamp3rrella Cienkowski. The organism appears Heliozoa-like because of numerous filopodia which radiate. The cytoplasm is distinctly differentiated into the ectoplasm and endoplasm. The latter is vacuolated or granulated and often con- tains reddish carotin granules. Numerous vesicular nuclei and contractile vacuoles. Size varies from 50 to 700 microns. Multi- nucleate cysts may possess a stalk. Feed on the contents of algae in both fresh and salt waters. Several species. Fig. a, b c, d. e. f. Vampyrella lateritia. X400. a, a rounded individual (after Leidy); b, young individuals budding out from a cyst (after Dofiiein). Nuclearia delicatula. X225 (After Cash). Arachmila impatiens. X500 (After Dobell). Chlamydomyxa montana, encysted, with numerous secondary cysts. X about 400. (After Penard). Vampyrella lateritia (Fresenius) ( = F. spirogyra Cienkowski) (Fig. 68, a, h). Body spherical and orange-red in color except the hyaline ectoplasm. Feed on Spirogyra and other algae. Genus Nuclearia Cienkowski. Body more or less rounded SARCODINA, PROTEOMYXA 181 and colorless. The filopodia branching, but not anastomosing, may be confined to only a limited part of the body. Sometimes with a gelatinous envelope. There are one to many nuclei. The cyst is covered by a double envelope. Free-living. Niiclearia simplex Cienkowski. Uninucleate. Nuclearia delicatiila Cienkowski (Fig. 68, c, d). Multi- nucleate; often bacteria adhering to the gelatinous envelope. Genus Arachnula Cienkowski. Body irregularly chain-form with filopodia extending from the ends of the branches. Nu- merous nuclei and contractile vacuoles. Feed on diatoms and other microorganisms. Arachnula impatiens Cienkowski (Fig. 68, e). Genus Chlamydomyxa Archer. The naked body which meas- ures up to 300 microns in diameter, is differentiated into the ectoplasm and endoplasm. The latter is often green-colored due to the presence of green spherules, and contains numerous vesic- ular nuclei and one or two contractile vacuoles. Secretion of a capsule round the body is followed by multiplication of the body into numerous secondary cysts. Cyst wall is cellulose. In Sphagnum swamp. Chlamydomyxa montana Lankester (Fig. 68,/). Diameter 20 to 300 microns. Genus Rhizoplasma Verworn. The body is spherical or sausage-shaped with anastomosing filopodia. The whole is orange-red in color. It contains a few nuclei and is said to measure from 5 to 10 millimeters. Found in Red Sea. Rhizo- plasma kaiseri Verworn. Genus Dictomyxa Monticelli. Similar to the above, but pseudopodia are said to be colorless ; also found in salt water. References Calkins, G. N. 1926 The biology of the Protozoa. Phila- delphia. DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- tozoenkunde. Jena. KuHN, A. 1926 Morphologic der Tiere in Bildern. H. 2; 2 T. Rhizopoden. Cash, J. 1905 The British freshwater Rhizopoda and Helio- zoa. Vol. 1. London. 182 HANDBOOK OF PROTOZOOLOGY DoBELL, C. 1913 Observations on the life-history of Cien- kowsky's Arachnula. Arch. f. Protistenk., Vol. 31. DuBOSCQ, O. 1921 Lahyrinthomyxa sauvageaui n.g., n.sp., Proteomyxee parasite de Laminaria lejolisii Sauvageau. C. R. Soc. Biol., Vol. 84. Leidy, J. 1879 Freshwater Rhizopods of North America. Report U. S. Geol. Survey, Vol. 12. RosKiN, G. 1927 Zur Kenntnis der Gettung Pseudospora Cienkowsky. Arch. f. Protistenk., Vol. 59. ZoPF, W. 1887 Handbuch der Botanik (A. Schenk), Vol. 3. CHAPTER XV ORDER 2 MYCETOZOA DE BARY THE MYCETOZOA Were formerly considered to be closely re- lated to fungi, being known as Myxomycetes or Myxogas- teres (the "slime molds")- Through extended studies, of their life-histories, 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 organisms. The Mycetozoa occur on dead wood or decaying vegetable matter of various kinds. The most conspicuous part of a mycetozoan is its Plasmo- dium which is formed by the cytoplasmic fusion of several myxamoebae (amoebulae) without nuclear fusion, thus pro- ducing a large multinucleate protoplasmic body (Fig. 69, a). The greater part of the cytoplasm is granulated, although there is a thin layer of hyaline and homogeneous cytoplasm surround- ing the whole body. The numerous vesicular nuclei are dis- tributed throughout the granular cytoplasm. Many small contractile vacuoles are present in the peripheral portion of the Plasmodium. The nuclei increase in number by multiplication as the body grows. The nuclear 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 Cal- carinea are made up of carbonate of lime. The Plasmodium is usually colorless, but sometimes yellow, green, or reddish. This coloration is due to numerous droplets of a fluid pigment scat- tered throughout the body. The food varies in different species. The great majority feed on decaying vegetable matter, but some, such as Badhamia, devour living fungi. Thus the Mycetozoa are holozoic or sapro- zoic in their method of nutrition. The Plasmodium is alkaline in reaction as a whole. Pepsin has been found in the plasmodium of Fuligo and is perhaps secreted into the food vacuoles, into [183] 184 HANDBOOK OF PROTOZOOLOGY which proteins are taken. The plasmodium of Badhamia is said to possess the power of dissolving the cellulose. When exposed to unfavorable conditions, such as desicca- tion, the protoplasmic movement ceases gradually, foreign bodies Fig. 69. Scheme of the life-cycle of an endosporous mycetozoan. Variously magnified. (Constructed after de Bary, Lister, and others). a, Plasmodium formation by fusion of numerous myxamoebae; b, c, sclero- tium formation; d, e, germination of sclerotium and formation of plasmodium; f, portion of a plasmodium showing streaming protoplasmic thickenings; g, beginning of sporangium formation; h, six sporangia; i, sporangium opened, showing capillitium; j, a spore; k, germination of spore; 1, myxamoeba; m, n, myxoflagellates; o-q, division of myxoflagellate; r, microcyst; s, myxamoeba. are extruded, and the whole plasmodium becomes divided into numerous cysts, sclerotia of de Bary, each containing ten to twenty nuclei and being surrounded by a resistant wall {b). • MYCETOZOA 185 These cysts may live as long as three years. Upon the re- turn of favorable conditions, such as the addition of water to the preparation, the contents of the sclerotia germinate, fuse together, and thus again produce plasmodia {c-e). When lack of food material occurs, the Plasmodium under- goes 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 course of the formation of the sporangium, foreign bodies are thrown out of the body, and around each sporangium there is secreted a wall which, when mature, possesses a wrinkled ap- pearance {h). The wall continues 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 for the stalk. This base is known as the hypothallus. \\'ith the external changes as outlined above, the interior of the sporangium becomes penetrated by an anastomosing network of flat bands which are continuous with the outer covering. This is called the capillitium {i). Soon after the differentiation of these protective and sup- porting structures, the nuclei divide simultaneously by mitosis and the cytoplasm breaks up, directly or indirectly, into as many small bodies as there are nuclei. These uninucleate bodies are the spores which measure about 3 to 20 microns in diameter and which soon become covered by a more or less thick mem- brane (j), variously colored in different species. The membrane seems to be composed of cellulose. The mature sporangium breaks open, sooner or later, and the spores are carried, and scattered, by the wind. When a spore falls into the water, its membrane ruptures, and the protoplas- mic contents emerge as an amoebula {k, I). The amoebula possesses a single vesicular nucleus and contractile vacuoles, and undergoes a typical amoeboid movement. It assumes an elon- gated form and protrudes a flagellum from the nucleated end, thus forming a myxoflagellate (zoospore, swarmer) (m, «), which undergoes a peculiar dancing movement and is capable of form- ing short and pointed pseudopodia from the posterior end. It 186 HANDBOOK OF PROTOZOOLOGY engulfs bacteria by means of its pseudopodia and grows in size. It multiplies by binary fission. In this process, the flagellum is withdrawn and the body becomes rounded. The nucleus under- goes a mitotic division, followed by a cytoplasmic constriction to form two daughter individuals {o-q). The multiplication seems to be repeated. The myxoflagellate may often become rounded and secrete a hyaline cyst-wall, thus forming the microcyst (r), which loses its flagellum permanently and trans- forms itself into a myxamoeba(5). The latter, through fusionwith many others, produces the Plasmodium described above. This is the general life-cycle of a typical endosporous mycetozoan. In the genus Ceratiomyxa, the only genus of the exosporous form, in which spores are produced on the surface of sporo- phores, the development is briefly as follows: The Plasmodium lives on or in decayed wood and presents a horn-like appearance (sporophore). The body is covered by a gelatinous hyaline substance, within which the protoplasmic movements may be noted. The protoplasm soon leaves the interior and accumu- lates at the surface of the mass; at first as a close-set reticulum, and then it becomes differentiated into a mosaic of polygonal cells, each containing a single nucleus. Each of these cells moves outward at right angles to the surface, still enveloped by the thin hyaline layer, which forms a stalk below it. These cells are the spores, which become ellipsoidal and are covered by a resistant membrane when mature. The spore is uninucle- ate at first, but soon becomes tetranucleate. When a spore reaches the water, the contents emerge as an amoebula which then divides three times, forming eight small bodies, each of which develops a flagellum and becomes a myxoflagellate. The remaining part of the development is presumably similar to that of the endosporous mycetozoan. An enormous number of mycetozoan genera are known. The order is here divided into two suborders according to Lister. Further division into tribes, legions, sublegions, and families is given below, together with one or two genera for each family. Spore develops into myxoflagellate; myxamoebae fuse completely and form the 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 MYCETOZOA 187 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 Lime in crystalline form Family 2 Didymiidae Sporangia without lime Sublegion 2 Amaurochaetinea Sporangia stalked Family 1 Stemonitidae Sporangia combined into aethalium Family 2 Amaurochaetidae Spores variously colored, but never 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 Sporangia solitary; sessile or stalked Family 2 Liceidae Sporangium-wall membranous without granular deposits Family 3 Tubulinidae Many sporangia more or less closely fused to form large bodies (ae- thalia); sporangium-wall incomplete and perforated Family 4 Reticulariidae Sporangia forming aethalium Family 5 Lycogalidae Capillitium a system of uniform threads Sublegion 2 Caloneminea Capillitium threads with spiral or annular thickenings Family 1 Trichiidae Capillitium combined into an elastic network with thickenings in forms of cogs, half-rings, spines, or warts Family 2 Arcyriidae Capillitium abundant; sporangia normally sessile Family 3 Margaritidae Spores develop on the surface of sporophores Tribe 2 Exosporeae Spores white; borne singly on filiform stalk Family 1 Ceratiomyxidae Family Physaridae Genus Badhamia Berkeley (Fig. 70, a, b). Capillitium, a coarse network charged with lime throughout. Genus Fuligo Haller (Fig. 70, c, d). Capillitium, a delicate network of threads with vesicular expansions filled with gran- ules of lime. Family Didymiidae Genus Didymium Schrader (Fig. 70, e, /). Lime crystals stellate; distributed over the wall of sporangium. Family Stemonitidae Genus Stemonitis Gleditsch (Fig. 70, g, h). Sporangium- 188 HANDBOOK OF PROTOZOOLOGY wall evanescent; capillitium arising from all parts of the colum- ella to form a network. Family Amaurochaetidae Genus Amaurochaete Rostafinski (Fig, 71, a, b). With irregularly branching thread-like capillitium. Fig. 70 a, b. Badhamia iitricularis Berkeley, a, cluster of sporangia (X4); b, part of capillitium and spore-cluster (X140). c, d. FiiHgo septica Gmelii. c, a group of sporangia (Xl/3); d, part of capillitium and two spores (X120). e, f. Didymium effusum Link, e, sporangium (X12); f, portion of capillitium and wall of sporangium showing the crystals of cal- cium carbonate and two spores (X200). g, h. Stemonitis splendens Rostafinski. g, three sporangia (X2); h, columella and capillitium (X42). (All after Lister.) Family Cribrariidae Genus Cribraria Persoon (Fig. 71, c). Sporangia stalked; wall is thickened and forms a delicate persistent network ex- panded at the nodes. Family Liceidae Genus Orcadella Wingate (Fig. 71, d). Sporangia stalked, furnished with a lid of thinner substance. Family Tubulinidae Genus Tubulina Persoon (Fig. 71, e). Sporangia without tubular extensions. MYCETOZOA 189 Family Recticulariidae Genus Reticularia Bulliard (Fig. 7\,f). Walls of convoluted sporangia incomplete, forming tubes and folds with numerous anastomosing threads. Family Lycogalidae Genus Lycogala Adanson (Fig. 71, g). Fig. 71 a, b. Amaurochaete fidiginosa MacBride. a, group of sporangia (Xl/2); b, capillitium (XIO). c. Sporangium of Cribraria aurantiaca Schrader, from which the spores have been dispersed. X20. d. Orcadella operciilata Wingate. Sporangium with lid opened. X80. e. Tubulina fragiformis Per soon. Cluster of sporangia. X3. f. Aethalium of Reticularia lycoperdon Bull. Natural size. g. Aethalium of Lycogala miniatum Persoon. Natural size. h-j. Trichia affinis de Bary. h, group of sporangia (X2); i, elater (X250); j, spore (X400). k, 1. Arcyria punicea Persoon. k, four sporangia (X2); 1, part of capillitium (X250) and a spore (X560). m, n. Ceratiomyxa fruticulosa MacBride. m, sporophore (X40); n, part of mature sporophore, showing two spores (X480). (All after Lister.) 190 HANDBOOK OF PROTOZOOLOGY Family Trichiidae Genus Trichia Haller (Fig. 71, h-j). Capillitium abundant, consisting of free elasters with spiral thickenings. Family Arcyriidae Genus Arcyria Wiggers (Fig. 71, k, L). Sporangia stalked; sporangium-wall evanescent above, persistent and membranous in the lower third. Family Margaritidae Genus Margarita Lister. Capillitium profuse, long, coiled hair-like. Family Ceratiomyxidae Genus Ceratiomyxa Schroter (Fig. 71, m, n). Suborder 2 Sorophora Lister Pseudo-plasmodium incomplete; myxamoeba a Umax type Family 1 Guttuliniidae Pseudo-plasmodium complete; myxamoeba with short pointed pseudopodia Family 2 Dictyosteliidae Appendix The Proteomyxa and the Mycetozoa as outlined above, are not distinctly defined groups. In reality, there are a number of forms which stand on the border line between them. Phytomyxinae Schroter These organisms which possess a large multinucleate amoe- boid 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 roots of cabbages and other Cruciferae. The organism produces knotty enlargements, sometimes known as "root-hernia," or "fingers and toes" (Fig. 72, a). The small spore {b) gives rise to a myxoflagellate {c-e) 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 MYCETOZOA 191 cells. The nuclei undergo mitotic division. Finally the Plasmo- dium divides into a large number of simple spores. PlasmodiopJwra brassicae Woronin (Fig. 72). Parasitic in all species of Brassica. Other genera are Sorosphaera Schroter, parasitic in Veron- ica; Tetramyxa Goebel, forming gall in Ruppia, etc. '^© 6 I sy^. Fig. 72. Plasmodiophora brassicae. a, root-hernia of cabbage; b, a spore (X620); c-e, stages in germination of spore (X620); f, myxamoeba (X620 after Woronin); g, a host cell with several young parasites (X400); h, an older parasite (X400 after Nawaschin). References DE Bary. 1864 Die Mycetozoen. Second edition. Leipzig. Jahn, E. 1901-1920 Myxomycetenstudien Ber. I to X. Deutsch. Bot. Ges., Vols. 19, 20, 22-26, 29, 36, 37. Jones, P. M. 1928 Morphology and cultural study of Plas- modiophora brassicae. Arch. f. Protistenk., Vol. 62. Lister, A. 1924 A monograph on the Mycetozoa. Third edition. London. MacBride, T. H. 1922 North American slime moulds. Sec- ond edition. New York. CHAPTER XVI ORDER 3 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. 12). The majority live on the 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 in their habitat. The cytoplasm of the Foraminifera is ordinarily not dif- ferentiated into ectoplasm and endoplasm. Contractile vacuoles are usually absent. The cytoplasm streams out through the apertures, and in perforated forms through the numerous pores, of the test, forming rhizopodia which are fine and often very long and which anastomose with one another to present a characteristic appearance. The streaming movements of the cytoplasm in the pseudopodia are quite striking; the granules move toward the end of a pseudopodium and stream back along its periphery. The body cytoplasm, is often loaded with brown granules which are apparently waste matter. In some forms such as Peneroplis pertusus (Fig. 76), these masses are extruded from the body from time to time, especially prior to the forma- tion of a new chamber. The test of the Foraminifera varies greatly in form and struc- ture. When fresh, it may show various colorations — orange, pink, red or brown. The majority measure less than one milli- meter, although larger forms may reach frequently five milli- meters. The test may be siHcious or calcareous. In some forms, various foreign materials, such as sand-grains, sponge spicules, etc., which are more or less abundantly found where these or- ganisms live, are loosely or compactly cemented together by pseudochitinous or gelatinous substances. Certain forms show a specific tendency in the selection of foreign materials for the test. Silicious tests are comparatively rare, being found in [192] FORAMINIFERA 193 some species of Miliolidae inhabiting either the brackish water of deep sea. Calcareous tests are sometimes imperforated, but even in such cases those of the young are always perforated. By far the majority of the Foraminifera possess perforated cal- careous tests. The thickness varies considerably, as do also the a V Fig. 73 Diagram showing the development of Foraminifera. (After Kiihn). a-c, microspheric generation; d, uninucleate phase; e-g, megalspheric gen- eration; h, isogametes; i-j, isogamy. size and number of apertures, among different species. Fre- quently the perforations are very small in the young and later become large and coarse, while in others the reverse may be the case. 194 HANDBOOK OF PROTOZOOLOGY The form of the test 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. 74, a), or of a tubular body alone, as in Hyperammina (Fig. 74, d). The many-chambered, or poly- thalmous, forms possess tests of various spirals. The first chamber is called the proloculum. It may be formed either by the union of two swarmers or by asexual reproduction (Fig. 73). The former is ordinarily small and known as the microspheric proloculum (c), while the latter, which is usually large, is called the megalospheric proloculum (g). To the proloculum are added many chambers which may be closely or loosely coiled or not coiled at all. These chambers are ordinarily undivided, but in / V'^-w..--^ Fig. 74 a. Rhabdammina abyssorum. X5 (After Kiihn). b. Rhizammina algaeformiSyiragment o{. X 14 (After Cushman). c. Saccammina sphaerica. X8 (After Rhumbler). d. Hyperammina subnodosa. X4 (After Brady). e. Ammodiscus incertus, megalospheric and microspheric forms. X20 (After Kuhn). f. Silicina limitata. X 13 (After Cushman). g. Reophax nodulosus. X3 (After Brady). many higher forms they are divided into chamberlets. The chambers are delimited by the suture on the exterior of the test. The septa which divide the chambers are perforated by one or more foramina known as stolon canals, or passages, through which the living protoplasm extends throughout the chambers. FOR A MINIFERA 195 The last chamber has one or more apertures of variable size, through which the cytoplasm extends to the exterior as myxo- podia. The food of the Foraminifera consists mostly of diatoms and algae. 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 smaller megalospheric form with a large proloculum and the larger microspheric form with a small proloculum (Fig. 73). The former is usually much more numerous than the latter. The microspheric form is multinu- cleate, 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). The uninucleate bodies thus formed leave the parent body, and each secretes around itself a test which is much larger than the proloculum of the parent individual {d, e). To this prolocu- lum, new chambers are added one by one, as the animal 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 organism grows, endosomes appear in increasing numbers in the nucleus which multiplies finally into many nuclei {g). Each of these nuclei becomes the center of a swarmer. The swarmers leave the parent test and undergo fusion in pairs to produce zygotes {h-j). The zygote secretes a test around itself (a) and forms first a small proloculum, to which are added many cham- bers {h). This is the microspheric form. Thus here one sees an alternation of asexual and sexual generations. In some forms the microspheric generation appears to be unknown. More than three hundred genera of extinct and living Fora- minifera are now known. Cushman distinguished forty-five families. The present work follows Cushman in recognizing and differentiating forty-four families, and lists one genus as an example for each, but places the Allogromiidae in the order Testacea (p. 232). Test entirely or in part arenaceous Test single-chambered or rarely an irregular group of similar cham- bers loosely attached 196 HANDBOOK OF PROTOZOOLOGY Test with a central chamber and two or more arms; fossil and recent Family 1 Astrorhizidae Genus Rhabdammina Sars (Fig. 74, a) Test without a central chamber, elongate, open at both ends; fossil and recent Family 2 Rhizamminidae Genus Rhizammina Brady (Fig. 74, h) 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. 74, c) Test two-chambered, a proloculum and long undivided tubular second chamber Test with the second chamber, simple or branching, not coiled; mostly recent, fossils Family 4 Hyperamminidae Genus Hyperammina (Fig. 74, d) Test with the second chamber usually coiled at least in the young animal Test of arenaceous material with nmch cement, usually yellowish or reddish brown; fossil and recent. . . .Family 5 Ammodiscidae Genus Ammodiscus Reuss (Fig. 74, e) Test of silicious material, second chamber partially divided; fossils only Family 6 Silicinidae Genus Silicina Bornemann (Fig. 74,/) Test typically many-chambered Test with all chambers in a rectilinear series; fossil and recent. . . Family 7 Reophacidae Genus Reophax Montfort (Fig. 74, g) Test planispirally coiled at least in the young Axis of coil short, many uncoiled forms; fossil and recent Family 8 Lituolidae Genus Lituola Lamarck (Fig. 75, a) Axis of coil usually long, all close-coiled Interior not labyrinthic; fossil only Family 9 Fusulinidae Genus Fusulina Fisher (Fig. 75, b) Interior labyrinthic; fossil only Family 10 Loftusiidae Genus Loftusia Brady Test typically biserial at least in the young of the microspheric form; fossil and recent Family 1 1 Textulariidae FORAMINIFERA 197 Genus Textularia Def ranee (Fig. 75, c) Test typically triserial at least in the young of the microspheric form Aperture usually without a tooth, the test becoming simpler in higher forms; fossil and recent Family 12 Verneuilinidae Fig. 75 a. Lituola naiitiloidea. (After Cushman). b. Section through a Fusulina. (After Carpenter). c. Textularia agglutinans. X90 (After Rhumbler). d. Verneuilina propinqua. X8 (After Brady). e. Valvulina triangularis. (After d'Orbigny). f. Trochammina infiata. X32 (After Brady). g. Placopsilina cenomana. (After Reuss). h. Tetrataxis palaeotrochns. X 15 (After Brady). i. Spiroloculina limbata. X20 (After Brady). j. Triloculina trigonula. X15 (After Brady). k. Fischerina helix. X32 (After Heron-Allen and Earland). 1. Vertebralina striata. X40 (After Kiihn). m. Alveolinella mello. X35 (After Brady). Genus Verneuilina d'Orbigny (Fig. 75, d) Aperture typically with a tooth, the test becoming conical in higher forms; fossil and recent Family 13 Valvulinidae Genus Valvulina d'Orbigny (Fig. 75, e) Test with whole body labyrinthic, large, flattened, or cylindrical; recent Family 14 Neusinidae 198 HANDBOOK OF PROTOZOOLOGY Genus Neusina Goes Test trochoid at least while young Mostly free and typically trochoid throughout; fossils and recent Family 15 Trochamminidae Genus Trochammina Parker and Jones (Fig. 75, /) Attached; young trochoid, later stages variously formed; fossil and recent Family 16 Placopsilinidae Genus Placopsilina d'Orbigny (Fig. 75, g) Free; conical, mostly of large size; fossil only. .Family 17 Orbitolinldae Genus Tetrataxis Ehrenberg (Fig. 75, h) Test coiled in varying planes, wall imperforate, with arenaceous portion only on the exterior; fossil and recent Family 18 Miliolidae (in part) Genus Spiroloculina d'Orbigny (Fig. 75, i) Test calcareous, imperforate, porcellanous Test with the chambers coiled in varying planes, at least in the young, aperture large, toothed; fossil and recent Family 18 Miliolidae (in part) Genus Triloculina d'Orbigny (Fig. 75, j) Test trochoid; fossil and recent Family 19 Fischerinidae Genus Fischerina Terquem (Fig. 75, k) Test planispiral, at least in the young The axis very short, chambers usually simple; fossil and recent. . Family 20 Ophthalmidiidae Genus Vertebralina d'Orbigny (Fig. 75, 1) The axis short, test typically compressed and often discoid, cham- bers mostly with many chamberlets; fossil and recent Family 21 Peneroplidae Genus Peneroplis Montfort (Fig. 76) The axis typically elongate, chamberlets developed; mainly fossil Family 22 Alveolinellidae Genus Alveolinella Douville (Fig. 75, m) Test globular, apertures 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 FORAMINIFERA 199 Test planispirally coiled or becoming straight, or single cham- bered; fossil and recent Family 24 Lagenidae Genus Lagena Walker and Jacob (Fig. 77, c) Test biserial or elongate spiral; fossil and recent _ Family 25 Polymorphmidae L^iP^' f:&. J W. @ tu ■' /f '..f^ Fig. 76 Diagram showing the development of Peneroplis pertusus.^ (After Winter), a-f, megalospheric generation; g, gamete formation; h-k, isogamy; 1-n, microspheric generation; o, multiple division. 200 HANDBOOK OF PROTOZOOLOGY Genus Polymorphina d'Orblgny Test not vitreous, aperture not radiating Test planispiral, occasionally trochoid, then usually with processes along the suture lines, septa single, no canal system; fossil and recent Family 26 Nonionidae Genus Elphidium Montfort (Fig. 77, b) Test planispiral, at least in the young, generally lenticular, septa double, canal system in higher forms; fossil and recent Family 27 Camerinidae Genus Operculina d'Orbigny (Fig. 77, c) Test at least in the microspheric form generally biserial, aperture usually large, without teeth; fossil and recent Family 28 Heterohelicidae Fig. 77 a. Lagena striata. X50 (After Rhumbler). b. Elphidium strigilata. X40 (After Kiihn). c. Operculina ammonoides, two views. X50 (After Kiihn). d. Pavonina flabelliformis. X30 (After Brady). e Hantkenina alahamensis. X40 (After Cushman). f. Bolivina punctata. X 100 (After Kiihn). g. Rotalia beccarii. X40 (After Kuhn). h. Asterigerina carinata. X30 (after d'Orbigny from Cushman). Genus Pavonina d'Orbigny (Fig. 77, d) Test planispiral, bi- or tri-serial with elongate spines and lobed aperture; fossil and recent Family 29 Hantkeninidae FORAMINIFERA 201 Genus Hantkenina Cushman (Fig. 77, e) Test typically with an internal tube, elongate Aperture generally loop-shaped or cribrate; fossil or recent. ... Family 30 Buliminidae Genus Bolivina d'Orblgny (Fig. 77,/) Aperture narrow, curved, with an overhanging portion; mostly fossil and recent Family 31 Ellipsoidinidae Genus EUipsoidina Seguenza Test trochoid, at least in the young of the microspheric form, usually coarsely perforate; when lenticular, with equatorial and lateral chambers Test trochoid throughout, simple; aperture ventral. No alternating supplementary chambers on ventral side; fossil and recent Family 32 Rotaliidae Genus Rotalia Lamarck (Fig. 77, g) Alternating supplementary chambers on ventral side; fossil and recent Family ii Amphisteginidae Genus Asterigerina d'Orbigny (Fig. 77, h) Test trochoid and aperture ventral at least in the young With supplementary material and large spines, independent of the chambers; fossil and recent. . . .Family 34 Calcarinidae Genus Calcarina d'Orbigny (Fig. 78, a) With later chambers in annular series or globose with multiple apertures, but not covering the earlier ones; fossil and recent Family 35 Halkyardiidae Genus Halkyardia Heron-Allen and Earland (Fig. 78, h) With later chambers somewhat biserial; aperture elongate in the axis of coil; fossil and recent Family 36 Cassidulinidae Genus Cassidulina d'Orbigny (Fig. 78, c) With later chambers becoming involute, very few making up the exterior in the adult; aperture typically elongate, semi-circular; in a few species circular; fossil and recent Family 37 Chilostomellidae Genus Allomorphina Reuss (Fig. 78, d) With chambers mostly finely spinose and wall cancellated, adapted for pelagic life, globular forms with the last 202 HANDBOOK OF PROTOZOOLOGY chamber completely involute; aperture umbilicate or along the sutures; fossil and recent. . .Family 38 Globigerinidae " Genus Globigerina d'Orbigny (Fig. 78, e) Early chambers globigerine, later ones spreading and com- pressed; fossil and recent .Family 39 Globprotaliidae Genus Globorotalia Cushman Test trochoid at least in the young, aperture peripheral or becoming dorsa.1 Mostly attached, dorsal side usually flattened; fossil and recent Family 40 Anom&linidae Fig. 78 a. Calcarina defrancci. X23 (After Brady). b. Halkyardia radiata. X13 (After Cushman). c. Cassidtdina laevigata. X25 (After Brady). d. Allomorphina trigona. X40 (After Brady). e. Glohigerina btdloides. X30 (After Kiihn). f. Anomalina punctulata. (After d'Orbigny). g. Rupertia stabilis. X50 (After Brady). Genus Anomalina d'Orbigny (Fig. 78, /) Later chambers in annular series; fossil and recent Family 41 Planorbulinidae Genus Planorbulina d'Orbigny Test trochoid in the very young, later growing upward Later chambers in a loose spiral; fossil and recent Family 42 Rupertiidae FORAMINIFERA 203 Genus Rupertia Wallich (Fig. 78, g) Later chambers in masses or branching, highly colored; ' mostly recent and also fossil Family 43 Homotremidae Genus Homotrema Hickson Test trochoid in the very young of the microspheric form, cham- bers becoming annular later, with definite equatorial and lateral chambers, often with pillars; fossil only Family 44 Orbitoididae Genus Orbitoides d'Orbigny References Brady, B. H. 1884 Report on the Foraminifera dredged by H. M. S. Challenger, during the years 1873 to 1876. Rep. Voy. Challenger Zool., VoL 9. CusHMAN, J. A. 1928 Foraminifera: their classification and economic use. Sharon, Mass. I^HUMBLER, L. 1904 Systernatische Zusammenstellung der rezenten Reticulosa (Nuda u. Foraminifera). Arch. f. Protistenk., Vol. 3. CHAPTER XVII ORDER 4 AMOEBAEA EHRENBERG THE AMOEBAEA show a Very little cortical differentiation. There is no pellicle, test, or shell surrounding the body, although in some, such as Amoeba verrucosa, the surface seems to be much hardened. The cytoplasm is more or less distinctly differentiated into the ectoplasm and the endoplasm. The ecto- plasm is hyaline and homogeneous, and appears tougher than the end6plasm. In the endoplasm, which is granulated or vacuolated, are found one or more nuclei, various food vacuoles, water vacuoles, crystals, and other bodies. In the fresh-water forms there is at least one distinctly visible contractile vacuole. The pseudopodia are lobopodia, and ordinarily both ectoplasm and endoplasm are found in them. They are formed by stream- ing or fountain movements of the cytoplasm. In some members of the order, the formation of pseudopodia is described as erup- tive since the granules which are found in the endoplasm break through the border line between the ectoplasm and the endo- plasm and suddenly flow into the pseudopodia. The life-history is not completely known, even among such common forms as Amoeba proteus. Asexual reproduction is ordinarily binary fission, although occasionally multiple fission takes place. Encystment is common for both free-living and parasitic forms. Sexual reproduction, which has been reported for a few species, has not been confirmed. The Amoebaea inhabit all sorts of fresh, brackish and salt waters. They are also found in most soil and on ground covered with decaying leaves. Many are inhabitants of the digestive tract of various animals, and some of them are pathogenic. The taxonomic status of the group is highly uncertain and confusing, since their hfe-histories are mostly unknown and since numerous Protozoa other than the members of this group often possess amoeboid stages. Forms such as Pantostomatida, may rightly be considered as belonging to either the Sarcodina [204] AMOEBAEA 205 or the Mastigophora. In the present work they have been placed in the latter group (p. 129). According to Calkins, four families are recognized here. With amoeboid and flagellate stages Family 1 Bistadiidae Amoeboid stage only With one or more nuclei of one type Free-living Family 2 Amoebidae Parasitic Family 3 Endamoebidae With a cytoplasmic "secondary nucleus" Family 4 Paramoebidae Family 1 Bistadiidae Doflein The Amoebaea placed in this family possess both amoeboid and flagellate phases (diphasic). In the former, the organism undergoes amoeboid movement by means of lobopodia and in the latter the body is more or less elongated. Binary fission seems to take place during the amoeboid phase only. Thus the members are diphasic organisms, in which the amoeboid stage predominates over the flagellate. The amoeboid phase of this family is frequently called the "limax amoeba" which under cultural conditions may be changed into flagellated individuals, as for example, by the addition of water to the culture medium. Under natural circumstances, it is often exceedingly difficult by observing amoebae to determine whether they belong to this family or the family Amoebidae. There is a good deal of confusion with regard to the various generic names created for the amoebae of the "limax" type. Calkins' definition and difTerentiation are followed here. Genus Naegleria Alexeieff ( = Vahlkampfia Chatton and Lalung-Bonnaire (in part) ; Wasielewskia Hartmann and Chagas). Minute forms. The flagellate phase possesses two flagella. The amoeboid phase is much similar to the genus Vahlkampfia (family Amoebidae, p. 206), with lobopodia. The cytoplasm is difTerentiated into the ectoplasm and endoplasm. The vesicular nucleus contains a large endosome. There is usually a conspicuous contractile vacuole. Food vacuoles con- tain bacteria. Fission takes place in the amoeboid stage only. Encystment is common; the cyst contains a single nucleus. Free-living in stagnant water and moist soil; often coprozoic. Naegleria gniheri (Schardinger) (Fig. 79, a-c). Body about 206 HANDBOOK OF PROTOZOOLOGY 10 to 50 microns in diameter; the cyst wall possesses several openings. Naegleria histadialis (Puschkarew) (Fig. 7-9, d-f). Similar in size, but the cyst wall smooth. Genus Trimastigamoeba Whitmore. The flagellate stage bears three flagella of nearly equal length. The vesicular nucleus with a large endosome. The amoeboid stage is small, Fig. 79 a-c. Trophozoite, flagellate phase and cyst (all stained) of Naegleria gruberi. X750 (After Alexeieff). d-f. Similar stages of N. bistadialis. X750 (After Kiihn). g-j. Trophozoite, flagellate phase, cyst and excystation of Trimastigamoeba philippinensis. X950 (After Whitmore). being less than 20 microns in diameter. Uninucleate cyst with smooth wall. Coprozoic. One species. Trimastigamoeba philippinensis Whitmore (Fig. 79, g-j). Family 2 Amoebidae Doflein These amoebae do not show flagellated stage (monophasic). They are free-living in fresh or salt water, in damp soil, moss, etc. One, two, or many nuclei occur. Contractile vacuoles usually present in fresh-water forms. Multiplication by binary or multiple fission. Encystment is widely spread. The life-history is not well known. Genus Amoeba Ehrenberg. Body large; often one milli- meter in diameter. With short blunt lobopodia. As a rule, a single contractile vacuole, and typically one nucleus. Nuclear structure can be used for specific differentiation to a certain AMOEBAEA 207 extent. Holozoic on Protophyta, Protozoa, Rotifera, and in a few cases even Nematoda. The endoplasm contains crystals which are enclosed in vacuoles and which possess form and size characteristic of various species (Schaeffer). These crystals seem to be composed of calcium phosphate and probably meta- bolic products. Numerous species. Amoeba proteus (Pallas) (Fig. 80, a-d). A widely distributed large amoeba living in fresh water, reaching often 600 microns s% ^,fe,:Ari:^ m Fig. 80 a-d. Amoeba proteus. (After Schaeffer, except d). a, an active trophozoite (XlOO); b, typical form of crystal ; c, eight nuclei in optical section; d, encysted form (after Doflein). e-g. Amoeba discoides. (After Schaeffer). e, active trophozoite (XlOO); f, typical crystal; g, five nuclei in optical section. h-j. Amoeba dubia. (After Schaeffer). h, active trophozoite (XlOO); i, various forms of crystals found in it; j, two nuclei in optical section. or more in diameter. The amoeba creeps with a few large lobo- podia, but floating individuals may possess a large number of short blunt lobopodia which show longitudinal ridges. The differentiation of the cytoplasm into two regions is usually distinct. One nucleus occurs in each individual and is charac- 208 HANDBOOK OF PROTOZOOLOGY teristically discoidal. But various modifications in nuclear forms are equally characteristic of the species. Food vacuoles contain numerous organisms co-existing in the water. Crystals are elongated bipyramid and measure up to 4.5 microns in length (Schaeffer). The development is not well established. Asexual reproduction is usually binary fission, but under cer- tain conditions division into four individuals is said to be of common occurrence (Doflein). Encystment is common. By using this amoeba Gruber found the now well-established fact that'"the nucleus and cytoplasm are dependent upon each other. Amoeba discoides Schaeffer (Fig. 80, e-g). Body about 400 microns long during movement. A few blunt and smooth lobopodia. Endoplasm contains bipyramidal truncate crystals, about 2.5 microns in length. The nucleus is always discoidal in form, without infolded surface. Usually one contractile vacuole. In fresh water. Amoeba dubia Schaeffer (Fig. 80, h-j). Body about 400 microns in diameter. Numerous pseudopodia flattened and with smooth surface. The nucleus circular in front view, oblong in profile. Crystals few in number, but large and of various shape. Contractile vacuole one or more. In fresh water. Amoeba verrucosa Ehrenberg (Fig. 81, a, b). Body irregu- larly rounded with wart-like expansions. Body surface is usually wrinkled, as though invested with a membrane. The diameter varies from 50 to 200 microns. Pseudopodia short, broad, and blunt. Differentiation of the cytoplasm is fairly distinct. The nucleus is ovoidal. The contractile vacuole is soli- tary and large. Multiplication by binary fission. Fresh water among algae. Genus Pelomyxa Greeff. A large sluggish amoeba which contains a few to numerous nuclei. The cytoplasmic differentia- tion is poor. Pseudopodia small in number and are short and broad; the animal undergoing a rolling movement. Besides the nuclei, diatoms, bacteria, water vacuoles and sand-grains, endo- plasm usually contains refractile bodies which are thought to be either reserve food material similar to glycogen or metabolic products used by symbiotic bacteria. Contractile vacuole has not been noticed with certainty. Multiplication by binary fis- sion. Gamete formation has been reported; it is presumed that AMOEBAE A 209 uninucleate bodies undergo fusion to form zygotes which de- velop into multinucleate forms. Several species in fresh water. Pelomyxa palustris Greef (Fig. 81, c). Inhabitants of stag- nant water, creeping on the bottom in the mud. The amoeba is large, often measuring 2 mm. or more in diameter. Sluggish with one broad pseudopodium, by which the organism under- im^smmm c^:0 ' Fig. 81 a, b. Large and small individuals of Amoeba verrucosa. X500 (After Leidy). c. Pelomyxa palustris. X80 (After Kiihn). d. P. villosa. X250 (After Leidy). goes rolling movement. The cytoplasm is not at all differenti- ated into two regions. Numerous vacuoles and vesicular nuclei present. The nuclei exceed one thousand in number. Various inclusions often color the body brown to black and make it ap- pear opaque. Symbiotic bacteria, Cladothrix pelomyxae Veley, occur regularly. Some individuals extrude inclusions and en- 210 HANDBOOK OF PROTOZOOLOGY cyst, becoming covered by two or three cyst walls. The contents multiply into several multinucleate bodies. Cosmopolitan. Pelomyxa villosa (Leidy) (Fig. 81, d). Similar to the last species, but much smaller; 250 microns long. With numerous villi at the posterior extremity. In a similar habitat. Genus Vahlkampfia Chatton and Lalung-Bonnaire. The characteristics are: The nucleus contains a large endosome and peripheral chromatin, and divides by "promitosis" (p. 45). The cyst is uninucleate. It is a small amoeba, exhibiting snail- like movement and possessing a perforated wall when encysted. Body small, not exceeding 50 microns when fully extended. Ordinarily one broad pseudopodium is formed in the direction of movement,. although it cannot be made a basis for taxonomic consideration. ,' Fig. 82 a. Vahlkampfia Umax. X500. b. V. pdluxent. X500 (After Hogue). c, d. Hartmannella hyalina. X700 (After Dobell). c, tropbozoite; d, cyst, both stained. Vahlkampfia Umax (Dujardin) (Fig. 82, a). Body 30 to 40 microns long. Fresh water; soil. Vahlkampjifi patuxent Hogue (Fig. 82, h). The amoeba was found in the alimentary canal of the oyster. Fairly uniform in size being about 20 microns long during the first few days of artificial cultivation, but later reaching as long as 140 microns in diameter. Ordinarily one large pseudopodium composed of the ectoplasm is seen, presenting a broad fan-shape> In culture, pseudopodium-formatiouv is explosive. Holozoic on^bacteria. No contractile vacuoles. Multiplication by fission or budding. Encystment rare; the cyst contains a single nucleus. Genus Hartmannella Alexeieff. This genus ilicludes small amoebae with the following nuclear characteristics. Th? nucleus is vesicular. A large endosome is located in the center ahd numerous chromatin granules are scattered along the AMOEBAEA 211 periphery. At the time of division, the endosome disintegrates and chromosomes and spindle fibers appear. There are no so- called polar caps during division as are found in Vahlkampfia. Hartmannella hyalina (Dangeard) (Fig. 82, c, d). Easily cultivated from old feces of man and animals and also from water. More or less rounded body measures less than 20 microns in diameter. A single nucleus and a contractile vacuole. Binary fission. The spherical cyst measures 10 to 15 microns in diameter, covered with a smooth inner and a much wrinkled outer wall. Genus Sappinia Dangeard. With two closely associated nuclei. ... -." Sappinia diploidea (Hartmann and Nagler). -'"Coprozoic in the feces of widely different animals. The pseudopodia are short and broad, and few. The highly vacuolated endoplasm c&iijtains two nuclei, food vacuoles, and a contractile vacuole. A wrinkled surface is sometimes, noticed. The nuclei divide simultaneously. During encysthient, two mdividuals come, together and secrete a common cyst wall. The two nuclei fuse so that each individual possesses a single nucleus; finally the cytoplasmic masses of the two individuals.*inite into one. Each nucleus gives off reduction bodies which d^egenerate. Two nuclei now come in contact without fusion, thus a binucleate cyst is formed. After leaving' the cyst-wall, the binucleate amoeba grows and multipHes (Hartmann and Nagler),.*, Family 3 Endamoebidae Calkins^ ^ Endoparasitic amoebae wtth a wide zoological distribution. mostly witbeiri . . Mitiltiplication ... r . .19}£J 89Junim y:rn'j7/'j «d-jo;ji>; oniiZc by bmary fission. G JTitilbP^H}firc^(yrftll<^Y^#iV&raftul^^pfq|3gjf§rg^^zearon^ 212 HANDBOOK OF PROTOZOOLOGY actively moving individuals shows very prominent striations. Parasitic in invertebrates. Endamoeha hlattae (Biitschli) (Fig. 83). Cosmopolitan and often observed in the colon of several species of the cock- roach. Its size varies from 10 to 150 microns in diameter. Rounded amoebae which form broad lobopodia, show a dis- Fig. 83 Endamoeba blattae, as seen in life. X400 (After Kudo), a, b, active trophozoites; c, d, precystic forms; e, a stage in binary fission; f, the same amoeba twenty minutes later. tinct differentiation of the cytoplasm. Elongated forms with a few pseudopodia, show the ectoplasm only at the ends of the pseudopodia. The endoplasm of actively motile individuals shows a marked striation, a condition not seen in other amoebae. No contractile vacuoles are noted, although fluid-filled vacuoles are seen in large numbers The food consists of mainly starch |tains, yeast cells, bacteria, and Protozoa, all of which coexist AMOEBAEA 213 in the host's colon. The amoeba shows preference toward the starch grain. Prior to encystment, the body diminishes in size. Cyst membrane is formed and the nucleus undergoes repeated division, so that cysts containing over sixty nuclei are often encountered. The further development is unknown. Mercier holds that when the multinucleate cysts gain entrance to the intestine of a host insect through its mouth, each of the cyst nuclei becomes the center of a gamete. When the cyst-mem- brane ruptures, the gametes are set free and anisogamy takes place, resulting in the formation of numerous zygotes which develop into the habitual amoebae. This observation has not been confirmed. Fig. 84 Endamoebae of termites. (After Kirby). " a. Endamoeba disparata. X665. b. E. majestas. X350. c. E. simulans. X350. d. E. sahulosa. X665. Endamoeba thomsoni Lucas. Smaller amoebae occurring in the same habitat. Endamoeba disparata Kirby (Fig. 84, a). In the intestine of the termite, Microtermes hispaniolae. Body 20 to 40 microns long. Active. The amoeba feeds on bits of wood. Endamoeba majestas Kirby (Fig. 84, b). In the same habitat. Body 65 to 165 microns in diameter. Many short pseudopodia. Numerous food particles in the cytoplasm. Endamoeba simulans Kirby (Fig. 84, c). In the intestine of the termite, Microtermes panamaensis. Body 50 to 150 microns in diameter. Endamoeba sabulosa Kirby (Fig. 84, d). In the same habitat. Small, 19 to 35 microns in diameter. Genus Entamoeba Casagrandi and Barbagallo. This genus 214 HANDBOOK OF PROTOZOOLOGY was established by Casagrandi and Barbagallo who did not know the existence of the genus Endamoeba. The nucleus has the following characteristics: Vesicular; nuclear membrane is thin, but distinct. A comparatively small endosome is located in or near the center and there are varying numbers of peripheral chromatin granules free or attached to the nuclear wall. Numerous species in man, mammals, and invertebrates. A number of authors hold that there is not a sufficient difference between the genera Endamoeba and Entamoeba to justify their generic separation, and so combine them. A. Entamoebae of man Entamoeba histolytica Schaudinn (Fig. 85, a-f). The amoeba is small and measures 20 to 30 microns in diameter. Its cyto- plasm is usually differentiated distinctly. Large lobopodia are often formed in an explosive manner, and are composed ex- clusively of ectoplasm. The endoplasm contains a single vesicu- lar nucleus which appears in life as a ring and food vacuoles containing erythrocytes, tissue cells, leucocytes, etc., of the host in variable number. The typical nucleus shows upon staining the following parts: a nuclear membrane, peripheral chromatin granules, a centrally located small endosome rich in chromatin material surrounded by a clear ring and an indistinct achromatic network with a few scattered chromatin granules. This amoeba invades the tissues of the gut-wall and multiply by binary fission. Under certain circumstances not well under- stood, the active trophozoite extrudes its undigested food material and decreases in size, possibly by division also. Such a form is sluggish and shows frequently glycogen bodies and elongated refractile bodies which stain deeply with a nuclear stain (hence called the chromatoid bodies). This phase is known as the precystic stage. The cyst is formed when the pre- cystic stage ceases to move and becomes surrounded by a definite cyst-membrane. The cyst measures 5 to 20 microns in diameter. At first it contains a single nucleus which divides later twice and tetranucleate cyst is formed. The glycogen and chromatoid bodies become absorbed, as the cyst grows older. The changes between the cyst and the young trophozoite are not known, although in recent years numerous investigators AMOEBAE A 215 have been able to cultivate the amoeba in vitro and noted in some cases the excystation of the cyst contents as multinucleate amoebae. This amoeba was first definitely recognized by Losch in Russia in 1873. It is now known to have a wide geographical distribution. The incidence of infection among man depends mainly upon the sanitary conditions of the community, since the infection is carried from man to man through cysts. Craig estimates that ten per cent of the general population of the Fig. 85 Entamoebae of man. a-f. Entamoeba histolytica, a, a stained trophozoite (XIOOO); b, stained precystic stage (XIOOO); c, a stained cyst (XIOOO); d-f, excystation in culture (X700 after Yorke and Adams). g, h. Entamoeba coli. XIOOO. g, stained trophozoite; h, stained cyst. i-k. E. gingivalis. X500. i, j, living trophozoites; k, stained tropho- zoite. United States harbor this organism. An acute infection by Entamoeba histolytica is manifested clinically by dysentery. In chronic cases, the host may void a number of infective cysts without sulifering himself. Such a man is known as a "carrier." The amoeba invades the liver also and causes in it various abscesses of a serious nature. Numerous varieties are known. Entamoeba coli (Losch) (Fig. 85, g, li). The amoeba varies from 15 to 40 microns in diameter. Its cytoplasm is indistinctly differentiated. Lobopodia are slowly formed and body move- ment is sluggish. The endoplasm shows several food vacuoles 216 HANDBOOK OF PROTOZOOLOGY containing varying number of bacteria. The nucleus is observ- able in life. Compared with that of E. histolytica, the endosome is somewhat larger and located ordinarily eccentrically and the peripheral chromatin granules are more conspicuous in the present species. Multiplication by binary fission is known. The precystic stage is similar in appearance to that of the last species with the exception of the nuclear structure, and, there- fore, the differentiation of the two species at this stage is, as a rule, impossible. The cyst resembles also that of E. histolytica, but the mature cyst contains normally eight nuclei and meas- ures 10 to 30 microns in diameter. In young cysts there are glycogen bodies which are larger than those found in E. his- tolytica. The chromatoid bodies are 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 intes- tine and widely distributed throughout the world. Entamoeba gingivalis Gros { = E. huccalis Prowazek) (Fig. 85, i-k). The amoeba is a fairly active form. A few blunt pseudopodia are formed and retracted actively. It varies in size from 10 to 40 microns, the majority measuring 10 to 20 microns in diameter. The cytoplasm is ordinarily distinctly differentiated ; the ectoplasm is very hyaline and the endoplasm granulated. A single nucleus, numerous food particles which consist of degenerating tissue or pus cells, leucocytes, bacteria, erythrocytes, etc., are found in the endoplasm. The nucleus resembles that of E. histolytica, but the location of the endo- some is inconstant. The amoeba multiplies by binary fission. Cyst is unknown. The transmission of the amoeba from man to man is, therefore, considered direct. This amoeba was the first endoparasitic amoeba discovisred and observed by Gros in 1849 in the human tartar. As to the effect of the amoeba upon the host, some investigators believe that it is the probable cause of pyorrhoea alveolaris, but the majority of the investigators are inclined to think that it is a commensal of the human mouth. B. Entamoebae of domestic animals Almost all domestic animals harbor one or more amoebae in their digestive tracts and many of them resemble those oc- AMOEBAEA 217 curring in man, although distinct specific names were given to them. Iji horses Entamoeba intestinalis Gedoelst. In colon and caecum. Entamoeba equi Fantham. Found in feces; contained ery- throcytes; cysts tetranucleate. Entamoeba gingivalis var. equi Nieschulz. Found around the teeth. hi cattle Entamoeba hovis Liebetanz. In stomach. Diameter 5 to 20 microns. In sheep Entamoeba ovis Swellengrebel. With uninucleate cyst. In goats Entamoeba caprae Fantham. In swine Entamoeba polecki (Prowazek). In the large intestine; 10 to 12 microns in diameter; the cyst with a single nucleus. Entamoeba debliecki Nieschulz. Smaller form; 5 to 10 mi- crons in diameter; the cyst with a single nucleus. In dogs Entamoeba venaticum Darling. In the large intestine. Simi- lar to E. histolytica. As the dog is experimentally infected with the latter, this amoeba which was discovered from spontaneous amoebic dysentery cases of dogs, in one of which w^as noted ab- scesses of liver, is probably E. histolytica. An Entamoeba from the mouth and indistinguishable from Entamoeba gingivalis of the human mouth. In cats Entamoeba histolytica Schaudinn. Cats are easily infected by E. histolytica and show typical symptoms. Spontaneous dys- entery due to this human amoeba was also noted. C. Entamoebae of other mammals In rabbits Entamoeba cuniculi Brug. This amoeba is said to resemble E. coli in both the trophic and encysted stages. 218 HANDBOOK OF PROTOZOOLOGY In guinea-pigs Entamoeba cohaye Walker { = E. caviae Chatton). Similar to E. coli. In rats apd mice Entamoeba muris (Grassi). The amoeba also resembles E. coli. An Entamoeba resembling E. histolytica has been recognized o"ften and is probably identical with the latter. D. Entamoebae of birds Entamoeba lagopodis Fantham. Tetranucleate cysts were found in the intestine of the grouse, Lagopus scoticus. Entamoeba anatis Fantham, An amoeba with mono- or tetra-nucleate cysts were found in the intestine of a duck. Entamoeba gallinarum Tyzzer. This amoeba occurs in the intestine of fowls. Cysts octonucleate. Fig. 86 Entamoeba testudinis from the large intestine of Terrapene Carolina. X665. a, b, living; c, stained trophozoites. E. Entamoebae of reptiles Entamoeba testudinis Hartmann (Fig. 86). In the intestine of turtles, Testudo graeca, T. argentina and T. calcarata; and also in Terrapene Carolina. Entamoeba barreti Taliaferro and Holmes. In the large in- testine of the snapping turtle, Chelydra serpentina. It shows a close resemblance to the last species. Entamoeba serpentis da Cunha and da Fonseca. In th6 iifi- testine of the snake, Drimobius bifossatus of South Anjericam ) F. Entamoebae of amphibians Entamoeba ranarum (Grassi) (Fig. 87, a, b). In the large in- testine of various species of frogs. It sQl^^A^hat^AJPe^^TOfcllg? ^• histolytica. Its size varies 10 to 50 tJlii^^WP f^l?:J 4i?(5ge|(?rj\o^l5|; A AMOEBAEA 219 cysts are usually tetranucleate, but some contain as many a.s 16 nuclei. Amoebic abscess of the liver was reported 'in a frog. Entamoeba sp. Chatton. In the rectum of the newt, Triton palmatus. Entamoeba sp. Alexeieff-. In Triton taeniatus. These two forms resemble closely E. ranarum. Fig. 87 a, b. Trophozoite and cyst of Entamoeba ranarurn'.- X650 (After Mercier and Math is), c, d. Trophozoite and cyst of £«f/o/i'wax na«a. XlOOO. e, f. Trophozoite and cyst of E. ranarum. X500 (After Epstein and Ilovaisky). g, h. Trophozoite and cyst of lodamoeba biitschli. XlOOO. i-k. A living and two stained trophozoites of Dientamoeha fragilis. XI 100 (After Kudo). G. Entamoebae of invertebrates Entamoeba aulastomi Noller. In the intestine of the horse leech, Aulastomum gulo. Trophozoites measure about 35 mi- crons or larger. The cysts are ordinarily tetranucleate and meas- ure 7 to 11 microns in diameter. Entamoeba minchini Mackinnon. In the intestine of the tip- ulid larvae. Size 5 to 30 microns. Cysts contain Huclei up to ten in number. Entamoeba mesnili Keilin. In the intestine of the larva of the dipterous insects, Trichocera hiemalis and T. annulata. Body 6 to 24 niicrons long and multinucleate. Plasmotomy. The cysts 8 to 11 microns in diameter, contain two or four nu- clei. Entamoeba apis Fantham and Porter. In Apis mellifica. Somewhat- resembles E. coli. 220 HANDBOOK OF PROTOZOOLOGY Entamoeba helostomae Brug. In the intestine of Belstoma sp., a water bug. Genus Endolimax Kuenen and Swellengrebel. Small parasitic amoeba. The genus is ill-defined. The nucleus pos- sesses a definite membrane and there is a comparatively large irregularly shaped endosome which is composed of chromatin granules embedded in an achromatic ground mass. Several achromatic threads may be seen connecting the endosome with the membrane. One species occurs in the human intestine. Commensal. Endolimax nana (Wenyon and O'Connor) (Fig. 87, c, d). Inhabitant of the large intestine of man. The amoeba is, as a rule, sluggish, although lobopodial formation may be quite active. It varies in diameter from 6 to 12 microns. The cyto- plasm is fairly well differentiated into the ectoplasm and endoplasm. The latter contains a nucleus which is difficult to make out in life, and food vacuoles which contain bacteria. The cyst is usually ovoid, measures 8 to 10 microns in diameter, and contains when mature four nuclei. Widely distributed. It is considered as a commensal. Endolimax gregariniformis (Tyzzer). In the caecum of the fowls. The small amoeba measures 4 to 12 microns in diameter. Nucleus vesicular with a large endosome. Rounded cysts are uninucleate. Endolimax ranarnm Epstein and Ilovaisky (Fig. 87, e, f). In the large intestine of frogs. Small amoeba of the Vahlkampfia type. The vesicular nucleus shows a large endosome, radiating achromatic strands, and small peripheral chromatin granules. The cyst measures up to 25 microns long and contains eight nuclei. Endolimax hlattae Lucas. In the colon of the cockroach. Genus lodamoeba Dobell. Small amoeba parasitic in the intestine of man and mammals. The vesicular nucleus possesses the following structure, if properly stained: A distinct mem- brane, a large endosome rich in chromatin, a layer of globules which surround the endosome and which do not stain deeply, and achromatic strands between the endosome and the mem- brane. The cysts are ordinarily uninucleate and contain a AMOEBAEA 221 large glycogen vacuole which stains conspicuously with iodine. lodamoeha biitschli (Prowazek) ( = /. williamsi Prowazek) (Fig. 87, g, h). Inhabitant of the large intestine of man. The sluggish trophozoites vary in size from 9 to 13 microns. The cy- toplasm is ill-defined and contains bacteria which are taken in as food. The cysts are mostly of irregular shape and measure 6 to 15 microns in diameter. In the nucleus of the cyst, the large endosome comes in contact with the nuclear membrane at one point. A large iodinophilous vacuole. lodamoeha suis O'Connor. In the intestine of pig; widely distributed. Indistinguishable from the last species. It is considered by some that the pigs are probably reservoir hosts of this human parasite. Genus Dientamoeba Jepps and Dobell. Small parasitic amoeba of the large intestine of man. The number of the binucleate trophozoites is often greater than that of the uni- nucleate forms. The nucleus has a delicate membrane. Its central endosome consists of several chromatin granules em- bedded in plasmosomic substances and is connected with the nuclear membrane by delicate achromatic strands. One species. Dientamoeba fragilis Jepps and Dobell (Fig. 87, i-k). Com- mensal in the human intestine. Genus SchiXamoeba Davis. The nucleus of the trophozoite is vesicular and without any endosome, but with chromatin granules arranged along the nuclear wall. Each trophozoite possesses one to many nuclei. The cyst nuclei which are formed by the fragmentation of those of the trophozoite, possess a large rounded chromatic endosome connected at one side with the nuclear membrane by achromatic strands, in which are embedded chromatin granules. Parasitic in the stomach of salmonoid fish. One species. Schizamoeha salmonis Davis (Fig. 88, a, h). The amoeba is sluggish and measures 10 to 25 microns in diameter. Multi- plication by binary fission, the nuclear division being amitotic. The amoeba contains from one to several nuclei. The cysts are said to be usually more abundant than the trophozoites and their appearance seems to be correlated with the amount of available food. The cysts are spherical and measure 15 to 35 microns in diameter, being surrounded by a thin membrane. 222 HANDBOOK OF PROTOZOOLOGY The number of nuclei in each varies from three to a large num- ber. During the encystment, the chromatin bodies of the trophozoite become collected in several masses which then dis- integrate and each chromatin grain becomes the endosome of the newly formed nucleus. Sooner or later, the cyst contents divide into several (four to eleven) multinucleate bodies and the whole increases in size. Finally the cyst membrane dis- integrates and the multinucleate bodies become set free. The Schizamoeba salmonis. X800 (After Davis).' Hydramoeba hydroxena. (After Reynolds and Looper). c, a heavily attacked Hydra oligactis which lost its tentacles (X70); d, section of an infected hydra showing a trophozoite feeding on ectodermal cells (X350). Paramoeba pigmentifera with its nucleus in the center. X600. (After Janicki). amoeba is said to occur in the mucous covering of the stomach of the salmonoid fish and the cysts occur in both stomach and intestine. Aside from the loss of certain amount of food avail- able to the host fish, no pathogenic effect of the amoeba upon the host fish was noted by the discoverer. Genus Hydramoeba Renolds and Looper. Ectoparasitic on Hydra. The nucleus has the following characteristics in stained condition : There is a large central endosome composed of a centrosome (?) and chromatin granules are embedded in an achromatic mass. Fine achromatic strands radiate frorn the endosome to the membrane. In the nuclear sap zone, there is a ring composed of numerous rod-shaped chromatin bodies arranged regularly. The cytoplasm contains one or more AMOEBAEA 223 contractile vacuoles. This genus may be looked upon as a primitive parasitic amoeba. Hyd'ramoeba hydroxena (Entz) (Fig. 88, c, d).' Parasitic in various species of Hydra. First found by Entz; Wermel found in Russia that 90 per cent of Hydra he studied were infected; Reynold and Looper made experimental studies and concluded that infected Hydra die on an average in 6.8 days and that the amoeba disappears in from 4 to 10 days if removed from a host Hydra. The body is more or less rounded with blunt lobopodia. Size 60 to 380 microns. The nucleus shows some twenty re- fractile peripheral granules in life. Contractile vacuoles are one to many. Food vacuoles contain the contents of the host cell such as pigments, nuclei, cnidoplasts, etc. It multiplies by binary fission. Encystment has not yet been observed. Family 4 Paramoebidae Poche The amoebae possess a nucleus and nucleus-like secondary cytoplasmic structure. These two cell-organs multiply by division simultaneously. Free-living or parasitic. Genus Paramoeba Schaudinn. With the family characters. Pardmoeba pigmentifera (Grassi) (Fig. 88, e). Sluggish amoeba with an average length of 30 microns. The cytoplasm is distinctly differentiated. The secondary nucleus-like body is larger than the nucleus. Flagellate swarmers are said to occur. Parasitic in the coelom of Chaetognatha, such as Sagitta claparedei, Spadella bipunctafa, S. inflata, and S. serratodentata. References A. Free-living forms Cash, J. 1905 The British freshwater Rhizopoda and Helio- zoa. Vol. 1. Dellinger, O. p. 1906 Locomotion of amoebae and allied forms. Jour. Exper. Zool., Vol. 3. Leidy, J. 1879 Freshwater Rhizopods of North America. Report U. S. Geol. Surv. Terr., Vol. 12. Penard, E. 1902 Faune rhizopodique du Bassin du Leman. Geneva. Schaffer, a. a. 1917 Notes on the specific and other char- acteristics of Amoeba pr oteus' VsWdiS (Leidy), A. discoides 224 HANDBOOK OF PROTOZOOLOGY spec, nov., and A. duhia spec. nov. Arch. f. Protistenk., Vol. 37. . 1926 The taxonomy of the amebas with descriptions of thirty-nine new marine and fresh-water species. Publ. Carnegie Inst, of Washington, No. 345. Taylor, Monica. 1924 Amoeba proteus. Quart. Jour. Mire. Sci., Vol. 69. Wilson, C. W. 1916 On the life-history of a soil amoeba. Uni. California Publ. Zool., Vol. 16. B. Parasitic forms BoECK, W. C. AND C. W. Stiles. 1923 Studies on various intestinal parasites (especially amoebae) of man. U. S. Publ. Health Service, Hyg. Lab. Bulletin, No. 133. Craig, C. F. 1926 A manual of parasitic Protozoa of man. DoBELL, C. 1919 The amoebae living in man. London. DoBELL, C. AND F, W. O'CoNNOR. 1921 The intestinal Pro- tozoa of man. London. KiRBY, H. Jr. 1927 Studies on some amoebae from the term- ite Microtermes, with notes on some other Protozoa from the Termitidae. Quart. Jour. Micr. Sci., Vol. 71. Kudo, R. 1926 Observations on Endamoeha hlattae. Amer. Jour. Hyg., Vol. 6. NoLLER, W. 1922 Die wichtigsten parasitischen Protozoan des Menschen und der Tiere. I Teil, Vol. 1. Berlin. Wenyon, C. M. 1926 Protozoology. Vol. 1. London. CHAPTER XVIII ORDER 5 TESTACEA SCHULTZE /■T-VHis ORDER, which is also known as the Thecamoeba, com- X prises those amoeboid organisms which are covered by a single-chambered shell, or test, within which the body can be completely withdrawn. The test has usually a single aperture through which the cytoplasm is extruded as pseudopodia. The test varies somewhat in shape and structure. A chitinous or pseudochitinous membrane forms the basis of all tests. It may be thickened, as in Arcella, or composed of foreign bodies cemented together, as in Difflugia. In Euglypha silicious platelets are formed in the endoplasm and deposited on the membrane. The cytoplasm is well differentiated into the ectoplasm and the endoplasm. The ectoplasm is conspicuously observable at the aperture of the shell where the pseudopodia are formed. The pseudopodia are slender and composed of ectoplasm only. Thus they are mainly filopodia. The endoplasm is, on the whole, granulated or vacuolated and contains food vacuoles, con- tractile vacuoles and nuclei. The number of nuclei present in a single individual varies from one to many. In some forms there are present regularly in the cytoplasm numerous deeply staining chromatin granules known as chromidia (p. 22). Asexual reproduction is either by longitudinal fission, in forms with a soft shell, or by transverse division or budding. In some forms multiple division occurs. Sexual reproduction by amoeboid or flagellate gametes has been observed in a number of species. Encystment is known to occur in the majority of forms here grouped. The Testacea are mostly inhabitants of fresh water, but a few live in salt water. A number of species are semi-terrestrial, being found in moss or moist soil, es- pecially peaty soil. This group is divided into the following four families: [225] 226 HANDBOOK OF PROTOZOOLOGY ^ Test simple and membranous , . " ; Pseudopodia filose or simply branched Family 1 Arcellida'e Pseudopodra.reticulate , . . ." Family 2 Allogromiidae Test with foreign bodies, plates, or scales ., Chitinous test with foreign bodies Family 3 Difflugiidae Chitinous test with platelets or scales '. . . .Family 4 Euglyphidae Family 1 Arcellidae Schulze The generic differentiation of the family is based mainly upon the form and structure of the test. ^ Genus Arcella Ehrenberg-. • Test tra«sparent, chitinous, •colorless to brown (when old), and densely punctafted. In dorsal view it is circular, angular, or stellate; in profile plano- convex to hemispherical. Variously ornamented. Apertu/e circular, central, and inverted like a funnel. Occasionally spinous. The protoplasmic body does not fill the test and is connected wi^^ the latter by ectoplasmic s-trands. Pseudopodia few, digitate,-blunt, simple or branched. Two nuclei, chromidia, and several contractile vacuoles. Fresh water. Numerous species. A rcella vulgaris Ehrenberg (Figs. 4 ; 89, a) . Height of test about one-half the diameter. Hemispherical. Dome evenly convex; aperture central and circular. Test colorless, yellow, or brown. The protoplasmic body conforms with the shape of the test, but does not fill the latter. Pseudopodia are lobose and hyaline. Two vesicular nuclei; numerous food vacuoles, chromidia, and contractile vacuoles conspicuously present. Diameter of test 50 to 150 microns. In the ooze of stagnant water and on sub- merged plants. Also in moist soil. Cosmopolitan. Arcella dentata Ehrenberg (Fig. 89, h). Test in aperture view 'circular and dentate; in profile crown-like. Diameter more than twice the height. Aperture circular and large. Color- less to brown. The .protoplasm as in A. vidgaris. Diameter of test 130 to 200 microns. In the ooze of fresh water ponds. Arcella discoides Ehrenberg (Fig. 89, c). Test circular in aperture view; plano-convex in profile. Diameter is about three or four times the height. Test coloration and body struc- ture similar to those of the last two species. Diameter of test 70 to 260 microns. In ponds and niarshes. Genus Pyxidicula Ehrenberg. Test patelliform ; rigid, trans- TESTA CE A 227 parent, and punctate'. -Aperture is circular and almost the full diameter of the test. The cyfoplasm is similar to that of Arcella, but the nucleus is usually one. Contradtile vacuojes one or more. Fresh water. Pyxidicula operculata (Agardh) (Fig. 89, d). Test smooth; colorless or brown. A single vesicular nucleus. Pseudopodia short, lobose or- digitate. Diameter about 20 microns. On aquatic 'plants. ' Genus Pseudochlamys Claparede and Lachmann.- Test discoid, flexible wh^n young. Tjie body protoplasm contains .a central nucleus and several contractile vacuoles.' Fig. 89 a. Arcella vulgaris. X200. b. A. dentata. X200. c. A. discoides. X200. d. Pyxidicula operculata. X800 (After Penard). • Pseudochlamys patella Claparede and Lachmann (Fig. 90, a). Young test flexible and hyaline, older ones rigid and brown. . Young forms often rolled up like a scroll. A short finger-like pseudopodium is protruded between the folds. Diameter 40 to 45 microns. Freshwater plants, under moss, or in soil. ■ Genus Difflugiella Cash. Test ovoid, not compressed, flexible transparent membrane; colorless protoplasm filling up the test, usually with chlorophyllous food material. Median pseudopodia lobular or digitate with aciculate ends; lateral pseudopodia long, straight, and fine, tapering to a point. One species. 1 Difflugiella apiculata Cash (Fig. 90, h, c). Length about 40 -microns. Among floating vegetation. Genus Cryptodifflugia Penard. Minute test yellowish or 228 HANDBOOK OF PROTOZOOLOGY brownish. Difflugia-like in general appearance, compressed; with or without foreign bodies. Pseudopodia long and acutely pointed. Cryptodiffliigia oviformis Penard (Fig. 90, d). Test ovoid, compressed; without foreign bodies. Crown hemispherical. Aperture truncate. The cytoplasm contains chlorophyllous food particles. Length about 15 to 20 microns. In marshy ground among Sphagnum. Genus Lesquereusia Schlumberger. Test compressed, oval or globular in profile, narrowed at the neck which is bent; semi-spiral in appearance. With curved or comma-shaped rods or with sand-grains (in one species). The protoplasmic body does not fill the test. Pseudopodia long, blunt; simple or branched. . Fig. 90 a. Pseudochlamys patella. X500. b, c. Difflugiella apiculata. X400. d. Cryptodifflugia oviformis. X480 (AH after Cash). Lesquereusia spiralis (Ehrenberg) (Fig. 91, a). Aperture circular; border distinct. The cytoplasm appears pale yellow. A single nucleus. About 120 microns long by 95 microns broad. In marsh. Genus Hyalosphenia Stein. Test ovoid or pyriform; aper- ture convex; homogeneous and hyaline, mostly compressed. Crown uniformly arched. Protoplasm partly filling the test. Several blunt pseudopodia simple or digitate. Some ten species. Hyalosphenia papilio Leidy (Fig. 91, b). Test yellowish; transparent or delicately punctated ; in front view, pyriform or oblong. A minute pore on each side of crown and sometimes one also in the center. Aperture convex. In narrow lateral view, elongate pyriform, aperture a shallow notch. The protoplasm contains chlorophyllous particles and oil globules. Posteriorly TESTACEA 229 located nucleus is indistinct. Pseudopodia digitate. Length 110 to 150 microns. In swamp among sphagnum. Genus Leptochlamys West. Test ovoid, thin transparent chitinous membrane, circular in optical section. Aperture end slightly expanded from a very short neck. Circular aperture often oblique. Body fills the test and without vacuoles. Pseudopodium is single, short, broadly expanded and sometimes cordate. One species. ^tvsuvvvwui^v^ Fig. 91 a. Lesquereusia spiralis. X200 (After West from Cash). b. Hyalosphenia papilio. X250 (After Leidy). c. Leptochlamys ampullacea. X250 (After West). d. Chlamydophrys stercorea. X500 (After Wenyon). e. Cochlio podium bilimbosum. X500 (After Leidy). f. Amphizonella violacea. X 200 (After Greeff). Leptochlamys ampullacea West (Fig. 91, c). A large nucleus posterior. Green or brown food particles. Length 45 to 55 microns. Among algae. Genus Chlamydophrys Cienkowski. Rigid test circular in cross-section. Aperture often on the drawn-out neck. The protoplasm fills the test and contains a vesicular nucleus, with chromidia in the endoplasm. The zonal differentiation of the cytoplasm distinct. Refractile waste granules give the animal 230 HANDBOOK OF PROTOZOOLOGY a characteristic appearance. The pseudopodia are variously branched. Free-living or coprozoic. Chlamydophrys stercorid Cienkowski (Fig. 91, d). Coprozoic and in soil. Test 18 to 20 microns long by 12 to 15 microns broad. Mature aysts yellowish fcrown and measure 12 to 15 microns in diameter. The organism multiplies by budding from the aperture end. Genus Cochliopodium Hertwig and Lesser. Minute test thin flexible, chitinous, capable of expansion and contraction, with or without extremely fine hair-like processes. Pseudopodia blunt or pointed, but not acicular. Several species. Cochliopodium bilimbosmn (Auerbach) (Fig. 91, e). Test hemispherical. Pseudopodia conical with pointed ends. Dimen- sions 24 to 56 microns. Among algae and in the ooze in ponds, springs, ditches and other freshwater bodies. Genus Amphizonella Greeflf. Test membranous with a double marginal contour. The inner membrane smooth and well-defined; the outer serrulate. Aperture inverted. A single nucleus. Pseudopodia blunt, digitate, and divergent. Amphizonella violacea Greeff (Fig. 91,/). Test patelliform, violet-tinted; endoplasm with chlorophyllous corpuscles and grains. Movement sluggish. Average diameter 150 microns. Genus Zonomyxa Niisslin. Test rounded pyriform, flexible, chitinous, violet-colored. Endoplasm vacuolated, with chloro- phyllous particles. Several nuclei. Pseudopodia simple, not digitate. Zonomyxa violacea Niisslin (Fig. 92, a). A single lobular pseudopodium with an accuminate end. Four nuclei. Diameter 140 to 160 microns. Actively motile forms 250 microns or more long. Among Sphagnum. Genus Microcorycid. Cockerell. Test discoidal or hemispher- ical, flexible, with a diaphanous continuation or fringe around the periphery, being folded together or completely closed; crown of test with circular and radial ridges. The body proto- plasm does not fill the test; one or two nuclei; pseudopodia lobular or digitate. A few species. Microcorycia flava '(Greeff) (Fig. 92; h). Test yellowish brown. Crown with few small foreign bodies. Endoplasm with TESTA CEA 231 yellowish brown granules. Two nuclei close together; contrac- tile vacuoles. Diameter 80 to 100 microns. In mosses. Genus Parmulina Penard. Test ovoid, chitinoid with foreign bodies. Aperture capable of being closed, a single nucleus, one or more contractile vacuoles. A few species. Parmulina cyathus Penard (Fig. 92, c). Small test flexible; ovoid in aperture view; hemi-circular in profile. Aperture a long narrow slit when the test is closed; circular or^elliptical when opened. Length 40 to 55 microns. In mosses. Fig. 92 a. Zonomyxa violacea. XI 50 (After Penard). b. Microcorycia flava. X 180 (After Wailes). c. Parmulina cyathus. X375 (After Penard). d. Capsellina timida. X200 (After Brown). e. Diplochlamys leidyi. X200 (After Wailes). Genus Capsellina Penard. Test hyaline, ovoid, mem- branous; with or without a second outer covering. Aperture linear. A single nucleus; one or more contractile vacuoles; pseudopodia filose. Two species. Capsellina timida Brown (Fig. 92, d). Small, oval; elliptical in cross-section. Endoplasm with numerous oil-like globules. A single filopodium. 35 microns long by 25 microns broad. In mosses. Genus Diplochlamys Greeff. Test hemispherical or cup- shaped, flexible with a double envelope. Inner envelope a membranous sac with an elastic aperture, the outer envelope with loosely attached foreign bodies. Aperture large. Nuclei one to over one hundred in number. Pseudopodia few, short; digitate or pointed. Several species. 232 HANDBOOK OF PROTOZOOLOGY Diploclilamys leidyi Greeff (Fig. 92, e). Test dark grey; inner envelope projecting beyond the outer aperture. One to twenty nuclei. Diameter 80 to 100 microns. In mosses. Family 2 Allogromiidae Cash and Wailes This family is frequently included in the Foraminifera. Genus AUogromia Rhumbler. Test a thin chitinoid mem- brane, rather rigid, smooth or slightly coated with extraneous matter; broadly ovoid or spherical; aperture terminal. One or more nuclei. Numerous contractile vacuoles. Pseudopodia are filopodia and numerous, being formed from a short peduncle, branching and anastomosing, with numerous motile granules. Several species in fresh or marine water. AUogromia fluvialis (Dujardin). Test spherical or sub- spherical; smooth or sparsely covered with silicious particles. Cytoplasm yellowish, filling the test, with foreign particles; aperture not seen. A single large nucleus and numerous con- tractile vacuoles. Pseudopodia long, anastomosing, often en- veloping the test. 50 to 250 microns long. On aquatic plants, moss, and soil. AUogromia ovoidea Rhumbler (Fig. 93, a). In salt water. Genus Microgromia Hertwig and Lesser. Test small, hyaline, spherical or pyriform, not compressed; terminal aper- ture circular. Pseudopodia long straight or branching, filose or anastomosing, arising from a peduncle. A single nucleus; one contractile vacuole. Solitary or colonial. Microgromia socialis (Archer) (Fig. 93, h). The cytoplasm is bluish in color. A contractile vacuole near the aperture. Pseudopodia arise from a peduncle, attenuate, branching, anastomosing; often connecting numerous individuals into a more or less closely aggregated colony. Multiplication by fission of the body and also by the formation of zoospores. Diameter 25 to 35 microns. Among aquatic vegetation. Genus Lieberkiihiiia Claparede and Lachmann. Test ovoidal or spherical, with or without attached foreign par- ticles. Aperture usually single, lateral, or subterminal; flexible. One or more nuclei; numerous contractile vacuoles. Pseudo- podia formed from a long peduncle located in the test, reticu- late, often enveloping the test. TESTACEA 233 LieberkUhnia wagneri Claparede and Lachmann (Fig. 93, c). Test ovoid or subspherical, usually devoid of adherent particles. Aperture subterminal, oblique, flexible. Slightly yellowish protoplasm fills the test. Nucleus vesicular and numerous (80 to 150 in number) ; numerous contractile vacuoles. Pseudopodia long and anastomosing. Length 60 to 160 microns. On fresh- water or marine algae. :i M i' / / ^ A/ 1 \ // / i // t X:;::^> /'■■ .< h^"^ Fig. 93 a. Allogromia ovoidea. Xabout 50 (After Schultze). b. Microgromia socialis. X165 (After Cash). c. LieberkUhnia wagneri. X 140 (After Verworn). d. Rhynchogromia nigricans. X200 (After Cash and Wailes) e. Diplophrys archeri. X700 (After Hertwig and Lesser). f. Amphitrema flavum. X355 (After Cash and Wailes). 234 HANDBOOK OF PROTOZOOLOGY Genus Rhynchogromia Rhumbler. Test rigid or flexible, chitinous, and elongate, with foreign bodies. Aperture terminal or slightly oblique. Finely granulated cytoplasm fills the test. Nucleus one or more. One to several contractile vacuoles. Pseudopodia arise from a peduncle; numerous, branching or anastomosing; often enveloping the test. Rhynchogromia nigricans (Penard) (Fig. 93, d). Test large; circular in cross-section. With a single nucleus. Length 220 to 400 microns. In submerged moss in ponds. Genus Diplophrys Barker. Test thin, spherical; aperture two, located at opposite poles. Cytoplasm colorless; a single nucleus; several contractile vacuoles. Filopodia radiating. One species. Diplophrys archeri Barker (Fig. 93, e). Invariably with one, two, or three colored oil droplets. Pseudopodia highly attenu- ated, radiating, straight or branched. Multiplication into two or four daughter individuals. Solitary or colonial. Diameter 8 to 20 microns. In submerged plants in fresh water. Genus Amphitrema Archer. Test ovoid, symmetrical, com- pressed; composed of a transparent membrane, with or without adherent foreign bodies. Aperture two, located at opposite poles. The endoplasm contains Zoochlorellae. A central nuc- leus; one to several contractile vacuoles. Straight filopodia, sparsely branched, radiating. Several species. Amphitrema flavum (Archer) (Fig. 93,/). Test chitinoid, brown, cylindrical with equally rounded ends in front view; elliptical in profile; ovoid with a small central oval aperture in end-view. Size about 45 to 80 microns long by 23 to 45 microns broad. In Sphagnum. Genus Lecythium Hertwig and Lesser. Test thin, flexible, colorless. Aperture elastic and terminal. Colorless cytoplasm fills the test. A large nucleus located posteriorly. Numerous filopodia, long, branching, not anastomosing. Lecythium hyalinum (Ehrenberg) (Fig. 94, a). Spheroidal. Aperture circular with a short flexible neck. A single contractile vacuole. Diameter 20 to 45 microns. In submerged vegetation. Genus Pseudodifflugia Schlumberger. Test ovoid, usually rigid, with foreign bodies; circular or elliptical in cross-section. Aperture terminal. Granulated cytoplasm colorless or greyish. TESTA CEA 235 A single nucleus, posterior; a single contractile vacuole. Filo- podia long straight or branching, but not anastomosing. Several species. Pseudodifflugia gracilis Schlumberger (Fig. 94, b). Test yellowish or brownish. Subspherical, with fine sand-grains; aperture without neck. About 30 to 55 microns long. In fresh water. Fig. 94 a. Lecythium hyalinum. X500 (After Cash and Wailes). b. Pseudodifflugia gracilis. X500 (After Cash). c. Diaphoropodon mobile. X400 (After Cash and Wailes). d. Clypeolina niarginata. X500 (After Cash and Wailes). Genus Diaphoropodon Archer. Test ovoid flexible, with minute foreign bodies and a thick covering of fine, hyaline hair-like projections ("cil"). Pseudopodia long, filose, branch- ing, but not anastomosing. Diaphoropodon mobile Archer (Fig. 94, c). Test brown; 236 HANDBOOK OF PROTOZOOLOGY aperture terminal, of various shape. Granulated cytoplasm does not fill the test. A single nucleus, large; one or two con- tractile vacuoles. Length 60 to 120 microns; projections 8 to 10 microns long. Among aquatic plants. Genus Clypeolina Penard. Test ovoid, compressed, formed of a double envelope; the outer envelope is composed of two valves with scales and particles; the inner envelope a mem- branous sac. Filopodia long, often branched. Clypeolina marginata Penard (Fig. 94, d). The outer test- valves yellow to dark brown; lenticular in cross-section. Aper- ture terminal, wide. The endoplasm contains numerous small globules. A single nucleus; a contractile vacuole. Length 80 to 150 microns. Among aquatic plants in ponds and marshes. 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. The cytoplasmic body almost fills the test. A single nucleus and numerous contractile vacuoles. Pseudopodia several, cylindrical, simple or branching; end rounded or pointed. Numerous species occur in fresh water, peat, woodland soil and meadows. Difflugia oblonga Ehrenberg { = D. pyriformis Perty) (Fig. 95, a). Test pyriform, flask-shaped, or ovoid; neck variable in length. Fundus rounded with occasionally one to three conical processes. Aperture terminal, typically circular. Test composed of angular sand-grains and diatoms. The cytoplasm contains chlorophyllous bodies and is therefore bright green in color. Length 100 to 300 microns, width 50 to 100 microns. In the ooze of freshwater ponds, ditches and bogs. Also in moist soil. Several varieties. Difflugia urceolata Carter (Fig. 95, 6). A large ovoid, rotund test, with a short neck and a rim around the aperture. Length 200 to 230 microns, breadth 150 to 200 microns. In ditches, ponds, sphagnous swamps, etc. Difflugia arcula Leidy (Fig. 95, c). Test hemispherical, base slightly concave, but not invaginated; aperture triangular, central, trilobed. Test yellowish with scattered sand-grains TESTACEA 237 or diatoms. Diameter 100 to 140 microns. In sphagnous swamp, moss, and soil. Difflugia lobostoma Leidy (Fig. 95, d). Test ovoid to sub- spherical. Aperture terminal; with 3 to 6 lobes. Test usually composed of sand-grains and rarely with diatoms. The endo- plasm is colorless or greenish. Diameter 80 to 120 microns. In ponds, ditches, soil, and moss. Fig. 95 a. Difflugia oblonga. XlOO (After Cash). b. D. urceolata. XlOO (After Leidy). c. D. arcula. X125 (After Leidy). d. D. lobostoma. XlOO (After Leidy). e. D. constricta. X150 (After Cash). f. Centra pyxis aculeata. X 150 (After Cash). g. Cucurbitella mespiliformis. X 150 (After Wailes). h. Plagiopyxis callida. X150 (After Wailes). i. Pontigulasia vas. X150 (After Cash), j. Phryganella acropodia. X 140 (After Cash), k. Bullinula indica. XlOO (After Wailes). 1. Heleopera petricola. X 140 (After Cash). Difflugia constricta (Ehrenberg) (Fig. 95, e). Test laterally ovoid, fundus more or less prolonged obliquely upward, rounded, and simple or provided with spines. Soil forms are spineless. Aperture antero-inferior, large, circular or oval and its edge inverted. Test composed of quartz sand-grains. Colorless to 238 HANDBOOK OF PROTOZOOLOGY brown. The cytoplasm is colorless. Length 80 to 340 microns. In the ooze of ponds and in soil. Genus Centropyxis Stein. Test circular, ovoid, or discoid. Aperture eccentric, circular or ovoidal, often with a lobate border. With or without spines. The cytoplasm is colorless; pseudopodia digitate. Centropyxis aculeata Stein (Fig. 95,/). Test variable in con- tour and size; with 4 to 6 spines; opaque or semi-translucent; with fine sand-grains or diatom shells. Pseudopodia sometimes knotted or branching. When encysted, the protoplasm assumes a spherical form in the thicker part of the test ; granulated, color- less or with green globules. Diameter 100 to 150 microns; aper- ture 50 to 60 microns. Genus Cucurbitella Penard. Test ovoid with sand grains, not compressed; aperture terminal, circular, surrounded by a four-lobed annular collar. The cytoplasm is grey, granular, and contains symbionts, the Zoochlorellae. A single large nucleus; one to many contractile vacuoles; pseudopodia numerous, digitate. Cucurbitella mespiliformis Penard (Fig. 95, g). Length 115 to 140 microns; diameter 80 to 105 microns. In the ooze or on vegetation in ponds and ditches. Genus Plagiopyxis Penard. Test sub-circular in dorsal view; ovoid in profile; aperture linear or lunate. Cytoplasm grey, with a single nucleus and a contractile vacuole. Plagiopyxis callida Penard (Fig. 95, h). Test grey, yellowish, or brown. A large vesicular nucleus; pseudopodia numerous, radiating, short, pointed or palmate. Diameter 55 to 135 microns. Genus Pontigulasia Rhumbler. Test similar to that of DifBugia, but with a constriction of the neck and internal to it, a diaphragm made of the same substances as those of the test. Pontigulasia vas (Leidy) (Fig. 95, i). Test rounded or ovoid, constriction deep and well-marked; with sand-grains and other material. Aperture terminal. Length 125 to 170 microns. Fresh water ponds. Genus Phryganella Penard. Test spheroidal to ovoid, with sand-grains and minute diatom shells. Aperture terminal, TESTACEA 239 rounded. Pseudopodia drawn out to a point. Fresh water bodies. Phryganella acropodia (Hertwig and Lesser) (Fig. 95, j). Test circular in aperture view; hemispherical in profile. Yel- lowish or brownish, semi-transparent, and covered with sand- grains and scales. Aperture terminal. In aperture view, the sharply pointed pseudopodia radiating. Colorless endoplasm contains a single nucleus and a variable number of chlorophyl- lous bodies. Diameter 30 to 50 microns. In the sphagnous ooze of ponds and ditches. Genus BuUinula Penard. Test ellipsoidal, flattened on one face, with silicious plates. On the flattened surface, oo- shaped aperture. A single nucleus; pseudopodia digitate or spatulate, simple or branched. BuUinula indica Penard (Fig. 95, k). Test dark brownish. Diameter 140 to 250 microns. In sphagnum and other mosses. Genus Heleopera Leidy. Test variable in color; fundus hemi-spherical, almost always with sand-grains. Test surface covered with amorphous scales, often overlapping. Aperture truncate, narrow, elliptic, notched in narrow lateral view. A single nucleus; pseudopodia variable in number, thin, digi- tate or branching. Fresh water. Heleopera petricola Leidy (Fig. 95, l). Test variable in size and color, strongly compressed; fundus rough with sand-grains of various size. Aperture linear or elliptic, its edge thin, convex in front view. A single nucleus posterior. Pseudopodia numer- ous, slender, branching. Length 80 to 100 microns. In sphag- num and boggy places. Genus Averintzia Schouteden. Test similar to that of Heleopera, but small aperture elliptical. Test thickened around the aperture. Averintzia cyclostoma (Penard). Test dark violet color, with sand-grains of different size; elliptical in cross-section. Pseudo- podia unobserved. Length 135 to 180 microns. In sphagnum and other aquatic plants. Family 4 Euglyphidae Wallich Genus Euglypha Dujardin. Test hyaline, ovoid, composed of circular, oval, or scutiform silicious imbricated scales, ar- 240 HANDBOOK OF PROTOZOOLOGY ranged in longitudinal rows; aperture bordered with regularly arranged denticulate scales. Usually with spines. One or two nuclei large, placed centrally; contractile vacuoles. Filopodia, dichotomously branched. Numerous species. Euglypha acanthophora (Ehrenberg) ( = E. alveolata Du- jardin) (Fig. 1). Test ovoid, or slightly elongate toward the aperture. 3 to 7 scales protruding around the circular aperture. Body-scales elliptical. The cytoplasm almost fills the test. Length 50 to 100 microns. In sphagnum and submerged plants. Euglypha cristata Leidy (Fig. 96, a). Elongated test small, not compressed, with a long neck, fundus rounded with 3 to 8 spines.. Scales oval. Aperture circular and bordered by a single row of 5 or 6 denticulated scales. Cytoplasm colorless. A single posterior nucleus. Filopodia fine. Reserve scales are collected around the exterior of the aperture, unlike other forms in which they are kept within the cytoplasm. Length 30 to 70 microns; diameter 10 to 25 microns. In mosses. Euglypha mucronata Leidy (Fig. 96, h). Test large, fundus conical, with one or two terminal spines. Aperture circular bordered by a single row of 6 to 8 denticulated scales. Length 100 to 150 microns; diameter 30 to 60 microns. In sphagnum. Genus Paulinella Lauterborn. Test small ovoid, not com- pressed; with silicious plates in alternating transverse rows. Aperture terminal. The body cytoplasm does not fill the test completely. A single nucleus located posteriorly. Paulinella chromatophora Lauterborn (Fig. 96, c). Scales arranged in 11 or 12 rows, five plates in each row. The cyto- plasm with one or two curved chromatophores; no food par- ticles. One contractile vacuole. Length 20 to 32 microns; diameter 14 to 23 microns. Among vegetation of fresh or brackish water. Genus C3rphoderia Schlumberger. Test retort-shaped; colorless to yellow, made up of a thin chitinous membrane covered with discs or scales. Aperture terminal, oblique, circular. The cytoplasm does not fill the test completely. Nucleus large, posteriorly located. Pseudopodia few, long, filose, simple or branched. Cyphoderia ampulla (Ehrenberg) (Fig. 96, d). Test usually yellow, translucent, composed of discs arranged in diagonal TESTACEA 241 rows. Circular in cross-section. Aperture circular; oblique. Cytoplasm grey, contains many granules and food particles. A single nucleus; two contractile vacuoles. Pseudopodia long straight or curved filopodia. Length 60 to 200 microns; diame- ter 30 to 70 microns. Genus Campascus Leidy. Test retort-shaped with curved neck, rounded triangular in cross-section. Aperture circular, oblique, with a thin transparent discoid collar. Fig. 96 a. Euglypha cristata. X250 (After Wailes). b. E. mucronata. X2S0 (After Wailes). c. PauUnella chromatophora. X750 (After Wailes). d. Cyphoderia ampulla. XI 50 (After Cash). e. Camptiscus corniitus. X 125 (After Leidy). f. Trinema enchelys. X250 (After Wailes). Campascus cornutus Leidy (Fig. 96, e). Test pale-yellow, retort-shaped ; with a covering of small sand particles ; triangular in cross-section. A single nucleus and a contractile vacuole. Filopodia straight. Length 110 to 140 microns. In the ooze of mountain lakes. Genus Trinema Dujardin. Test small, hyaline, ovoid, com- pressed anteriorly, with circular silicious plates. Aperture circular, oblique, invaginated. A single nucleus placed pos- teriorly. Filopodia not branched. 242 HANDBOOK OF PROTOZOOLOGY Trinema enchelys (Ehrenberg) (Fig. 96, /). One or two contractile vacuoles ; pseudopodia attenuate, radiating and long. Length 30 to 100 microns, breadth 15 to 60 microns. In mosses and other vegetation. Genus Cor3rthion Taranek. Test small, hyaline, composed of small oval silicious plates; compressed; elliptical in optical cross-section. Aperture subterminal, ventral or oblique; circular or oval. Numerous filopodia. Fig. 97 a. Corythion pulchellum. X350 (After Wailes). b. Placocista spinosa. X200 (After Wailes). c. Assulina seminulum. X400 (After Wailes). d. Nebela collaris. X200 (After Cash). e. Quadrula symmetrica. X200 (After Cash). Corythion pulchellum Penard (Fig. 97, a). Aperture lenticu- lar, cytoplasm colorless. Contractile vacuoles 2 to 3. 25 to 35 microns long by 15 to 20 microns broad. In mosses. Genus Placocista Leidy. Test ovoid, hyaline, compressed; lenticular in optical cross-section, with oval or subcircular silicious scales. Aperture wide, linear, with flexible undulate borders. A large nucleus posterior. Often with Zoochlorellae. Pseudopodia filose, branching and numerous, generally arising from a protruded portion of the cytoplasm. Placocista spinosa (Carter) (Fig. 97, b). Margin of the test with spines, either single or in pairs. Two contractile TESTA CEA 243 vacuoles; cytoplasm colorless, but occasionally with Zoochlorel- lae. Several filopodia, branching. Test 115 to 170 microns long by 70 to 100 microns wide. In sphagnum. Genus Assulina Ehrenberg. Test brown or colorless, ovoid, compressed, with elliptical scales, arranged in diagonal rows. Aperture oval, terminal, bordered by a thin chitinous dentate membrane. A single nucleus is located posteriorly; contractile vacuoles. Several filopodia, divergent, sometimes branched. Assulina seminuliim (Ehrenberg) (Fig. 97, c). Protoplasm not completely filling up the test, with numerous food particles; one contractile vacuole. Pseudopodia few, straight, divergent, slender, seldom branched. Test 60 to 150 microns long by 50 to 75 microns broad. In mosses. Genus Nebela Leidy. Test thin, ovate or pyriform; com- pressed, with circular or oval plates or discs of uniform or various size; highly irregular. The endoplasm with oil-globules; a single nucleus posterior. The protoplasm does not fill the test and is connected with the latter by numerous ectoplasmic strands at the fundus end. Pseudopodia blunt, rarely branched. Numerous species. Nebela collaris (Ehrenberg) (Fig. 97, d). Test pyriform, fundus obtuse in profile, aperture without any notch. The endoplasm contains chlorophyllous food particles. Pseudopodia digitate, short, usually 3 to 6 in number. Test 130 microns long by 85 to 90 microns broad. In marshes among sphagnum. Genus Quadrula Schulze. Test pyriform, hemi-spherical, or discoidal, consisting of a homogeneous chitinous film, with quadrangular silicious or calcareous plates, arranged generally in oblique series, not overlapping. A single nucleus. The body and pseudopodia similar to those of Difflugia. Fresh water. Quadrula symmetrica (Wallich) (Fig. 97, e). Compressed, smaller plates near the aperture. The cytoplasm very clear, containing chlorophyllous granules. Three to five pseudopodia digitate. A single nucleus posterior. Test about 95 microns long by 60 to 70 microns broad. In sphagnum and other mosses. References Cash, J. 1905, 1909 The British freshwater Rhizopoda and Heliozoa. Vols. 1, 2. 244 HANDBOOK OF PROTOZOOLOGY Cash, J. and G. H. Wailes. 1915, 1918 The British fresh- water Rhizopoda and HeHozoa. Vols. 3, 4. Deflandre, G. 1928 Le genre Arcella Ehrenberg. Arch f. Protistenk., Vol. 64. GoETTE, A. 1916 Ueber den Lebenscyclus von Difflttgia lohostoma. Arch. f. Protistenk., Vol. 37. Hegner, R. W. 1920 The relations between nuclear number, chromatin mass, cytoplasmic mass, and shell characteristics in four species of the genus Arcella. Jour. Exper. Zool., Vol. 30. Jennings, H. S. 1916 Heredity, variation and the results of selection in the uniparental reproduction of Diffliigia corona. Genetics. Vol. 1. Leidy, J. 1879 Freshwater Rhizopods of North America. Rep. U. S. Geol. Survey. Vol. 12. Penard, E. 1905 Les Sarcodines des Grands Lacs. Geneva. CHAPTER XIX SUBCLASS 2 ACTINOPODA CALKINS THE SARCODINA placed in this subclass possess axopodia and are divided into two orders: the Heliozoa and the Radio- laria. ORDER 1 HELIOZOA HAECKEL The Heliozoa are, as a rule, spherical in form with radiating axopodia. They are somewhat similar in appearance to the Radiolaria, but do not possess the central capsule of the latter. The body of a typical heliozoan, such as Actinophrys, is spherical when undisturbed and shows numerous radiating axopodia. The cytoplasm is differentiated, distinctly in Actinosphaerium, or indistinctly in other forms, into the coarsely vacuolated ectoplasm and the less transparent and highly vacuolated endoplasm, in which is located the nucleus. The food of the Heliozoa consists of living Protozoa or Protophyta. Thus their mode of obtaining nourishment is holozoic. 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 axo- podium, it seems to become suddenly paralyzed and, there- fore, 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 digested. The ectoplasm contains several contractile vacuoles and numerous refractile granules which are scattered throughout. The endoplasm is denser and is usually devoid of granules. In the axopodium, the cytoplasm undergoes streaming move- ments. 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. [245 1 246 HANDBOOK OF PROTOZOOLOGY When the pseudopodium is withdrawn, its axial filament dis- appears completely. The latter sometimes disappears without the withdrawal of the pseudopodium itself. In Acanthocystis the nucleus is eccentric (Fig. 100, b). There is, however, a central granule, or centroplast, in the center of the body from which radiate the axial filaments of the axopodia. In multinucleate Actinosphaerium, the axial filaments terminate at the periphery of the endoplasm. In Camptonema, an axial filament arises from each of the numer- ous nuclei (Fig. 98, c). The skeletal structure of the Heliozoa varies among dif- ferent species. The body may be naked, covered by a gelatinous mantle, or provided with a lattice-test with or without spicules. The spicules are variable in form and location and may be used for specific difterentiation. In some forms there occur colored bodies bearing chromatophores, which are considered as holophytic Mastigophora living in the Heliozoa as symbionts. The Heliozoa multiply by binary fission or budding. In- complete division may result in the formation of colonies, as in Rhaphidiophrys. In Actinosphaerium, mitotic division of the nucleus has been observed by Hertwig, who described the appearance of some 150 chromosomes, conspicuous centrosomes, and spindle fibers. In Acanthocystis and Oxnerella (Fig. 19), the central granule behaves somewhat like the centrosome in a metazoan mitosis. Budding has been known in numerous species. In Acanthocystis the nucleus undergoes amitosis several times, thus forming several nuclei, one of which re- mains in place while the others migrate toward the body sur- face. Each peripheral nucleus becomes surrounded by a protruding 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 granule being produced from the nucleus during the growth. Formation of swarmers is known in a few genera. Sexual reproduction occurs in some forms (p. 57). The Heliozoa live chiefly in fresh water, although some in- habit the sea. Only a few are attached forms. According to Hertwig and Lesser, the Heliozoa are here divided into four suborders: HELIOZOA 247 Without skeleton; no jelly mantle Suborder 1 Aphrothoraca With gelatinous mantle; no silicious spicules Suborder 2 Chlamydophora With isolated or united spicules Suborder 3 Chalarothoraca Skeleton glubular, silicious with many apertures. . .Suborder 4 Desmothoraca Suborder 1 Aphrothoraca Hertwig Without envelope or skeleton in the active stage; envelope in encysted stage. Fig. 98 a. Actinophrys sol. X265. b. Actinosphaerium eichhorni. X30. c. Camptonema nutans. X230 (After Schaudinn). Genus Actinophrys Ehrenberg. Spherical with a smooth membranous envelope; cytoplasm vacuolated, especially ecto- plasm. With symbiotic Zoochlorellae. A central nucleus; one large contractile vacuole. Axopodia straight, numerous, axial filament arising from the surface of the nucleus. "Sun animal- cules." Several species. Actinophrys sol Ehrenberg (Fig. 98, a). Spherical. Ecto- plasm contains numerous large vacuoles; endoplasm granulated with numerous small vacuoles. A large central nucleus. Solitary but may be colonial when young. Body diameter 40 to 50 microns. Among plants in still fresh water. Genus Actinosphaerium Stein. Spherical. Ectoplasm con- sists almost entirely of large vacuoles in one or several layers; endoplasm with numerous small vacuoles. Numerous nuclei. Axial filaments of the pseudopodia end in the ectoplasm. Two species. Actinosphaerium eichhorni Ehrenberg (Fig. 98, h). Numer- ous nuclei scattered in the peripheral portion of the endoplasm. 248 HANDBOOK OF PROTOZOOLOGY Two or more contractile vacuoles large. Axial filaments arise from a narrow zone of dense cytoplasm at the border line be- tween endoplasm and ectoplasm. Body large, diameter 80 to 1000 microns. Among aquatic plants in freshwater ponds. Genus Camptonema Schaudinn. Body spheroidal. Axial filaments of axopodia end in the nuclei which are about 50 in number. Contractile vacuoles (?) numerous and small in size. Marine. Camptonema nutatis Schaudinn (Fig. 98, c). About 150 microns 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 vacuoles. Nuclear division is typical mitosis (Fig. 19). Oxnerella maritima Dobell (Fig. 19). Small, diameter 10 to 22 microns. Solitary, floating or creeping. Salt water. Suborder 2 Chlamydophora Archer Body is covered by a gelatinous envelope containing no silicious scales. Genus Astrodisculus GreefT. Spherical with gelatinous en- velope, free from inclusions, sometimes absent. No demarcation between the two regions of the cytoplasm. Freshwater inhabi- tants. Four species. Astrodisculus radians Greeff (Fig. 99, a). Outer surface of the investment often with adherent foreign bodies and bacteria. The cytoplasm is often loaded with green, yellow, or brown granules. A single nucleus eccentric; a contractile vacuole. Diameter of body 13 to 25 microns. In pools and ditches. Genus Actinolophus Schulze. Body pyriform, enveloped in a gelatinous mantle. With a stalk which is apparently hollow. Axopodia long and numerous. An eccentric nucleus. Marine. Actinolophus pedunculatus Schulze (Fig. 99, h). Diameter 30 microns. Stalk about 100 microns long. In marine water. Genus Heterophrys Archer. Body spherical, mucilaginous envelope thick, with numerous radial, chitinoid spicules which project beyond its periphery; nucleus single, eccentric. Axial filaments of axopodia originate in a central granule. Four species. HELIOZOA 249 Fig. 99 a. Astrodisculus radians. X600 (After Penard). b. Actinoloplms pedunculatiis. X400 (After Schultze). c. Heterophrys myriopoda. X250 (After Calkins). d. Elaeorhanis ocidea. X300 (After Penard). e. LithocoUa globosa. X250 (After Penard). f. Sphaerasirum fockei. X300 (After Stubenrauch). 250 HANDBOOK OF PROTOZOOLOGY Heterophrys myriopoda Archer (Fig. 99, c). Endoplasm and nucleus eccentric; ectoplasm is loaded with spherical algae, living probably as symbionts. Contractile vacuoles indistinct. Diameter 50 to 80 microns. In pools and marshes, and also among marine algae. Genus Elaeorhanis Greeff. Body spherical. Mucilaginous envelope with sand-grains and diatom frustules. The cytoplasm with a large oil globule; a single nucleus, eccentric; one or more contractile vacuoles; pseudopodia not granular. One species. Elaeorhanis oculea (Archer) (Fig. 99, d). The cytoplasm bluish with a large yellow oil globule; without any food par- ticles. No central granule. Pseudopodia rigid, but apparently without axial filament (?), sometimes forked. Young forms are colonial; solitary when old. Outer diameter 50 to 60 microns, body itself 25 to 30 microns. In lakes and pools. Genus LithocoUa Schulze. Spherical body; outer envelope with usually one layer of sand-grains and diatom frustules. No oil globule. Nucelus eccentric. Two species. LithocoUa glohosa Schulze (Fig. 99, e). The ectoplasm is reddish in color with numerous small colored granules. Nucleus large; central granule is unknown. Diameter of envelope 35 to 50 microns. In lakes, ponds, and rivers; also in brackish water. Genus Sphaerastrum Greeff. Body somewhat flattened. The greater part of the axopodia and the body are covered by a thick gelatinous mantle. A central granule and an eccentric nucleus. Sphaerastrum fockei Greeft" (Fig. 99,/). Diameter about 30 microns. Often colonial. In swamps. Suborder 3 Chalarothoraca Hertwig and Lesser Heliozoa with isolated or united spicules. Genus Pompholyxophrys Archer. Spherical body; outer mucilaginous envelope with minute colorless spherical granules arranged in concentric layers. Nucleus single, eccentric; con- tractile vacuoles. Pseudopodia long, straight, acicular. Pompholyxophrys punicea Archer (Fig. 100, a). The cyto- plasm colorless or reddish, with usually many colored granules and green to brown food particles; nucleus large, eccentric. IIELIOZOA 251 Solitary, active. Diameter 25 to vS5 microns. Outer envelope 5 to 10 microns larger. In pools. Genus Acanthocystis Carter. Spherical without mucila- ginous mantle, but with silicious scales arranged tangentially and radiating silicious spines with ends pointed or bifurcated. Nucleus and endoplasm eccentric. The central granule distinct. Several species. Fig. 100 a. Pompholyxophrys punicea. XI 70 (After West). b. Acanthocystis aculeata. X200 (After Stern). c. Raphidiophrys pallida. X200 (After Penard). d. Raphidiocystis tubifera. X330 (After Penard). e. Wagnerella borealis. X50 (After Kiihn). f. Pinaciophora fluviatilis. X165 (After Penard). Acanthocystis aculeata Hertwig and Lesser (Fig. 100, h). Tangential scales stout and pointed, curved and nail-headed. The cytoplasm greyish; nucleus eccentric; a single contractile vacuole. Diameter 35 to 40 microns. Spines about one-third the diameter of body. In lakes, ponds, and pools. Genus Raphidiophrys Archer. Spherical. Mucilaginous en- velope with spindle-shaped or discoidal spicules which extend normally outwards along the pseudopodia. Nucleus and endoplasm eccentric. Solitary or colonial. Several species. Raphidiophrys pallida Schulze (Fig. 100, c). Outer gela- tinous envelope crowded with curved lenticular spicules, form- 252 HANDBOOK OF PROTOZOOLOGY ing accumulations around the pseudopodia. Ectoplasm granu- lated; nucleus eccentric. Contractile vacuoles. Axial filaments arise from the central granule. Solitary. Diameter 50 to 60 microns. In vegetation in still water. Genus Raphidiocystis Penard. Spicules unlike those oc- curring in the last genus. With radiating needle-like spicules. Raphidiocystis tubifera Penard (Fig. 100, d). With charac- teristic spicules. Body diameter about 18 microns; envelope 25 microns. Fresh water. Genus Wagnerella Mereschkowsky. Body spherical, sup- ported by a cylindrical stalk with an enlarged base. Small silicious spicules. The nucleus is located in the base of the stalk. Reproduction through budding. Wagnerella borealis Mereschkowsky (Fig. 100, e). Body up to 180 microns in diameter. Stalk often up to 1.1 mm. in length. In marine water. Genus Pinaciophora Greeff. Spherical. Outer envelope is composed of imbricated circular discs, each being perforated with nineteen minute pores. Cytoplasm reddish. One species. Pinaciophora fluviatilis Greeff (Fig. 100,/). Diameter 45 to 50 microns, but somewhat variable. In ponds. Suborder 4 Desmothoraca Hertwig and Lesser Homogeneous capsule, with or without perforation, often with a pedicel or stalk. Genus Clathrulina Cienkowski. Envelope spherical, homo- geneous, with numerous openings regularly arranged. With a stalk. Body protoplasm central, not filling the capsule. The single nucleus centrally located. Pseudopodia numerous, straight or forked, granular. A few species. Clathrulina elegans Cienkowski (Fig. 101, a). Envelope colorless to brown, perforated by numerous comparatively large openings which are circular or polygonal. One or more contractile vacuoles. Nucleus central. Diameter 30 to 90 microns; openings 6 to 10 microns; stalk 120 to 350 microns long by 3 or 4 microns wide. Solitary or colonial. Among vegetation in ponds and pools. Genus Hedriocystis Hertwig and Lesser. Envelope spheri- HELIOZOA 253 cal, openings minute, surrounded by polyhedral facets or ridges. With stalk. Solitary or colonial. Thiee species. Hedriocystis reticulata Penard (Fig. 101, h). Envelope colorless or pale yellow, proliferations regularly polygonal with raised borders. Stalk solid, straight; a single nucleus, located near the center; one contractile vacuole. Axopodia(?), each arising from a pore in the center of a facet. Solitary. Capsule about 25 microns in diameter; body about 12 microns in diam- eter; stalk about 70 microns long by 1 to 1.5 microns in width. In marshy pools. Genus Choanocystis Penard. Spherical envelope with per- forations which possess conical borders; the openings of the cones are provided with funnel-like extensions, the edges of which nearly touch one another. Fig. 101 a. Clathrulina elegans. X165 (After Leidy). b. Hedriocystis reticulata. X330 (After Brown from Cash). c. Choanocystis lepidula. X460 (After Penard). Choanocystis lepidula Penard (Fig. 101, c). Diameter 10 to 13 microns. In freshwater body. References Belar, K. 1922, 1924 Untersuchungen an Actinophrys sol Ehrenberg. I, II. Arch. f. Protistenk., Vols. 46, 48. Cash, J. and G. H. Wailes. 1921 The British freshwater Rhizopoda and Heliozoa. Vol. 5. London. KtJHN, A. 1926 Morphologic der Tiere in Bildern. 2 H., 2 T. Rhizopoden. Berlin. Leidy, J. 1879 Freshwater Rhizopods of North America. Rep. U. S. Geol. Survey. Vol. 12. Penard, E. 1904 Les Heliozoaires d'eau douce. Geneva. 1905 Les Sarcodines des Grands Lacs. Geneva. CHAPTER XX ORDER 2 RADIOLARIA MULLER THE RADIOLARIA are pelagic forms found abundantly in the sea. A very large number of species occur in various oceans. In fact a vast area of the ocean floor is 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 forma- tions. Thus this group is the second group of Protozoa impor- tant to geologists. The body is mostly spherical in form, although radially or bilaterally symmetrical forms are also encountered. The cyto- plasm is divided into two distinct 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 the use of reagents. Its shape varies accord- ing to the form of the organism. In spherical forms it is spheri- cal, 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 animal 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 and contains reserve food material, while the extracapsular portion is nutritive and hydrostatic in function. The intracapsular cytoplasm is granulated, often greatly vacuo- lated, and is stratified 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 structure, vary among different species and also at different stages of development even in one and the same species. [254] ] RADIOLARIA 255 A thin assimilative layer, or matrix, surrounds the central capsule. In Tripylea, waste material forms a brownish mass, known as the 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 vertical movement of some Radiolaria is due to the forma- tion and expulsion of a fluid which consists of water saturated with carbon dioxide. Under ordinary weather and temperature conditions, the interchange between the alveoli and the ex- terior 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 in extraordinary tempera- ture, the pseudopodia are withdrawn, the alveoli burst, and the organisms descend into deeper water, where the alveoli are formed again. The Radiolaria feed on microplankton such as copepods, diatoms, and other Protozoa. The food is taken in through the pseudopodia and passed down into the deeper region of the calymma where it is digested in a food vacuole. The Radio- laria 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, although they are, as a rule, located in the calymma. In Actipylea they are found only in the intracap- sular cytoplasm, and in Tripylea they are absent altogether. They are spherical bodies, about 15 microns in diameter, with a cellulose wall, two chromatophores, a pyrenoid, starch, and a single nucleus. They appear to multiply by fission. These bodies are considered as Zooxanthellae (p. 93). In the absence of organic food material, the Radiolaria use the products of the holophytic nutrition of these symbiotic organisms. The axopodia arise either from the extracapsular cytoplasm or from the intracapsular 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. 103, c). They connect the peripheral portion of the body with the pseudopodial covering of the spicule and 256 HANDBOOK OF PROTOZOOLOGY possess a great contractile power, supposedly with hydrostatic function. The skeletal structure of the Radiolaria varies considerably from simple to complex and has taxonomic value. The chemical nature of the skeleton is used in distinguishing the major sub- divisions of the group. 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 silicious substances. The skeleton of the Actipylea is sharply marked from that of others in form and structure. The ma- jority of this group possess twenty rods arranged in a diverse way, and radiating from the center. The rod-shaped skeletons emerge from the body in most cases along five circles, which are comparable to the equatorial, the two tropical and the two circumpolar circles of the globe. This is known as Miiller's law, since J. Miiller first noticed the arrangement in 1858. The life history of the Radiolaria is very incompletely known (Fig. 102). Binary or multiple fission or budding has been observed in some Peripylea, Actipylea, and Tripylea. Multiple division is known to occur in Thalassophysidae, in which it is the only known means of reproduction. The central capsule becomes very irregular in its outline and the nucleus breaks up into numerous chromatin globules. Finally the cap- sule and the intracapsular cytoplasm become transformed into numerous small bodies, each containing several nuclei. Fur- ther changes are unknown. Formation of swarmers is known in some forms. In Thal- lassicolla, the central capsule becomes separated from the re- maining part of the body and the nucleus divides into a number of small nuclei, around each of which condenses a small ovoidal mass of cytoplasm. These small bodies soon develop flagella. In the meantime the capsule descends to a depth of several hundred meters, where its wall bursts and the flagellate swar- mers are liberated. Two kinds of swarmers, isoswarmers and anisoswarmers, are recognized. 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, while the microswarmers contain a granular nucleus. Some forms possess two flagella, one of which is coiled around the RADIOL ARIA 257 groove of the body, which makes them resemble certain Dino- flagellida. Further development is unknown; it is, however, supposed that the anisoswarmers are sexual and isoswarmers are asexual generations. Fig. 102 The life-cycle of Actipylea. (After Kiihn, modified). a, grown individual; b, c, binary fission; d, e, budding process; f, adult individual similar to a; g, formation of swarmers; h-j, supposed, but not ob- served, gametogony of two swarmers producing a zygote; k, 1, young individu- als. Enormous number of species of the Radiolaria are now known. An outline of the classification is given below, together with a few examples of the genera. 258 HANDBOOK OF PROTOZOOLOGY Skeleton composed of strontium sulphate Suborder 1 Actipylea Skeleton not composed of strontium sulphate The central capsule uniformly perforated; skeletons are either tangential to the capsule or radiating without reaching the intracapsular region Suborder 2 Peripylea The central capsule not uniformly perforated The capsule monaxonic which bears at one pole a perforated plate form- ing the base of an inward directed cone Suborder 3 Monopylea The capsule with three openings (one astropyle and two parapyles) .... Suborder 4 Tripylea Suborder 1 Actipylea Hertwig Radial spines, 10 to 200, not arranged according to Muller's law Legion 1 Actinelida Spines radiate from a common center. Haeckel considered these as the ancestral forms Family 1 Actineliidae Genus Actinelius (Fig. 103, a) With 10 to 16 diametral spines irregularly arranged Family 2 Acanthociasmidae h \\ /Y Fig. 103 a. Actinelius primordialis . X24 (After Haeckel). b. Acanthociasma planum. X65 (After Miehk). c. Acanthometron elasticum. (After Hertwig). d. Acanthoma tetracopa. X40 (After Schewiakoff). e. Amphilonche hydrometrica. X130 (After Haeckel). f. Hexaconus serratus. XlOO (After Haeckel) (From Kiihn). Genus Acanthociasma (Fig. 103, h) Radial spines few, arranged according to Muller's law; without tangential skeletons Legion 2 Acanthometrida RADIOLARIA 259 Spines more or less uniform in size Spicules circular in cross-section Family 1 Acanthometridae Genus Acanthometron (Fig. 103, c) Spicules cruciform in cross-section Family 2 Acanthoniidae Genus Acanthoma (Fig. 103, d) Two opposite spines much larger Family 3 Amphilonchidae Genus Amphilonche (Fig. 103, e) Radial spines few, arranged according to Muller's law; with tangential skele- tons Legion 3 Acanthophractida 20 radial spines of equal size; shell composed of small plates, each with one pore Family 1 Sphaerocapsidae Genus Sphaerocapsa Two or six larger spines Two enormously large conical sheathed spines. . .Family 2 Diploconidae Genus Diploconus Six large spines Family 3 Hexalaspidae Genus Hexaconus (Fig. 103,/) Suborder 2 Peripylea Hertwig Solitary; skeleton wanting or simple spicules; mostly spherical Legion 1 Collodaria The nucleus spherical with smooth membrane With intracapsular vacuoles; with or without spicules Family 1 Physematiidae Genus Lampoxanthium (Fig. 104, a) With extracapsular vacuoles; with or without spicules Family 2 ThalassicoUidae Genus Thalassicolla (Fig. 104, h) The nuclear wall not smooth The nuclear wall branching out into pouches; structure similar to the last Family 3 Thalassophysidae Genus Thalassophysa The nuclear wall crenate With a huge double spicule; large forms. .Family 4 Thalassothamnidae Genus Thalassothamnus With a latticed skeleton with branched and thorny spines Family 5 Orosphaeridae 260 HANDBOOK OF PROTOZOOLOGY Genus Orosphaera Solitary; skeleton highly developed and complex; often concentric; small spherical Legion 2 Sphaerellaria Central capsule and skeleton spherical Family 1 Sphaeroidae \ ^\jffyr^:///. -To Fig. 104 a. Lampoxanthium pandora. X20 (After Haeckel). b. Thalassicolla nucleata. X16 (After Huth) (From Kiihn). Genus Hexacontium (Fig. 105, a) Central capsule and skeleton elliptical or cylindrical. .Family 2 Prunoidae Genus Pipetta (Fig. 105, b) Central capsule and skeleton discoidal or lenticular. . . .Family 3 Discoidae ^^^mN:^ ^^tT^"-^ Fig. 105 a. Hexacontium asteracanthion. X130. b. Pipetta tuba. XIOO. c. Staurocyclia phacostaiirus. X130. d. Cenolarus primordialis. XIOO. e. Sphaerozoum ovodimare. y.ii (All after Haeckel from Kiihn). RADIOLARIA 261 Genus Staurocyclia (Fig. 105, c) Similar to the above, but flattened Family 4 Larcoidae Genus Cenolarus (Fig. 105, d) Colonial; individuals with anastomosing extracapsular cytoplasm, embedded in a jelly mass Legion 3 Polycyttaria Without latticed skeleton, but with silicious spicules arranged tangentially to the central capsule Family 1 Sphaerozoidae Genus Sphaerozoum (Fig. 105, e) The 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. 106, a) With skeleton Without a complete latticed skeleton Legion 2 Plectellaria Skeleton a basal tripod Family 1 Plectoidae Fig. 106 a. Cystidium prince ps. X120. b. Triplagia primordialis. X25. c. Lithocircus magnificus. XIOO. d. Dictyophimus hertwigi. X83 (All after Haeckel from Kiihn). Genus Triplagia (Fig. 106, h) Skeleton a simple or multiple sagittal ring Family 2 Stephoidae Genus Lithocircus (Fig. 106, 6) With a complete latticed skeleton Legion 3 Cyrtellaria Lattice skeleton single, without constriction Family 1 Cyrtoidae Genus Dictyophimus (Fig. 106, d) Lattice skeleton is multiple Family 2 Botryoidae Genus Phormobothrys 262 HANDBOOK OF PROTOZOOLOGY Suborder 4 Tripylea Hertwig Without skeleton; with isolated spicules Legion 1 Phaeocystlna Skeleton consists of radial hollow rods and fine tangential needles Family 1 Aulacanthidae Genus Aulacantha (Fig. 107, a) With foreign skeleton covering body surface Family 2 Caementellidae Genus Caementella (Fig. 107, b) With skeleton One or two (concentric) usually spherical skeletons. .Legion 2 Phaeosphaeria Outer lattice skeleton with triangular or areolar meshes Family 1 Sagosphaeridae Genus Sagenoscene One lattice skeleton with hollow radial bars.. Family 2 Aulosphaeridae b // Fig. 107 a. Aulacantha scolymantha. XH (After Kiihn). b. Caementella stapedia. X65 (After Haeckel). c. Aulosphaera labradoriensis. X9 (After Haecker) (From Kiihn). Genus Aulosphaera (Fig. 107, c). Two 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, 108, a) Skeleton smooth or with small spines Family 2 Medusettidae Genus Medusetta (Fig. 108, h) RADIOLARIA 263 One skeleton; spherical or polyhedral, with an opening (phylom) and with radiating spines Legion 4 Phaeocalpia Skeleton spherical or polyhedral, with uniformly distributed large rounded pores Family 1 Castanellidae Genus Castanidium (Fig. 108, c) Skeleton similar to the last, but the base of each radial spine is surrounded by pores Family 2 Circoporidae Genus Circoporus (Fig. 108, d) Skeleton flask-shaped with one or two groups of spines Family 3 Tuscaroridae Fig. 108 a. Challenger on wyvillei. X105 (After Haeckel). b. Medusetta ansata. X230 (After Borgert). c. Castanidium niurrayi. X25 (After Haecker). d. Circoporus octahedriis. X65 (After Haeckel). e. Tuscarora murrayi. X7 (After Haeckel). f. Coelodendrum ramosissimum. X 10 (After Haecker) (From Kiihn). Genus Tuscarora (Fig. 108, e) Central portion of the skeleton consists of two valves Legion 5 Phaeoconchia Valves thin, each with a conical process which divides into branched tubes Family 1 Coelodendridae Genus Coelodendrum (Fig. 108,/) 264 HANDBOOK OF PROTOZOOLOGY References Brandt, K. 1905 Zur Systematikder koloniebildenden Radiolarien. Zool. Jahrb. Suppl., Vol. 8. BoRGERT, A. 1905-1913 Meherere Arbeiten uber Familien der Tripyleen. Ergebnis. d. Planktonexpedition. Vol. 3. Haeckel, E. 1862-1887 Die Radiolarien. Eine Monographic. I, II. 1887 Report 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 XXI CLASS 3 SPOROZOA LEUCKART ALL SPOROZOA are parasitic and produce spores. As a rule, 1\. they are incapable of movement, but some when im- mature move about by means of pseudopodia. They have no cilia or flagella. In the forms that are confined to one host, the spore usually possesses a resistant envelope to withstand unfavorable conditions. In those having two hosts, as in Plas- modium, the sporozoite does not have a definite membrane or wall. The method of nutrition is by osmosis only. The food ma- terial absorbed from the host, may be dissolved cytoplasm, tissue fluid, body fluid, or dissolved food material in the diges- tive tract of the host. Both asexual and sexual reproduction are known in num- erous forms. Asexual reproduction is by binary or multiple fission, or by budding. The rate of division of the trophozoite is much greater than that of protozoans belonging to other classes, and this results in the formation of a large number of individuals. This multiplication is collectively known as the schizogony (or agamogony), and the products are schizonts (or agamonts, merozoites). The sexual reproduction is by isogam- ous or anisogamous copulation or autogamy. This reproduc- tion marks the beginning of the sporogony, or spore-formation, and the initial stages are called gametocytes, or sporonts. In some groups sexual reproduction has not been clearly observed. The Sporozoa are parasitic in animals of almost every phy- lum from Protozoa to Chordata. Numerous important para- sites are, therefore, placed in this group. Schaudinn divided the Sporozoa into two groups, Telosporidia and Neosporidia, and this scheme has been followed by several students. Some recent authors consider these two groups as separate classes. This, however, does not seem to be wise, as the basis of dis- tinction between them is entirely different from that used for [ 265 ] 266 HANDBOOK OF PROTOZOOLOGY distinguishing the other four classes: Sarcodina, Mastigophora, Ciliata, and Suctoria. For this reason, the Sporozoa are put together in a single class and divided into three subclasses as follows: The spore with the polar filament which is typically coiled within a polar capsule Subclass 2 Cnidosporidia The spore without polar filament The spore simple, with one sporozoite; incompletely known Subclass 3 Acnidosporidia Simple spore with one to several sporozoites or without resistant envelope; asexual and sexual reproduction typically alternate . . . Subclass 1 Telosporidia SUBCLASS 1 TELOSPORIDIA SCHAUDINN In this subclass of the Sporozoa the spores have neither polar capsule nor polar filament. Each spore contains one to several sporozoites and is formed at the end of the trophic life of the individual. In the forms which parasitize two hosts, there occur naked sporozoites instead of spores. The infection of a new host begins with the entrance of mature spores through the mouth, or with the introduction of the sporozoites by blood-sucking invertebrates directly into the blood stream, of the host. The sporozoites enter specific host cells and there grow at the expense of the latter. In the Coc- cidia and the Haemosporidia, the trophozoite continues its intracellular existence, but in the Gregarinida it leaves the host cell and grows in an organ cavity of the host. Except Eugre- garinina, the trophozoite of the Telosporidia undergoes schi- zogony and produces a large number of schizonts, or merozoites, which invade new host cells, thus spreading the infection within the host body. The schizonts sooner or later develop into game- tocytes. In the Coccidia and the Haemosporidia, anisogametocytes are often noted. Each macrogametocyte develops into a single macrogamete and each microgametocyte into several micro- gametes. Anisogamy results in the formation of a large number of zygotes. Each zygote develops into a spore which contains one to many sporozoites or into a number of naked sporozoites. In the Gregarinida two fully mature trophozoites (gametocytes) SPOROZOA, TELOSPORIDIA, COCCIDIA 267 encyst together and the nucleus in each divides repeatedly to form numerous gametes. The gametes fuse in pairs with those produced in the other gametocyte within the common envelope. The zygotes develop into spores, each containing 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. The subclass is divided into three orders, as follows: Mature trophozoite intracellular and small Zygote non-motile; sporozoites within spore Order 1 Coccidia Zygote motile; sporozoites without envelope Order 2 Haemosporidia Mature trophozoite extracellular, large; zygote non-motile; sporozoites in spore Order 3 Gregarinida ORDER 1 COCCIDIA LEUCKART The Coccidia show a wide zoological distribution, attacking the vertebrates and higher invertebrates alike. The majority are parasites of the epithelium of the digestive tract and its associated 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. The Coccidia are ordinarily divided into two suborders: Gametocytes similar in size; independent; each microgametocyte de- veloping into numerous microgametes Suborder 1 Eimeridea Gametocytes dissimilar; associated with each other during the latter part of trophic life; a few microgametes Suborder 2 Adeleidea Suborder 1 Eimeridea Leger These Coccidia are, as a rule, intracellular parasites of the epithelium of the digestive tract of the hosts. In many of them, there occurs an alternation of asexual (schizogonic) and sexual (sporogonic) generations. In some there is also alterna- tion of hosts. As an example of the life-cycle of a typical coccidian, that of Eimeria schubergi, a parasite of the intestine of the centipede, Lithohitis forficatus, as worked out by Schaudinn, may be stated here briefly (Fig. 109). The infection begins when the oocysts of the coccidian gain entrance into the host through the mouth. 268 HANDBOOK OF PROTOZOOLOGY 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 the gut epithelium and enter the host cells (a). These schizonts grow into large rounded bodies. The nucleus multiplies in number. The newly formed nuclei move to the body surface, and each becomes surrounded Fig. 109 Scheme of development of Eimeria schuhergi. X400 (After Schaudinn). a, entrance of a sporozoite in the gut epithelium of host and growth of schizont; b, three stages in schizogony to form merozoites, which repeat schizo- gony or; c, become macro- and micro-gametocyte; d, e, formation of macro- gamete; f-h, formation of microgametes; i, mature gametes; j, k, fertilization; 1-n, stages in spore formation; o, oocyst containing four mature spores, each with two sporozoites; p, germination of spores. by a small mass of cytoplasm, forming what is called a mero- zoite. When the host cells rupture, the merozoites are set SPOROZOA, TELOSPORIDIA, COCCIDIA 269 free in the gut lumen, make their way into new host cells and repeat the process {b). Instead of growing into schizonts, some merozoites transform themselves into macro- or micro- gametocytes (c). Each macrogametocyte contains refractile bodies, and becomes mature macrogamete, after extruding part of its nuclear material {d. e). In the microgametocyte, the nucleus divides several times and each division-product as- sumes a compact appearance {f-h). The biflagellate comma- shaped microgametes thus produced, show activity when freed from the host cells {i). A microgamete and a macrogamete unite to form a zygote which secretes a distinct membrane around itself (j). The nucleus divides twice and produces four nuclei (k-m). This stage is known as the oocyst. Each of the four nuclei becomes the center of a sporoblast which secretes a membrane and transforms itself into a spore (n). Its nucleus, in the meantime, undergoes a division, so that two sporozoites become developed in the spore (o). Thus an oocyst of this spec- ies contains four spores and eight sporozoites. Oocysts in the fecal matter of the host become the sources of infection in new hosts. In dividing the suborder into the following four families, Reichenow's scheme has been adopted: Body cylindrical or vermiform ; schizogony in motile stage Family 1 Selenococcidiidae Body not cylindrical nor vermiform Alternation of generations and of hosts Family 2 Aggregatidae No alternation of hosts Association of gametocytes begin early; numerous microgametes. . Family 3 Dobellidae Gametocytes independent Family 4 Eimeriidae Family 1 Selenococcidiidae Leger and Duboscq Genus Selenococcidium Leger and Duboscq. Parasitic in the intestine of the lobster in Europe. The single nucleus of the vermiform trophozoite divides three times, producing eight nuclei. The trophozoite becomes rounded after entering the cell of the gut-epithelium and divides into eight schizonts. This is apparently repeated. From these develop gametocytes. Num- erous microgametes are formed from a microgametocyte. Copu- lation and sporogony unknown. Only one species. 270 HANDBOOK OF PROTOZOOLOGY Selenococcidium intermedium Leger and Duboscq (Fig. 110). Fig. 110 Selenococcidium intermedium. X550 (After Leger and Duboscq). a, a schizont in the host gut; b, c, schizogony; d, microgametocyte; e, microgametes; f, macrogametocyte; g, macrogamete; h, zygote or oocyst. Family 2 Aggregatidae Reichenow Genus Aggregata Frenzel. With alternation of generations and of hosts. The zygote forms numerous spores, each con- taining several sporozoites. Aggregata eherthi (Labbe) (Fig. 111). Schizogony in the crab, Portnnus depurator, and sporogony in the cephalopod. Sepia officinalis. The spore germinates in the digestive tract of the crab {a, b), and the sporozoites undergo growth and schizogony (during which six chromosomes are distinctly visi- ble) in the peri-intestinal connective tissue cells (c, d). When the crab is eaten by a cuttlefish, the merozoites penetrate the gut wall {e) and there develop into micro- and macro-gameto- cytes, and further into gametes. Anisogamy results in zygote- formation (g). The nucleus of the zygote or oocyst shows 12 chromosomes which become divided into two groups of six at the first nuclear division (Dobell, Belaf) {h). Each of these two nuclei undergoes mitotic division repeatedly and produce numerous sporoblasts (i) and finally spores (a). Each spore contains three sporozoites and a residual mass. Several other species have been observed in the same groups of the hosts. Genus Caryotropha Siedlecki. Oocysts develop numerous spores, each with many sporozoites. SPOROZOA, TELOSPORIDIA, COCCIDIA 271 Caryotropha mesnili Siedlecki. In the body cavity of the marine annelid, Polymnia nebulosa. ^ Genus Angeiocystis Brasil. Oocysts develop few spores, each containing about 30 sporozoites. e ) dy Fig. Ill Developmental stages of Aggregala ebertlii. (After Dobell). a. A fully mature spore with three sporozoites. X665. b. A spore germinating in the midgut of the crab. X665. c. A schizont in an epithelial cell of midgut of the same host. X665. d. Section of the midgut of the crab with four cysts containing merozoites. X20. e. A merozoite in a cell of caecal epithelium of Sepia. X330. f. A large cyst with microgametes. X 100. g. Fertilization. X330. h. Reduction division in the zygote. X330. i. A stage in spore-formation. X120. Angeiocystis aitdoniniae Brasil. In the marine worm, Au- doninia tentacidata . Family 3 Dobelliidae Ikeda Genus Dobellia Ikeda. The schizonts are differentiated sexually. Association of the two schizonts for gametogony be- gins early as in the Adeleidea, but numerous microgametes are produced, which condition is not found in the latter group. One species. Dobellia hinucleata Ikeda. In the gut of the sipunculoid Petalostoma minutum. Family 4 Eimeriidae Leger Genus Eimeria Schneider. The zygote develops four spores, each containing two sporozoites. Eimeria schuhergi (Schaudinn) (Fig. 109). 272 HANDBOOK OF PROTOZOOLOGY A. Eimeria in Mammals Eimeria stiedae (Lindemann) (Fig. 112). In the biliary epi- thelium of the liver of rabbits, especially young ones. Heavy infection is believed to be the cause of the death of host animals, which may occur in an epidemic form. The oocyst measures about 20 to 40 microns long. Eimeria zurnii (Rivolta). In the gut-epithelium of cattle. The oocyst is 13 to 28 microns long by 12 to 20 microns broad. Eimeria faurei (Moussu and Marotel) (Fig. 113, a). In sheep and goat. The oocyst is ovoid and measures 20 to 40 microns long by 17 to 26 microns broad. Eimeria debliecki Douwes (Fig. 113, b). In pigs. The ovoid oocysts vary greatly in size. Length 12 to 33 microns, breath 10 to 21 microns. Fig. 112 Eimeria stiedae. a, schizont; b, an epithelial cell with three schi- zonts; c, d, schizogony; e, macrogametocyte (X950 all after Hartmann); f-h, development of oocyst (X625 after Wasielewski). Eimeria canis Wenyon (Fig. 113, c, d). In dogs. The oocyst varies from 18 to 45 microns long by 11 to 28 microns broad. Eimeria felina Nieschulz. In cats. The oocysts are colorless and measure 21 to 26 microns long by 13 to 17 microns wide. Eimeria falciformis (Eimer) (Fig. 113, e). In mice. The oocysts are subspherical and measure 16 to 21 microns by 11 to 17 microns. Eimeria nieschulzi Dieben. In rats. The oocyst measures 18 to 26 microns by 14 to 20 microns. B. Eimeria in Birds Eimeria tenella (Railliet and Lucet) (Fig. 113, /). In the caecum, large intestine, and lower small intestine of chicken. SPOROZOA, TELOSPORIDIA, COCCIDIA in The oocysts are ovoid and measure 20 to 26 microns by 17 to 23 microns. Tyzzer found this species in cases of acute coccidiosis. Einieria mitis Tyzzer (Fig. 113, g). In the upper portion of the small intestine of chicken. The oocysts are subspherical and measure about 16 microns in diameter. Eimeria acervulina Tyzzer (Fig. 113, h). In the small in- testine of chicken. The oocyst oval, measures 18 to 20 microns by 14 to 16 microns. Associated with a serious chronic coccidio- sis (Tyzzer). Eimeria maxima Tyzzer (Fig. 113, i). In the middle por- tion of the small intestine of chicken. The oocyst is oval and measures 22 to 43 microns by 17 to 30 microns. Fig. 113 a. Eimeria faurei. X600 (After Wenyon). b. E. debliecki. X800 (After Wenyon). c, d. E. cams. X485 (After Wenyon). e. E. falciformis. X 550 (After Wenyon). f. E. tenella. X450 (After Tyzzer). g. E. mitis. X325 (After Tyzzer). h. E. acervulina. X325 (After Tyzzer). i. E. maxima. X350 (After Tyzzer). j. E. ranarum. X500 (After Laveran and Mesnil). k. E. ranae. X500 (After Dobell). I. E. prevoti. X500 (After Laveran and Mesnil). m. E. sardinae. X4S0 (After Thomson and Robertson). n. E. clupearum. X450 (After Thomson and Robertson). Eimeria meleagridis Tyzzer. In the caecum of the turkey. The oocyst is about 24 microns by 17 microns. Eimeria meleagrimitis Tyzzer. In the lower portion of the small intestine of the turkey. The oocyst measures about 18 microns by 15 microns. 274 HANDBOOK OF PROTOZOOLOGY C. Eimeria in Amphibians Eimeria ranarum (Labbe) (Fig. 113, j), E. prevoti (Laveran and Mesnil) (Fig. 113, /), and E. ranae Dobell (Fig. 113, k) have been found in the gut-epitheUum of the frog. Eimeria neglecta Noller. In the gut of the tadpole. D. Eimeria in Fish Not infrequently fish are infected by species of Eimeria. When such fish are used for food, coccidian oocysts occurring in them, may appear in human feces and may be mistaken as human parasites. Eimeria sardinae (Thelohan) (Fig. 113, m). In the testis of the sardine. Finding the oocysts which measure 30 to 50 microns in diameter in human stools, Dobell named it Eimeria oxyspora. Eimeria clupearum (Thelohan) (Fig. 113, n). In the liver of herrings, mackerels, and sprats. The oocyst measures 18 to 32) microns in diameter. Dobell found some oocysts of this species in human feces and called it Eimeria wenyoni. Genus Jarrina Leger and Hesse. The oocyst is ovoid; one end is rounded, the other drawn out into a short neck. With four spores, each with two sporozoites. Jarrina paludosa Leger and Hesse. In the intestine of birds, Fidica atra and Gallinula chloropus. The oocyst measures 15 microns by 11 microns. Genus Isospora Schneider. The oocyst produces two spores, each containing four sporozoites. Isospora hominis (Railliet and Lucet) ( = /. belli Wenyon) (Fig. 114, a-c). In the human intestine. The oocysts observed in the feces measure 25 to Z2) microns long. Isospora higemina (Stiles) (Fig. 114, d). In cats and dogs. The oocyst measures 10 to 14 microns by 7 to 9 microns. Isospora rivolta (Grassi) (Fig. 114, e). In cats and dogs. The oocyst measures 20 to 25 microns by 15 to 20 microns. Isospora felis Wenyon (Fig. 114, /). In cats and dogs. The oocyst measures 39 to 48 microns by 26 to 37 microns. Isospora lacazei (Labbe). Many passarine birds seem to be hosts to this coccidian. The oocyst measures 18 to 26 microns by 15 to 20 microns. SPOROZOA, TELOSPORIDIA, COCCIDIA 275 Isospora lieberkuhni (Labbe) (Fig. 114, g). In the kidney of the frog. The oocyst measures about 40 microns long. Genus Cyclospora Schneider. Development similar to that of Eimeria. The zygote develops into an oocyst with two spores, each possessing two sporozoites. Fig. 114 a-c. Isospora hominis. X700 (After Dobell). d. /. higemina. X465 (After Wenyon). e. /. rivolta. X465 (After Wenyon). f. I.felis. X465 (After Wenyon). g. /. lieberkuhni. X330 (After Laveran and Mesnil). Cyclospora caryolytica Schaudinn (Fig. 115, a). In the gut- epithelium of the ground mole. Genus Caryospora Leger. The zygote develops into an oocyst with a single spore containing eight sporozoites. Mem- brane thick and yellow in color. Fig. 115 a. Cyclospora caryolytica. XIOOO (After Schaudinn). b,c. Caryospora simplex. X 600 (After Leger). d. Pfeifferinella ellipsoides. XIOOO (After Wasielewski). e. P. impudica. X600 (After Leger and Hollande). f. Barrouxia ornata. XIOOO (after Schneider). g. Lankesterella minirtia, a mature cyst in an endothelial cell. X750 (After Noller). Caryospora simplex Leger (Fig. 1\5, b, c). In the gut-epi- thelium of the viper, Vipera aspis. Genus Pfeifferinella Wasielewski. The oocyst contains eight sporozoites; without any spore. The macrogamete forms a receiving tube for the microgamete. 276 HANDBOOK OF PROTOZOOLOGY Pfeifferinella ellipsoides Wasielewski (Fig. \\S, d). In the liver of Planorhis cornua. Pfeifferinella impudica Leger and HoUande (Fig. 115, e). In the liver of the land snail, Limax marginatus. Genus Barrouxia Schneider. The zygote develops into an oocyst, in which numerous spores, each containing a single sporozoite, develop. The spore membrane may be uni- or bi- valve and a caudal prolongation may occur in some species. Barrouxia ornata Schneider (Fig. 115,/). In Nepa cinerea. The spherical oocyst measures 34 to 37 microns; the spores 20 microns by 10 microns. Genus Lankesterella Labbe. Typically parasites of the en- dothelial cell of cold-blooded vertebrates. Development is not completely known. Lankesterella minima (Chaussat) (Fig. 115, g). The frog acquires infection through the introduction of the sporozoites by the leech. The sporozoites make their way into the blood capillaries of various organs. There they apparently enter the endothelial cells. Schizogony produces numerous merozoites which bring about infection of many host cells. Ultimately macro- and micro-gametocytes are formed; anisogamy produces zygotes. The zygotes transform themselves into oocysts, in which a number of sporozoites develop. These sporozoites are set free upon disintegration of the oocyst wall in the plasma and enter the erythrocytes (Noller). Genus Cryptosporidium Tyzzer. Lumen-dwelling form. The oocyst contains four sporozoites. Exceedingly minute organ- isms. Cryptosporidium muris Tyzzer. In the stomach lumen of the white mouse. Cryptosporidium parvum Tyzzer. In the intestine of the mouse. Suborder 2 Adeleidea Leger The Adeleidea are on the whole similar to the Eimeridea in their habitat and development. But the schizonts develop into micro- and macro-gametocytes which become attached to each other in pairs during the course of the development into gametes (Fig. 116,/, g). Each microgametocyte produces a few microgametes {h). The zygote divides into numerous sporo- SPOROZOA, TELOSPORIDIA, COCCIDIA 277 blasts, each of which develops into a spore with two or four sporozoites {i-j). Fig. 116 Development of Adelea ovata. X600 (After Schellack and Reiche- now). a, schizont which enters the gut epithelium of the host centipede; b-d, schizogony; e, larger forms of merozoites; f, microgametocyte (left) and macro- gametocyte (right); g, association of gametocytes; h, i, fertilization; j, zygote; k, nuclear di\'ision of the zygote; 1, mature oocyst with numerous spores. 278 HANDBOOK OF PROTOZOOLOGY The suborder is here divided into the following two famiUes: Parasitic in the epithelium of the digestive tract and its appended glands of chiefly invertebrates Family 1 Adeleidae Parasitic in the cells of the circulatory system of vertebrates Family 2 Haemogregarinidae Family 1 Adeleidae Leger Genus Adelea Schneider. The zygote develops into a thinly walled oocyst which contains numerous flattened spores, each with two sporozoites. In arthropods. Adelea ovata Schneider (Fig. 116). In the centipede, Litho- hius forficatus. Genus Adelina Hesse. The oocyst is thick-walled. The spore is spherical and comparatively small in number. Fig. 117 a. A spore of Adelitia dimidiata. XIOOO (After Schellack). b. An oocyst of A. octospora with eight spores. XIOOO (After Hesse). c. A spore of Orcheobius herpobdellae. X550 (After Kunze). d, e. Klossiella muris. X 280 (After Smith and Johnson), d, host's kidney cell with fourteen sporoblasts; e, a spore. f. An oocyst of Legerella hydropori. XIOOO (After Vincent). g. A spore of Karyolysus lacertarum. X700 (After Reichenow). Adelina dimidiata (Schneider) (Fig. 117, a). In the intes- tine of various species of myriapods belonging to the genus Scolopendra. Adelina octospora Hesse (Fig. 117, h). The spherical oocyst contains eight spores. In the coelom of Slavina appendiculata. Genus Klossia Schneider. The oocyst contains a large SPOROZOA, TELOSPORIDIA, COCCIDIA 279 number of spherical spores, each with four sporozoites. Para- sitic in the kidneys of the molluscs, Helix and Succinea. Klossia helicina Schneider. Kidney parasite of various species of land-snails, belonging to the genera Helix, Succinea, and Vitrina. Genus Orcheobius Schuberg and Kunze. Macrogametes vermiform. The spores are not so numerous, each with four sporozoites. Orcheobius herpobdellae Schuberg and Kunze (Fig. 117, c). In the testis of the leech, Herpobdella atomaria ( Nephelis vul- garis) . Genus Klossiella Smith and Johnson. The oocyst contains a number of spores, each with numerous sporozoites. A micro- gametocyte produces two microgametes. In the kidney of mammals. Klossiella muris Smith and Johnson (Fig. 117, d, e). In the kidney of the mouse. Genus Legerella Mesnil. The oocyst contains numerous sporozoites. Spores are entirely lacking. In arthropods. Legerella hydropori Vincent (Fig. 117,/). In the epithelium of the Malpighian tubules of the water beetles, Hydroporus and Hyphydrus. Family 2 Haemogregarinidae Leger Genus Haemogregarina Danilewsky. The schizogony takes place in the blood cells of vertebrates. Merozoites develop into gametocytes. The changes which result in the formation of one macrogamete from each of the macrogametocytes and of two or four microgametes from each microgametocyte, take place in the leech or other blood-sucking invertebrates. Zygotes are produced. Development of sporozoites in the invertebrate hosts are illustrated in Fig. 118. Haemogregarina stepanowi Danilewsky (Fig. 118). Schizo- gony in the turtle, Emys orbicularis and sexual reproduction in the leech, Placobdella catenigera. The sporozoites are intro- duced into the blood of the chelonian host by the leech {a). They enter the erythrocytes and grow {d-g). In the bone marrow, they undergo schizogony, each producing 12 to 24 merozoites Qi). The schizogony is repeated {i). Some mero- 280 HANDBOOK OF PROTOZOOLOGY Fig. 118 Development oi Haemogregarina stepanowi. X1200 (After Reiche- now). a, sporozoite; b-i, schizogony, j-k, gametocyte formation; 1, m, micro- gametocytes; n, o, macrogametocytes ; p, q, association of gametocytes; r, fer- tilization; s-w, division of the zygote nucleus to form eight sporozoites. SPOROZOA, TELOSPORIDIA, COCCIDIA 281 zoites produce only six merozoites (j, k) which become the gametocytes {l-o). The gametogony takes place in the leech. Four microgametes are formed from each microgametocyte and become associated with a macrogametocyte in the gut of the leech (p-r). The zygote (s) nucleus divides three times, and eight sporozoites are formed (t-w). Haemogregarina are commonly found in various frogs (Fig. 119, a-e) and in marine and fresh water fishes (Fig. \\9,f-j)^ Fig. 119 a-e. Haemogregarina of frogs. X1400 (After Kudo). f-j. Haemogregarina simondi Laveran and Mesnil, from the blood of the sole, Solea vulgaris. X1300 (After Laveran and Mesnil). f, extra corpuscular form; g-j, schizogonic stages in the erythrocyte. k. A spore of Hepatozoon muris. X415 (After Miller). Genus Hepatozoon Miller. The schizogony occurs in the cells of the liver, spleen, and other organs of vertebrates. The merozoites enter erythrocytes or leucocytes and develop into gametocytes. In blood sucking arthropods (ticks, mites), the microgametes and macrogametes develop and unite in pairs. The zygotes become oocysts which increase in size and develop sporoblasts, spores and sporozoites. 282 HANDBOOK OF PROTOZOOLOGY Hepatozoon muris (Balfour) (Fig. 119, ^). In various species of the rat, Rattus. Several specific names were proposed for the forms based upon the difference in host, locality, and effect upon the hosts, but they are so indistinctly defined that the specific separation is impossible. The invertebrate host is the mite. The schizogony occurs in the liver of the rat. Young gametocytes invade the mono- nuclear leucocytes and appear as haemogregarines. When the blood is taken up by the mite, Laelaps echidninus, the two gametes unite to form a vermicular body which penetrates the gut-epithelium and reaches the peri-intestinal tissue and grows. Becoming surrounded by a cyst-membrane, the cyst contents break up into a number of sporoblasts and then into spores, each of which contains a number of sporozoites. When a rat devours the infected mites, it becomes infected. Genus Karyolysus Labbe. The schizogony occurs in the endothelial cells of a vertebrate host (reptiles). Some mero- zoites which are in reality young gametocytes enter the ery- throcytes where they remain without further changes. When a mite sucks the infected blood, gametogony and fertilization takes place, producing zygotes which develop in the epithelial cells and become the oocysts. In the latter a number of sporo- blasts are formed and these are capable of vermicular move- ment and make their way into the ovum, where each transforms itself into a spore and develops a number of sporozoites. Karyolysus lacertarum (Danilewsky) (Fig. 117, g). In the lizard, Lacerta muralis. Transmission by the mite, Liponyssus saiirarum. References Calkins, G. N. 1926 The biology of the Protozoa. Phila- delphia. DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- tozoenkunde. Jena. Labbe, A. 1899 Sporozoa. Das Tiereich. 5 L. Wasielewski, V. 1896 Sporozoenkunde. Jena. Wenyon, C. M. 1926 Protozoology. Vols. 1 and 2. London. Andrews, J. M. 1926 Coccidiosis in mammals. Amer. Jour. Hyg., Vol. 6 SPOROZOA, TELOSPORIDIA, COCCIDIA 283 DoBELL, C. 1925 The life-history and chromosome cycle of Aggregata eherthi. Parasit., Vol. 17. Miller, W. W. 1908 Ilepalozoon perniciosum. U.S. Publ. Health Service, Hyg. Lab. Bull., No. 46. Perard, C. 1924, 1925 Recherches sur les coccidies et les coccidioses du lapin. Ann. Inst. Pasteur. Vols. 38, 39. Reichenow, E. 1921 Die Coccidien. Prowazek-Noller's Handbuch der pathog. Protozoen. Vol. 3. ScHAUDiNN, F. 1900 Untersuchungen iiber den Genera- tionswechsel bei Coccidien. Zool. Jahrb. Abt. Morph.. Vol. 13. Tyzzer, E. E. 1929 Coccidiosis in gallinaceous birds. Amer. Jour. Hyg., Vol. 10. Wenyon, C. M. 1926 Protozoology. Vol. 2. London. CHAPTER XXII ORDER 2 HAEMOSPORIDIA DANILEWSKY THE DEVELOPMENT of the Haemosporidia is, on the whole, similar to that of the Coccidiain 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 Haemo- sporidia do not pass any part of their development outside of a host body; hence, the sporozoites do not possess a resistant membrane. The Haemosporidia are minute and usually intracellular parasites of erythrocytes. The malarial parasites of man are typical members of this order. The development of Plasmodium vivax is as follows (Fig. 120): Infected anopheline mosquitoes introduce the sporozoites (a), which invade the erythrocytes {b), grow, and undergo schizogony, forming a number of mero- zoites (c-/). The latter upon liberation from the host cells, at- tack other erythrocytes. Some of the merozoites become macro- gametocytes (g) and others microgametocytes {i, j). No fur- ther changes ordinarily take place in the human body, but the schizogony is repeated. The protozoan produces melanin (or haemozoin) which is apparently the matabolic product of the organism at the expense of the haemoglobin. When the blood is taken into the stomach of a suitable species of anophe- line mosquito, the gametocytes undergo development, forming macrogametes and microgametes {h, k). They unite in pairs (/) 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 («). There they grow and the nuclei undergo rapid and repeated divisions, finally producing an enormous number of minute sporozoites {o, p). These sporozoites are set free through the rupture of the cyst wall in the body cavity, find their way into the salivary glands and wait for an opportunity of being inocu- [284 1 HAEMOSPORIDIA 285 lated into a new victim (g). The schizogony occurs regularly, and it is thought that the typical malarial fever is caused by some toxic substance which is liberated into the blood plasma when the merzoites become set free in the latter. The Haemosporidia are divided into three families, as follows: Schizogony in the peripheral blood of vertebrates Family 1 Plasmodiidae Gametocytes in the peripheral blood corpuscles; schizogony elsewhere . . Family 2 Haemoproteidae Minute parasites of erythrocytes; incompletely known. . . .Family 3 Babesiidae Fig. 120 Life-cycle of Plasmodium vivax. (Compiled after various authors). a. Sporozoite entering human blood plasma. b. Sporozoite entering erythrocyte. c. Young schizont. d-f. Schizogony. g, h. Macrogametocytes. i, j. Microgametocytes. k. Microgametes formed in the stomach of the mosquito. 1. Union of gametes, m. Zygote or ookinete, penetrating through gut wall, n. Rounding up of an ookinete between the gut wall and the elastic membrane. o. Oocyst in which sporozoites are being developed, p. Mature oocyst ruptured and the sporozoites set free in the body fluid. q. Sporozoites entering the salivary gland. 286 HANDBOOK OF PROTOZOOLOGY Family 1 Plasmodiidae Mesnil Genus Plasmodium Marchiafava and Celli. This genus contains the important malarial organisms of man and birds. As stated above, the schizogony takes place in the erythrocyte of a vertebrate host and anisogamy and sporozoite-formation occur in the mosquitoes belonging to the genus Anopheles or Culex. Numerous species. Three species in man. , ^ Sfe; Plasmodium vivax (Grassi and Feletti) (Fig. 121, a~g). The parasite of the benign tertian malaria of man. Schizogony is Fig. 121 a-g. Plasmodium vivax. XIOOO. h-n. P. falciparum. X 1000. o-u. P. malariae. XlOOO. a-e, h-1, o-s, schizogony; f, m, t, microgametocytes; g, n, u, macrogameto- cytes). completed in 48 hours. The infected erythrocyte becomes en- larged. As to its distinction with the other two species see below. Widely distributed over the temperate and tropical countries. Plasmodium falciparum (Welch) (Fig. 121, h-n). The para- site of the malignant tertian, subtertian, or aestivo-autumnal malaria of man. Schizogony is completed in about 48 hours, but frequently irregular. The schizonts adhere to the capil- lary wall, to which the malignancy of the species is attributed. The gametocytes are crescentic; some authors therefore place this species in another genus, Laverania. Of more limited dis- tribution in tropical and subtropical regions of the world. HAEMOSPORIDIA 287 Plasmodium malariae (Laveran) (Fig. 121, o-u). The para- site of the quartan malaria of man. Schizogony is completed in 72 hours. In tropical and subtropical countries. Numerous species of female mosquitoes belonging to the genus Anopheles transmit these organisms. The malaria para- sites are usually studied in stained blood films or smears and, therefore, the following comparison of the above-mentioned three species of Plamodium is based upon observations of stained specimens. P. vivax P. falciparum P. malariae Completion of schi- zogony 48 hours 24 to 48 hours 72 hours Diameter of ring One-third to one- One-sixth of the One-third to one- forms half of the host cell host cell half of the host cell Size of infected cells Greater than nor- mal cells Normal Normal Dots in infected cells Schiiffner's dots Maurer's dots Not seen Grown schizonts Round, large Round, small Elongate, medium Pigment granules Rod-shaped Small, triangular Large, irregular Number of mero- zoites from a single schizont 15 to 24 8 to 10 or more 6 to 12 Arrangement of merozoites within Two rings or scat- Two rings or scat- host cell tered tered One ring Gametocytes Rounded Crescent ic Rounded Plasmodium praecox (Grassi and Feletti) (Fig. 122, a-d). The organism is parasitic in birds, causing the so-called "bird malaria." Numerous birds such as lark, canary, sparrow, finch, barn-yard fowls, duck, pigeon, crow, owl, etc., are known to harbor the organism. The mosquito in which the sexual repro- duction takes place belongs to the genus Culex. The life-his- tory is similar to that of Plasmodium vivax outlined above. Family 2 Haemoproteidae Doflein The schizogony takes place in the endothelial cells of verte- brates. Certain merozoites penetrate into the circulating blood cells, in whic hthey develop into gametocytes. If the blood 288 HANDBOOK OF PROTOZOOLOGY is taken up by a specific blood-sucking invertebrate host, the gametocytes develop into gametes which unite to form the zygotes that undergo changes similar to the processes stated above for the family Plasmodiidae. Genus Haemoproteus Kruse. Young gametocytes enter erythrocytes. They produce pigment granules at the expense of the haemoglobin of the host cells. The fully formed gameto- cyte is halter-shaped and hence the name Halteridium (Labbe). Parasitic in birds and reptiles. Haemoproteus columbae Celli and Sanfelice (Fig. 122, e, /). A parasite of the pigeon, Columha livia, and has been found to be widely distributed. The schizogony takes place in the endothelial cells of the capillaries of the pigeon's lungs and other organs. The sexual reproduction occurs in species of flies be- longing to the genus Lynchia. i) OOOO 00©® Fig. 122 a-d. Plasmodium praecox. X800 (After Hartman). a, b, schizogony; c, microgametocyte; d, macrogameto- cyte. e, f. Micro- and macro-gametocyte of Haemoproteus columbae. X600. (After Aragao). g. Babesia bigemina. X 1000 (After Nuttall and Gra- ham-Smith), h. B. bovis. XIOOO (After Nuttall). i. Theileria parva. XIOOO (After Nuttall). Genus Leucocytozoon Danilewsky. Blood-parasites of vari- ous birds. Certain cells in the peripheral blood are infected by forms which are interpreted as macro- and micro-gametocytes. No pigments are produced. The infected host cells appear to be young erythrocytes, in which haemoglobin has not yet de- veloped and which has become spindle-shaped. Schizogony probably takes place in the endothelial cells of internal organs. Since their life-history is unknown, these organisms have been put in various places. Following the majority of recent authors, the genus is provisionally placed in this family. Several species. HAEMOSPORIDIA 289 Leucocytozoon ziemanni (Laveran). In the little owl, Athene noctna. Family 3 Babesiidae Poche The members of this family are minute and non-pigmented parasites of the erythrocytes of various mammals. They are transmitted from host to host by ticks. Numerous genera have been proposed. Genus Babesia Starcovici. Body pear-shaped. Arranged in couples. Multiplication by binary fission. Babesia bigemina (Smith and Kilborne) (Fig. 122, g). The organism of the "Texas fever" (or Red-water fever) of cattle. The very first demonstration that an arthropod plays an im- portant role in the transmission of a protozoan parasite. The infected cattle contain in their erythrocytes oval or pyriform bodies, in which a compact nucleus and vacuolated cytoplasm are noted. The division is peculiar in that it appears as a bud- ding process at the beginning. No other stages are known. The arthropod which transmits the organism is the tick belonging to the genus Margaropus. The tick remains fixed to one host during its entire growth period, but drops off to lay eggs. The infection is carried through the egg and embryo, and the young ticks which find a new host cattle are already infected. The Texas fever once caused a considerable amount of damage to the animal industry in the southern United States. Babesia bovis Starcovici (Fig. 122, h). A much smaller form which occurs in European cattle. Babesia are also known to occur in pigs, sheep, goats, horses, dogs, and other mammals. Genus Theileria Bettencourt, Franga, and Borges. Unlike Babesia, Theileria do not multiply actively in the erythrocite. The schizogony takes pice in the endothelial cells of the capil- laries of the spleen, liver, and other organs. The members are parasites of mammals. Theileria parva (Theiler) (Fig. 122, i). The cause of a cattle fever in Africa, known as the "East Coast fever," which differs from theTexas fever. The organism is transmitted by cattle ticks. Genus Cytamoeba Labbe. Small amoeboid, structureless organism occurring sometimes in amphibian erythrocytes. Cytamoeba bacterifera Labbe. In frogs of Europe and America. 290 HANDBOOK OF PROTOZOOLOGY References Aragao, H. 1908 Ueber die Entwicklungsgang und Ueber- tragung von Haemoproteus columhae. Arch. f. Protistenk., Vol. 12. Hartman, E. 1927 Three species of bird malaria. Ibid., Vol. 60. MacCallum, W. C. 1898 On the haematozoon infection of birds. Jour. Exper. Med., Vol. 3. Ross, R. 1928 Studies on malaria. London. Thomson, J. G. and A. Robertson. 1929 Protozoology London. Wenyon, C. M. 1926 Protozoology. Vol. 2. London. 1 I CHAPTER XXIII ORDER 3 GREGARINIDA LANKESTER THE GREGARINIDA are chiefly coelozoic parasites in inverte- brates, especially arthropods and annelids. They obtain their nourishment from the host's organ-cavity through osmos- is. The vast majority of the Gregarinida do not undergo schizo- gony, or asexual reproduction, and the increase in number is carried on solely by the sporogony following gametogony. In a small group, however, schizogony takes place as well as sexual reproduction and this is used as the basis for the division into two suborders, as follows: No schizogony Suborder 1 Eugregarinina Schizogony takes place Suborder 2 Schizogregarinaria Suborder 1 Eugregarinina Doflein This suborder includes the majority of the so-called gre- garines 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 large and protrude from the host cells to which they are now attached by various cell-organs of attachment. These trophozoites sooner or later become de- tached from the host cells and move about in the lumen of the gut. This stage is ordinarily most frequently encountered. It is usually vermiform and large. The body which is covered by a definite pellicle shows a clear differentiation into the ectoplasm and endoplasm. The former contains myonemes which enable the organism to undergo a gliding movement. In one group, Acephalina, the body is of a single compartment, but in another group, Cephalina, the body is divided into two compartments which are separated from each other by an ectoplasmic septum. The smaller anterior part is the protomerite and the larger posterior part, the deutomerite, contains a single nucleus. The protomerite may possess an attaching process with hooks or other structures at its anterior end; this is called the epimerite. [291] 292 HANDBOOK OF PROTOZOOLOGY Each trophozoite increases in size, and finally two encyst to- gether. These are gametocytes. Within the cyst membrane, the nucleus in each gametocyte undergoes 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 anisogamous. Each of the gametes produced in one gametocyte unites with one formed within the other, so that a large number of zygotes are produced. Each zygote becomes surrounded by a resistant membrane and its contents develop into the sporozoites which are usually Fig. 123 The development of Lankesteria culicis. X about 500. (After Wenyon). a. Entrance of sporozoites into the epithelial cell and growth stages of trophozoites. b. Trophozoite free in the host gut lumen. c. Association of grown trophozoites in pair, d-f. Stages in gamete-formation. g. Gametogony. h. Development of spores from zygotes. i. A spore. j. Germination of spore in the host gut. eight in number. These spores germinate when taken into the alimentary canal of a host animal and the liberated sporozoites undergo changes outlined above. GREGARINIDA 293 According to Wenyon, in a typical Eugregarinina, Lankes- teria culicis (Fig. 123) of Aedes aegypti, the development in a new host begins when a larva of the mosquito ingests the spores. From each spore are liberated eight sporozoites (j), which enter the epithelial cells of the stomach and grow (a). These tropho- zoites leave the host cells later and become mingled with the food material present in the stomach lumen of the host (6). When the larva pupates, the trophozoites enter the Malpighian tubules, where they become associated in pairs and encyst (c). The two nuclei divide repeatedly and produce large numbers of gametes {d-f) which copulate in pairs {g). The zygotes thus formed develop into spores, each possessing eight 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 the water. Larvae swallow the spores and acquire infection. Two legions are distinguished here: Trophozoite single-chambered Legion 1 Acephalina Trophozoite with more than one chamber Legion 2 Cephalina Legion 1 Acephalina Kolliker Genus Monocystis Stein. Body highly contractile and mo- tile. A large residual mass of cytoplasm after sporulation. Spore fusiform, symmetrical, with eight sporozoites. Common and widely distributed parasites in the seminal vesicles of various species of Lumbricus and Pachydrilus and also in microcrusta- ceans. Numerous species. Several species frequently may occur in a host individual at the same time and, consequently, specific identification is a matter of great difficulty. Monocystis rostrata Muslow (Fig. 124, a-d). In the seminal vesicle of Lumbricus terrestris. Genus Zygocystis Stein. Pyriform trophozoites are paired in young as well as mature stages. The endoplasm is not vacuo- lated. The spore contains eight sporozoites. In Lumbricus and crustaceans. Zygocystis cometa Stein. In the seminal vesicle and body cavity of Lumbricus agricola. Genus Pleurocystis Hesse. Trophozoites elongated spindle- 294 HANDBOOK OF PROTOZOOLOGY shape, attached to the host's cell in pairs. The spore contains eight sporozoites. One species. Pleiirocystis magna (Cuenot). In the seminal vesicle of Lumhricus terrestris and L. herculeus. Genus Pterospora Racovitza and Labbe. Body pyriform, the narrow end is prolonged into four bifurcated processes. Solitary or associated with broad ends. Body capable of move- ment. Cysts spherical or oval. The spore possesses dissimilar extremities and its outer envelope (epispore) is drawn out into three lateral processes. Number of sporozoites eight (?). Pterospora maldaneorum Racovitza and Labbe (Fig. 124, e,f). In the body cavity of the worm, Liocephalus liopygiis. a-d. MonocysHs rostrata. (After Muslow). a-c, grown trophozoites (X45); d, a spore (X600). , f. Pterospora maldaneorum. (After Labbe). e, grown trophozoites (X30); f, a spore (X400). h. Lithocystis brachycercus. XlOOO (After Pixell-Goodrich). g, a trophozoite attached to the coelomic side of the host gut; h, a spore from life, i. Two trophozoites of Urospora chiridotae in association. X150 (After Pixell-Goodrich). -1. Gonospora minchini. (After Goodrich and Pixell-Goodrich). j, a young sporozoite in host's egg ( X250) ; k, fully grown trophozoite in egg (X250); 1, free trophozoites in association (X60). Genus Cystobia Mingazzini. Body large; form irregular. Fully grown trophozoite contains two nuclei, on account of the early union of two individuals. The spore is oval and its enve- GREGARINIDA 295 lope is drawn out at one end in a bottle-neck fashion. Parasites of the blood vessel and coelom of Holothuria, Cystohia irregularis (Minchin). In the blood vessel of Holo- thuria nigra. Genus Lithocystis Giard. Body large; form ovoid or cylindri- cal. Body-surface with hair-like processes; endoplasm with crystals of calcium oxalate. The spore is ovoid, but its envelope with a long process; arranged radially. Number of sporozoites eight (?). Lithocystis scJineideri Giard. In the coelom of echinoderms. Lithocystis brachycercus Pixell-Goodrich (Fig. 124, g, h). In the coelom of Chiridota laevis. Genus Urospora Schneider. Body large; frequently in association. Cyst spherical. Each individual undergoes sporu- lation independently. The spore is oval and possesses a long filamentous process at one end. In the body cavity of Tubifex, Nemertinea, Sipunculus, Synapta, and Chiridota. Several species Urospora saeniiridis (Kolliker). In the seminal vesicle and general body cavity of Tiibifex tubifex Urospora chiridotae (Dogiel) (Fig. 124, i). In the blood vessel of Chiridota laevis. Genus Gonospora Schneider. Trophozoite large and poly- morphic, oval, pyriform or vermiform. Cysts spherical. The ends of the spore are dissimilar. In the coelom of polychaetes. Several species. Gonospora minchini Goodrich and Pixell-Goodrich (Fig. 124, J-/). In the coelom of Arenicola ecaudata. Young tropho- zoites invade and grow within the egg. Genus Lankesteria Mingazzini. Body more or less spatulate and small. Cysts spherical. The spore is oval and flattened and contains eight sporozoites. Lankesteria planariae (Mingazzini). In the gastro-vascular cavity of Planaria. Lankesteria culicis (Ross) (Fig. 123). In the gut of Aedes aegypti. Genus Nematocystis Hesse. Trophozoites are nematode- like. Nematocystis magna (Schmidt). In Lumbricus terrestris. 296 HANDBOOK OF PROTOZOOLOGY Genus Rhynchocystis Hesse. Body ovoid or cylindrical, with a proboscis-like process at the anterior end. Rhynchocystis pilosa (Cuenot). In Lumbricus terrestris, L. rubellus, and L. castaneus. Genus Allantocystis Keilin. Body elongate pyriform. Asso- ciation endwise without changing forms, hence the cyst is elongated. Spores asymmetrically fusiform. Number of sporo- zoites within a spore unknown. Allantocystis dasyhelei Keilin (Fig. 125, a-d). Grown tropho- zoite 70 microns by 20 microns. Cyst 150 microns by 20 mi- crons. The spore is 18 microns by 7 microns. In the space between the gut-epithelium and the peritrophic tube of larvae of Dasyhelea obscura, a ceratopognid insect of the elm and horse-chestnut trees. Legion 2 Ce^halina Delage The body is divided into the protomerite and deutomerite by an ectoplasmic septum. An endwise association of two tro- phozoites (syzygy), is common. The anterior individual is called the primite and the posterior satellite. Parasites of the digestive tracts of invertebrates, especially arthropods. Some of the representatives are as follows: Genus Gregarina Dufour. Trophozoites associative. The epimerite is small, globular or cylindrical. The spore is dolioform to cylindrical. The cyst opens by sporoducts. Many species. Gregarina blattarum Siebold (Fig. 125, e). In the digestive tract of the cockroach. Gregarina locustae Lankester (Fig. 125,/). In the intestine of the Carolina locust, Dissosteria Carolina. Gregarina oviceps Diesing (Fig. 125, g). In the intestine of the crickets, Gryllus spp. Genus Hirmocystis Leger. Two to twelve or more tropho- zoites are associated in a line. The epimerite a small cylindrical papilla. Thecyst opens by simple rupture. The spore is ovoidal. Hirmocystis harpali Watson (Fig. 125, h). In the intestine of the beetle, Harpalus pennsylvanicus erythropus . Genus Leidyana Watson. Solitary. Epimerite a simple globular sessile knob. The cyst possesses sporoducts. The spore dolioform. GREGARINIDA 297 Leidyana erralica (Crawley) (Fig. 125, i). In the intestine of the crickets, Gryllus abbreviatiis and G. pennsylvanicus. Genus Stenophora Labbe. Trophozoites solitary. Epimerite simple or absent. The cyst opens by simple rupture. The spore is ovoid and possesses an equatorial line. Parasites of myriapods Stenophora cockerellae Ellis (Fig. 125,7). Iri the gut of Ortho- morpha coarctata. Genus Acutispora Crawley. Trophozoites solitary. Pseudo- cyst. The spore is biconical and possesses a thick blunt endo- sporic rod at each end. In centipedes. Acutispora macrocephala Crawley (Fig. 125, ^). In the gut of Lithohius forficatus. Fig. 125 a-d. Allantocystis dasyhelei. X400 (After Keilin). a, b, trophozoites; c, two spores; d, cyst. e. Gregarina blattarum. X40. f. G. locustae. X50 (After Leidy). g. G. oviceps. X25 (After Crawley). h. Hirmocystis harpali. X37 (After Watson), i. Leidyana erratica. X125 (After Watson), j. Stenophora cockerellae. X50 (After Ellis). k. Acutispora macrocephala. X50 (After Crawley). 1. Asterophora philica. X50 (After Leidy). m. Amphoroides calverti. X 100 (After Watson), n. Steinina rotunda. XlOO (After Watson). o. Stylocephalus giganteus. X50 (After Ellis). p. Spore of Porospora portunidarum. X750 (After Leger and Duboscq). 298 HANDBOOK OF PROTOZOOLOGY Genus Nina Grebnecki. Protomerite formed of two long narrow horizontal lobes fused and upturned spirally at one end. Periphery shows many teeth, from which project long slender filaments. The spores are in chain form. In the intestine of myriapods. Nina gracilis Grebnecki. In the gut of Scolopendra cin- gulata. Genus Asterophora Leger. Epimerite a thick horizontal disc with a milled border and a stout style projecting from the center. The spore cylindro-biconical. In Neuroptera and Coleoptera. Asterophora philica (Leidy) (Fig. 125, /). In the gut of the coleopteran, Nyctohates pennsylvanica. Genus Amphoroides Labbe. Epimerite a globular sessile papilla. Protomerite cup-shaped. The spore is curved. In myriapods. Amphoroides calverti (Crawley) (Fig. 125, m). In the gut of Callipus and Lysiopetalum. Genus Steinina Leger and Duboscq. Solitary. Epimerite a short motile digitform process changing into a flattened struc- ture. The spore is biconical. In Coleoptera. Steinina rotunda Watson (Fig. 125, w). In the gut of Amara augustata. Genus Stylocephalus Ellis. Solitary. Epimerite a dilated papilla at the end of a long process. The cyst covered with small papillae and indentations. The spore is hat-shaped. In various arthropods and molluscs. Stylocephalus giganteus Ellis (Fig. 125, o). In the gut of co- leopteran insects belonging to the genera Eleodes, Eusattus, and Asida. Genus Porospora Schneider. The schizogony takes place in a crustacean and sporogony occurs in a molluscan host. The development is peculiar. The mature spore contains a single vermiform sporozoite which becomes attached to the gut- epithelium of the crab. It develops into a very long trophozoite. One, two, or sometimes three of them unite and encyst together. The nucleus divides repeatedly and finally a number of "gymno- spores" are formed. Certain authors hold this change as asexual, or schizogonic, reproduction, and hence include the genus in the GREGARINIDA 299 suborder Schizogregarinaria. When the parasites are passed in the feces of the host crab, the gymnospores enter the gill of a mollusc and there undergo copulation (Hatt). The zygotes develop into naked or encapsulated elongate vermiform bodies which, when taken into a host crustacean, develop into tropho- zoites. Several species. Porospora portunidaruni Frenzel (Fig. 125, p). The tropho- zoite is very large. In the crab, Portunus, and the mollusc, Cardium. Genus Dendrorhynchus Klein. Body elongated. Epimerite a disc, surrounded by numerous ramified papillae. Cyst ellip- tical; spores spindle-shaped (?). Dendrorhynchus system Keilin. Fully grown trophozoite 250 microns by 20 microns. The spore measures 19 microns by 7 microns. In the midgut of larvae of a dolichopodid fly, Systenus sp., found in the decomposed sap of the elm tree. Suborder 2 Schizogregarinaria Leger The Schizogregarines are intestinal parasites of arthropods, annelids, and tunicates. When the spore gains entrance to the digestive tract of a specific host through the mouth, it ger- minates and the sporozoites are set free (Fig. 126). These sporo- zoites develop into trophozoites either in the gut-lumen or within the host cells, and undergo schizogony (c), which may be binary or multiple fission or budding. The fully grown tropho- zoites become paired as in Eugregarinina and encyst, in which condition they undergo sexual reproduction followed by sporo- gony. Each individual which is now a gametocyte, produces gametes id-e). Fusion of two gametes follows (/). The zygote develops into a spore containing one to eight sporozoites (g, a). Several genera. Genus Schizocytsis Leger. Mature trophozoite multinucle- ate; ovoid or cylindrical with differentiated anterior end. Schiz- ogony by multiple division. The trophozoites become associ- ated, encyst, and produce a large (up to 30) number of spores, each of which contains eight sporozoites. In Diptera, Annelida, and Sipunculoida. Schizocystis gregarinoides Leger (Fig. 126). In the gut of Ceratopogon larvae. 300 HANDBOOK OF PROTOZOOLOGY Genus Ophryocystis Schneider. Parasites of the Malpighian tubules of Coleoptera. Schizogony by binary fission or multiple division. The schizonts are conical and are attached to the sur- face of the host cells by pseudopodial processes. From a pair of trophozoites, a single spore is produced, in which eight sporo- zoites develop. Fig. 126 Development o{ Schizocystis gregarinoides. X 1000 (After Leger) 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 (a). GREGARINIDA 301 Ophryocystis mesnili Leger (Fig. 127, a). In the mealworm, Tenehrio molitor. Genus Lipotropha Keilin, Schizogonic and sporogonic stages intracellular. The oocyst contains sixteen spores, each possessing eight sporozoites. In the fat body of Systenus larvae. One species. Lipotropha niacrospora Keilin (Fig. 127, b, c). The spore measures about 13.5 microns by 3 microns. iMg. 127 a. A.sporn\2L.t\ngsta.gQoi Ophryocystis mesnili. XlOOO. (After Leger). b, c. Spores of Lipotropha macrospora. X600 (After Keilin). d, e. Caulleryella pipientis. (After Buschkiel). d, a spore (X900); e, section of gut of Culex pipiens, showing the trophozoites (X150). Genus Caulleryella Keilin. Schizogony into 16 schizonts. Each gametocyte gives rise to 8 gametes, and hence 8 zygotes The spore contains 8 sporozoites. Parasitic in the intestine of dipterous larvae. Caulleryella pipientis Buschkiel (Fig. 121 , d, e). In the gut of Culex pipiens. References DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- tozoenkunde. Jena. Hesse, E. 1909 Contribution a I'etude des Monocystidees des Oligochetes. Arch. Zool. Exper,, T. 3. Watson Kamm, Minnie. 1916, 1922 Studies on gregarines. I. II. Illinois Biological Monogr., Vols. 2 and 7. CHAPTER XXIV SUBCLASS 2 CNIDOSPORIDIA DOFLEIN THE CHARACTER common to all Sporozoa belonging to this subclass is the presence of resistant spores which are of unique structure. Each spore possesses one to four polar cap- sules and one to many sporoplasms. The membrane which en- velops 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 orders Myxosporidia and Actinomyxidia, there ap- pear several cells during the process of sporulation. These cells give rise to one to many sporoplasms, or generative cells, cap- sulogenous cells, and spore membrane. This condition is not observed in other groups of Protozoa. For this reason some writ- ers recognize 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 mul- tiple fission, budding, or plasmotomy. The nuclear division varies from amitosis to mitosis. Isogamous, anisogamous, and autogamous reproduction have been reported in a number of forms. In many cases, 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 occur frequently in epidemic forms among such eco- nomically important animals as the silkworm, honey bees, and commercial fishes, the organisms possess considerable practical significance. The Cnidosporidia are here divided into four orders as follows : The spore large; with bivalve membrane; one, two or four polar capsules visible in vivo Order 1 Myxosporidia The spore large; with trivalve membrane; three distinctly visible polar capsules Order 2 Actinomyxidia [302 1 CNIDOSPORIDIA, MYXOSPORIDIA, ACTINOMYXIDIA 303 The spore is small; with one-piece membrane; one (rarely two) polar filament; polar capsule, if present, invisible in vivo Order 3 Microsporidia The spore small, barrel-shaped; a thick filament, coiled beneath the spore membrane; three sporoplasms Order 4 Helicosporidia ORDER 1 MYXOSPORIDIA BUTSCHLI The Myxosporidia are characterized by the possession of a spore which shows the following structure: The spore is of various shape and dimension. It is covered by a bivalve chitin- oid 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 desig- nated as the anterior end of the spore. Below or between (in Myxidiidae) the polar capsules there is a sporoplasm. Ordi- narily a young spore possesses two nuclei which fuse into one 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 (iodo- phile) 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 Reptilia, 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 amoebula 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. 128). The sporonts grow and their nuclei divide several times, forming six to eighteen daughter nuclei, each with a small mass of cytoplasm. The number of the nuclei thus 304 HANDBOOK OF PROTOZOOLOGY produced depends upon the structure of the mature spore, and also upon whether one or two spores are developed in a sporont. When the sporont develops into a single spore, it is called a monosporoblastic sporont. If two spores are formed within a sporont, which is usually the case, the sporont is called disporo- blastic, or pansporoblast. The spore-formation begins usually in the central area of the large trophozoite, which continues to grow. The surrounding host tissue becomes degenerated or modified and forms an envelope which is often large enough to be visible to the naked eye. This is ordinarily 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 confined to internal Fig. 128 Stages in spore-formation of Myxosoma catostomi. Y.llS (After Kudo), a, sporont; b-j, developmental stages of spores; k, 1, two views of stained spores; m, n, o, front, end, and side views of preserved, unstained spores. organs, the spores will not be set free while the host fish lives. Upon its death and distintegration of the body, however, the liberated spores become the sources of new infection. The more primitive Myxosporidia are coelozoic in the host's organs, such as the gall bladder, uriniferous tubules of the kidney, urinary bladder, etc. In these forms, the liberated amoebulae make their way into the specific organ and there grow into multinucleate amoeboid trophozoites which are capa- ble of forming pseudopodia of various types. They multiply by exogenous or endogenous budding or plasmotomy. One to several spores are developed in the trophozoite. The site of infections by Myxosporidia varies among dif- ferent species. They have been found in almost all kinds of tissues and organs of host fish, although each myxosporidian CNIDOSPORIDIA, MYXOSPORIDIA, ACTINOMYXIDIA 305 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 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 resulting changes are quite conspicuous (Fig. 129). The infection in the gills is usually manifest by whitish pustules which can be frequently detected with the unaided eye. When the wail of the alimentary canal, the mesentery, liver, and other organs are attacked, one sees considerable Fig. 129 External symptoms of myxosporidian infection in fish. (After Kudo), a. Head of the short-headed red-horse, Moxostoma breviceps, showing the cysts of Myxobolus conspicuus. One-half natural size. b. A blunt-nosed min- now, Pimephales notatus, showing three tumors which were caused by Myxo- bolus notatus. Five-eighths natural size. c. A sucker, Catostomus commersonii, with a large tumor due to an infection by Myxosoma catostomi. About one- third natural size. changes in them. Heavy myxosporidian infection of the gall bladder or urinary bladder of the host fish may cause abnormal appearance and coloration or unusual enlargement of the organ, but under ordinary circumstances the infection is detected only by a microscopical examination of its contents. 306 HANDBOOK OF PROTOZOOLOGY 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 niuscularis, which invades the muscular tissue of the host fish. The "boil disease" of the barbel, Barhiis barbus and others, of European waters, is caused by Myxoboliis pfeifferi. Lentospora cerebralis which attacks the supporting tissues of salmonoid fish, is known to be responsible for the so-called "twist disease," which is often fatal, especially to young fishes and which occurs in an epidemic form.^ The Myxosporidia are divided into three suborders, as fol- lows: The largest diameter of the spore at right angles to the sutural plane; one polar capsule on each side of the plane; sporoplasm with- out iodinophilous vacuole Suborder 1 Eurysporea The spore spherical or subspherical with one, two, or four polar capsules; sporoplasm without iodinophilous vacuole. Suborder 2 Sphaerosporea The sutural plane coincides with, or is at an acute angle to, the largest diameter of the spore; one, two, or four polar capsules; sporo- plasm with or without iodinophilous vacuole Suborder 3 Platysporea Suborder 1 Eurysporea Kudo Family Ceratomyxidae Doflein Genus Ceratomyxa Thelohan. Shell-valves conical and hol- low, attached on the bases; sporoplasm usually not filling the intrasporal cavity. The majority in the gall-bladder of marine fish. Numerous species. Ceratomyxa mesospora Davis (Fig. 130, a). In the gall bladder of Cestracion zygaena. The dimensions of the spore: Sutural diameter 8 microns, width 50 to 65 microns. Genus Leptotheca Thelohan. Shell-valves hemi-spherical. The majority live in the gall bladder or urinary bladder of marine fish and one in amphibians. Several species. Leptotheca ohlmacheri (Gurley) (Fig. 130, b-h). In the urini- ferous tubules of the kidney of frogs and toads. Dimensions of spore: Sutural diameter 9.5 to 12 microns; breadth 13 to 14.5 microns. Genus Myxoproteus Doflein. Spores pyramidal with or with- CNIDOSPORIDIA, MYXOSPORIDIA, ACTINOMYXIDIA 307 out distinct processes at the base of the pyramid. Rare. In the urinary bladder of marine fish. Three species. Myxoproteus cordiformis Davis (Fig. 130, i). In the urinary bladder of Chaetodipteriis faber. The spore measures 12 microns long by 10 to 11 microns wide. Genus Wardia Kudo. Spores isosceles triangle with two convex sides; oval in profile. Two large polar capsules. Tissue parasites of freshwater fish. Two species. Wardia ovinocua Kudo (Fig. 130, j)- Ir^ the ovary of Lepo- mis humilis. The spore measures 9 to 11 microns in sutural di- ameter by 10 to 12 microns in width. Fig. 130 a. Ceratomyxa mesospora, a fresh spore. X500 (After Davis). b-h. Leptotheca ohlmacheri. c-h, X750. (After Kudo), b, section through a uriniferous tubule of Rana pipiens, showing the trophozoites in its lumen (X400); c, a trophozoite containing an endogenous gemmule; d, e, trophozoites, each containing two spores, from life; f, stained trophozoite with two spores; g, a spore with extruded polar filaments; h, surface view of a fresh spore. i. A spore of Myxoproteus cordiformis. X500 (After Davis), j. A spore of Wardia ovinocua. X665 (After Kudo), k. A fresh and a stained spore of Mitraspora elongata. X500 (After Kudo). Genus Mitraspora Fujita. Spores circular or ovoidal in front view; somewhat flattened in profile. Two polar capsules; shell longitudinally striated; with or without posterior fila- ments. In the kidneys of freshwater fishes. This genus appar- ently includes border-line forms between this and the other sub- orders. Three species. 308 HANDBOOK OF PROTOZOOLOGY Mitraspora elongata Kudo (Fig. 130, k). In the kidney of Lepomis cyanellus. The spore is 15 to 17 microns long by 5 to 6 microns wide. Suborder 2 Sphaerosporea Kudo With four polar capsules Family 1 Chloromyxidae With one or two polar capsules Family 2 Sphaerosporidae Family 1 Chloromyxidae Thelohan Genus Chloromyxum Mingazzini. Spore with four polar capsules, grouped at the anterior end. Surface often striated or with ridges. The sutural line is often obscure. Histozoic and coelozoic in freshwater and marine fishes and also in amphibians. Numerous species. Chloromyxum leydigi Mingazzini (Fig. 131, a, 6). In the Fig. 131 a, b. Chloromyxum leydigi. (After Thelohan). a, trophozoite (X250); b, a spore (X500). c. Trophozoite of C. trijiigum with mature and developing spores. X565 (After Kudo). d. Spore of Sphaerospora polymer pha. X500 (After Davis). e, f. Sinuolinea dimorpha. (After Davis), e, a living trophozoite with three buds (X210); f, a spore (X465). g. A spore of Unicapsula muscularis. X830 (After Davis). gall bladder of various species of Raja, Torpedo, and Cestra- cion. The spore is 6 to 9 microns by 5 to 6 microns. Widely distributed. Chloromyxum trijugum Kudo (Fig. 131, c). In the gall bladder of Lepomis megalotis. The spore measures 8 to 10 microns by 5 to 7 microns. Family 2 Sphaerosporidae Davis Genus Sphaerospora Thelohan. The spore with two polar capsules. Histozoic or coelozoic parasites of marine and fresh- water fish. CNIDOSPORIDIA, MYXOSPORIDIA, ACTINOMYXIDIA 309 Sphaerspora polymorpha Davis (Fig. 131, d). In the urinary bladder of Opsaus tau. The spore measures 7 to 10 microns in diameter. Genus Sinuolinea Davis. The spore with or without lateral processes. Sutural line sinuous; two polar capsules. In the urinary bladder of marine fish. Sinuolinea dimorpha Davis (Fig. 131, e, f). In Cynoscion regalis. The spore is 15 microns in diameter. Genus Unicapsula Davis. Spore with one polar capsule. Shell-valves asymmetrical; sutural line sinuous (?). Histozoic in marine fish. One species. Unicapsula tnuscularis Davis (Fig. 131, g). The spore is about 6 microns in diailieter. In the muscle fibers of the halibut on the Pacific coast of North America. The cause of the "wormy" halibut (Davis). Suborder 3 Platysporea Kudo Without iodinophilous vacuole Two polar capsules; one at each pole Family 1 Myxidiidae One polar capsule Family 2 Coccomyxidae 2 or 4 polar capsules at anterior end Family 3 Myxosomatidae With an iodinophilous vacuole Family 4 Myxobolidae Family 1 Myxidiidae Thelohan Genus Myxidium Biitschli. The spore fusiform with pointed or rounded ends. Polar filament is comparatively long and fine. Coelozoic or histozoic in fishes and also in reptiles. Numerous species. Myxidium lieberkuhni Biitschli (Fig. 132, a-d). In the uri- nary bladder of various species of Lucius. The spore measures 18 to 20 microns by 5 to 6 microns. Widely distributed. Genus Sphaeromyxa Thelohan. Spore fusiform, but ends are usually truncate. Polar filament short and thick. Tropho- zoites large and discoid. Coelozoic in marine fish and amphi- bians. Several species. Sphaeromyxa balbianii Thelohan (Fig. 132, e-g). In the gall bladder of species of Motella and other marine fishes in Europe and of Siphostoma in the United States. The spore measures 15 to 20 microns long by 5 to 6 microns broad. 310 HANDBOOK OF PROTOZOOLOGY Sphaeromyxa sahrazesi Laveran and Mesnil (Fig. 132, h, i). In the gall bladder of Hippocampus, Motella, etc. The spore measures 22 to 28 microns long by 3 to 4 microns wide. Genus Zschokkella Auerbach. The spore hemi-circular in front-view; fusiform in profile; circular in cross-section. Ends pointed obliquely. The polar capsules are large and spherical. The sutural line is usually in S-form. In organ-cavities of fish. A few species. Zschokkella hildae Auerbach (Fig. 132, j, k). In the urinary bladder of varous species of Gadus. The spores measures 16 to 29 microns long by 13 to 18 microns wide. Family 2 Coccomyxidae Leger and Hesse The spore ellipsoidal, circular in cross-section. One polar capsule. Undoubtedly a border-line form between the Myxo- sporidia and the Microsporidia. Fig. 132 a-d. Myxidium lieberkiihni. a, large trophozoite (XllO after Lieberkiihn) ; b, a small trophozoite from life ( X500 after Kudo) ; c, d, fresh and stained spores (X700 after Kudo). e-g. Sphaeromyxa balbianii. e, a living trophozoite (natural size after Thelohan); f, a spore (X700 after Davis); g, a spore with the extruded polar filaments (X420 after Thelohan). h, i. S. sahrazesi. (After Schroder), h, a trophozoite from life (X5); i, two stained spores (X500). j, k. Zschokkella hildae. (After Auerbach). j, a trophozoite (X300); k, stained spore (X530). 1. A spore of Coccomyxa morovi. X330 (After Leger and Hesse). Genus Coccomyxa Leger and Hesse. The polar filament long and fine. Coelozoic parasites in marine fish. Coccomyxa morovi Leger and Hesse (Fig. 132, /). In the gall bladder of the sardine, Clupea pilchardus. The spore measures 14 microns long by 5 to 6 microns broad. CNIDOSPORIDIA, MYXOSPORIDIA, ACTINOMYXIDIA 311 Family 3 Myxosomatidae Poche Genus Myxosoma Thelohan. The spore ovoidal, flattened and more or less elongated. Two polar capsules. Histozoic parasites in freshwater and marine fishes. Several species. Myxosoma catostomi Kudo (Figs. 28; 128; 129, c). In the muscle and connective tissue of the body of the sucker, Cato- stonius commersonii. The spore measures 13 to 15 microns by 10 to 11.5 microns. Genus Lentospora Plehn. The spore circular to oval in front view. Two polar capsules. Histozoic parasites. Several species. Lentospora cerehralis (Hofer) (Fig. 133, a, b). In the cartilage and perichondrium of the salmonoid fishes. Young fishes are especially affected by the infection. The disease is known as the Fig. 133 a,b. Lentospora cerehralis. X400 (After Plehn). a, trophozoite; b, five spores in different views. c. A spore of Agarella gracilis. X830 (After Dunkerley). d. Two views of a spore of Myxobolus notatus. X765. (After Kudo), e-g. Myxobolus pfeifferi. e, part of section of a cyst; f, a spore treated with Lugol's solution (X890 after Keysselitz); g, a fresh spore (X500 after Thelohan). h, i. M. orhiculatiis. (After Kudo), h, a fresh spore and one treated with Lugol's solution (X500) ; i, infected host muscle (X300). j. Spores of M. conspicuus. X765 (After Kudo), k. A spore of Henneguya psorospermica. X665 (After Thelohan). 1-n. H. mictospora. (After Kudo). 1, m, two spores in life (X665); a stained monosporous trophozoite (X565). "twist-disease" (Drehkrankheit). The spore is 6 to 10 microns in diameter. Genus Agarella Dunkerly. The spore is elongated oval. Four polar capsules at the anterior end. Shell is prolonged posteriorly into long processes. One species. 312 HANDBOOK OF PROTOZOOLOGY Agarella gracilis Dunkerly (Fig. 133, c). In the testis of South American lung-fish, Lepidosiren paradoxa. Family 4 Myxobolidae Thelohan Genus Myxobolus Butschli. The spore ovoidal or ellipsoidal, flattened. One or two polar capsules at the anterior end. The sporoplasm contains an iodinophilous vacuole. Rarely with a posterior prolongation of the shell. Exclusively histozoic para- sites in freshwater fishes and amphibians. Numerous species. Myxobolus notatus Mavor (Fig. 129, h; 133, d). In the sub- dermal connective tissue of the blunt-nosed minnow, Pimephales notatus, and of Leuciscus rutilus. The tumor enclosing a tropho- zoite reaches a diameter of 7 mm. With a single polar capsule. Fresh spore 17 to 18 microns by 7.5 to 10 microns. The host tissue around the parasite becomes so highly changed that it appears as an epithelium. Myxobolus pfeifferi Thelohan (Fig. 133, e-g). In the muscle and connective tissue of the body and various organs of Barbus barbies, B. fluviatilis, and B. plebejus. The tumor containing the parasites reaches a diameter of 7 cm. Most of the infected fish die from the effect (Keysselitz). The spore measures 12 to 12.5 microns long by 10 to 10.5 microns broad. Myxobolus orbiculatus Kudo (Fig. 133, h, i). In the muscle of the minnow, Notropis gilberti. The preserved unstained spore measures 9 to 10 microns in diameter and 6.5 to 7 microns in thickness. Myxobolus conspicuus Kudo (Fig. 133, _;')• In the corium of the head of the short-headed red-horse, Moxostoma breviceps. The trophozoites form tumors or cysts varying in diameter from one-half to 4 mm. (Fig. 129, a). The preserved spore measures 9 to 11.5 microns long by 6.5 to 8 microns broad. Genus Henneguya Thelohan. The spore circular or ovoidal in front view; flattened. Two polar capsules at the anterior end. Each shell-valve is prolonged posteriorly into a long pro- cess. The sporoplasm contains an iodinophilous vacuole. Most- ly histozoic (some coelozoic) parasites in freshwater fishes. Nu- merous species. Henneguya psorospermica Thelohan (Fig. 133, ^). In the CNIDOSPORIDIA, MYXOSPORIDIA, ACTINOMYXIDIA 313 gills of Lucius and Perca. Cyst formation. The total length of the spore 35 to 40 microns. Henneguya mictospora Kudo (Fig. 133, l-n). In the urinary bladder of species of Lepomis and Micropterus salmoides. The spore measures 13.5 to 15 microns long, 8 to 9 microns broad, and 6 to 7.5 microns thick; caudel prolongation 30 to 40 microns long. ORDER 2 ACTINOMYXIDIA STOLC The Cnidosporidia placed in this order have been less frequently studied and, therefore, not so well known as the My- xosporidia. The spore is enveloped by a membrane, or shell, composed of three valves which are sometimes drawn out into simple or bifurcated processes. There are also three polar cap- sules in the spore and the polar filaments are plainly visible in vivo. Several sporoplasms occur as a rule in each spore. In the fully grown stage, the body is covered by a membrane and con- tains always eight sporoplasts which develop in turn into eight spores. Whether the pansporoblast is formed by the union of two cells or not, is yet to be confirmed. The nuclei and cyto- plasm divide and isogamy takes place. The zygote thus formed is the sporont, from which a single spore is produced by re- peated nuclear division combined with cytoplasmic differenti- ation. The Actinomyxidia are parasitic in the body cavity or the gut-epithelium of fresh or salt water annelids. The order is divided into two families as follows: The spore with a double membrane; inner membrane a single piece and the outer trivalve. A single binucleate sporoplasm. Probably border-line forms between the Myxosporidia and the present order Family 1 Tetractinomyxidae The spore membrane is a single trivalve shell. A single octonucleate sporoplasm or at least eight uninucleate sporoplasms Family 2 Triactinomyxidae Family 1 Tetractinomyxidae Genus Tetractinomyxon Ikeda. Parasitic in the coelom of the sipunculid, Petalostoma minutum. The spore is tetrahedron in form and does not possess any processes. When the tropho- zoite reaches maturity, it is a rounded body, the pansporoblast, in which eight spores are developed. 314 HANDBOOK OF PROTOZOOLOGY Tetractinomyxon intermedium Ikeda (Fig. 134, a), and T. irregulare Ikeda. Parasitic in the coelom of the sipunculid, Petalostoma minutum. Family 2 Triactinomyxidae Genus Triactinomyxon Stole. The three valves of the spore membrane are drawn out into long processes and the whole spore appears as an anchor. Parasitic in the gut-epithelium of oligochaetes. Triactinomyxon ignotum Stole (Fig. 134, d). Each spore pos- sesses eight sporoplasms. IVk/^' Fig. 134 a. Stained spore of Tetractinomyxon intermedium. X600 (After Ikeda). b. Spore of Sphaeractinomyxon stolci. X450 (After Caullery and Mesnil). c. Spore of 5. gigas. X500 (After Granata). d. Spore of Triactinomyxon ignotum. X200 (After Leger). e. Spore of Hexactinomyxon psammoryctis. X225 (After Stole), f , g. Polar and side view of spore of Synactinomyxon tubificis. X450 (After Stole). h. A fresh spore of Neoactinomyxum globosum. X650 (After Granata). Triactinomyxon legeri Mackinnon and Adam. With 24 sporoplasms. Triactinomyxon dubium Granata. With 32 sporoplasms. CNIDOSPORIDIA, MYXOSPORIDIA, ACTINOMYXIDIA 315 Triactinomyxon mrazeki Mackinnon and Adam. With 50 sporoplasms. All in Tubifex tubifex, occurring in various parts of Europe. Triactinomyxon magnum Granata. Each spore with 16 sporoplasms. In Limnodrilus udekemianus . Genus Sphaeractinomyxon Caullery and Mesnil. Parasitic in the coelom of oligochaetes. The spore is rounded and without any processes. In the early stage of development, there are two uninucleate bodies surrounded by a binucleate envelope. The two inner cells multiply into 16 cells which unite in pairs. The nucleus of the zygote or sporont divides first into two. One of the nuclei divides into six nuclei which form three valves of the spore membrane and three polar capsules, while the other nuc- leus together with a portion of the cytoplasm remains outside the envelope, and undergoes multiplication. Later the multi- nucleate sporoplasm migrates into the spore. The sporoplasm later divides into a large number of uninucleate sporoplasms which, when the spore enters a new host, begin development. Sphaeractinomyxon stolci Caullery and Mesnil (Fig. 134, b). The spore is spherical. Parasitic in Clitellis arenarius and Hemi- tubifex benedii. Sphaeractinomyxon gigas Granata (Fig. 134, c). In the body cavity of Limnodrilus hoffmeisteri. Genus Hexactinomyxon Stole. Each of the three shell-valves is prolonged into two processes. Thus the spore appears as a six-armed anchor. Hexactinomyxon psammoryctis Stole (Fig. 134, e). In the gut-epithelium of Psammoryctes barbatus. The sporoplasm is multinucleate. Genus Synactinomyxon Stole. The spore with two prolonged shell-valves and one conical valve. Synactinomyxon tubificis Stole (Fig. 134, /, g). Parasitic in the gut-epithelium of Tubifex tubifex. Genus Neoactinomyxum Granata. The three shell-valves without any process, but distended to hemi-sphere. Neoactinomyxum globosum Granata (Fig. 134, h). Numerous sporoplasms. In the gut-epithelium of Limnodrilus udeke- mianus. 316 HANDBOOK OF PROTOZOOLOGY References AuERBACH, M. 1910 Die Cnidosporidien. Leipzig. Caullery, M. and F. Mesnil. 1905 Recherches sur les Actinomyxidies. 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 Gli Attinomissidi. Arch. f. Protistenk., Vol. 50. Kudo, R. 1920 Studies on Myxosporidia. Illinois Biol Monogr., Vol. 5. CHAPTER XXV ORDER 3 MICROSPORIDIA BALBIANI THE MICROSPORIDIA are far more widely distributed as parasites among various animal phyla than are the Myxo- sporidia. They are, however, typically parasites of arthropods and fishes. Aside from one or two species, al! Microsporidia invade and destroy host cells. Frequently these infected cells Fig. 135 Effects of microsporidian infection upon the hosts. (From Kudo). a. The central nervous system of Lophius piscatoris infected by Nosema lophii. b. A smelt showing a heavy infection by Gluges, hertwigi. c. A larva of Culex territans infected by Thelohania opacita. X8. d. A simulium larva infected by T. mulHspora. X6. e. Portion of the testis of Barbus harbus infected by Plistophora longifilis. Three-fourths natural size. f, g,. The normal and hypertrophied nuclei of the adipose tissue of larvae of Culex pipiens, the latter affected by Stempellia magna. X750. may show enormous hypertrophy of both the cytoplasmic body and the nuclei (Fig. 135), a characteristic feature of the host reaction toward this particular group of protozoan parasites. The microsporidian spore is relatively small. In the vast majority it measures from 3 to 6 microns in length. The spore [317] 318 HANDBOOK OF PROTOZOOLOGY membrane, which is apparently 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 myxospori- dian or actinomyxidian 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 specific host (Fig. 136), the polar filaments are extruded and perhaps anchor the spores to the gut-epithelium. The sporo- Fig. 136 Diagram showing the probable development of Stempellia magna. X800 (After Kudo), a, b, germination of spore in the mid-gut of culicine larva; c-k, stages in schizogony; I-p, sporont formation; q-t, formation of one, two, four and eight sporoblasts; u, a sporoblast; v-x, transformation of a sporoblast into a spore. plasms emerge through the opening after the filaments become completely detached. By amoeboid movements they penetrate through the intestinal 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 latter. The schizonts become sporonts. MICROSPORIDIA , HELICOSPORIDIA 319 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 de- generation of enormous numbers of cells thus attacked. Such fatal infections may occur in an epidemic form, as is well known in the case of the pebrine disease of silkworms, the nosema- disease of honey bees, microsporidiosis of mosquito larvae, etc. According to the scheme of Leger and Hesse, the Micro- sporidia are divided into two suborders as follows: The spore with a single polar filament Suborder 1 Monocnidea The spore with two polar filaments Suborder 2 Dicnidea Fig. 137 a, b. Nosema bomhycis. (After Kudo), a, a fresh spore (XllOO); b, a silk- worm larva showing typical symptoms of heavy infection (one-half natural size), c, d. N. bryozoides. c, portion of infected faniculus cut longitudinally (X200 after Braem); d, a stained spore (X900 after Schroder). e. Four fresh spores and one stained spore of A'', apis. X1170 (After Kudo). f. Four spores of N. cyclopis. X1170 (After Kudo). g. Two spores of N. anophelis. XI 200 (After Kudo), h, i. Glugea anomala. h, cross-section of Gasterosteus aculeatus infected by the microsporidian (after Thelohan); a spore (X1125 after Stempell). j. Stained spore of G. hertwigi. X1250 (After Weis- senberg). k. Two spores of Perezia mesnili. X600 (After Pail- lot). 1, m. A pansporoblast and a spore with its extruded polar filament of Gurleya richardi. X900 (After Cepede). 320 HANDBOOK OF PROTOZOOLOGY Suborder 1 Monocnidea Leger and Hesse This suborder will be divided into three families as follows: The spore is oval, ovoid or pyriform; if subcylindrical, the length is less than four times the breadth Family 1 Nosematidae The spore spherical or subspherical Family 2 Coccosporidae The spore tubular or cylindrical (length is greater than five times the breadth) Family 3 Mrazekiidae Family 1 Nosematidae Labbe Genus Nosema Nageli. Each sporont develops into a single spore. Numerous species. Nosema homhycis Nageli (Fig. 137, a, b). In all tissues of the &gg, larva, pupa and adult of the silkworm, Bonibyx mori. The cause of the pebrine disease. Nosemahryozoides {K^OTOtne^) (Fig. 137, c, d). In the germ cell and cavity of the bryozoans, PhimateUa fungosa and P. repens. The spore is 7 to 10 microns long by 5 to 6 microns broad. Nosema apis Zander (Fig. 137, e). In the honey bee. The spore measures 4 to 6 microns long by 2 to 4 microns wide. Nosema cyclopis Kudo (Fig. 137, /). In Cyclops fiiscus. The spore measures 4.5 microns by 3 microns. Nosema anophelis Kudo (Fig. 137, g). In larvae of Ano- pheles quadrimacidatns . The spore measures 5 to 6 microns long by 2 to 3 microns. Genus Glugea Thelohan. Each sporont develops into two spores. The infected host cells become much hypertrophied, producing the so-called Glugea cysts. Numerous species. Glugea anomala (Moniez) (Fig. 137, h, i). In the connective tissue of the stickle back. The spore measures 4 to 6 microns long by 2 to 3 microns. Glugea miilleri Pfeiffer. In the muscle of species of Gam- marus. One of the several species of Microsporidia occurring in this host. The spore measures 5 to 6 microns by 2 to 3 microns. Glugea hertwigiWeissorvhevg (Figs. 135, b\ 137, j). In various tissue cells of the smelt, Osmerus. The spore measures 4 to 5.5 microns by 2 to 2.5 microns. Genus Perezia Leger and Duboscq. Each sporont produces two spores as in Glugea, but the host cells are not hypertrophied. Four species. MICROSPORIDIA, HELICOSPORIDIA 321 Perezia mesnili Paillot (Fig. \?>1 , k). In the cells of the silk glands and Malpighian tubules of the larva of Pieris hrassicae. The spore measures 3.4 microns by 1.5 to 2 microns. Genus Gurleya Doflein. Each sporont produces four sporo- blasts and finally four spores. Rare. Gurleya richardi Cepede (Fig. \37,l,m). In Diaptomus castor. The spore measures 4 to 6 microns long by 2.8 microns broad. Genus Thelohania Henneguy. Each sporont develops into eight sporoblasts and ultimately into eight spores. The sporont membrane may degenerate at different times during develop- ment. Numerous species. Thelohania legeri Hesse (Fig. 138, a-f). In the fat bodies of anopheline larvae. The spore measures 4 to 6 microns long by 3 to 4' microns broad. Widely distributed. Heavily infected larvae die without metamorphosing into adults. Thelohania opacita Kudo (Figs. 135, c; 138, g, h). In the fat bodies of larvae of culicine mosquitoes. The spore measures 5.5 to 6 microns by 3.5 to 4 microns. Genus Stempellia Leger and Hesse. Each sporont produces 1, 2, 4, or 8 sporoblasts and in turn 1, 2, 4, or 8 spores. Two species. Stempellia magna Kudo (Figs. 135,/, g; 136; 138, k-o). In the fat bodies of various Culex larvae. The spore measures 12.5 to 16.5 microns long by 4 to 5 microns broad. The polar cap- sule is visible in vivo. The filament when extruded under mechanical pressure, reaches a length of 350 to 400 microns. Genus Duboscqia Perez. Each sporont produces 16 sporo- blasts and later 16 spores. Only one species. Duboscqia legeri Perez. In the body cavity of Termes luci- fugus. The spore measures 5 microns by 2.5 microns. Genus Plistophora Gurley. Each sporont develops into many (more than 16) sporoblasts, each of which becomes a spore. Several species. Plistophora simulii (Lutz and Splendore). In various species of Simulium larvae. The spore measures 4.5 to 8 microns long by 3 to 5 microns. Plistophora longifilis Schuberg (Fig. 135, e; 138, p, q). In the testis of Barhiis fluviatilis. The spore measures 3 microns by 2 microns up to 12 microns by 6 microns. 322 HANDBOOK OF PROTOZOOLOGY b c 0 6 '^h I ^^ ' Fig. 138 a-f. g-j- k-o. P. q- r, s. t, u. Thelohania legeri. XI 180 (After Kudo), a-c, stages in sporogony; d, e, mature pansporoblasts; f, spore from life. T.opacita. X1180 (After Kudo), g, h, octosporous and tetrasporous pansporoblasts; i, j, fresh spores. Stempellia magna. XI 180 (After Kudo), k-n, fresh spores; o, a spore with its extruded polar filament. Stained spores of Plistophora longifilis. (After Schuberg). Spores of Coccospora. XlOOO (After Leger and Hesse). s, a spore with its extruded polar filament. Mrazekia caudata. t, an infected host cell (X350 after Mrazek); u, a spore (X875 after Leger and Hesse). A spore of Octosporea nmscae-domesticae. (After Chatton and Krempf). Spores of Spiroglugea octospora. X500; one X1500. (After Leger and Hesse). Spores oi Toxoglugea vibrio. X500; one X1500. (After Leger and Hesse). Fresh and stained spore of Telomyxa glugeiformis . X1500 (After Leger and Hesse). MICROSPORIDIA, HELICOSPORIDIA 323 Family 2 Coccosporidae Kudo ( = Cocconemidae Leger and Hesse) Genus Coccospora Kudo ( = Cocconema Leger and Hesse). The spore is spherical or subspherical. Several species. Coccospora slavinae (Leger and Hesse) (Fig. 138, r, s). In the gut-epithelium of Slavina appendiculata, an oligochaete worm. The spore is about 3 microns in diameter. Family 3 Mrazekiidae Leger and Hesse Genus Mrazekia Leger and Hesse. The spore straight tubu- lar. The polar filament possesses a rod-like basal portion. Several species. Mrazekia caiidata Leger and Hesse (Fig. 138, /, u). In the lymphocyte of Limnodrilus and Tubifex. The spore measures 16 to 18 microns long by 1.3 to 1.4 microns broad. Genus Octosporea Flu. The spore is cylindrical ; more or less curved; ends similar. Two species. Octosporea muscae-domesticae Flu (Fig. 138, v). In the gut and germ cells of the flies, Musca and Drosophila. The spore 5 to 8 microns long. Genus Spiroglugea Leger and Hesse ( = Spironema Leger and Hesse; Spirospora Kudo). The spore tubular and spirally curved. Polar capsule large. One species. Spiroglugea octospora Leger and Hesse (Fig. 138, w). In the fat body of the larva of Ceratopogon sp. (Diptera). The spore measures 8 to 8.5 microns by 1 micron broad. Genus Toxoglugea Leger and Hesse ( = Toxonema Leger and Hesse; Toxospora Kudo). The minute spore is curved or arched in hemi-circle. One species. Toxoglugea vibrio Leger and Hesse (Fig. 138, x). In the fat body of Ceratopogon sp. (Diptera). The spore measures 3.5 microns long by less than 0.3 microns broad. Suborder 2 Dicnidea Leger and Hesse Family Telomyxidae Leger and Hesse Genus Telomyxa Leger and Hesse. The spore possesses two polar capsules. Each sporont produces 8, 16 or more sporoblasts and later spores. One species. 324 HANDBOOK OF PROTOZOOLOGY Telomyxa glugeiformis Leger and Hesse (Fig. 138, 3'). In the fat body of the larva of Ephemera vulgata. The spore measures 6.5 microns by 4 microns. ORDER 4 HELICOSPORIDIA This order has been created to include the interesting organ- ism, Helicosporidium, observed by Keilin. Although quite pe- culiar in the structure of its spore, the organism seems to be best placed in the Cnidosporidia, if it is a protozoan. Fig. 139 Diagram showing the probable development of Helicosporidia. X about 1600. (After Keilin). a-c, schizont and stages in schizogony; d, sporont (?); e, three stages in formation of four-celled stage; f, hypothetical 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 larva. MICROSPORIDIA, HEUCOSPORIDIA 325 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 tissues or body cavity. They undergo schizogony , at the end of which uninucleate sporonts become differentiated. A sporont 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. Schizo- gony and sporogony. The spore with central sporoplasms and a single thick coiled filament. One species. Helicosporidium parasiticum Keilin (Fig. 139). In the body cavity, fat body, and nervous sytem of the larva of Dasyhelea ohscura (Diptera), also in Mycetobia \pallipes (Diptera), and Hericia hericia (Acarina), all of which inhabits wounds of elm and horse-chestnut trees. The schizont is minute. The spore measures 5 to 6 microns in diameter; extruded filament 60 to 65 microns long by 1 micron thick. References Keilin, D. 1921 On the life-history of Helicosporidium parasiticum. Parasit., Vol. 13. Kudo, R. 1924 A biologic and taxonomic study of the Microsporidia. Illinois Biol. Monogr., Vol. 9. CHAPTER XXVI SUBCLASS 3 ACNIDOSPORIDIA CEPEDE THE SPOROZOA which are provisionally grouped here are mostly incompletely known, although some of them are widely distributed among the higher vertebrates. They possess spores which are quite simple in their structure, while their de- velopment is so far as is known wholly different from that of the Telosporidia. Two orders make up the subclass. Muscle parasites of higher vertebrates Order 1 Sarcosporidia Parasites of invertebrates and fish Order 2 Haplosporidia ORDER 1 SARCOSPORIDIA BALBIANI These Sporozoa 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 Fig. 140 a. Sarcocystis tenella in the wall of oesophagus of sheep. b. S. miescheriana in the muscle of pig. Both natural size. (After Schneidemiihl from Doflein). corpuscle," is crescent-shaped. One end is rounded and the other pointed. Near the former end there is a single nucleus, and the cytoplasm contains numerous granules. Infection of a new host begins with the entrance of spore into the digestive tract of a specific animal through the mouth. The delicate spore mem- brane 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 [326] A CNIDOSPORIDIA 327 parasitic mass is an elongated multinucleate body which may or may not divide into as 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. 141). According to some authors, the 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. ^ Connective tissue layer Fibrous zone External Median Internal Cyst membrane Sporoblasts Spores Fig. 141 Schematic drawing showing part of a cyst of Sarcocystis tenella in sheep. X about 1000 (After Alexeieff). 140). They are cylindrical with more or less pointed extremities and with a somewhat lobulated surface, and opaque whitish. They were formerly called "Miescher's tubes" (Fig. 140). As to the pathogenic effect of the parasites upon the host animal, 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, to which Laveran and Mesnil gave the name sarcotoxin, and which 328 HANDBOOK OF PROTOZOOLOGY when injected is highly toxic to other animals. The order is represented by one genus. Genus Sarcocystis Lankester. Numerous species have been described from various mammals on the basis of difference in host species and slight difference in the dimensions of the spore. They are, however, morphologically indistinguishable from one another. Sarcocystis lindemanni (Rivolta). In man. Sarcocystis tenella Railliet (Figs. 140, a; 141). In sheep. Sarcocystis miescheriana Kiihn (Fig. 140, b). In pigs. Sarcocystis muris Blanchard. In rats and mice. Sarcocystis bertrami Doflein. In horses. Sarcocystis cimiculi Brumpt. In rabbits. Sarcocystis rileyi Stiles. In ducks. ORDER 2 HAPLOSPORIDIA LUHE This order includes those sporozoans which produce simple spores. In some species the spores may resemble superficially those of the Microsporidia, but do not possess the polar capsule or the filament. The boundaries and affinities of this order to other groups are indistinctly known. The Haplosporidia are cytozoic, histozoic, or coelozoic para- sites of invertebrates and lower vertebrates. The spore is spheri- cal 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 lid which, when opened, will enable the sporoplasm to emerge as an amoebula. The sporoplasm is uninucleate and fills the intrasporal cavity. The development of a haplosporidian, Ichthyosporidium giganteum, as worked out by Swarzcewsky, is as follows (Fig. 142) : 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 number, thus forming plasmodia. The Plas- modia divide into smaller bodies, while the nuclei continue to divide (b-e). Presently the nuclei become paired (/, g) and the nuclear membranes disappear (h). The plasmodia now break up ACNIDOSPORIDIA 329 into numerous small bodies, each of which contains one set of the paired nuclei {i, j). This is the sporont (j) which develops into two spores by further differentiation {k-o). Several genera have been recorded. A few genera will be briefly mentioned here. Fig. 142 The development of Icthyosporidiuni giganteum. Variously magni- fied. (After Swarczewsky). a-e, schizogony; f-n, sporogony; o, a stained spore (X about 1275). Genus Haplosporidium Caullery and Mesnil. After develop- ing into a large form, the Plasmodium divides into uninucleate bodies, each of which develops into a spore. The spore is trun- cate at one end where a lid occurs. The envelope is sometimes prolonged into processes. In salt and fresh water annelids and molluscs. 330 HANDBOOK OF PROTOZOOLOGY Haplosporidium chitonis (Lankester) (Fig. 143, a, b). In the liver and connective tissue of Chiton, Craspido chilus cinereus. The spore proper is oval and measures 10 microns by 6 microns. With two prolonged projections of envelope. Haplosporidium limnodrili Granata (Fig. 143, c). In the gut- epithelium of Limnodriliis udekemianus. The spore measures 10 to 12 microns long by 8 to 10 microns wide. Haplosporidium nemertis Debaisieux (Fig. 143, d).- In the connective tissue of Lineus bilineatus. The spore is oval with a flat operculum, but without any projections, and measures 7 microns by 4 microns. f g 00 Fig. 143 a, b. Haplosporidium chitonis. X500 (After Pixell-Goodrich) . a, fresh and b, pressed and stained spore. c. A spore of H. limnodrili. X500 (After Granata). d. Two spores of H. nemertis. X500 (After Debaisieux). e. A spore of H. heterocirri. X500 (After Caullery and Mesnil). f. A spore of H. scolopli. X500 (After Caullery and Mesnil). g. A spore of H. vejdovskii. X500 (After Caullery and Mesnil). h, i. Different views of spore of Urosporidium fuliginosum. X500 (After Caullery and Mesnil). j, k. Bertramia asperospora. X520 (After Minchin). j, cyst with spores; k, empty cyst. 1. Spores oi Coelosporidium periplanetae. X750. Haplosporidium heterocirri Caullery and Mesnil (Fig. 143, e). In the gut-epithelium of Heterocirrus viridis. Haplosporidium scolopli Caullery and Mesnil (Fig. 143,/). In Scoloplos mulleri. Haplosporidium vejdovskii Caullery and Mesnil (Fig. 143, g). In a fresh-water oligochaete, Mesenchytraeus flavus. A CNIDOSPORIDIA 33 1 Genus Urosporidium Caullery and Mesnil. Similar to Haplo- sporidium, but the spheroidal spore with a long projection. Urosporidium fuliginosum Caullery and Mesnil (Fig. 143, h, i). In the body cavity of the polychaete, Syllis gracilis. Not common. Genus Anurosporidium Caullery and Chappellier. Similar to Haplosporidium, but the operculate spore is spherical. Anurosporidium pelseneeri Caullery and Chappellier. In the sporocyst of a trematode parasitic in Donax trunculus. Schizogony intracellular; the cysts extracellular. The spore is small, about 5 microns long. Genus Bertramia Caullery and Mesnil. Parasitic in aquatic worms and rotifers. Sausage-shaped bodies occur in the body cavity of the host. The spherical spores which develop in them, possess a uninucleate sporoplasm and a well-developed membrane. Bertramia asperospora (Fritsch) (Fig. 143, j, k). Parasitic in the body cavity of rotifers (Brachionus, Asplanchna, Syn- chaeta, Hydatina, etc.). Fully grown vermicular body measures 70 to 90 microns and contains 80 to 150 spores. Bertramia capitellae Caullery and Mesnil. Parasitic in the annelid, Capitella capitata. Spore very small; 2.5 microns in diameter. Bertramia euchlanis Konsuloff. In the body cavity of the rotifier, belonging to the genus Euchlanis. Genus Ichthyosporidium Caullery and Mesnil. Parasitic in fish. Often looked upon as Microsporidia, as the organism develops into large bodies in the body muscles, connective tissue, or gills, which appear as conspicuous "cysts." The latter are surrounded by a thick wall and contain numerous spores. Ichthyosporidium giganteum (Thelohan) (Fig. 142). In the various organs of Crenilabrus melops and C. ocellatus. The cysts vary 30 microns to 2 mm. in diameter. The spore measures 5 to 8 microns long. Ichthyosporidium hertwigi Swarczewsky. In Crenilabrus paro. The organism produces cysts which measure 3 to 4 mm. in diameter on the gills of the host fish. The spore measures 6 microns long. Genus Coelosporidium Mesnil and Marchoux. Parasitic 332 HANDBOOK OF PROTOZOOLOGY in the body cavity of Cladocera or the Malpighian tubules of the cockroach. Body small, forming cysts. The spore has a slight resemblance in its appearance to a microsporidian spore, but without a filament. Coelosporidium periplanetae (Lutz and Splendore) ( = C. hlattellae Crawley) (Fig. 143, /). In the Malpighian tubules of various species of the cockroach. Common and cosmopolitan. References Alexeieff, a. 1913 Recherches sur Sarcosporidies. Arch. Zool. Exper., T. 51. Caullery, M. and F. Mesnil. 1905 Recherches sur les Haplosporidies. Ibid., T. 4. Crawley, H. 1914 The evolution of Sarcocystis muris in the intestinal cells of the mouse. Proc. Acad. Nat. Sci., Philadelphia. Vol. 66. Lambert, S. W. Jr. 1927 Sarcosporidial infection of the myocardium in man. Amer. Jour. Path., Vol. 3. Swarczewsky, R. 1914 Ueber den Lebenscyklus einiger Haplosporidien. Arch. f. Protistenk., Vol. 33. Teichmann, E. 1912 Sarcosporidia. Prowazek's Handbuch der Path. Protozoen., Vol. 1. Weissenberg, R. 1921 Fischhaplosporidien. Ibid., Vol. 3. CHAPTER XXVII SUBPHYLUM 2 CILIOPHORA DOFLEIN THE CILIOPHORA possess cilia which serve as cell-organs of locomotion and food-capture. In Suctoria the cilia are absent in the adult stage, but always present during the de- velopmental stages. The members of this subphylum possess a unique organization not seen in the Plasmodroma. Except a small group (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 processes. Nutrition is holozoic or parasitic. Sexual reproduction is mainly by conjugation. Asexual reproduction is by binary fission or budding. The majority are free-living and free-swimming, while the Suctoria are ordinarily attached forms. A number of parasitic forms occur also within this group. The Ciliophora are ordinarily subdivided into two classes: Cilia present throughout trophic life Class 1 Ciliata Adult with tentacles; cilia only while young Class 2 Suctoria CLASS 1 CILIATA BUTSCHLI The class Ciliata includes Protozoa of various habitats and body structures. All members possess cilia or cirri during the trophic stage of life. They inhabit all sorts of fresh and salt water bodies by free-swimming, creeping, or being attached to other objects. Some are parasitic in animals. Free-swimming forms are usually spherical to elliptical, while the creeping forms are, as a rule, dorso-ventrally flattened. The cilia are extremely fine and comparatively short, and are arranged in rows. In some forms they diminish in number and are replaced by cirri. The cilia are primarily the organelles of locomotion, but secondarily through their movements bring the food matter into the cytostome. The food of Ciliata consists [333] 334 HANDBOOK OF PROTOZOOLOGY 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 10 microns up to 2 mm. in large forms (as in an extended Spirostomum). The cytoplasm is distinctly dif- ferentiated into the ectoplasm and the endoplasm. The ecto- plasm gives rise to cilia and trichocysts and is covered by a pellicle. The endoplasm contains nuclei, food vacuoles, con- tractile vacuoles, pigment granules, crystals, etc. In the ma- jority of the 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 plate- lets and in others, such as Trichodina, into hook-like processes. The outer half of the ectoplasm may show alveolar structure which, in section, exhibits radiating and parallel lines. In this portion the myonemes are lodged. The deeper layer of the ectoplasm is structureless and free from granules. In the ecto- plasm are embedded the basal granules of cilia, which are ar- ranged in longitudinal, oblique, or spiral rows. The cilia may fuse to form cirri, membranellae, and undulating membranes which are invariably present in certain groups. In Euciliata contractile vacuoles with one to several radiating canals are one of the prominent structures. The endoplasm is more fluid in nature and the ground substance is finely granulated or reticulated. It undergoes rotation movement, called cyclosis. Two types of nuclei are present in all Euciliata. The massive macronucleus is of various forms. In Paramecium it is oblong; in Vorticella it is band-form, often curved; in Stentor it is beaded. The chromatin granules fill compactly the intranuclear space. The macronucleus multiplies by amitosis as was stated before. The micronucleus is ordinarily so minute that it is diffi- cult to see in a living specimen. It is spherical and usually ve- sicular in structure, although in some it appears to be compact, and consists of a centrally located endosome, the nucleoplasm, and the membrane. The number of the micronucleus present in CILIOPHORA, CI LI ATA, PROTOCILIATA 335 an individual varies: thus, one in Paramecium caiidatum; two in P. aurelia; three in Spirochona; four in Paramecium multimi- cronucleatiim; up to as many as 28 in Stentor roeseli. At the time of reproduction it increases in size and divides mitotically. Dur- ing conjugation it apparently undergoes a meiotic division. The Protociliata possess from one to many hundreds of nuclei of a uniform structure and numerous ovoid or spindle- 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 a comparatively small number of astomous forms, there is a cytostome located either at the anterior end or between this point and the middle of the body. In its simplest form the cytostome is represented by a small opening on the pellicle, which may or may not be closed when the animal is not feeding. The cytostome opens into the cytopharynx (or gullet), a canal which ends in the deeper portion of the endoplasm. In the cytopharynx there may be present an undulating membrane to facilitate the intaking of the food. Occasionally the cytostome is surrounded by trichites (p. 34). When the cytostome is not at the anterior region as for instance in Paramecium, there is a peristome (or oral groove) which starts at the anterior end and runs posteriorly. The ridges of the peristome are ciliated so that food particles are thrown down along it and ultimately into the cytostome which is located at its posterior end. Solid waste particles are extruded from the cytopyge, or cell-anus, which is usually noticeable only at the time of actual defecation (p. 34). Following Metcalf, the Ciliata are here divided into two subclasses : Two to many nuclei of one type; sexual reproduction copulation Subclass 1 Protociliata Nuclei of two types: macronucleus and micronucleus; sexual reproduc- tion conjugation Subclass 2 Euciliata SUBCLASS 1 PROTOCILIATA METCALF The members of this group are parasitic in the intestine of Amphibia with the exception of a few species which occur in 336 HANDBOOK OF PROTOZOOLOGY the intestine of a fish. The body is leaf-like or ellipsoidal, and covered uniformly by cilia of equal length. There is no cyto- stome and the nutrition is parasitic. The number of nuclei varies from two to several hundreds, and the nuclei are of one type. Asexual reproduction is by binary fission. In a number of species copulation of the gametes has been observed. Encyst- ment is common. One family. Fig. 144 a-e. Protoopalina intestinalis. (After Metcalf). a, stained trophozoite f X265); b-e, stages in anisogamy. f, g. P. saturfialis. X400 (After Leger and Duboscq). g, cyst. Family Opalinidae Claus Genus Protoopalina Metcalf. The body cylindrical or spindle-shaped, circular in cross-section. Two similar nuclei CILIOPHORA, CI LI AT A, PROTOCILIATA 337 which are invariably in a stage of mitotic division, are con- spicuously present. In the rectum of various species of Am- phibia with one exception. Protoopalina intestinalis (Stein) (Fig. 144, a-e). In the in- testine of various species of frogs and toads. Protoopalina saturnalis Leger and Duboscq (Fig. 144,/, g). In the intestine of the marine fish, Box boops. Protoopalina mitotica (Metcalf) (Fig. 145, a). Body 300 microns long by 37 microns broad. In the intestine of Amby- stoma tigrinum. Fig. 145 a. Protoopalina mitotica. X150. b. Zelleriella scaphiopodos. X150. c. Cepedia cantabrigensis. X150. d. Opalina hylaxena. X150. e-m. 0. obtrigonoidea. X^O. e-i, irom Bufofowleri; j-m, from Rana pipiens. (All after Metcalf). Genus Zelleriella Metcalf. The body is greatly flattened. Two similar nuclei which are in a mid-mitotic condition. All in Amphibia. Zelleriella scaphiopodos Metcalf (Fig. 145, b). In Scaphiopus solitarius. Body about 150 microns long by 90 microns broad by 13 microns thick. Genus Cepedia Metcalf. The body is cylindrical or pyriform as in Protoopalina, but contains many similar nuclei. All in Amphibia. 338 HANDBOOK OF PROTOZOOLOGY Cepedia cantahrigensis Metcalf (Fig. 145, c). In Rana cantahrigensis. Length 350 microns, width 84 microns. Genus Opalina Purkinje and Valentin. Body highly flat- tened. Multinucleate. In amphibians. Numerous species. Opalina hylaxena Metcalf (Fig. 145, d). In Hyla versicolor. Larger individuals measure about 420 microns in length, 125 microns in width, and 28 microns in thickness. Opalina ohtrigonoidea Metcalf (Fig. 145, e-rri). Length 400 to 840 microns, breadth 175 to 180 microns, thickness 20 to 25 microns. In various species of frogs and toads (Rana, Hyla, Bufo, Gastrophryne, etc.). References Calkins, G. N. 1926 The biology of the Protozoa. Phila- delphia. DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- tozoenkunde. Jena. Kent, W. S. 1880 to 1882 A manual of Infusoria. Metcalf, M. M. 1923 The opalinid ciliate infusorians. Smithsonian Inst., U. S. Nat. Museum, Bull., No. 120. 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. T CHAPTER XXVIII SUBCLASS 2 EUCILIATA METCALF HE EUCILIATA are subdivided into five orders according to the arrangement of the cilia, cirri, and adoral zone: Without adoral zone Order 1 Holotrichida With adoral zone Adoral zone turns to left Cilia over the entire body Order 2 Heterotrichida Cilia on body absent or a few Order 3 Oligotrichida Cilia or cirri on the ventral side only Order 4 Hypotrichida Adoral zone turns to right Order 5 Peritrichida ORDER 1 HOLOTRICHIDA STEIN The members of this order possess cilia which are uniformly distributed over the entire body surface. A cytostome may or may not be present. Adoral zone is never present. The position of the cytostome varies among different forms. In connection with the cytostome, there may be a proboscis in some forms and in one group the so-called pharyngeal apparatus may be well developed. Mode of nutrition is holozoic or parasitic. Asexual reproduction is usually by transverse fission. Sexual reproduction is ordinarily isogamous conjugation. Encystment is common. These Euciliata are parasites or free-living in all sorts of freshwater body and less frequently in marine water. The order is here divided into three suborders. Without cytostome Suborder 1 Astomina With cytostome Cytostome usually closed; oral membrane absent Suborder 2 Gymnostomina Cytostome usually opened; oral membrane present Suborder 3 Trichostomina Suborder 1 Astomina Cepede Genus Rhizocaryum Caullery and Mesnil. One species, R. concavum (Fig. 146, a), an intestinal inhabitant of the marine [339] 340 HANDBOOK OF PROTOZOOLOGY worms, Polydora caeca and P.flava. Body ovoid with depressed ventral surface. Macronucleus branches out characteristically. Genus Biitschliella Awerinzew. Body elongate cylindrical. Macronucleus elongated; several contractile vacuoles arranged in a longitudinal row. Biitschliella opheliae Awerinzew (Fig. 146, b). In the marine worm, Ophelia limacina. Fig. 146 a. Rhizocaryum concavum, dividing form. X665. b. Biitschliella opheliae. X350. c. Anoplophrya naidos. X200. d. Mesnilella clavata. X200. e. Hoplitophrya liimbrici. X 140. f. Maupasella nova. X280. g. Schultzellina mucronata. X665. h. Kojoidella eleutheriae. X265 (All from Cepede). EU CI LI AT A, HOLOTRICHIDA 341 Genus Anoplophrya Stein. Body elongated vermiform with rounded ends. An elongated macronucleus irregularly outlined. Micronucleus small. Parasitic in the intestine of Annelida, Gastropoda, and Crustacea. Anoplophrya naidos (Dujardin) (Fig. 146, c). In the digestive tract of the polychaete, Nais serpentina. Body about 200 microns long. Genus Mesnilella Cepede. Elongated body similar to Anoplophrya, but containing a rigid rod. Mesnilella clavata (Leidy) (Fig, 146, d). Found in the in- testine of Lumbricus variegatus. Length up to 160 microns. With a number of contractile vacuoles arranged in a longitu- dinal row. Genus Hoplitophrya Stein. Body oval. There is a protru- sible chitinous structure embedded in the cytoplasm, which serves for attachment of the body to the intestinal epithelium of the host. Parasites of Lumbricus. Hoplitophrya lunibrici (Dujardin) (Fig. 146, e). In the in- testine of Lumbricus terrestris. Genus Maupasella Cepede. With a spinous fixing cell-organ at the anterior end of the body. A number of myonemes run inward from the base. Parasitic in the intestine of Lumbricus. Maupasella nova Cepede (Fig. 146,/). In the intestine of an African Lumbricus. Genus Schultzellina Cepede. Similar to Maupasella, but attaching cell-organ making some angles with the main axis of the body. Schultzellina mucronata Cepede (Fig. 146, g). In the in- testine of the earthworm, Allurus tetraedurus . Genus Kofoidella Cepede. Broadly pyriform organism, 30 to 80 microns long. A large macronucleus; a contractile vacuole in the posterior third. Kofoidella eleutheriae Cepede (Fig. 146, A). Commonly found in the gastrovascular cavity of the medusa, Eleutheria dichotoma. Genus Intoshellina Cepede. Body elongate, and ciliary rows are slightly spiral. Macronucleus long. Contractile vacuoles five to seven in number. A cell-organ of attachment, vestigial cytostome and cytopharynx at the anterior end. 342 HANDBOOK OF PROTOZOOLOGY Intoshellina maupasi Cepede (Fig. 147, a). In the intestine of Tubifex sp. Genus Haptophrya Stein. Body elongate, uniformly ciliated; anterior end without neck-like constriction. On the ventral side there is a circular sucker surrounded by one or two rows of cilia; but no other fixing cell-organ. In the intestine of Am- phibia. Haptophrya michiganensis Woodhead (Fig. 147, b). In the intestine of the four-toed salamander, Hemidactyliiim scutatum. Frequent. Length 1.1 to 1.6 mm. Genus Sieboldiellina Collin. Similar to Haptophrya, but with neck-like constriction and there is a single row of cilia around the ventral sucker. Without other fixing organ. Sieboldiellina planariarum (Stein) (Fig. 147, c). In the gas- trovascular cavity of Tuberllaria. Genus Lachmannella Cepede. Without sucker, but fixing organ is present. Lachmannella recurva (Claparede and Lachmann) (Fig. 147, d) in the gastro-vascular cavity of the turbellarian, Planaria limacina. Genus Steinella Cepede. Sucker without encircling cilia; with two fixing cell-organs. One species in Tuberllaria. Genus Lada Vejdovsky. Antero-ventral portion bears a large sucker surrounded by a thick ciliated horseshoe-shaped rim. Lada wrzesniowskii Vejdovsky. In the oligochaete, Phreato- thrix pragensis. Genus Cepedella Poyarkofif. Body small, pyriform with a pointed anterior end, where there is a concavity for fixation of body, from which longitudinal myonemes arise. No contractile vacuole. Macronucleus globular. Cepedella hepatica Poyarkofif. Body 16 to 26 microns long; intracellular parasite of the liver of Sphaerium corneum, a cyclad mollusc of France. Genus Herpetophrya Siedlecki. Body ovoid, anterior end possesses a pointed, mobile, tactile (non-ciliated) cone. Con- tractile vacuoles absent. Macronucleus globular. Herpetophrya astoma Siedlecki. In the body cavity of an annelid worm, Polymnia. E U CI LI A TA , HOW T RICH ID A 343 Genus Perezella Cepede. Body ovoid, the ventral surface is concave and serves as a sucker. Macronucleus ellipsoidal; a contractile vacuole at the posterior end. Perezella pelagica Cepede (Fig. 147, e). A coelomic parasite of copepods (Clausia, Acartia, and Paracalanus). Fig. 147 a. Intoshellina maupasi. X280 (After Cepede). b. Haptophrya michiganensis. X34 (After Woodhead). c. Sieholdiellina planariarum. X about 100 (After Cepede). d. Lachmannella recurva. X95 (After Cepede). e. Perezella pelagica. X340 (After Cepede). f. Collinia circulans. (After Balbiani). g, h. Protophrya ovicola. (From Cepede). h., Sl young Liltorina rudis with P. ovicola. X80. i. Orchitophrya stellarum. X865 (After Cepede). j. Monomastix ciliatus. X665 (After Roux). 344 HANDBOOK OF PROTOZOOLOGY Genus CoUinia Cepede. Body ovoid; without cytostome. Cilia are arranged in longitudinal rows. One to several con- tractile vacuoles. Parasites in the coelom of fresh-water Crusta- cea (Gammarus, Neoniphargus, and Asellus.) CoUinia circulans (Balbiani) (Fig. 147,/). Polymorphic. In the blood vessel of Asellus aquaticus. Genus Protophrya Kofoid. Body ellipsoidal to pyriform. Macronucleus elliptical; a micronucleus; contractile vacuole at the posterior end. One species. Protophrya ovicola Kofoid (Fig. 147, g, h). Body about 60 microns long. Parasitic in the uterus of the mollusc, Littorina rudis. Genus Isselina Cepede. Similar to Protophrya. One species in the mantle cavity of Littorina ohtusata. Genus Orchitophrya Cepede. Body pyriform; ciliary rows are curved. Macronucleus spherical. Orchitophrya stellarum Cepede (Fig. 147, i). In the gonads of the echinoderm, Asteracanthion (Asterias) rubens. Genus Monomastix Roux. Elongated cylindrical; body flattened; ciliation uniform. Pointed anterior end with trichites and a long flagellum. Two macronuclei and micronuclei. Free- living. Saprozoic. Monomastix ciliatus Roux (Fig. 147, j). Body about 75 microns long by 14 microns broad. In stagnant water. Suborder 2 Gymnostomina Butschli The Holotrichida placed in this suborder possess a cyto- stome which is closed except at the time of actual food taking. In several genera longer cilia form a peristomal ring; the cyto- stome is, as a rule, terminal. The body form is usually definite, a distinct pellicle being present in all forms, and in some, plate- lets are developed. The suborder is divided into four families: Thick cortex on various parts of body; peristome narrow and long; all parasitic Family 1 Nicollellidae No thick cortex With terminal cytostome Family 2 Holophryidae Cytostome not terminal Anterior end with proboscis Family 3 Trachelinidae Usually with an oral basket; no proboscis Family 4 Chilodontidae E U CI LI A TA , HOLO TRICHIDA 345 Family 1 Nicollellidae Chatton Genus Nicollella Chatton and Perard. Body elongate ovoid. The thickened cortex on the anterior half of the oral surface. Nicollella ctenodactyli Chatton and Perard (Fig. 148, a). In the caecum and large intestine of Ctenodactylus gundi of Tunisia. Genus Collinella Chatton and Perard. Body form similar to Nicollella, but the thickened cortex reaches the posterior end on the oral surface. Fig. 148 a. Nicollella ctenodactyli. X125 (After Chatton and Perard). b. Holophrya discolor. X250 (After Butschli). c. Balanitozoon agile. X400 (After Stokes). d. Urotricha } areata. X3S0 (After Lieberkiihn from Butschli). e. Coleps hirttis. f. C. elongatus. g. C. bicuspis. h. C. octospinus. All four X400 (After Noland). i. Plagiopogon coleps. X 125 (After Perty). j. Metacystis tnincata. X200 (After Cohn). Collinella gundii Chatton and Perard. In the caecum and large intestine of Ctenodactylus gundi. Genus Pycnothrix Schubotz. Elongated body with thick- ened cortex on both oral and aboral surfaces. 346 HANDBOOK OF PROTOZOOLOGY Pycnothrix monocystoides Schubotz. In the intestine of Procavia capensis of Africa. Family 2 Holophryidae Schouteden Genus Holophrya Ehrenberg. Body ovate or globose. Cilia- tion uniform. Cytostome simple, without any special ciliary ring around it. Fresh or marine water. Holophrya discolor Ehrenberg (Fig. 148, b). Body ovoid to subspherical, about 150 microns long. In still fresh water. Genus Balanitozoon Stokes. Oval or rounded triangular in shape. Cilia only on the anterior half. A single nucleus, con- tractile vacuole, and cytopharynx. A long seta at the posterior extremity. Swimming as well as leaping movement. Fresh water. Balanitozoon agile Stokes (Fig. 148, c). Body small, about 15 microns long. In standing water with Sphagnum. Genus Urotricha Claparede and Lachmann. Body oval or ellipsoidal in form; ciliation uniform; one or more posterior setae as long as the body. A small circular cytostome at an- terior end. Contractile vacuole posterior. Fresh water. Urotricha /areata Claparede and Lachmann (Fig. 148, d). Length about 24 microns. Holozoic on bacteria. Pond-water and infusion. Genus Actinobolus Stein. Body ovate or spherical. Cilia are uniformly short; extensible tentacles among the cilia. Con- tractile vacuole conspicuous; macronucleus a curved band. Actinobolus radians Stein. In fresh water among Lemnae. Genus Coleps Ehrenberg. Body barrel-shaped and constant; covered with platelets which are variously sculptured. Spinous projections often at the posterior end. The cytostome is sur- rounded by slightly larger cilia. Division stages common. Fresh or salt water. Several species. Coleps hirtus (Miiller) (Fig. 148, e). Body 40 to 65 microns long. 20 longitudinal rows of platelets and 3 posterior spines. Coleps elongatiis Ehrenberg (Fig. 148,/). Body slender, 40 to 55 microns long. 13 rows of platelets; 3 posterior spines. Coleps bicuspis Noland (Fig. 148, g). Body about 55 microns long. With two posterior spines and 16 longitudinal rows of platelets. EUCILIATA, HOLOTRICHIDA 347 Coleps octospinus Noland (Fig. 148, h). Body large, 100 to 110 microns long. With eight posterior spines. All fresh water. Genus Tiarina Bergh. Somewhat similar to Coleps, but the posterior end pointed. Marine. Rare. Genus Plagiopogon Stein. Similar to Coleps, but with rounded posterior end. Fresh or salt water. Plagiopogon coleps Stein (Fig. 148, i). Body about 80 microns long. Genus Metacystis Cohn. Body oblong, symmetrical, defi- nite; the entire surface ciliated, except the posterior end. Ciliary circle around the cytostome. Metacystis truncata Cohn (Fig. 148, j). About 40 microns long. Among decaying marine algae. Genus Trachelocerca Ehrenberg. Body highly extensible, flask-shaped ; the anterior portion forms a long flexible neck- like process. The cytostome is often quadrangular in form. Numerous contractile vacuoles irregularly situated. Trachelocerca phoenicopterus Cohn (Fig. 149, a). In salt water. Body extended measures 1.7 mm, in length. Genus Trachelophyllum Claparede and Lachmann. Elon- gated, ribbon-like, flexible. Peristomal ciliary ring is well de- veloped. A knob oh the end of a neck-like proboscis. Contrac- tile vacuole at the posterior end. Numerous micronuclei. Fresh or salt water, Trachelophyllum clavatum Stokes (Fig, 149, b). Length about 180 microns. In fresh water. Genus Lacrymaria Ehrenberg. Body flask-shaped but changeable, with a comparatively long contractile proboscis. Posterior end is rounded. Cytostome round. There is a neck- like constriction with a circle of longer cilia around the cyto- stome. Cytopharynx. Fresh or salt water. Lacrymaria olor Miiller (Fig. 149, c, d). Highly contractile. When extended the body measures 400 microns in length. Fresh water, Lacrymaria lagenula Claparede and Lachmann (Fig, 149, e,f). Length 90 to 160 microns. Marine. Lacrymaria coronata Claparede and Lachmann (Fig, 149, g). Length 85 microns. Marine, Genus Chaenia Quennerstedt. Elongated body highly con- 348 HANDBOOK OF PROTOZOOLOGY tractile; inconspicuous cytostome widely dilated during the passage of food material. Peristomal ciliary circle present, but no neck-like constriction, nor proboscis. Chaenia teres Dujardin (Fig. 149, h). Length about 250 microns. In salt water. Fig. 149 a. Trachelocerca phoenicopterus. X40 (After Calkins), b. Track elo phyllum clavatum. X 75 (After Stokes), c, d. Lacrymaria olor. X200 (After Calkins). e, f. L. lagenula. X300 (After Calkins). g. L. cornata. X400 (After Calkins), h. Chaenia teres. X 140 (After Quennerstedt). i. Prorodon griseus. X250 (After Conn). Genus Prorodon Ehrenberg. Body constant in form; ovate; rounded at the extremities. Cytopharynx conspicuous often with rod-like structures. A single contractile vacuole posterior. A massive macronucleus oval or band-form. Fresh or salt water. E U CI LI A TA , HOW TRICHIDA 349 Prorodon griseus Claparede and Lachmann (Fig. 149, i). Body oblong, about 50 to 70 microns long. Fresh water. Genus Ichthyophthirius Fouquet. Body oval. Ciliation uni- form; pellicle longitudinally striated. Cytostome at or near the anterior end, followed by a short cytopharynx with cilia. A single horseshoe-shaped macronucleus and a small micronucleus. Multiplication by binary fission during the actively motile Fig. 150 Ichthyophthirius multifiliis. a, free-swimming Individual (X 75 after Biitschli); b-e, development within cyst; f, a young individual (X400 after Fouquet); g, section through fin of a carp showing numerous parasites (XlO); h, a catfish, Ameiurus albidus, heavily infected by the parasites (after Stiles). 350 HANDBOOK OF PROTOZOOLOGY phase or by multiple division in the encysted condition, which produces two hundred or more individuals (30 to 45 microns long). Conjugation is also reported. Parasitic in the integument of numerous freshwater fishes in small ponds or especially in aquaria. Widely distributed. Ichthyophthirius muUifiliis Fouquet (Fig. 150). Body meas- ures 300 to 800 microns in length. The ciliate attacks the epidermis or gills and forms pustules. When heavily infected, the host fish dies apparently from the infection. Genus Enchelys Ehrenberg. The anterior portion is drawn out into flask-shaped body which is obliquely truncated. Peri- stomal cilia are more conspicuous than those of the general body surface. Free-living in fresh water. Several species. Enchelys teres (Stokes) (Fig. 151, a). About 170 to 200 microns long. In standing water among decaying vegetation. Enchelys truncata (Stokes) (Fig. 151, h). About 125 microns long. In fresh water among dead leaves. Genus Enchelyodon Claparede and Lachmann. Similar to Enchelys, but with long trichites around the cytopharynx. In salt or fresh water. Enchelyodon farctus Claparede and Lachmann (Fig. 13, d). Body about 240 microns long. In marshes. Genus Lagynus Quennerstedt. Body elongated ; anterior end sharply truncated. The cytopharynx is rather conspicuous. Encystment observed. In fresh or salt water. Lagynus elegans Engelmann (Fig. 151, c). Body about 85 to 175 microns long. Fresh water. Genus Spathidium Dujardin. Flask- or sack-shaped; an- terior end is slightly narrowed into a neck with a truncate extremity. Cytostome occupies the whole of the end and is or- dinarily closed. Contractile vacuole posterior; elongate macro- nucleus and several micronuclei. Trichites around the cystotome and also scattered throughout the endoplasm (Fig. 13, c). Spathidium spathula (Ehrenberg) (Fig. 151, d, e). Body up to 250 microns in length. Fresh water. Genus Didinium Stein. Body barrel-shaped. Two girdles of long cilia, but no other cilia. The anterior end possesses a proboscis-like elevation, at the end of which is located an ex- pansible cytostome. Macronucleus is horseshoe-shaped. A E U CILIA TA , HOLO TRICHIDA 351 contractile vacuole posterior. Feeding on other ciliates, es- pecially Paramecium. Fresh water. Fig. 151 a. Enchelys teres. X 100 (After Stokes). b. E.truncata. X 200 (After Stokes). c. Lagynus elegans. X 165 (After Engelmann). d,e. Spathidium spathula. X200 (After Woodruff and Spencer), e, individual swallowing a Colpidium. f-j. Didinium nasutum. X165. f, g, living specimens; h, a stained specimen; i, dividing form, stained; j, an individual swallowing Paramecium caudatum. k. Monodinium balhiayiii. X285 (After Butschli). 1. Mesodinium pulex. X665 (After Calkins). m. Dinophrya Heberkiihni. X300 (After Butschli). 352 HANDBOOK OF PROTOZOOLOGY Dinidium nasutum (Miiller) (Fig. 151, f-j). Body length 80 to 200 microns. Cysts common. In fresh water; often abun- dantly found in Paramecium cultures. Genus Monodinium Fabre. Body somewhat similar to Didinium, but with a single girdle of cilia located at the an- terior end. Monodinium balbianii (Biitschli) (Fig. 151, k). About 70 microns long. Fresh water. Genus Mesodinium Stein. Body spherical with a deep con- striction, in which are located strong cilia. Anterior end is conical. Cytostome is connected with a cytopharynx. Four tentacle-like retractile processes occur around the cytostome. Nuclei similar to those of Didinium. Fresh or marine water. Mesodinium pulex Claparede and Lachmann (Fig. 151, /). Length about 35 microns. In salt water. Genus Dinophrya Biitschli. Body elongate; posterior end drawn out. Anterior end conical with a cytostome at its ex- tremity. Besides being ciliated on general body surface, several girdles of long cilia near the anterior end. Ellipsoidal macro- nucleus central; a contractile vacuole posterior. Fresh water. Dinophrya lieberkuhni Biitschli (Fig. 151, m). Length 70 to 80 microns. In fresh water. Family 3 Tracheliidae Kent Cilia occur uniformly over the entire body surface except in a few forms in which they are considerably reduced. An- terior end is drawn out into a proboscis. The location of the cytostome is not constant, it may be on the proboscis, dorsal side, or ventral side. Genus Trachelius Schrank. Body large, spherical to ellip- soidal. The anterior region is drawn out into a massive dorsally bent moveable proboscis. The cytostome is located on the ventral side at the base of the proboscis. Cytopharynx basket- like. Contractile vacuoles numerous; macronucleus central and simple or band-form. Movement slow. With spherical cyst. Trachelius ovum Ehrenberg (Fig. 152, a). Body about 350 microns long. Fresh water. Genus Dileptus Dujardin. Body much elongated, anterior end is drawn out into a long proboscis, on the ventral side of / E U CILIA TA , HOLO TRICHIDA 353 which is a row of long cilia. The open circular cytostome is situated at the base of the proboscis. Numerous contractile vacuoles on the dorsal side or scattered. The body surface is uniformly ciliated. Macronucleus moniliform. Conjugation. Spherical cysts. Fresh or salt water. Dileptus anser Miiller (Figs. 4, h; 152, b). Extended body 1 mm. or more in length. In fresh or salt water. Genus Lionotus Wrzesniowski. Body elongated and flat- tened. Ventral surface flat, dorsal surface convex. The an- terior end is drawn out into a proboscis and the posterior end terminates usually in a cone. A row of long cilia on the pro- Fig. 152 a. Trachelius ovum emerging irom a cyst. X65 (After Biitschli). b. Dileptus anser. X50 (After Biitschli). c. Lionotus fasciola. X 100 (After Calkins). d. Loxodes rostrum. XlOO (After Biitschli). e. Loxophyllum setigerum var. armatum. X350 (After Calkins). f. Amphileptus branchiarum. X370 (After Wenrich). boscis. The long slit-like cytostome is located on the ventral side of the proboscis and is ordinarily closed. One to many contractile vacuoles. Two spherical macronuclei. Fresh or salt water. Several species. Lionotus fasciola Ehrenberg (Fig. 152, c). Body large 200 to 600 microns long. In fresh or salt water. Genus Loxodes Ehrenberg. Body elongated, flattened, and more or less constant in form. Ventral surface flattened with 354 HANDBOOK OF PROTOZOOLOGY longitudinal rows of cilia, the dorsal surface convex. Stronger cilia are present on the margin. Anterior end is bent toward one side and just below it is a slit-like cytostome. Cytopharynx is small and indistinct. Numerous nuclei and contractile vacuoles. Fresh water. Loxodes rostrum Miiller (Fig. 152, d). Body about 300 to 375 microns long. In stagnant water. Genus Loxophyllum Dujardin. Body flattened; ventral sur- face flat; dorsal surface convex. Anterior end narrowed; hyaline cytoplasm asymmetrically arranged. Cytostome straight slit- like with trichocysts on the border in papilla-like groups or scattered. Nucleus simple to moniliform. One to many con- tractile vacuoles, posterior. Fresh or salt water. Loxophyllum setigerum var. armatum (Claparede and Lach- mann) (Fig. 152, e). Body about 100 microns long. In salt water. Loxophyllum meleagris Ehrenberg. Pond water. Genus Amphileptus Ehrenberg. Body flask-shaped, some- what compressed. Anterior end is drawn out into an acute proboscis at the base of which is located the cytostome. Con- tractile vacuole one to many. One or two macronuclei. Fresh or salt water. Amphileptus claparedei Stein. Fresh or salt water. Amphileptus branchiarum Wenrich (Fig. 152,/). On the skin and gills of the tadpole of common frogs (Rana). Swimming individuals killed with iodine, measure 100 to 135 microns long by 40 to 60 microns broad. Family 4 Chilodontidae Biitschli Body is usually flattened. Ciliation seems to be limited to the oral surface. Cytostome is surrounded by trichites, pre- senting a basket-like appearance. Free-living; a few parasitic. Genus Chilodon Ehrenberg. Body small to medium large; on the whole dorso-ventrally flattened, flexible. Dorsal surface convex, ventral surface flat. Uniformly ciliated. Cytostome in the center of the anterior half and toward the left. Pharyn- geal basket is protrusible beyond the cytostomal aperture. Contractile vacuole variable in number; macronucleus oval, central. Cysts oval. Common in fresh or salt water infusion. EUCILIATA, HOLOTRICHIDA 355 Chilodon cucullulus Miiller (Fig. 153, a). Length 100 to 300 microns. Fresh or salt water. Chilodon vorax Stokes (Fig. 153, h). Length about 200 microns. Fresh water among algae. Chilodon caudatus Stokes (Fig. 153, c). About 40 microns long. In standing water. Chilodon fliiviatilis Stokes (Fig. 153, d). About 50 microns long. Fresh water. Chilodon cyprini Moroff (Fig. 153, e). Body about 50 to 70 microns long by 30 to 40 microns broad. In the integument and gills of the cyprinoid fishes. The organism, if freed from the host skin, dies in from 12 to 24 hours. Genus Nassula Ehrenberg. Body large, oval to elongate, flexible. Usually brightly colored. Often flattened dorso- ventrally. The extremities are equally rounded. Cytostome toward the left side. In some a poorly developed adoral zone may occur. The cytopharynx is conspicuous by the presence of a pharyngeal basket. Spherical macronucleus central. Con- tractile vacuole one to several. Cysts are spherical. Fresh or salt water. Several species. Nassula aurea Ehrenberg (Fig. 153, /). About 200 to 250 microns long. Fresh water. Nassula microstoma Cohn (Fig. 153, g). About 100 microns long. Marine. Genus Opisthodon Stein. Body medium large, ovoid or pyri- form. Dorsal surface convex, ventral flat. Cytostome located at about one-fourth from the posterior end of body. Pharyngeal basket is conspicuous. Two spherical macronuclei; one con- tractile vacuole. Ciliation uniform. Fresh water. Opisthodon niemeccensis Stein (Fig. 153, h). Body about 200 microns long. In fresh water. Genus Orthodon Gruber. Body, oval, medium-large, con- tractile and colorless. Much flattened; anterior end is curved toward the left, while the posterior end rounded. Ventral side is distinctly striated and ciliated. Dorsal surface is also finely ciliated, although the striation is less distinct. Cytostome on the right side margin. Cytopharynx with a conspicuous basket. Oval macronucleus central; one contractile vacuole terminal. Salt or fresh water. 356 HANDBOOK OF PROTOZOOLOGY Orthodon hamatus Gruber (Fig. 153, i). Length about 150 to 180 microns. In salt water. Fig. 153 a. Chilodon cucullulus. X200 (After Stein). b. C. vorax. X150 (After Stokes). c. C. caudatus. X750 (After Stokes). d. C.fluviatilis. X 600 (After Stokes). e. C. cypfini. X500 (After Moroff). f. Nassula aurea. X90 (After Biitschli). g. iV. microstoma. X500 (After Calkins). h. Opisthodon niemeccensis. XlOO (After Stein), i. Orthodon hamatus. X 120 (After Entz). j. Dysteria lanceolata. X400 (After Calkins), k. Phascolodon vorticella. X250 (After Stein). I. Scaphidiodon navicula. XlOO (After Stein), m. Trochilia palustris. X300 (After Stein). n. Aegyria oliva. X165 (After Entz). EU CI LI AT A, HOLOTRICHIDA 357 Genus Dysteria Huxley. Body ovoid on the whole, constant. Colorless or variously colored. Ventral side narrowly ciliated. Cytostome toward one side near the anterior end with a distinct basket. A spinous projection from a point near the posterior end. A globular macronucleus; contractile vacuoles several. Marine. Dysteria lanceolata Claparede and Lachmann (Fig. 153, j). Body 45 to 70 microns long. Marine. Dysteria armata Huxley. Body length 40 to 100 microns. Marine. Genus Phascolodon Stein. Body rounded; anterior end broadly truncate and curved dorsally; posterior end narrowed. Dorsal surface convex; ventral surface flattened. Ciliation general. Cytostome near the anterior end on the ventral side and with a pharyngeal basket. Two contractile vacuoles ven- tral. Fresh water. Phascolodon vorticella Stein (Fig. 153, k). About 80 to 90 microns long. Fresh water. Genus Scaphidiodon Stein. Body spheroid or boat-shaped; colorless. Dorsal surface convex ; ventral surface flat. Posterior end drawn out into a spinous projection; the anterior edge possesses a lip-like border. Cytostome near the anterior end with a pharyngeal basket. Macronucleus oval, central. Con- tractile vacuoles. Marine. ' Scaphidiodon navicula Stein (Fig. 153, /). About 150 microns long. In salt water. Genus Trochilia Dujardin. Body small, ovate. Dorsal sur- face convex; ventral surface flat. Anterior portion bent toward the left. There is a movable spinous structure attached at the posterior end. Cilia confined to a subcentral, curved, band-like area on the ventral surface. Cytostome in the anterior half of the body. Cytopharynx visible. There is a long cirrus near the cytostome. Fresh or salt water. Trochilia palustris Stein (Fig. 153, m). Body about 30 microns long. Fresh water. Genus Aegyria Claparede and Lachmann. Body medium large. General appearance similar to Chilodon. Colorless or variously colored. ■ Ventral side flattened or slightly convex, longitudinally striated. At the posterior end, there is a movable 358 HANDBOOK OF PROTOZOOLOGY caudal style. Cytostome antero-ventral. Pharyngeal basket short. Salt or fresh water. Rare. Aegyria oliva Claparede and Lachmann (Fig. 153, n). About 100 microns long. Marine. Suborder 3 Trichostomina Butschli The cytostome is a permanent opening and is located at the posterior end of the peristome (oral groove). There is one (or more) undulating membrane which runs into the cyto- pharynx or borders the cytostome. The membrane is inconspicu- ous in many, but in others it is a large sail-like expansion apparently used for capturing the food. The cilia are usually uniformly developed and distributed, although in some they may be much reduced. The group contains both free-living and parasitic forms. The suborder is divided into six families: Cilia on two broad zones and on the posterior tip Family 1 Urocentridae Cilia not arranged in zones With small circular or ellipsoidal peristome Cystotome in the anterior half of body Family 2 Ophryoglenidae Cytostome in the posterior half of body Family 3 Microthoracidae With large peristome Undulating membrane in the cytopharynx Family 4 Parameciidae Huge undulating membrane in peristome Family 5 Pleuronematidae Parasitic in the digestive tract of mammals. .. .Family 6 Isotrichidae Family 1 Urocentridae Schouteden Genus Urocentrum Nitzsch. Somewhat short cocoon-shaped, with a constriction slightly behind the middle. Two broad zones of cilia and a conspicuous tuft of fused cilia at the pos- terior end. Large and oval cytostome posterior; with a distinct cytopharynx. Macron ucleus horseshoe-shaped and a micro- nucleus. A contractile vacuole at the posterior end with four radiating canals. Movement rapid. Fresh water. Urocentrum turbo Mliller (Fig. 154, a). About 100 microns long. Fresh water. Family 2 Ophryoglenidae Kent The body uniformly ciliated, with or without peristome. Cytostome is at the anterior half of the body. EU CI LI AT A, HOLOTRICHIDA 359 Genus Ophryoglena Ehrenberg. Body elliptical or some- what cylindrical. Ends are equally rounded or attenuated. Cytostome usually crescentic, near the anterior fourth. An undulating membrane. Contractile vacuole one or more and with numberous radiating canals. Macronucleus elongated or band-form; micronucleus fusiform. Ophryoglena flava Ehrenberg (Fig. 154, b). Body 500 to 550 microns long. Stagnant water. Genus Cyrtolophosis Stokes. Body oblong; secretes muci- laginous envelope in which the organism lives, but from which it emerges at will. A tuft of curved vibratile coarse cilia at the anterior end. Cytostome at the end of a short peristome and circular. Long cilia on the peristome. Macronucleus central and spherical. A posterior contractile vacuole. Fresh water. Cyrtolophosis mucicola (Fig. 154, c). Body 25 to 30 microns long. In infusion of dead leaves. Genus Loxocephalus Eberhard. Body elliptical ; anterior end obliquely truncate and bent to one side. Near this end, one or more short, curved setae on one or both sides. Usually one (sometimes more) long caudal setae at the posterior extremity. The cytostome below the bent anterior portion, indistinct. Macronucleus ovoid, central; one contractile vacuole. Fresh water. Loxocephalus granulosus Kent (Fig. 154, d). Body about 50 to 60 microns long. In decaying vegetation. Genus Uronema Dujardin. Body elongate ovoid. Cyto- stome ventral; oblong with an extensible trap-like membrane. Ciliation uniform. One or more caudal setae at the posterior end. A contractile vacuole posterior. Fresh or salt water. Uronema marina Dujardin (Fig. 154, e). Body about 30 to 50 microns long. Common in decaying algae. Genus Dallasia Stokes. Body elongate-ovate, subcylindrical, produced posteriorly into a more or less retractile tail-like pro- longation. One side convex, the other flattened. Cytostome near the anterior end and roughly triangular with two undu- lating membranes. Nucleus oblong, central. One contractile vacuole. Dallasia frontata Stokes (Fig. 154, /). Body 65 to 140 microns long. Polymorphic. Fresh water. 360 HANDBOOK OF PROTOZOOLOGY Genus Frontonia Ehrenberg. Elongated cylindrical; ex- tremities rounded or pointed. Ciliation and striation uniform. Cytostome near the anterior end, oblong; surrounded by elevat- ed ridges which extend posteriorly for some distance. Cyto- pharynx short with rods and two undulating membranes. Macronucleus ellipsoidal; several micronuclei. One or two con- tractile vacuoles with radiating canals. Trichocysts. Fresh or salt water. Frontonia leucas Ehrenberg (Fig. 154, g). Body 250 to 300 microns long. In infusion. Genus Glaucoma Ehrenberg. Body ovoid, ventral surface flattened; dorsal surface convex. Cytostome about one-fourth from the anterior end ; triangular or crescent in form, with Fig. 154 a. Urocentrum turbo. X150 (After Biitschli). b. Ophryoglena fiava. X55 (After Biitschli). c. Cyrtolophosis mucicola. X500 (After Stokes). d. Loxocephalus granulosus. X300 (After Kent). e. Uronema marina. X350 (After Calkins). f. Dallasia frontata. X 580 (After Calkins and Bowling). g. Frontonia leucas. X 150 (After Edmondson). h. Glaucoma scintillans. X180 (After Biitschli). i. G. pyriformis. X 1000 (After McArthur). EU CI LI AT A, HOLOTRICHIDA 361 two undulating membranes. Ciliation and striation uniform. Macronucleus central and spherical. A single micronucleus. Glaucoma scintillans Ehrenberg (Fig. 154, h). Body 90 to 100 microns long. Pond water and infusion. Glaucoma pyriformis MacArthur (Fig. 154, i). In the body cavity of larvae of the mosquito, Theohaldia annulata. Genus Colpoda Miiller. Body kidney-shaped, laterally com- pressed; aboral surface hemi-circular, oral surface somewhat flattened. Cytostome some distance from the anterior end. Long cilia around the opening. Contractile vacuole often ter- minal. Macronucleus central and rounded. Fresh water. Common in infusion. Colpoda helia (Stokes) (Fig. 155, a). Body about 85 to 95 microns long. In standing water with algae. Colpoda campyla (Stokes) (Fig. 155, b). Body about 50 to 60 microns long. In standing water with dead leaves. Colpoda cucullus Miiller (Fig. 155, c). Body about 90 microns long. In infusion. Colpoda inflata (Stokes) (Fig. 155, d). Body about 40 to 50 microns long. In standing water. Genus Colpidium Stein. Similar to Colpoda. Body oval to reniform, elongated, but not so compressed. Peristome shallow, nearer the anterior end, with an undulating membrane. Cyto- stome roughly triangular. Cytopharynx short. Macronucleus central and spherical. A single micronucleus. One contractile vacuole in the posterior half. Fresh or salt water. Very com- mon in infusion. Colpidium striatum Stokes (Fig. 155, e). Length about 50 microns. In infusion of decaying vegetation. * Colpidium colpoda Ehrenberg (Fig. 155,/). The figure shows a marine form, 45 microns long by 20 microns wide. Fresh or salt water. Genus Lambornella Keilin. Body oval; dense ciliation; small cytostome fusiform near the anterior end (?). A spherical macronucleus and a micronucleus. Cysts hemi-spherical. Para- sitic. One species. Lambornella stegomyiae Keilin (Fig. 155, g, h). In the coelom of Stegomyia scutellaris. Body about 50 to 70 microns long. 362 HANDBOOK OF PROTOZOOLOGY Cysts 30 to 40 microns in diameter, 20 microns in width. Keilin studied preserved material. Genus Entorhipidium Lynch. Large and colorless body pyri- form, flattened. Anterior end broadly rounded, posterior end drawn out. Permanently opened cytostome on the dorsal sur- face near the right border in a depression. Cytopharynx indis- Fig. 155 a. Colpoda helia. X400 (After Stokes). b. C. campyla. X400 (After Stokes). c. C. cucullus. X400 (After Maupas from Biitschli). d. C. inflata. X400 (After Stokes). e. Colpidium striatum. X500 (After Stokes). f. C. colpoda from salt water. X500 (After Calkins). g. h. Trophozoite: and cyst oi Lambornella stegomyiae. X250 (After Keilin). i. Entorhipidium echini. X200 (After Lynch), j. Microthorax sulcatus. X400 (After Engelmann). k. Cinetochilum margaritaceum. X400 (After Schewiakoff). tinct. Trichocysts present. A single macronucleus and one to several micronuclei; several "excretory" vacuoles. Several EU CI LI AT A, HOLOTRICHIDA 363 species in the intestine of sea urchins belonging to the genus Strongylocentrotus. Entorhipidium echini Lynch (Fig. 155, i). Large, 253 microns long. With a single micronucleus. Family 3 Microthoracidae Schouteden Genus Microthorax Engelmann. Body small, up to 60 microns in length. Roughly ovoid; ventral side flat, dorsal side convex. Cytostome at the posterior end, with an undulating membrane. Cilia few. Rounded macronucleus central. A con- tractile vacuole between the macronucleus and cytostome. Fresh water. Microthorax sulcatus Engelmann (Fig. 155, j). 45 to 60 microns long. In pond water and infusion. Genus Cinetochilum Perty. Body irregularly ovoid or len- ticular. With d-eep spiral furrows. Beginning at the posterior end on the ventral surface, there is a short oral groove, at the anterior end of which a cytostome surrounded by an undulating membrane, is located. Macronucleus rounded, central; a con- tractile vacuole. Fresh water. Cinetochilum margaritaceum Ehrenberg (Fig. 155, k). Body about 40 microns long. Fresh water. Family 4 Parameciidae Grobben Genus Paramecium Hill ( = Paramaecium O. F. Miiller). Cigar-shaped; circular or ellipsoidal in cross-section. With a single macronucleus and one to many micronuclei which are either vesicular or compact. The peristome long, broad, and conspicuous. Cosmopolitan and common in the stagnant water and infusion. Several species of which nine are here described briefly. Paramecium caudatum Ehrenberg (Fig. 156, a). The most widely distributed and, therefore, most frequently observed species. Length 200 to 260 microns. With a compact micro- nucleus and a massive macronucleus. Two contractile vacuoles on the aboral surface. Posterior end bluntly pointed. Paramecium aurelia Miiller (Fig. 156, h). Length 120 to 250 microns. Two small vesicular micronuclei and a massive macro- 364 HANDBOOK OF PROTOZOOLOGY nucleus. Two contractile vacuoles on the aboral surface. The posterior end is more rounded than P. caudatum. Paramecium miiltimicronucleatiim Powers and Mitchell (Fig. 156, c). Body as a rule is slightly larger than P. caudatum. With three to seven contractile vacuoles. Four or more vesicular micronuclei and a single macronucleus. Paramecium hursaria (Ehrenberg) (Fig. 156, d). Foot- shaped, somewhat compressed. Body about 100 to 200 microns long by 50 to 60 microns broad. Containing Zoochlorellae as symbionts. A single compact micronucleus; two contractile vacuoles. Paramecium putrinum Claparede and Lachmann (Fig. 156, e). Similar to P. hursaria, but a single contractile vacuole and an elongated macronucleus. No Zoochlorellae. Body about 80 to 150 microns long. Paramecium calkinsi Woodruff (Fig. 156,/). Foot-shaped; posterior end broadly rounded. Body 100 to 130 microns long by 50 microns broad. With two vesicular micronuclei. Two contractile vacuoles. The rotation of the body is clockwise, viewed from the posterior end. Fresh or brackish water. Paramecium trichium Stokes (Fig. 156, g). Body oblong; somewhat compressed; about 70 to 100 microns long. A single compact micronucleus. Two contractile vacuoles deeply situa- ted, each with a convoluted outlet. Paramecium polycaryum Woodruff and Spencer (Fig. 156, h). Body form similar to P. hursaria. Length 70 to 110 microns. Two contractile vacuoles. Vesicular micronuclei three to eight in number. Paramecium woodruffi. Wenrich (Fig. 156, i). Similar to P. polycaryum. Length 150 to 210 microns. Two contractile vacuoles. Three or four micronuclei, vesicular. Brackish water. Although Paramecium occurs widely in various fresh-water bodies and has been studied extensively by numerous investi- gators 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 in which encystment did not occur. But stages of encystment have been observed in 1899 in P. hursaria (by Prowazek) and in P. putrinum (by Lindner) , In recent years, three observers recorded E U CI LI A TA , HOW TRICHIDA 365 their findings on the encystment of Paramecium. Curtis (1927) gives figures showing the encystment in Paramecium (P. cauda- tum?) (Fig. 157, a-c), while Cleveland (1927) injected Para- Fig. 156 Semi-diagrammatic drawings of nine species of Paramecium in oral surface view, showing distinguishing characteristics taken from fresh and stained specimens. X230 (Combined after several authors). a. P. caudatum f. P. calkinsi b. P. aurelia g. P. trichium c. P. multimicronucleatum h. P. polycaryum d. P. bursalia i. P. woodruffi e. P. putrinum 366 HANDBOOK OF PROTOZOOLOGY mecium culture (species not mentioned) into the rectum of frogs and observed that the ciliate encysted within a thin mem- brane. Michelson (1928) found that if Paramecium caudatum is kept in Knop-agar medium, the organism becomes ellip- soidal, later spherical to oval, losing all cell-organs except the nuclei, and develops a thick membrane. The fully formed cyst is elongated and angular, and resembles a sand particle (Fig. 157, d-f). Michelson considers its resemblance to a sand grain as the chief cause of the cyst having been overlooked by workers. Fig. 157 a-c. Encystment in a species of Paramecium (after Curtis), d-f. Encystment of Paramecium caudatum. X about 380 (After Michelson). d, e, young cysts; f, old cyst. Family 5 Pleuronematidae Kent One or more well developed undulating membranes are con- spicuously present. Genus Pleuronema Dujardin. Body medium large; elliptical to lenticular, compressed. The ends are equally rounded. Peri- stome is a long groove starting at the anterior extremity, from which is expanded a conspicuous membrane. Longitudinal rows of long cilia. Trichocysts are said to be occasionally present. E U CILIA TA , IIOLO TRICHIDA 367 Macronucleus ovoid; contractile vacuole near the posterior end. Fresh or salt water. Pleuronema chrysalis Ehrenberg (Fig. 158, a). Body about 50 to 70 microns long. In fresh or salt water. Genus Cyclidium Ehrenberg. Body small ovoid, slightly compressed. Cytostome ventral; peristome narrow, with a con- spicuous membrane. One caudal filament. Fresh or salt water. Cyclidium glaucoma Ehrenberg (Fig. 158, b). Body about 20 to 30 microns long. Fresh water. Fig. 158 a. Pleuronema chrysalis. X400 (After Calkins). b. Cyclidium glaucoma. X500 (After SchewiakofT). c. Lembadion bullinum. X 150 (After SchewiakofT). d. Lembus pusillus. X550 (After Calkins). e. L. infusionum. X550 (After Calkins). f. Pleurocoptes hydractiniae. X350 (After Wallgren). g, h. Calyptotricha inhaesa. (After Kellicott). g, lorica (XlOO); h, the body (X250). Genus Lembadion Perty. Body medium large; form con- stant. Oval, slightly flattened dorso-ventrally. Peristome very large and with a large membrane. Cytostome at the end of the peristome. Macronucleus reniform near the posterior end where several long and firm cilia are located. A single contractile vacuole towards the right side near the middle. Fresh water. 368 HANDBOOK OF PROTOZOOLOGY Lemhadion hullinum Perty (Fig. 158, c). About 100 to 150 microns long. Fresh water. Genus Lembus Cohn. Body rather small; elongated and flexible. Peristome narrow and possesses one or two (?) mem- branes. There are one or more long caudal filaments. Marine. Lembus pusillus Quennerstedt (Fig. 158, d). About 26 to 30 microns long. In marine infusion. Lembus infusionum Calkins (Fig. 158, e). 70 to 75 microns long by 10 to 12 microns wide. Marine. Genus Pleurocoptes Wallengren. Body ovoid. Dorsal side hemi-spherical, ventral side flattened or concave. Peristome large; cytostome near one-third from the posterior end; cyto- pharynx indistinct. Longer cilia along peristome. Macronucleus spherical; several micronuclei. A contractile vacuole posterior. Ectoparasitic on Hydractinia. Pleurocoptes hydractiniae Wallengren (Fig. 158, /). Body measures 60 to 70 microns long. On Hydractinia echinata. Genus Calyptotricha Phillips. Resembles Pleuronema, but dwelling in a lorica which is opened on both ends. The body is actively motile. Fresh water. Calyptotricha inhaesa (Kellicott) (Fig. 158, g, h). In swamp water. Attached laterally to filamentous algae. Lorica 180 to 210 microns long; body about 30 microns long. Family 6 Isotrichidae Schouteden The majority of the members of this family live in the mid- gut of ruminants and are covered by a thick pellicle. Ciliation uniform and thick. Genus Isotricha Stein. Body ovoid. Ciliation heavy and uniform. Cytostome is either at the anterior end or somewhat toward one side. Oblong macronucleus nearer the anterior end, with a micronucleus. Contractile vacuoles numerous. Cytopyge is usually noticeable at the posterior extremity. Two species in the stomach of cattie and sheep. Isotricha prostoma Stein (Fig. 159, a). 80 to 200 microns long. Isotricha intestinalis Stein (Fig. 159, b). 97 to 130 microns long. E U CI LI A TA , HOLOTRICHIDA 369 Genus Dasytricha Schuberg. Body regularly ovoid. Cyto- stome at the anterior end with a curved cytopharynx. A macro- nucleus and a micronucleus. A single contractile vacuole. One species. Dasytricha riiminantium Schuberg (Fig. 159, c). In the rumen of cattle and sheep. 50 to 75 microns long. Genus Conchophthirus Stein. Body colorless and not con- tractile. Oval in profile; ventral side less convex. Peristome occurs towards the right side. Cytostome large, in the middle or near the posterior end. Cytopharynx distinct. Usually a few Fig. 159 a. Isotricha prostoma. X375 (After Becker and Talbott). b. /. intestinalis. X375 (After Becker and Talbott). c. Dasytricha ruminantium. X245 (After Becker and Talbott). d. Conchophthirus steenstrupii. XlOO (After Quennerstedt). e. Buxtonella sulcata. X295 (After Jameson). longer cilia at the posterior end. Occasionally adoral zone in the anterior portion of the peristome. Macronucleus spherical, several. Free-living in fresh water or parasitic in the mucous membrane of various molluscs. Conchophthirus steenstrupii Quennerstedt (Fig. 159, d). About 175 microns long. Genus Buxtonella Jameson. Body oval. A prominent curved ridge runs from one end to the other on the dorsal side, and ex- tends to the ventral side, where a cytostome is located. In the caecum of cattle. Buxtonella sulcata Jameson (Fig. 159, e). Body 55 to 124 microns long by 40 to 72 microns broad. 370 HANDBOOK OF PROTOZOOLOGY References Becker, E. R. and Mary Talbott. 1927 The protozoan fauna of the rumen and reticulum of American cattle. Iowa State Coll. Jour. Sci., Vol. 1 Calkins, G. N. 1926 The biology of the Protozoa. Phila- delphia. Cepede, C. 1910 Recherches sur les Infusoires astomes. Arch. Zool. Exper., T. 3. Conn, H. W. 1905 A preliminary report of the Protozoa of the fresh-water of Connecticut. Conn. State Geol. and Nat. Hist. Survey, Bull. No. 2. DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- tozoenkunde. Jena. Edmondson, C. H. 1906 The Protozoa of Iowa. Proc. Davenport Acad. Sci., Vol. 11. Kahl, a. 1926 Neue und wenige bekannte Formen der holotrichen und heterotrichen Ciliaten. Arch. f. Protis- tenk., Vol. 55. . 1927 Neue und erganzende Beobachtungen holo- tricher Ciliaten. Ibid., Vol. 60. Michelson, E. 1928 Existenzbedingungen und Cystenbild- ung bei Paramecium caudatum Ehrenberg. Ibid., Vol. 61. Noland, L. E. 1925 Factors influencing the distribution of fresh-water ciliates. Ecology, Vol. 6. Penard, E. 1922 Etudes sur les Infusoires d'eau douce. Geneva. Wenrich, D. H. 1928 Eight well-defined species of Para- mecium. Trans. Amer. Micr. Soc, Vol. 47. Wenyon, C. M. 1926 Protozoology. Vol. 2. London, CHAPTER XXIX ORDER 2 HE'TEROTRICHIDA STEIN THIS ORDER includes those Euciliata which possess an adoral zone that is wound to the left. The adoral zone is composed either of strong cilia or membranellae. As a rule, the body is covered by delicate cilia which, however, may be reduced in some forms. The cytopharynx possesses a conspicuous undulat- ing membrane. In one group Tintinnoinea, the animal secretes a lorica. Free-living or parasitic. Following an extensive study of Kofoid and Campbell, the Euciliata which were formerly placed in the family Tintinnidae, are removed from Oligotrichida into the present order. The Heterotrichida are, therefore, divided into two suborders as follows: Without a lorica Suborder 1 Gymnoheterotrichina With a lorica Suborder 2 Tintinnoinea Suborder 1 Gymnoheterotrichina The group will be divided into six families: Adoral zone parallel to the main body axis Peristome is narrow and long Family 1 Plagiotomidae Peristome is wide, triangular, and deep Family 2 Bursariidae Adoral zone not parallel to the main body axis Body funnel-shaped; adoral zone strong Cytopharynx tubular; free-living Family 3 Stentoridae Cytostome not permanently open; ectoparasitic . . . . Family 4 Boveriidae Body form medusoid Family 5 Caenomorphidae Body asymmetrical; sapropelic; cilia reduced Family 6 Epalcidae Family 1 Plagiotomidae Poche Genus Plagiotoma Dujardin. Body form constant, ovoid; convex dorsally, flattened ventrally. Peristome extends from the anterior end to the middle of the body, where a cytostome is located. Cytopharynx distinct. There is a single bristle ex- tending out of the cytostome. Parasitic. [371] 372 HANDBOOK OF PROTOZOOLOGY Plagiotoma lumhrici Dujardin (Fig. 160, a). In the intestine of the common earthworm, Lumhricus terrestris. Length 130 to 210 microns. Genus Nyctotherus Leidy. Body oval or reniform, more or less compressed dorso-ventrally. Body surface uniformly cili- ated. Peristome begins a little back of the anterior end of the body, winding slightly toward the middle of the body, and forms the cytostome, from which a small cytopharynx continues down. The macronucleus is oval or sausage-shaped and an- teriorly located. Contractile vacuole at the posterior end, where a permanent cytopyge is present. Several species. Nyctotherus ovalis Leidy (Fig. 160, b, c). In the colon of the cockroach. Common. Body length up to 350 microns. Nyctotherus cordiformis Stein (Fig. 160, d, e). In the large intestine of frogs and toads. Length about 165 to 240 microns. Genus Blepharisma Perty. Body medium large, constant in form; often reddish in color. Anterior part compressed, pointed, sickle-shaped, and curved toward the left. Peristome deep, oblique, but straight; with an adoral zone and undulating membrane at the posterior part. Cytopharynx inconspicuous, curved. Striation spiral and uniform. Macronucleus elongate or spherical; contractile vacuole near the posterior end. Fresh water. Blepharisma lateritia Ehrenberg (Fig. 160, /). Body rose- red due to the presence of zoopurpurin (p. 23). 50 to 150 microns long. Fresh water, often in infusion. Genus Spirostomum Ehrenberg. Body highly elastic and contractile. When extended it is quite long. Cylindrical or slightly flattened. Anterior end rounded, posterior end trun- cate. Peristome narrow and long. Adoral zone on the left side ridge; no undulating membrane. Cytostome and cytopharynx small. Contractile vacuole canal-like with a large reservoir near the posterior end. Uniform ciliation. Fresh or salt water. Spirostomum amhiguum Ehrenberg (Fig. 160, g). Cosmo- politan in fresh water and infusion. Some authors distinguish varieties, based chiefly upon the dimensions. Thus, Roux holds that var. major is more than 2 mm. long when extended and that var. minor seldom reaches 500 microns in length. Kahl adds to them var. inflatum which measures 300 to 400 microns HETEROTRICHIDA 373 in length. For our purpose, we ignore the varieties. Length 500 microns to 2 mm. when extended. The macronucleus monili- form. Spirostomum teres Claparede and Lachmann (Fig. 160, h). In habitats similar to the last species. Smaller with an oblong macronucleus. Length 150 to 400 microns. Fig. 160 a. Plagiotoma lumbrici. X 140 (After Stein). b, c. Nyctotherus ovalis. X130 (After Stein), c, cyst, d, e. N. cordiformis. X130 (After Stein), e, cyst. f. Blepharisma lateritia. X 100 (After Stein). g. Spirostomum ambiguum. X70 (After Stein). h. S. teres. XI 25 (After Stein). i-k. Metopus sigmoides. i, from life ( X 100 after Stein) ; j, a stained specimen (X250 after Noland); k, encysted exconjugant after life (X210 after Noland). Genus Metopus Claparede and Lachmann. Body elastic. When extended it is oblong or fusiform, with rounded extremi- ties. Circular or oval in cross-section. Anterior part of the body spirally twisted. Peristome with an adoral zone on its left side; 374 HANDBOOK OF PROTOZOOLOGY undulating membrane on the right. When contracted, the peri- stome is much spirally coiled. The cytostome with a short cyto- pharynx at the end of the peristome. Body ciliation uniform, with longer cilia at the extremities. Contractile vacuole pos- terior; macronucleus elongated. Fresh or salt water. Numerous species. Metopus sigmoides Claparede and Lachmann (Fig. 160, i-k). Fresh or rarely salt water. Body about 200 microns in length. Family 2 Bursariidae Kent Peristome is wide, more or less triangular, and of variable length. The adoral zone is on the left margin of the peristome. The right side ridge may or may not bear an undulating mem- brane. Free-living or parasitic. Genus Bursaria Miiller. Body ovoid with the truncate an- terior end. Dorsally convex, ventrally flattened. Deep peri- stome begins at the anterior end, and forms on the ventral side a slit reaching the middle where it passes into a long cyto- pharynx. Adoral zone. No undulating membrane. Striation and ciliation uniform. Macronucleus elongated band, often curved. Micronucleus numerous. Contractile vacuole when visible, numerous and scattered. Cysts are spherical with a double thick membrane, the inner cover being connected at places with the outer. Fresh water. Bursaria truncatella (Fig. 161, a). 500 to 600 microns long. Pond or marshy water. Genus Balantidium Claparede and Lachmann. Body large, oval to subcylindrical, slightly truncate anteriorly. Peristome medium wide and slightly oblique in direction. At its posterior end, is located a cytostome with a short cytopharynx. Ciliation uniform. Macronucleus elongated. One or more contractile vacuoles. A cytopyge. Several species. Parasitic in the intes- tine of man, mammals and amphibians. Balantidium coli (Malmsten) (Fig. 161, b, c). In the intes- tine of pigs and man. Body about 50 to 100 microns long by 30 to 70 microns broad. The infection in man is presumably acquired from the cysts produced in pigs, and is responsible for a serious intestinal disturbance in the unfortunate patient. Genus Balantidiopsis Blitschli. Body ovoid. Cytostome HETEROTRICHIDA 375 a narrow slit, opening at the anterior end. One contractile vacuole at the posterior end. Macronucleus spherical and pos- terior. Parasitic. Balantidiopsis duodeni (Stein) (Fig. 161, d). Body about 110 microns long. In the mid-gut of various frogs (Rana). Genus Condylostoma Dujardin. Body colorless and oval to cylindrical or club-shaped. Contractile; flattened slightly dorso- ventrally. Peristome short at the anterior region, the left mar- gin bears the adoral zone and the right ridge an undulating membrane. Macronucleus moniliform. One or several contrac- tile vacuoles. If one is present, there is a long canal leading into it. Cytopyge posterior. Fresh or salt water. Condylostoma patens Mliller (Fig. 161, e). Body large 350 to 550 microns long. Salt water. Condylostoma vorticella Ehrenberg (Fig. 161,/). 150 microns long. Fresh water. Family 3 Stentoridae Claus The anterior end is broad and at about right angles to the longitudinal axis of the body. Almost all of them free-living. Genus Stentor Oken. Attached or free-swimming. When ex- tended, the body is cylindrical or trumpet-shaped. Occasion- ally with a mucilaginous lorica. When free-swimming, the body is oval to pyriform. The anterior end possesses a peristome which is spiral in its course and at its end is located a cyto- stome. A row of strong cilia marks the peristomal ridge. Cilia- tion fine and regular. Macronucleus rounded to elongate or moniliform. Several micronuclei indistinguishable in vivo. The cytopyge is located near the left end of the adoral spiral. A single contractile vacuole which is usually present near the anterior end possesses a long canal which runs posteriorly in a more or less straight course. Sometimes with chlorophyll. Fresh or salt water. Johnson (1893) distinguishes the following species. Stentor igneus Ehrenberg (Fig. 161, g). On plants in fresh- water. When extended 350 microns long. Stentor pyriformis ]o\inson {Y'xg. \6\,h). Freshwater. When extended 500 microns long, diameter of the anterior end 200 microns. 376 HANDBOOK OF PROTOZOOLOGY Stentor roeseli Ehrenberg, Standing fresh water among de- caying vegetation. Body colorless ; when extended, reaches over 1 mm. The posterior end often in a tubular envelope. Stentor polymorphus (Miiller) (Fig. 161, i). Among fresh- water plants. Extended body measures 1.25 mm. Fig. 161 a. Bursaria truncatella. X50 (After Calkins), b, c. Balanlidium coli. X400. c, a cyst. d. Balantidiopsis duodeni. X 125 (After Stein). e. Condylostoma patens. X 135 (After Calkins). f. C.vorticella. X 160 (After Butschli). g. Stentor igneus. XI 15 (After Stein), h. S. pyriformis. XI 15 (After Johnson), i. S. polymorphus. X 50 (After Stein). HE TERO TRICHIDA 377 Stentor coeruleus Ehrenberg. In fresh water. Body bluish in color and measures 130 to 265 microns in length. Stentor jnultiformis (Mliller). In salt water. Social. Ex- tended body measures about 140 microns in length. Genus Folliculina Lamarck. Peristome is drawn out ; with two wings; with a membranella. With an elongated pseudo- chitinous lorica. Marine. Folliculina ampulla Miiller (Fig. 162, a). Body more than 1 mm. in length when extended. Salt water. Genus Climacostomum Stein. Medium large. Colorless or green with Zoochlorellae. Body form constant, compressed dorso-ventrally; right side convex. Peristome conspicuous; Fig. 162 a. Folliculina ampulla. X125 (After Stein). b. Climacostomum virens. X75 (After Stein). c. Boveria teredinidi. X410 (After Pickard). d. Caenomorpha medusula. X 150 (After Blochmann). cytopharynx long and curved. Contractile vacuole posterior with two radiating canals. Macronucleus band-form, central. Cysts pyriform or oval. Fresh water. Climacostomum virens (Ehrenberg) (Fig. 162, b). Body about 250 microns long. Family 4 Boveriidae Pickard Genus Boveria Stevens. Ectoparasitic on gills of various marine animals, such as Teredo, Bankia, Tellina, Capsa, and Holothuria. Body conical, adoral zone conspicuous. One macronucleus central and one micronucleus. One contractile vacuole. 378 HANDBOOK OP PROTOZOOLOGY Boveria teredinidi Pickard (Fig. 162, c). Body about 27 to 173 microns long. On gills of Teredo navalis. Family 5 Caenomorphidae Poche Genus Caenomorpha Perty ( = Gyrocoris Stein). Body con- stant and colorless. Free-swimming. The anterior portion bell- shaped, posterior half drawn out. Peristome long, oblique with strong cilia. Elongated macronucleus with a constriction. A single contractile vacuole. Fresh or salt water. Several species. Caenomorphn medusula Perty (Fig. 162, d). Fresh water. Body about 100 to 130 microns long. Fig. 163 a. Epalxis mirabilis. X900 (After Roux). b. Pelodinium reniforme. X450 (After Lauterborn). c. Discomorpha pectitiata. X165 (After Kahl). d. Saprodinium dentatum. X320 (After Kahl). e. Tintinnidium fluviatile. X 100 (After Kent). f, g. T. semiciliatum. XlOO (After Sterki). Family 6 Epalcidae Wetzel Asymmetrical body discoid, compressed laterally; cilia re- duced. Spines and comb-like structures about the cytostome. Sapropelic. Genus Epalxis Roux. Body rounded triangular; anterior end bluntly pointed, posterior end drawn out into 7 or 8 blunt processes. Dorsal surface convex. Cytostome at the anterior HETEROTRICHIDA 379 third with comb-like structure posterior to it. Oval macro- nucleus dorsal. Fresh water. Epalxis mirahilis Roux (Fig. 163, a). Body 32 to 40 microns long by 27 to 30 microns broad. Genus Pelodinium Lauterborn. Body form constant. Simi- lar to Epalxis, but the posterior end narrowed. Pelodinium reniforme Lauterborn (Fig. 163, b). Body 40 to 50 microns long. Genus Discomorpha Levander. Anterior end with a ven- trally pointed spine. There are two spines on the right side of the body. Discomorpha pectinata Levander (Fig. 163, c). Body 60 to 80 microns long. Genus Saprodinium Lauterborn. With six or eight posterior spines, but none on the sides. Saprodifiium dentatum Lauterborn (Fig. 163, d). Body 80 microns by 72 microns. Suborder 2 Tintinnoinea Kofoid and Campbell These Hetrotrichida possess a conical or trumpet-like body, attached inside a lorica which is composed of gelatinous or pseudochitinous substances and which varies in shape. Body with several longitudinal rows of cilia, and two macronuclei and two micronuclei are present in the majority. The organisms are mostly pelagic, a few inhabiting brackish or fresh water. Kofoid and Campbell distinguished more than 300 species and placed them in 12 families and 51 genera, of which 23 genera were es- tablished by them. Here a fresh water genus is mentioned. Genus Tintinnidium Kent. With an elongated lorica, highly irregular in form ; soft in consistency. Aboral end closed or with a minute opening. Wall viscous and freely agglomerates foreign objects. Salt or fresh water. Tintinnidium fliiviatile (Stein) (Fig. 163, e). Lorica about 125 microns high by 45 microns broad. Widely distributed on aquatic plants in fresh water. Tintinnidium semiciliatum (Sterki) (Fig. 163, /, g). Body length 40 to 60 microns. Widely distributed on aquatic plants in fresh water. 380 HANDBOOK OF PROTOZOOLOGY References Calkins, G. N. 1926 The biology of the Protozoa. Johnson, H. P. 1893 A contribution to the morphology and biology of the stentors. Jour. Morph., Vol. 8. Kahl, a. 1927 Neue und erganzende Beobachtungen hetero- tricher Ciliaten. Arch. f. Protistenk., Vol. 57. Kent, W. S. 1881-1882 A manual of Infusoria. Vol. 2. London. KoFOiD, C. A. AND A. S. Campbell. 1929 A conspectus of the marine and fresh-water Ciliata, belonging to the suborder Tintinnoinea, with descriptions of new species principally from the Agassiz Expedition to the eastern tropical Pacific 1904 to 1905. Uni. Cahfornia Publ. Zool., Vol. 34. Stein, F. 1867 Der Organismus der Infusionstiere. Vol. 2. CHAPTER XXX ORDER 3 OLIGOTRICHIDA BUTSCHLI THE CILIA are greatly reduced in number in the Oligotrichida. The adoral zone which is invariably present, is a complete ring bordering the left-side margin of the peristome which is at right angles to the main body axis. The Oligotrichida are chiefly parasitic forms. The order is divided into two families as follows: Free-living small forms Family 1 Halteriidae Parasitic in the digestive tract of mammals. . . .Family 2 Ophryoscolecidae Family 1 Halteriidae Claus Genus Halteria Dujardin. Small spherical body. Adoral zone at the anterior end. Near the middle of the body there is a circle of long cirri which serve for springing movement. No other cilia. Macronucleus spherical or oval; a single contrac- tile vacuole. Fresh water. Halteria grandinella Miiller (Fig. 164, a). Body length 20 to 30 microns. Common in infusion, pond, and stagnant water. Genus Strombidium Claparede and Lachmann. Similar to Halteria, but without springing cirri. Sometimes yellowish in color. The adoral zone is protrusible; frequently with tricho- cysts. A single cilium or a few cilia may be present on the vent- ral side. Salt or fresh water, Strombidium typicum (Lankester) (Fig. 164, b). About 35 microns in length. Marine. Family 2 Ophryoscolecidae Claus Genus Ophryoscolex Stein. In the stomach of ruminants. Body more or less pyriform. Posterior end is drawn out into a number of processes; at the anterior end there is a conspicuous ring of cirri which continues through the cytostome into the cytopharynx. A little toward the back there is an incomplete circle of cirri. With numerous contractile vacuoles. [3811 382 HANDBOOK OF PROTOZOOLOGY Ophryoscolex caudatus Eberlein (Fig. 164, c). In the stomach of cattle. Body about 200 microns in length. Genus Entodinium Stein. In the stomach of ruminants. Body ovoid; anterior end with a spiral row of cirri extending through the cytostome into the cytopharynx; posterior end drawn out into one or several processes. Macronucleus rod- shaped, micronucleus small. One contractile vacuole. Entodinium caudatum Stein (Fig. 164, d). About 50 to 80 microns long. In cattle and sheep. Genus Diplodinium Schuberg. In the stomach of ruminants. Body oblong. Cytostome is located near the anterior end at one side and surrounded by a peristome with a spiral row of cirri. Towards the dorsal side, there is another spiral of cirri. The posterior end of the body is with or without prolongations. An elongated macronucleus with a closely associated micronucleus, is situated near the dorsal surface. Two contractile vacuoles; a cytopyge at the posterior end of body. Diplodinium bursa Fiorentini (Fig. 164, e). In the stomach of cattle. Body 100 to 150 microns long. Genus Spirodinium Fiorentini. Body oblong; with about three turns of a spiral row of cirri. Macronucleus oblong. Spirodinium equi Fiorentini (Fig. 164,/). In the caecum of the horse. About 230 microns long. Genus Triadinium Fiorentini. Body is rounded at the an- terior end, and pointed at the posterior end. With three rings of cirri, and a caudal tuft of cilia. Macronucleus elongate. Triadinium caudatum Fiorentini (Fig. 164, g). In the caecum of the horse. About 130 microns long. Genus Cycloposthium Bundle. Body large, barrel-shaped. Cytostome is in the center of a conical elevation at the anterior end, surrounded by a circle of cirri. Near the posterior end there are two groups of long processes. Macronucleus elongate. Several contractile vacuoles in a row along the macronucleus. Cycloposthium bipalmatum (Fiorentini) (Fig. 164, h). In the caecum of the horse. About 255 microns long. Genus TTipalmaria Gassovsky. Body oblong, similar to Cycloposthium, but three bundles of long processes, two on the sides near the posterior end and one on the dorsal side near the anterior end. Two longitudinal ridges. OLIGOTRICHIDA 383 Fig. 164 a. Halteria grandinella. X400 (After Schewiakoff). b. Stromhidium typicum. X800 (After Biitschli). c. Ophryoscolex caudatus. X250 (After Becker and Talbott). d. Entodinium caudatum. X375 (After Becker and Talbott). e. Diplodinium bursa. X250 (After Becker and Talbott). f. Spirodinium equi. X 130 (After Gedoelst). g. Triadinium caudatum. XI 70 (After Gedoelst). h. Cycloposthium bipalmatum. X225 (After Bundle), i. Tripalmaria dogieli. X 135 (After Gassovsky). j. Telratoxum unijasciculatum. X135 (After Gassovsky). k. Cochliatoxum periachtum. X65 (After Gassovsky). 1. Ditoxum funinucleum. X 135 (After Gassovsky). 384 HANDBOOK OF PROTOZOOLOGY Tripalmaria dogieli Gassovsky (Fig. 164, i). In the colon of the horse. About 100 to 200 microns long. Genus Tetratoxum Gassovsky. Body oblong slightly com- pressed and medium in size. There are four arched membranes, two being near each end. Slit-like cytostome surrounded by cilia at the anterior end. There are six to eight longitudinal ridges. Macronucleus band-form. A contractile vacuole near the macronucleus. Tetratoxum unifasciculatum (Fiorentini) (Fig. 164,7). In the colon of the horse. Genus Cochliatoxum Gassovsky. Similar to Tetratoxum; body much larger; two contractile vacuoles. Cochliatoxum periachtum Gassovsky (Fig. 164, k). In the colon of the horse. About 400 to 500 microns long. Genus Ditoxum Gassovsky. Somewhat similar to Tetra- toxum, but with a single posterior arched membrane. Macro- nucleus elongated. Ditoxum funinudeum Gassovsky (Fig. 164, /). In the colon of the horse. Body about 145 to 225 microns long. References Becker, E. R. and Mary Talbott. 1927 The protozoan fauna of the rumen and reticulum of American cattle. Iowa State Coll. Jour. Sci., Vol. 1. DoGiEL, V. 1925 Die Geschlechtsprozess bei Infusorien. Arch. f. Protistenk., Vol. 50. Gassovsky, G. 1918 Ueber die Mikrofauna des Pferdedarms. Trav. Soc. Nat. Petrograd. Vol. 49. CHAPTER XXXI ORDER 4 HYPOTRICHIDA STEIN THE MEMBERS of this Order are usually dorso-ventrally flat- tened and cilia or cirri are restricted to the ventral surface. In some forms there occur dorsal processes which apparently are used as tactile organelles. Peristome possesses an adoral zone which is a left-handed spiral. The undulating membrane often occurs. According to their location, the cirri may be called frontals, ventrals, laterals or marginals, anals, and caudals (Fig. 10, b). There are usually two macronuclei and two micro- nuclei. Contractile vacuoles vary in number and do not possess radiating canals. Asexual reproduction is by binary fission and sexual repro- duction through isogamous conjugation is common, Encyst- ment often takes place. Mostly free-living in fresh or salt water, undergoing creeping movement. A few are parasitic. The order is divided into the following five families: With ventral cilia; adoral zone conspicuous Family 1 Peritromidae With cilia and cirri Family 2 Oxytrichidae With cirri only With frontals, ventrals, anals, marginals Family 3 Euplotidae With frontals, ventrals, anals; without laterals Family 4 Aspidiscidae Frontals and ventrals much reduced Family 5 Psilotrichidae Family 1 Peritromidae Stein Genus Peritromus Stein. Simplest form of the Hypotrichida. Cilia present uniformly and densely on the ventral surface. No stouter cilia nor cirri. Marine. Peritromus emmae Stein (Fig. 165, a, 6). In salt water. Body about 90 microns long. Family 2 Oxytrichidae Kent Genus Oxytricha Ehrenberg. Flexible body ellipsoid, rounded at the extremities. Ventral surface flat; dorsal convex. 8 frontals, 5 ventrals, 5 anals, and short caudals. Numerous species. [385] 386 HANDBOOK OF PROTOZOOLOGY Oxytricha fallax Stein (Fig. 165, c). In fresh or salt water. About 150 to 180 microns long. Genus Stylonychia Ehrenberg. Inflexible body, ovoid or reniform. Ventral surface flat; dorsal convex. Peristome broadly triangular. 8 frontals, 5 ventrals, 5 anals. Usually 3 caudals which break up the marginal rows of cilia. Fresh or salt water. Stylonychia mytilus (M tiller) (Fig. 165, d). Fresh water and infusion. Body about 85 to 350 microns in length. Stylonychia pustulata Ehrenberg (Fig. 165, e). Fresh or salt water. Body about 85 to 210 microns long. Stylonychia putrina Stokes (Fig. 165,/). Fresh water. 125 to 150 microns long. Stylonychia notophora Stokes (Fig. 165, g). Standing water. Body about 125 microns long. Genus Urostyla Ehrenberg. Flexible body ellipsoidal; ends rounded. Ventral surface flattened, covered with 5 to 7 longi- tudinal rows of fine cilia, besides two marginal rows. Dorsal side curved. Peristome triangular. Frontals 3 or more, anals 5 to 12. A single contractile vacuole and a single macronucleus.. Fresh or salt water. Urostyla grandis Ehrenberg (Fig. 165, h). Fresh water. Body 400 to 420 microns in length. Genus Kerona Ehrenberg. Body reniform. No caudals. Six oblique rows of ventral cilia. Fresh water. Kerona pediculiis (Muller) (Fig. 165, i). On various species of freshwater Hydra. Body 120 to 210 microns in length. Genus Epiclintes Stein. Spoon-shape; ventral side flat with 5 or 6 rows of cilia. Without caudals. Salt water. Epiclintes radiosa Quennerstedt (Fig. 165, j). Body about 45 microns long. In salt water. Genus Amphisia Sterki. Ovate or ellipsoidal. Two rows of marginal cirri; 2 or 3 rows of ventral cirri; 3 to 5 frontals; 5 to 10 anals. Macronucleus double; a single contractile vacuole. Peristome long and narrow; with an undulating membrane on the right margin. Fresh or salt water. Amphisia kessleri Wrzesniowski (Fig. 165, k). Marine. About 135 microns long. HYPOTRICniDA 387 Fig. 165 a,b. c. d. e. f. g- h. Peritromus emmae. X330 (After Calkins). Oxytricha fallax. X 1 70 (After Stein) . Stylonychia mytilus. XI 50 (After Stein). S. pustulata. XlOO (After Stein). 5. putrina. X150 (After Stokes). S. notophora. X150 (After Stokes). Urostyla grandis. XlOO (After Stein). Kerona pediculus. X140 (After Stein). Epiclintes radiosa. X400 (After Calkins). Atnphisia kessleri. X300 (After Calkins). Holosticha rubra. X200 (After Entz). 388 HANDBOOK OF PROTOZOOLOGY Genus Holosticha Enz. Two ventral and two marginal rows of cirri. Caudals. Salt or fresh water. Holosticha rubra Ehrenberg (Fig. 165, /). Marine. Body about 180 microns long. Genus Stichotricha Perty. Body contractile, elongate cylin- drical. Long peristome reaches the middle of the body. Rows of cilia spiral. Sometimes tube-dwelling, then colonial. Fresh or salt water. Stichotricha secunda Perty (Fig. 166, a). Fresh water. About 180 to 200 microns long. Fig. 166 a. b. c-e. f. g- h. Sty chotrich a secunda. X150 (After Stein). Uroleptus musculus. X180 (After Stein). Pleurotricha lanceolata. X275 (After Meanwell). c, active form; d, encysting form; e, encysted individual. Gastrostyla steini. X200 (After Calkins). Onychodromus grandis. X170 (After Stein). Actinotricha saltans. X200 (After Maupas from Biitschli). HYPOTRICHIDA 389 Genus Uroleptus Ehrenberg. Body sometimes rose or violet in color. Elongate to cylindrical. The anterior end rounded, posterior end more or less drawn out. Three frontals; 4 or 5 rows of ventral cirri, but no posterior cirri. Peristome about one-third the length of the body. Fresh or salt water. Uroleptus musculiis Ehrenberg (Fig. 166, h). Fresh water. Body about 130 to 210 microns long. Genus Pleurotricha Stein. Body oblong with rounded ends. Marginal rows of cilia continuous. Five anals. Ventral cilia in two rows or somewhat irregular. Between the ventral and marginal rows are 1 to 3 rows of coarse cilia. Peristome broad, one-third the body length. Fresh water. Pleurotricha lanceolata (Ehrenberg) (Fig. 166, c-e). Fresh water. Body measures 100 to 165 microns long. Genus Gastrostyla Engelmann, Body flexible; with broken rows of ventral cirri. Fresh or salt water. Gastrostyla steini Engelmann (Fig. 166, /). Body about 220 microns long by 80 microns broad. Genus Onychodromus Stein. Inflexible body large, some- what rectangular. Anterior end truncate; posterior end rounded. Ventral surface flat; dorsal convex. Peristome broadly tri- angular. Three frontals. Parallel to the right ridge of the peri- stome run three rows of cirri in oblique direction. Five or six anals. Marginals uninterrupted. Four to eight macronuclei; one contractile vacuole. Onychodromus grandis (Fig. 166, g). Fresh water. Body about 100 to 350 microns long. Genus Actinotricha Cohn. Body colorless, flexible; peri- stome small. Its left border bears a small number of large membranellae arranged in the form of a fan. Marine. Actinotricha saltans Cohn (Fig. 166, h). Salt water. Body about 100 microns long. Family 3 Euplotidae Glaus Genus Euplotes Ehrenberg. Inflexible body ovoid; ventral surface flattened; dorsal surface convex. Longitudinally ribbed. Peristome broadly triangular and large; its right edge is slightly drawn out. Nine or more frontal-ventrals, 5 anals, 4 scattered 390 HANDBOOK OF PROTOZOOLOGY caudals. Band-like macronucleus and a micronucleus. Con- tractile vacuole single. Salt or fresh water. Euplotes charon (Miiller) (Fig. 167, a). Fresh or salt water. Body about 80 to 100 microns long. Euplotes patella (Miiller) (Fig. 167, b). Fresh or salt water. Body about 130 microns long. Genus Uronychia Stein. Without frontals or caudals. Marine. Fig. 167 a. Euplotes charon. X500 (After Calkins). b. E. patella. X150 (After Stein). c. Uronychia setigera. X650 (After Calkins). d. Diophrys appendiculatus. X500 (After Calkins). Uronychia setigera Calkins (Fig. 167, c). Salt water. Body about 40 microns long. Genus Diophrys Dujardin. Peristome long, reaching the row of anal ciri. Three posterior giant cirri; 7 to 8 frontal-vent- rals. Marine. Diophrys appendiculatus Stein (Fig. 167, d). Marine. Body about 50 microns long. Family 4 Aspidiscidae Stein Genus Aspidisca Ehrenberg. Body small, inflexible, oval. Right side convex. Ventral side flattened; dorsal side convex. Adoral zone runs more or less straight. Seven ventrals; 5 anals. Macronucleus ring or horseshoe shape. A single contractile vacuole. Salt or fresh water. HYPOTRICHIDA 391 Aspidisca lynceus Ehrenberg (Fig. 168, a). Body about 45 to 50 microns long. Fresh or salt water. Aspidisca hexeris Quennerstedt (Fig. 168, h). Body about 68 microns long. Salt water. Aspidisca polystyla Stein (Fig. 168, c). Body about 36 microns long. Salt water. Family 5 Psilotrichidae Butschli Genus Psilotricha Stein. Body oblong, compressed. An- terior end broad, posterior end more constricted. Two rows of longitudinal cirri; two macronuclei. Peristome very broad. Fresh water. Fig. 168 a. Aspidisca lynceus. X220 (After Stein). b. A. hexeris. X500 (After Calkins). c. A. polystyla. X500 (After Calkins). d. Psilotricha acuminata. X170 (After Stein). e. Balladina elongata. X600 (After Roux). Psilotricha acuminata Stein (Fig. 168, d). Body length 85 to 100 microns. Fresh water. Genus Balladina Kowaleski. With numerous elongated cirri. Fresh water. Balladina elongata Roux (Fig. 168, e). Fresh water. Body 32 to 35 microns long by 11 to 12 microns broad. References Stein, F. 1867 Der Organismus der Infusionstiere. Vol. 2. Stokes, A. C. 1888 A preliminary contribution toward a history of the fresh-water Infusoria of the United States. Jour. Trenton Nat. Hist. Soc, Vol. 1. CHAPTER XXXII ORDER 5 PERITRICHIDA STEIN THE PERITRICHIDA possess a much enlarged disc-like anterior end which is conspicuously ciliated. The adoral zone is a right-handed spiral unlike those of the other orders men- tioned in the preceding pages. Aside from a few genera such as Trichodinopsis and young free-swimming individuals of the stalked forms, the general body surface Is not ciliated. Both free-swimming and stalked forms occur. The latter pro- duce colonial forms. A test occurs among the members of Cothurnia. Asexual reproduction is by binary fission and sexual repro- duction occurs commonly. The majority are free-living, often attached to various aquatic animals and plants, although a few are parasitic. The order is here divided into four families: Without stalk; body barrel-shaped Family 1 Trichodinidae With stalk; body more or less conical Peristome not spirally rolled Free-living attached forms; posterior end inflexible . Family 2 Vorticellidae Attached; posterior end flexible Family 3 Licnophoridae Peristome spiral; sessil, with or without stalk. . . .Family 4 Spirochonidae Family 1 Trichodinidae Claus Genus Trichodina Ehrenberg. Body barrel-shape with a row of posterior cilia. Posterior end forms a sucking disc. Adoral zone at the anterior end. Nucleus band-form ; a contrac- tile vacuole. All ectoparasitic. Trichodina pedicidus Ehrenberg (Fig. 169, a). On Hydra, tadpole, etc. Body diameter 55 to 70 microns. Trichodina sp. Diller. On the skin and gills of the tadpoles of Rana and Bufo. Body 30 to 40 microns in diameter. Trichodina asterisci Gruber. On starfish. Genus Cyclochaeta Jackson. Body on the whole similar to [392] PERITRICHIDA 393 I Fig. 169 a. Trichodina pediculus. X400 (After James-Clark). b. Cyclochaeta spongillae. X450 (After Jackson). c. C. domergui. X600 (After Wallengren). d. Trichodinopsis paradoxa. X200 (After Claparede and Lachmann). e. Vorticella campanula. X150. f. V. nutans. X150. g. V. alba. X150. h. V. longifilum. X150. i. V. telescopa. X150. j. V. quadrangularis. X150. (e-j, after Kent). k. Car chesium poly pinum. X 150 (After Stein). 1. Zoothamnium arbuscula. X150 (After Stein). 394 HANDBOOK OF PROTOZOOLOGY Trichodina, but with rigid bristles external to the posterior girdle of cilia. Cydochaeta spongiUae Jackson (Fig. 169, h). In the inter- stices of the freshwater sponge, Spongilla fluviatilis. Cydochaeta domerqui Wallengren (Fig. 169, c). In the integument of freshwater fishes. Body about 55 microns in diameter. Genus Trichodinopsis Claparede and Lachmann. Body conical in form; oral end much constricted; body surface covered with long cilia. Trichodinopsis paradoxa Claparede and Lachmann (Fig. 169, d). Inhabit the gut and respiratory cavity of Cydostoma elegans. When extended about 140 microns long. Family 2 Vorticellidae Fromental Genus Vorticella Linnaeus. Body inverted bell-form ; color- less, yellowish, or greenish; peristome more or less outwardly extended. Pellicle frequently annulated. Always with a con- tractile stalk. Adoral zone prominent; a single macronucleus curved band-form; one micronucleus; one or two contractile vacuoles. Solitary, never colonial. Free-living in fresh or salt water. Numerous species. Specific identification is very diffi- cult because of variation. Vorticella campanula Ehrenberg (Fig. 169, e). Fresh water. Body about 150 microns long; stalk thick, usually 5 to 6 times the body length. Vorticella nutans Miiller (Fig. 169,/). Fresh water. About 40 to 85 microns long when extended. The body is curved characteristically toward the base of the stalk, Vorticella alba Fromentel (Fig. 169, g). Fresh water. 45 to 55 microns long. Vorticella longifilum Kent (Fig. 169, h). Fresh water. The stalk is 10 to 15 times the body length. Vorticella telescopa Kent (Fig. 169, i). Fresh water. With two annular grooves in the posterior part. About 45 to 50 microns long. Vorticella quadrangularis Kent (Fig. 169, j). Fresh water. Body about 200 microns long. Genus Carchesium Ehrenberg. Individuals similar to those I PERITRICHIDA 395 of Vorticella, but colonial; individuals are all alike. The myonemes in the stalks are not continuous, and, therefore, in- dividual stalks contract independently. The macronucleus is a curved band; one contractile vacuole. Attached to animals and plants. Some reach 4 mm. in height. Fresh or salt water. Carchesium polypinum Ehrenberg (Fig. 169, k). Ordinarily in fresh, sometimes in salt, water. Body about 45 to 60 microns long. Genus Zoothamnium Ehrenberg. Similar to Carchesium except that the contractile myonemes of all stalks are con- tinuous with one another, so that the entire colony contracts or expands. Sometimes several millimeters high. Fresh or salt water. Zoothamnium arhiiscula Ehrenberg (Fig. 169, /). In fresh or salt water. Individuals about 60 microns long; colonies often more than 6 mm. high. Genus Epistylis Ehrenberg. Body similar to that of Vorti- cella, but usually in a dichtomous colonial form, resembling superficially Carchesium; but the stalk not contractile. At- tached to fresh or salt water animals. Colonies may reach several millimeters in height. Epistylis plicatilis Ehrenberg (Fig. 170, a). Fresh water. Body about 90 to 100 microns long. Colony often 3 mm. in height. Epistylis flavicans Ehrenberg. On fresh water plants. Body about 130 to 360 microns long. Genus Ophrydium Ehrenberg. Colonial. The whole is em- bedded in a common mucilaginous mass. Stalk not contractile. Fresh or salt water. Ophrydium sessile Kent (Fig. 170, b, c). Attached to fresh- water plants. Body fully extended about 300 microns long. Ovoid colony measures 5 mm. by 3 mm. Genus Opercularia Stein. The peristome end is oblique; with an undulating membrane in the persitome. Short, not contractile stalk branched and rigid. Fresh water. Several species. Opercularia stenostoma Stein (Fig. 170, d). Fresh water; often attached to Crustacea. When extended the body meas- ures about 125 microns long. 396 HANDBOOK OF PROTOZOOLOGY Fig. 170 a. Epistylis plicatilis. X 150 (After Stein). b, c. Ophrydium sessile. (After Kent), b, an entire colony, natural size; c, a colony more magnified (X50). d. Opercularia stenostoma. XlOO (After D'Udekem). e. Gerda vernalis. X 120 (After Stokes). f. Scyphidia constricta. X270 (After Stokes). g. Glossatella tintinnahulum. X300 (After Kent), h. Rhabdostyla vernalis. X240 (After Stokes). i. Astylozoon fallax. X 125 (After Engelmann). Hastatella aesculacantha. X380 (After Jarocki). Cothurnia crystallina. X200 (After Calkins). C. nodosa. X350 (After Calkins). Vaginicola crystallina. XlOO (After Kent). Lagenophrys ampulla. X150 (After Stein). Licnophora macfarlandi. X625 (After Calkins). Spirochona gemmipara. X225 (After Hertwig). ]• PERITRICHIDA 397 Genus Gerda Claparede and Lachmann. Body elongated and cylindrical, highly contractile. Cytostome at the anterior end; adoral zone spiral, leading into the cytostome. Macro- nucleus band-form. A contractile vacuole. No stalk; not firmly attached. Gerda vernalis Stokes (Fig. 170, e). In shallow freshwater ponds in early spring. About 250 microns long when extended. Genus Scyphidia Dujardin. Somewhat similar to Gerda. Posterior end drawn out and suctorial in function. Stalk is non-contractile. Attached. Fresh water. Several species. Scyphidia constricta Stokes (Fig. 170,/). Pond water, often attached in clusters of 2 to 4 to Nais. Body about 55 microns long. Genus Glossatella Butschli. Non-contractile stalk rudi- mentary. An enormously large undulating membrane around the peristomal margin. Often attached to Triton larvae. Glossatella tintinnahuliini (Kent) (Fig. 170, g). On the epi- dermis and gills of the young Triton. Body about 40 microns long. Genus Rhabdostyla Kent. Solitary with non-contractile stalk. Attached to aquatic animals. Fresh or salt water. Several species. Rhabdostyla vernalis Stokes (Fig. 170, h). Attached to Cy- pris and Cyclops in the pools in early spring. Body about 50 microns long. Genus Astylozoon Engelmann. Without stalk, two pos- terior setae. Free-swimming. Rare. Astylozoon fallax Engelmann (Fig. 170, i). Fresh water. Body about 70 to 100 microns long. Genus Hastatella Erlanger. With several conical projec- tions. Free-swimming. Fresh water. Two species. Hastatella aesculacantha Jarocki and Jakubowska (Fig. 170, j). In stagnant water. Extended body 30 to 52 microns long by 24 to 40 microns wide. Genus Cothurnia Ehrenberg. Vorticella-like body in pseu- dochitinoid lorica which is attached directly, or by a short stalk, to submerged objects. Salt or fresh water. Cothurnia crystallina Ehrenberg (Fig. 170, k). Fresh or salt water. Lorica 70 to 200 microns in length. 398 HANDBOOK OF PROTOZOOLOGY Cothurnia nodosa Claparede and Lachmann (Fig. 170, /). Cup 75 microns long; stalk 35 to 40 microns long. Genus Vaginicola Lamarck. Body elongate and cylindrical ; ciliation and peristomal structure similar to those of Vorti- cella, but with a vase-like lorica. Several species in fresh water. Vaginicola crystallina Ehrenberg (Fig. 179, m). On fresh- water plants. Lorica about 120 microns long. Genus Lagenophrys Stein. Similar to Vaginicola, but the aperture of the lorica narrow and thickened. Attached to freshwater animals. Lagenophrys ampulla Stein (Fig. 170, n). Attached to Gammarus and Asellus. Diameter of the sheath 50 to 70 microns. Family 3 Licnophoridae Stevens Genus Licnophora Claparede. Spiral girdle left-handed and ciliated. Adoral sucker surrounded by a circle of cilia. Salt water. Licnophora macfarlandi Stevens (Fig. 170, o). Attached to various marine invertebrates, such as medusae, polychaetes, etc. Body length about 60 microns. Family 4 Spirochonidae Grobben Genus Spirochona Stein. A delicate spiral membrane at the anterior end of the body. The posterior end serves for ad- hesion, often showing pseudopodial lobes. Exogenous budding. One macronucleus, one to three micronuclei. Attached to Crustacea. Several species. Spirochona gemmipara Stein (Fig. 170, p). Attached to fresh-water crustaceans. Body 40 to 110 microns in length. References Kent, W. S. 1881-1882 A manual of the Infusoria. Vol. 2. Stein, F. 1868 Der Organismus der Infusionstiere. Vol. 2. Stokes, A. C. 1881 A preliminary report toward a history of the fresh-water Infusoria of the United States. Jour. Trenton Nat. Hist. Soc, Vol. 1. CHAPTER XXXm CLASS 2 SUCTORIA BUTSCHLI THE SUCTORIA, which are also called the Acineta, Acinetaria, Tentaculifera, etc., do not possess any cilia 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 are lost with the development of a stalk or an attaching disc, and of tentacles. Therefore, an adult suctorian is incapable of active movement. The body is covered with a pellicle and occasionally possesses a lorica. There is no cyto- stome, and the food-capturing is carried on exclusively by the tentacles. Tentacles are of two kinds. One is suctorial in func- tion and bears a rounded knob on the extremity. It is found in many genera. The other kind of tentacle is for piercing and is, more or less, sharply pointed, as in Ephelota. These tentacles may be confined to limited areas or may be formed from the entire body surface. The prey is usually small ciliates. Nutri- tion is holozoic. The body of a suctorian may be spherical, elliptical, den- dritic, etc. Asexual reproduction is by binary fission or budding. The buds which are formed by either exogenous or endogenous gemmation are ciliated, and swim around actively after leav- ing the parent individual. Finally becoming attached to a suitable object, they metamorphose into adult forms. Sexual reproduction is through copulation. The Suctoria live attached to animals, plants, or non-living matter submerged in fresh or salt water. According to Collin, the Suctoria are here divided into eight families as follows: Adult without cilia With Suctorial tentacles only Body irregular or branching Without proboscis or special arms. Body form highly variable; often with stolon ; but usually without a stalk Family 1 Dendrosomidae [399] 400 HANDBOOK OF PROTOZOOLOGY With proboscis or special arms With a retractile proboscis which bears tentacles Family 2 Ophryodendridae With special arms with tentacles Family 3 Dendrocometidae Body somewhat bilaterally symmetrical Exogenous budding and division Family 4 Podophryidae Endogenous budding With delicate pellicle. With or without cup-like test; with or without stalk Family 5 Acinetidae With tough pellicle; tentacles may be small in number and variable in form; stalk short and stout . . .Family 6 Discophryidae With both suctorial and prehensile tentacles; with or without test; exogenous budding; ectoparasitic on marine hydroids Family 7 Ephelotidae Adult with cilia Family 8 Hypocomidae Family 1 Dendrosomidae Biitschli Genus Trichophrya Claparede and Lachmann. Body small and form variable. Without stalk. Tentacles in fascicles. No branches. Attached usually to animals in both fresh and salt water. About ten species known. Trichophrya epistylidis Claparede and Lachmann (= T. sinuosa Stokes) (Fig. 171, a). Fresh water. About 40 microns in length. Trichophrya salparum Entz (Fig. 171, h). Living on the external body surface of various tunicates, such as Molgula manhattensis . Genus Astrophrya Awerinzew. Body with eight processes, each with a fascicle of tentacles. Astrophrya arenaria Awerinzew (Fig. 171, c). Found in the plankton of the Volga. The main body measures 145 to 188 microns in diameter; the length of the processes 86 to 190 microns. Genus Lernaeophrya Perez. Body large; with numerous short prolongations bearing very long fascicled tentacles. With a branching nucleus. Lernaeophrya capitata Perez (Fig. 171, d). Attached to the stalk of the hydrozoan, Cordylophora lacustris. Body 400 to 500 microns long; tentacles 400 microns long. Genus Dendrosoma Ehrenberg. Large form often 2 mm. SUCTORIA 401 in height. Body ramification more advanced, with basal stolon and upright branches which are branched. Dendrosoma radians Ehrenberg (Fig. 171, e). On plants in rivers and ponds. Fully grown form measures 1.2 to 2.5 mm. in height. Fig. 171 a. Trichophrya epistylidis. X 250 (After Stokes). b. T. salparum. XI 65 (After Collin). c. Astrophrya arenaria. X65 (After Awerinzew). d. Lernaeophrya capitata. X35 (After P6rez). e. Dendrosoma radians. X35 (After Kent). f. Dendrosomides paguri. X200 (After Collin). Genus Dendrosomides Collin. Branched body similar to Dendrosoma, but with a peduncle. Reproduction by budding of vermicular individual. 402 HANDBOOK OF PROTOZOOLOGY Dendrosomides paguri Collin (Fig. 171, f). Length about 200 to 300 microns; vermicular individuals measure 350 mi- crons in length. Attached to the hermit crabs, Eupagurus excavatus and E. cuanensis. Genus Rhabdophrya Chatton and Collin, Body cylindrical or rod-shaped with a short peduncle. Not branched. Tentacles distributed over the entire body surface. The macronucleus ellipsoidal and the micronucleus small. Two or three contrac- tile vacuoles. Rhabdophrya trimorpha Chatton and Collin (Fig. 172, a). Family 2 Ophryodendridae Stein Genus Ophryodendron Claparede and Lachmann. With a retractile proboscis which bears suctorial tentacles. Several species; attached to Crustacea, Annelida, etc. Ophryodendron porcellanum Kent (Fig. 172, b). Attached to Crustacea, especially Porcellana platycheles. Family 3 Dendrocometidae Stein Genus Dendrocometes Stein. The arms are branched and each branch terminates in a sucker. Dendrocometes paradoxus Stein (Fig. 172, c). Fresh water. On amphipods. Body about 85 microns in diameter. Genus Stylocometes Stein. Each of the arms which are not branched, terminates in a sucker. Stylocometes digitatus Stein. Family 4 Podophryidae Biitschli Genus Podophrya Ehrenberg. Body subspherical, normally with a rigid stalk. Suctorial tentacles in fascicles or distributed over the entire body surface. Encystment common. Specific identification is often difficult. Several species. Podophrya fixa (Miiller) (Fig. 172, d, e). In fresh water among vegetation. Podophrya gracilis Calkins (Fig. 172, /). Stalk long and filiform, not rigid. One or two contractile vacuoles. A single nucleus near the attachment of the stalk. Body 8 microns in diameter; stalk 40 microns long. Rare. Salt water. Genus Sphaerophrya Claparede and Lachmann. Body SUCTORIA 403 spherical, without a peduncle or stalk. Suctorial tentacles radiating. Several species; free-living and two parasitic species. Sphaerophrya stentoris Maupas. Parsitic in various Eu- ciiiata such as Bursaria, Stentor, etc. Fig a. b. c. d,e f. Rhabdophrya trimorpha. X645 (After Collin). Ophryodendron porcellanum. X330 (After Collin). Dendrocometes paradoxus. X265 (After Wrzesnowski) . Podophrya fixa. X330 (After Collin). P. gracilis. XIOOO (After Calkins). Sphaerophrya soliformis. X200 (After Lauterborn). Paracineta limbata. A bud is just escaping. Stalk on right. X460 (After Collin). 404 HANDBOOK OF PROTOZOOLOGY Sphaerophrya soliformis Lauterborn (Fig. 172, g). Saplo- pelic. Diameter about 100 microns. Genus Paracineta Collin. Body covered by a closely fitting delicate test. Stalked; several species. Many which had been called Acineta have been placed in this genus by Collin. Paracineta limhata (Maupas) (Fig. 172, h). Marine; among algae, bryozoans, hydrozoans, etc. Genus Metacineta Biitschli. Test coarse; with fasciculated tentacles. Metacineta mystacina (Ehrenberg) (Fig. 173, a). Fresh or salt water. Genus Urnula Claparede and Lachmann. Tentacles one to three in number. Urnula episiylidis Claparede and Lachmann. Family 5 Acinetidae Biitschli Genus Acineta Ehrenberg. Body usually pyramidal, and encased in a cup- or funnel-like stalked test. The test has no free margin. Suctorial tentacles in groups or scattered at the non-stalked end. More than twenty species recorded. Acineta divisa Fraipont (Fig. 173,/). Salt water. Body 27 microns long; tentacles 65 microns long; length of stalk 100 microns . Acineta tuberosa Ehrenberg (Fig. 173, g). Salt water. Body large, 330 microns long. Genus Tokophrya Biitschli. Stalked; body pyriform or pyramidal; with fasciculated tentacles. Numerous species. Tokophrya infusionum (Stein) (Fig. 173, b-d). Tokophrya cyclopum Claparede and Lachmann (Fig. 173, e). Attached to Cyclops, Diaptomus, Gammarus, etc. Genus Thecacineta Collin. Body more or less elongated. The stalked test rigid and shows free margin. Suctorial ten- tacles from the anterior end. Several species. Thecacineta cothurnioides Collin (Fig. 173, h). Attached to the copepod, Cletodes longicaudatus . Genus Periacineta Collin. Close-fitting test elongated and attachment by a short narrowed test or stalk(?). The other end is open without free margin. Fasciculated tentacles at the anterior end. SUCTORIA 405 Fig. 173 a. Metacineta mystacina, capturing Halteria grandinella. X400 (After Collin), b-d. Tokophrya infusionum. b, an adult organism (X400); c, free-swimming bud ( X800) ; d, a young attached form(X800). (After Collin). e. A young T. cyclopum. X500 (After Collin). f. Acineta divisa. X465 (After Calkins). g. A. tuberosa. X665 (After Calkins). h. Thecacineta cothurnioides. X400 (After Collin). 406 HANDBOOK OF PROTOZOOLOGY Periacineta bucket (Kent) (Fig. 174, a). Attached to Lym- naea, etc. Genus Hallezia Sand. Without test; with or without a short stalk; body variable in form. Tentacles in fascicles. Hallezia br achy poda (Stokes) (Fig. 174, b). Standing water with dead leaves. Body about 34 to 42 microns in diameter. Genus Solenophrya Claparede and Lachmann. Body not filling the cup-like test. Attached by the base of the test. Solenophrya inclusa Stokes (Fig. 174, c). Standing fresh water. Lorica subspherical and about 44 microns in diameter. Solenophrya pera Stokes (Fig. 174, d). Test satchel-shaped; 44 microns high. Body about 35 microns long. Standing fresh water. Genus Acinetopsis Robin. Close-fitting test polyhedral and short stalked. One to six long and active tentacles in the center of the anterior end. Acinetopsis tentaculata Root (Fig. 174, e, /). Attached to species of Obelia. Test 185 microns long; stalk 285 microns long; body about 138 microns by 100 microns. Genus Tachyblaston Martin. Ectoparasitic on Ephelota. No contractile vacuoles. Tachyblaston ephelotensis Martin (Fig. 174, g, h). Genus Dactylophrya Collin. Test with a short stalk. 12 to 15 arm-like tentacles, each terminating in a sucker, extended from the anterior end. Dactylophrya roscovita Collin (Fig. 174, i). Rare; on the stalk of the hydrozoan, Diphasia attenuata. Genus Pseudogemma Collin. Parasitic in other Suctoria, such as Acineta or Paracineta, Pseudogemma pachystyla Collin (Fig. 174, j). In Acineta tuber osa. Genus Endosphaera Engelmann. Body spherical and with- out axial differentiation. Tentacles and stalk absent. Endo- parasitic in other Protozoa. Endosphaera engelmanni Entz. In Trichodina pediculus, Didinium nasutum, Vorticellidae, etc. SUCTORIA 407 ¥'\g. 174 a. Periacineta bucket with Chilodon sp. X530 (After Collin). b. Hallezia brachypoda. X200 (After Stokes). c. Solenophrya inclusa. X 225 (After Stokes). d. S. pera. X225 (After Stokes). e. f. Acinetopsis tentaculata. e, X125; f, with a bud, X230. (After Root). g, h. Tachyblaston ephelotensis. (After Martin), g, a young indi- vidual in Ephelota (X255 ); h, adult individual (X500). i. Dactylophrya roscovita. X830 (After Collin). j. Pseudogemma pachystyla. X400 (After Collin). 408 HANDBOOK OF PROTOZOOLOGY Family 6 Discophryidae Collin Genus Discophrya Lachmann. Body triangular to ellip- soidal. Attached with a short stalk. Tentacles fasciculated or distributed. Discophrya elongata (Claparede and Lachmann) (Fig. 175, a). Attached to the shell of Vivipara contecta. Genus Thaumatophrya Collin. Tentacles numerous and each tapers toward the free end. Thaumatophrya trold (Claparede and Lachmann) (Fig. 175, h). Salt water. Body diameter about 70 microns. Genus Rhynchophrya Collin. Body oblong, bilaterally symmetrical. A short stalk. One main tentacle and a few secondary tentacles. Rhynchophrya palpans Collin (Fig. 175, c). Body 85 mi- crons long by 50 microns broad; tentacles 10 to 200 microns; style 20 microns by 10 microns. Genus Choanophrya Hartog. Body spheroidal with a stalk. Tentacles expansible at their distal ends to engulf voluminous food particles. Choanophrya infundibulifera (Hartog) (Fig. 175, d). Genus Rhyncheta Zenker. Protoplasmic body is attached directly to an aquatic animal. With a long mobile tentacle bear- ing a sucker at its end. Rhyncheta cyclopnm Zenker (Fig. 175, e, f). On species of Cyclops. When extended the body measures about 170 microns long. Family 7 Ephelotidae Sand Genus Ephelota Wright. No test; with or without stalk. Ectoparasitic on hydroids. Ephelota coronata Wright (Fig. 175, g). Salt water. On hydroids, algae, bryozoans, etc. Body 90 to 200 microns long. Ephelota sessilis Collin. Attached to the ascidian, Pyrosoma elegans. Genus Podocyathus Kent. Conspicuous test and stalk. Salt water. Podocyathus diadema Kent (Fig. 175, h). Salt water. Lorica about 42 microns long. SUCTORIA 409 Fig. 175 a. b. c. d. e, f. h. Discophrya elongata. X435 (After Collin). Thaumatophrya trold. XI 15 (After Claparedeand Lachmann). Rhynchophrya palpans. X435 (After Collin). Choanophrya infundibulifera, feeding on disintegrated parts of a Cyclops. X400 (After Collin). Rhyncheta cyclopiim. e, the whole organism (XlOO); f, end of tentacle enlarged (X400). (After Zenker). Ephelota coronata. X65 (After Calkins). Podocyathus diadema. X200 (After Kent). Dorsal and side view of Hypocoma acinetarum. X400 (After Collin). 410 HANDBOOK OF PROTOZOOLOGY Family 8 Hypocomidae Biitschli Genus Hypocoma Gruber. The cilia are present throughout the life-cycle. Hypocoma acinetarum Collin (Fig. 175, i,j). Ectoparasitic on Acineta papillifera and Ephelota gemmipara. References Collins, B, 1912 Etude monographique sur les Acinetiens. Arch. Zool. Exper., T. 51. APPENDIX COLLECTION, CULTIVATION, AND OBSERVATION OF PROTOZOA Collection IN THE FOREGOING chapters it has been pointed out that the various species of Protozoa have characteristic habitats and that many of the free-living forms are widely distributed in bodies of water: fresh, brackish, and salt; while the parasitic forms are limited to specific host organisms. Of the free-living Protozoa, certain species may occur in large numbers within a small area under favorable conditions, but the majority are present in comparatively small numbers. If a student who has become acquainted with the representative forms intends to make collections, it is well to carry a compound microscope to the field in order to avoid bringing back numerous jars con- taining much water but few organisms. Submerged plants, decaying leaves, surface scum, ooze, etc., should be examined with the microscope. When desired forms are found, they should be collected together with a quantity of the water in which they occur. When the collected material is brought into the laboratory, it is often desirable to concentrate the organisms in a relatively small volume of water. For this purpose the material may be partly filtered rapidly through a fine milling cloth or an ordi- nary filter paper and the residue quickly poured back into a suitable glass container before the filtration is completed. The container should be placed in a cool, well-lighted room to allow the organisms to become established in the new environment. Euglena and other stigma-bearing Phytomastigina will then be found on the side of the container facing the strongest light, just below the surface of the water, and members of the Sarco- dina will be found among the debris on the bottom. Many forms will not only live for several weeks under these conditions in the laboratory, but also increase in number. [411] 412 HANDBOOK OF PROTOZOOLOGY In order to collect parasitic forms, one must, of course, find the host animals that harbor them. Various species of frogs, tadpoles, cockroaches, etc., which are of common occurrence or easily obtained and which are hosts to numerous species of Protozoa, are useful material for class work. In the case of in- testinal Protozoa of vertebrates, freshly voided fecal matter should be collected in a clean and dry container, and micro- scopical examination should be made immediately. Cultivation For extensive study or for class work, large numbers of a certain species of Protozoa are frequently desirable, and this makes it necessary to provide favorable conditions for their growth and multiplication. Success in culturing Protozoa de- pends upon several factors. First, an abundant supply of proper food material is needed to enable the organisms to grow and multiply more rapidly than under natural conditions. For example, several species of Paramecium live almost exclusively on bacilli, while Coleps, Didinium, and allied forms depend on other ciliates as sources of food supply. For cultivating the Phytomastigina successfully, good light and a fairly large amount of inorganic substances are necessary. In the second place, the temperature and chemical constituents of the medium seem to have a far greater influence on the multiplication of protozoans than was thought heretofore. As a rule, a lower temperature seems to be much more favorable for culture than a higher one, although this is not the case with the parasitic forms occurring in warm-blooded animals. Recent investigations show also the importance of a proper hydrogen ion concentration. In the third place, both protozoans and metazoans which prey upon the forms under cultivation must be excluded from the culture. For instance, it is necessary to remove Didinium nasiitum in order to obtain a rich culture of Paramecium. Mixed cultures of several free-living forms are compara- tively easily maintained by adding a small amount of cut-up hay to the water, although the protozoan population changes a great deal from time to time. Amoeba, Vahlkampfia, Arcella, Peranema, Bodo, Paramecium, Stylonychia, and many other forms often multiply abundantly in such cultures. To obtain APPENDIX 413 large numbers of a single species, individuals are taken out by means of a finely drawn pipette and transferred to a suitable ripe culture medium which contains proper food material. Aside from the successful cultures of blood-inhabiting Pro- tozoa, the so-called protozoan cultures are by no means "pure" cultures in the bacteriological sense, even if only one species of Protozoa is present, since bacteria and other Protophyta are invariably present abundantly in them. Some of the more commonly used culture media will here be mentioned. Cultivation of Free-living Forms Euglena, Phacus, and other holophytic Mastigophora. — These flagellates usually do not live long in ordinary collection jars, but rich cultures of them may be obtained in Zumstein's medium, which is made up as follows: Peptone 0.5 to 1 gm. Grape sugar 0.4 to 0.5 gm. Citric acid 0.2 to 0.4 gm. Magnesium sulphate 0.2 gm. Potassium phosphate 0.05 gm. Ammonium nitrate 0 to 0.05 gm. Distilled water 100 c.c. Goniiim, Eudorina, and other Phytomonadida. — Several au- thors have obtained excellent results with one of the following media: Knop's solution : Magnesium sulphate 0.25 gm. Calcium nitrate 1.0 gm. Potassium phosphate 0.25 gm. Potassium chloride 0.12 gm. Iron chloride Trace Distilled water 1000 c.c. Benecke's solution : Ammonium nitrate 0.3 gm. Calcium chloride 0.15 gm. Potassium phosphate 0.15 gm. Magnesium sulphate 0.15 gm. Iron chloride One drop Distilled water 1500 c.c. 414 HANDBOOK OF PROTOZOOLOGY Peranema, Chilomonas, and other holozoic or saprozoic Masti- gophora. — Although ripe hay infusion is frequently adequate for these flagellates, it is often worth while to prepare the following medium. Mix 10 gm. of peptone and 5 gm. of sodium chloride and dissolve in 1000 c.c. of distilled water. Add 3 gm. of Liebig's beef-extract and 1.5 gm. of shredded agar, to the solution and boil the whole slowly, stirring frequently until the agar is dis- solved. Add distilled water to make up for the loss by evapora- tion. The reaction should be slightly alkaline (pH 7.4), Filter while hot through cotton in a steam sterilizer. Then divide the filtrate into a number of test tubes, insert cotton plugs, and autoclave for 15 minutes under 15 pounds pressure. The tubes thus sterilized can be kept indefinitely. Before using, each test tube is heated and the melted contents poured into a Petri dish and allowed to cool. Amoeba proteus and allied forms.- — These amoebae feed on diatoms, bacteria, protozoans, and not infrequently small meta- zoans. Hay infusion makes a satisfactory medium if a few wheat grains are added. Knop's and Benecke's solutions men- tioned above are also suitable for culturing these free-living holozoic amoebae. Some workers recommend cutting and boil- ing aquatic plants, such as Elodea, for this purpose. Upon cooling, pour the plants and extract into a deep, wide-mouthed, glass jar and add aerated rain water. A weaker solution is, on the whole, much better than a stronger one, although the development of amoebae may be slow. After leaving the jar standing exposed for several days, introduce into it the amoebae that have been previously collected. The inoculated jar should be kept in a cool, well-lighted place. Vahlkampfia, Naegleria, etc.- — These small mono- or di-phasic amoebae which feed on bacteria can easily be cultivated on the agar medium mentioned above for Peranema and others. A sim- ilar medium, devised by Musgrave and Clegg, and modified by Walker, consists of the following: Agar 2.5 gm. Sodium chloride 0.05 gm. Liebig's beef-extract 0.05 gm. Normal NaOH solution 2.0 gm. Distilled water 100 c.c. APPENDIX 415 By subcultures, almost a pure culture with bacteria can be obtained. Hay infusion is also excellent for these small free- living amoebae. Arcella and other Testacea. — These forms commonly multi- ply in a mixed culture in hay infusion. Hegner cultivated Arcella by the following method: Pond water and weeds are collected. In the laboratory they are shaken up violently and filtered through eight thicknesses of cheese cloth, which ap- parently prevents passage of particles larger than Arcella. The filtrate is distributed among Petri dishes, and when the sus- pended particles settle down to the bottom of the dish, Arcella are introduced. They multiply rapidly. Actinophrys, Actinosphaerium, etc. — Belaf cultivated these heliozoans successfully in Knop's solution. Paramecium, Euplotes, Stylonychia, and other ciliates. — Ail these ciliates are easily cultivated in a weak solution of hay infusion, with or without wheat grains. The crystallization jars containing the medium should be left standing uncovered for several days to allow a rich bacterial growth in them. Seed them with material such as submerged leaves or scum contain- ing these ciliates. When once started, separate cultures can be easily made and maintained by the isolation method. If desired, a culture can be started with a single individual. Sub- cultures should be made from time to time. Mixtures of beef- extract and hay infusion have also been used for cultivating free-living holozoic ciliates. Cultivation of Parasitic Forms Embadomonas , Trichomonas, Chilomastix, etc — There are numerous media which have been used for successful cultiva- tion of these flagellates in vitro. For Trichomonas hominis and T. vaginalis. Lynch used nutrient broth with 0.05 per cent acetic acid, incubated at 30° C, making subcultures every two to three days. Hogue's ovo-mucoid medium is made as follows: Whites of six eggs are broken in a sterile flask with beads. Add 600 cc. of 0.7 per cent salt solution and cook the whole for 30 minutes over a boiling water bath, shaking the mixture constantly. Filter through a coarse cheese cloth and through cotton-wool with the aid of a suction pump. Put 5 cc. 416 HANDBOOK OF PROTOZOOLOGY of the filtrates in each test tube. Autoclave the test tubes for 15 minutes under 15 pounds pressure. After cooling, a small amount of fresh fecal matter containing the flagellates is intro- duced into the tubes. Incubation at 37° C. Lophomonas blattarum and L. striata. — A mixture of one part sterile egg albumen and three parts autoclaved Ringer's solution, to which a small amount of yeast cake has been added, is excellent for the culture of these cockroach flagellates. In- cubation is at room temperature, and subcultures are made every fourth day. Trypanosoma and Leishmania. — -Blood-agar medium, com- monly called N.N.N, medium because it was originally de- veloped by Novy and MacNeal and simplified by Nicolle, is prepared in the following manner: 14 gm. of agar and 6 gm. of sodium chloride are dissolved by heating in 900 c.c. of dis- tilled water. When the mixture cools to about 50° C, 50 to 100 c.c. of sterile defibrinated rabbit blood is gently added and carefully mixed so as to prevent the formation of bubbles. The blood agar is now quickly distributed among sterile test tubes to the height of about 3 cm., and the test tubes are left in a sloping position until the medium becomes solid. The tubes are then incubated at 37° C. for 24 hours to determine sterility and further to hasten the formation of condensation water. Sterile blood containing Trypanosoma or Leishmania is introduced by a Pasteur pipette to the condensation water, in which the organisms multiply. This medium is also good for intestinal flagellates and amoebae of vertebrates. Entamoeba harreti.- — Barret and Smith used a mixture of 9 parts of 0.5 per cent sodium chloride and 1 part of human blood serum. After inoculation the culture is incubated at from 10 to 15° C. Entamoeba histolytica and other intestinal amoebae. — Since Boeck and Drbohlav (1925) successfully cultivated Entamoeba histolytica by using a medium composed of Locke's solution, egg, and human blood serum, several authors have repeated their experiments and have obtained positive results. This method has been modified and simplified in various ways. Per- haps the simplest of all is that proposed by Craig as salt-serum (or S.S.) medium, in which 0,85 per cent sodium chloride solu- APPENDIX 417 tion is autoclaved for 15 minutes under 15 pounds pressure and cooled; then to seven parts of the solution is added one part of inactivated human blood serum. In this culture me- dium, the dysentery amoeba undergoes active multiplication. Some investigators find that N.N.N, medium given above for Trypanosoma is also suitable for intestinal amoebae. Plasmodium. — Bass' method is as follows: 10 c.c. of defi- brinated human blood containing Plasmodium and 0.1 c.c. of 50 per cent sterile dextrose solution are mixed in test tubes and incubated at 40° C. The cultures are centrifuged to separate the erythrocytes, which sink to the bottom, from the leucocytes, which become collected above. The erythrocytes are now trans- ferred to fresh culture tubes. Several modifications have been made. Balantidium coli — Barret and Yarbrough's method is as follows: The medium consists of 16 parts of 0.5 per cent so- dium chloride and 1 part of inactivated human blood serum. It is divided among test tubes. Introduce a small amount of the fecal matter containing the cilitate to the bottom of the tubes and incubate at 37°C. Maximum development is reached in from 48 to 72 hours. Subcultures should be made every second day. Reese used a mixture of 16 parts of Ringer's solu- tion and 1 part of Loffler's dehydrated blood serum. Observation Protozoa should be studied as much as possible in life. In making fresh preparations care should be exercised to avoid any deformities which might occur owing to the pressure of the coverglass. If small bits of detritus or debris are included in the preparation, the coverglass will be supported by them and the organisms will not receive any mechanical pressure. Al- though ordinary plain slides are used for this purpose, it is often advantageous to use depression slides instead. To make a fresh preparation with a depression slide, the following pro- cedure may be followed: By means of a fine pipette, a small drop of water containing the desired protozoans is placed on a large square coverglass, and is covered with a small circular coverglass, which in turn is covered by a depression slide smeared with vaseline along the edge of the depression, so as 418 HANDBOOK OF PROTOZOOLOGY to make an air-tight compartment. In turning over the whole, in order to examine the preparation through the square cover- glass, care must be taken to prevent the small circular cover- glass from touching any part of the slide; for this would allow the water to run down into the depression. In such a prepara- tion, individual protozoans can be observed and studied for several days without further treatment. The members of the Sarcodina give little trouble to an ob- server, since they are not actively motile. To retard the active movement of the Mastigophora and the Ciliata, various methods have been advocated. Most of them, however, cause abnormal- ity in form, structure, or behavior of the organisms, and should be avoided as much as possible. Addition of a solution of picric acid often will retard the movements of an actively mov- ing protozoan without causing any deformity. When the organisms are obtainable in large numbers some of them may be stained on a plain slide by adding a drop of Lugol's solution in order to bring out the number, location, or arrange- ment of cilia, cirri, or flagella. Lugol's solution consists of 1 gm. of iodine, 5 gm. of potassium iodide, and 500 c.c. of distilled water. Living protozoans, when treated with highly diluted watery solutions of certain dyes, exhibit some of their parts stained without being injured or killed by the treatment. Thisintra- vitam staining is accomplished either by adding a drop of the dye solution to the edge of the coverglass, or by allowing a drop of the dye solution to dry on the slide before the water containing the protozoans is added. Some of the dyes used for this purpose are as follows: Auramin (1:2,000) to stain the nucleus. Bismarck brown (1:3,000 to 30,000) to stain the cytoplasm yellowish and the granules reddish brown. Brilliant cresyl blue (1:10,000) to stain many granules in the cytoplasm violet or blue. This dye frequently shows the endosome of the nucleus. It may also be used for blood para- sites such as trypanosomes, haemogregarines, etc. Congo red (1:1,000) to test the alkalinity and the presence of organic acids (reddish color) and mineral acids (bluish). Methylene blue (1:10,000) to stain cytoplasmic granules. APPENDIX 419 structures in the nucleus, and also protoplasmic projections. Neutral red (1:3,000 to 30,000) to stain the nucleus and to test the alkalinity (yellowish red) or acidity (cherry red) of food vacuoles. Parasitic Protozoa should be studied in the tissue or body fluid of the host animals in which they occur. When these are unavailable or too small in amount to make a suitable prepara- tion, one of the following solutions may be substituted: Physiological salt solution. The standard concentration of the solution of sodium chloride is 0.7 per cent for cold-blooded animals and 0.85 per cent for warm-blooded animals. Ringer's solution. Various modifications have been pro- posed. The commonly used one consists of the following: Sodium chloride 0.8 gm. Potassium chloride 0.02 gm. Calcium chloride 0.02 gm. Sodium bicarbonate 0.02 gm. Distilled water 100 c.c. References Belar, K. 1928 Untersuchung der Protozoen. Methodik der wiss. Biologie. Vol. 1. DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Proto- zoenkunde. Jena. Gatenby, J. B. AND E. V. CowDRY. 1928 Bolles Lee's micro- tomist's vade mecum. London. Hegner, R. and J. Andrews. 1930 Problems and methods of research in protozoology. New York. McClung, C. E. 1929 Handbook of microscopical technique. New York. INDEX Numbers in bold-face type indicate pages on which are given the defini- tions, explanations, and discussions of technical terms; the explanations or dif- ferentiations of taxonomic subdivisions; or the descriptions of genera and species. Since the technical terms and names of systematic subdivisions are in bold-face type in the text, this combination serves the purpose of a glossary. Numbers in italics indicate pages on which appear those illustrations that could not be placed on the same pages as the related text matter. Abiogenesis, 13 Acanthociasma, 71, 258 Acanthociasma planum, 258 Acanthociasmidae, 71, 258 Acanthocystis, 71, 246, 251 Acanthocystis aculeata, 251j Acanthometrida, 71, 258 ^ Acanthometridae, 71, 259^1 Acanthometron, 7l, 259 Acanthometron elasticum, 258 Acanthonia, 71, 259 Acanthoma tetracopa, 258 , Acanthoniidae, 71, 259 Acanthophractida, 71, 259 Acarina, 325 Acartia, 343 Acephalina, 74, 291, 293-296 Achromatic strands, 21 Acineta, 81, 399, 404, 406 Acineta divisa, 404, 405 papillifera, 410 tuberosa, 404, 405, 406 Acinetaria, 399 Acinetidae, 81, 400, 404, 406 Acinetopsis, 81, 406 Acinetopsis tentaculata, 406, 407 Acnidosporidia, 76, 266, 326-332 Actinelida, 71, 258 Actineliidae, 71, 258 Actinelius, 71, 258 Actinelius primordialis, 258 Actinobolus, 77, 346 Actinobolus radians, 346 Actinolophus, 71, 248 Actinolophus pedunculatus, 248, 249 Actinomonas, 31, 63, 132 Actinomonas mirabilis, 131, 132 Actinomyxidia, 75-76, 302, 313-315, 318 Actinophrys, 71, 245, 247, 415 Actinophrys sol, 247 Actinopoda, 71-73, 245-263 Actinosphaerium, 13, 21, 71, 246,247, 415 Actinosphaerium eichhorni, 57, 247- 248 Actinotricha, 80, 389 Actinotricha saltans, 388, 389 Actipylea, 71-72, 255, 256, 258-259 Acutispora, 74, 297 Acutispora macrocephala, 297 Adelea, 74, 278 Adelea ovata, 277, 278 Adeleidae, 74, 278-279 Adeleidea, 74, 267, 271, 276-282 Adelina, 74, 278 Adelina dimidiata, 278 octospora, 278 Adinida, 61, 97, 98 Adoral zone, 29 30, 371, 392 Aedes aegypti, 293, 295 Aegyria, 78, 357-358 Aegyria oliva, 356, 358 Aethalium, 187 Agamogony, 265 Agamont, 265 Agar-beef-peptone medium, 414 Agarella, 75, 311 Agarella gracilis, 311, 312 Aggregata, 49, 73, 267, 270 Aggregata eberthi, 57, 270, 271 Aggregatidae, 73, 269, 270-271 Akaryomastigont, 164 Alexeieff, 43, 332 Algae, 35, 91, 95, 107, 116, 178, 179, 180, 195 Allantocystis, 74, 296 Allantocystis dasyhelei, 296, 297 AUogromia, 70, 232 Allogromia fluvialis, 232 ovoidea, 232, 233 AUogromiidae, 70, 195, 226, 232-236 AUomorphina, 69, 201 421 422 AUTHOR AND SUBJECT INDEX Allomorphina trigona, 202 Allurus tetraedurus, 341 Alternation of generations, 267, 270, 284 Alveolinella, 68, 198 Alveolinella mello, 197 Alveolinellidae, 68, 198 Amara augustata, 298 Amaurochaete, 67, 188 Amaurochaete fuliginosa, 189 Amaurochaetidae, 67, 187, 188 Amaurochaetinea, 67, 187 Amaurosporales, 66-67, 187 Ambystoma tigrinum, 337 Ameiurus albidus, 349 Amitosis, 41-42, 43, 44 Ammodiscidae, 67, 196 Ammodiscus, 67, 196 Ammodisctis incertiis, 194 Amoeba, 69, 206-207, 412, 414 Amoeba discoides, 39, 207, 208 dubia, 39, 207, 208 proteus, 5, 6, 13, 25, 39, 204, 207- 208, 414 verrucosa, 204, 208, 209 Amoebaea, 47, 53, 69-70, 176, 177, 204-223 Amoebic dysentery, 215 Amoebidae, 69, 205, 206-211 Amoeboid, 133, 176 Amoebula, 183, 185, 303, 328 Amphibia, 10, 16, 130 140-142, 146, 158, 159, 218-219, 220, 274, 275, 281, 289, 303, 335, 337, 338, 342, 354. 372, 375,392, 397,412 Amphidinium, 62, 104-105 Amphidinium scissum, 103, 105 Amphileptus, 78, 354 Amphileplus branchiarum, 353, 354 claparedei, 354 Amphilonche, 71, 259 Amphilonche hydrometrica, 258 Amphilonchidae, 71, 259 Amphimonadidae, 64, 133, 147-148 Amphimonas, 64, 147 Amphimonas globosa, 147, 148 Amphipoda, 320, 321, 344, 402 Amphisia, 80, 386 Amphisia kessleri, 386, 387 Amphisolenia, 61, 101 Amphisolenia clavepes, 101 Amphisteginidae, 69, 201 Amphitrema, 70, 234 Amphitrema flavum, 233, 234 Amphizonella, 70, 230 Amphizonella violacea, 229, 230 Amphoroides, 74, 298 Amphoroides calverti, 297, 298 Anal cirri, 29, 30 Andress, 282, 419 Aneminea, 67, 187 Angeiocystis, 73, 271 Angeiocystis audoniniae, 271 Anguilla vulgaris, 142 Anisogametes, 51, 266 Anisogamous conjugation, 53-54 Anisogamy, 52-53, 107 Anisonema, 63, 126 Anisojtema acinus, 125, 126 emarginata, 125, 126 truncatum, 125, 126 Anisoswarmer, 256 Annelida, 11, 105, 140-142, 219, 271, 278, 279, 293, 294, 295, 299, 313, 314, 315, 317, 323, 329, 330, 331, 340, 341, 342, 372, 398 Annulus, 96, 97, 98, 99 Anomalina, 69, 202 Anomalina punctualata, 202 Anomalinidae, 69, 202 Anopheles, 8, 9, 286, 321 Anopheles quadrimaculatus , 320 Anoplophrya, 77, 341 Anoplophrya naidos, 340, 341 Anterior body, 167 Anthophysa, 51, 64, 150 Anthophysa vegetans, 149, 150 Anurosporidium, 76, 331 Anurosporidium pelseneeri, 331 Aphrothoraca, 71, 247-248 Apis mellifica, 219 Apocynaceae, 144 Apodinium, 62, 105 Apodinium mycetoides, 103 Arachnula, 66, 181 Arachnula impatiens, 180, 181 Aragao, 290 Arboroid colony, 49, 51 Arcella, 22, 25, 49, 70, 225, 226, 412. 415 Arcella dentata, 226, 227 discoides, 226, 227 vulgaris, 20, 22, 226, 227 Arcellidae, 70, 226-232 Archotermopsis wroughtoni, 161, 171 Arcichovskij , 23 Arcyria, 67, 190 Arcyria punicea, 189 Arcyriidae, 67, 187, 190 Arenicola ecaudata, 295 Ascidian, 408 Asclepiadaceae, 144 Asclepias sp., 143 Ascoglena, 63, 121 Ascoglena vaginicola, 122 Asellus, 344, 398 Asellus aquaticus, 344 Asexual reproduction, 41-51 AUTHOR AND SUBJECT INDEX 423 Asida, 298 Aspidisca, 80, 3Q0 Aspidisca hexeris, 391 lynceus, 391 polystvla, 391 Aspidiscidae, 80, 385, 390-391 Asplanchna, 331 Assulina, 71, 243 Assulina seminulum, 342, 243 Astasia, 63, 123 Astasia margaritifera, 123, 125 ocellata, 123 Astasiidae, 63, 117, 123-124 Asteracanthion rubens, 344 Asterias rubens, 344 Asterigerina, 69, 201 Asterigerina carinata, 200 Asterophora, 74, 298 Asteroplwra philica, 297, 298 Astomina, 76-77, 339-344 Astrodisculus, 71, 248 Astrodisculus radians, 248, 249 Astrophrya, 81, 400 Astrophrya arenaria, 400, 401 Astropyle 255 Astrorhizidae 67, 196 Astylozoon, 80, 397 Astylozoon fallax, 396, 397 Athene noctua, 140, 289 Audoninia tentaculata. 111 Auerbach, 316 Aulacantha, 73, 262 Aulacantha scolymantha, 262 Aulacanthidae, 73, 262 Aulastornum gulo, 219 Aulosphaera, 73, 262 Aulosphaera labradoriensis, 262 Aulosphaeridae, 73, 262 Auramin, 418 Autogamy, 57, 58 Autotrophic nutrition, 35 Averintzia, 70, 239 Averintzia cvclostoma, 239 Axial core, 172, 173 Axial filament, 26, 27, 28, 29, 39, 155, 245 Axolotles, 146 Axopodia, 26, 43, 130, 245, 247, 250, 260 Axostyle, 39, 155, 157, 160 B Babesia, 17, 74, 289 Babesia bigemina, 288, 289 bovis, 288, 289 Babesiidae, 74, 285, 289 Bacteria and Protozoa, 11, 12, 92, 116, 170, 208, 209, 413 Badhamia, 66, 183, 184, 187 Badhamia utricularis, 188 Baker, 13 Balanitozoon, 77, 346 Balanitozoon agile, 345, 346 Balantidiopsis, 79, 374-375 Balantidiopsis duodeni, 375, 376 Balantidium, 37, 79, 374 Balantidium coli, 10, 16, 18, 374, 376, 417 Balbiani, 15, 17 Balladina, 80, 391 Balladina elongata, 391 Bankia, 377 Barbagallo, 214 Barbus barbus, 306, 312, 317 fiuviatilis, 312, 321 plebejus, 312 Barraud, 153 Barret, 18, 416, 417 Barret and Smith's medium, 416 Barret and Yarborough's medium, 417 Barrouxia, 73, 276 Barrouxia ornata, 275, 276 Basal granule, 23, 27, 30, 32, 33, 136 Basal plate, 30 Bass, 18, 417 Bass' medium for Plasmodium, 417 Becker, 132, 370, 384 Belaf, 57, 58, 253, 270, 415, 419 Belostoma sp., 220 Benecke's solution, 413, 414 Bertramia, 76, 331 Bertramia asperospora, 330, 331 capitellae, 331 etichlanis, 331 Bicosoeca, 64, 135 Biscosoeca socialis, 135 Bicosoecidae, 64, 133, 135-136 Binary fission, 42, 45, 49 Bird malaria, 287 Birds, 17, 18, 140, 146, 218, 220, 272- 273, 274, 287, 288, 289, 328 Bisexual reproduction, 113 Bismarck brown, 418 Bistadiidae, 69, 205-206 Black-head of turkeys, 10, 146 Blastodiniidae, 62, 102, 105 Blastodinium, 62, 105 Blastodinium spinulosum, 103, 105 Blastula, 4 Blepharisma, 79, 372 Blepharisma lateritia, 23, 39, 372, 373 Blepharoplast, 22, 23, 27, 47, 136 Blood-agar medium, 18, 416 Bodo, 64, 150, 412 Bodo caudatus, 150, 151 edax, 150, 151 Bodonidae, 64, 133, 150-152 424 AUTHOR AND SUBJECT INDEX Boeck, 18, 224, 416 Boeck and Drbohlav's medium, 416 Boil disease of barbel, 306 Bolivina, 69, 201 Bolivina punctata, 200 Bombyx mori, 12, 16, 302, 319, 320 Border-line Protozoa, 31, 82, 90, 91, 95, 128, 129-132, 161, 177, 181. 183-191, 205-206, 223, 344 Borgert, 264 Botryoidae, 72, 261 Bouillon-agar, 18, 414 Boveria, 79, 377 Boveria teredinidi, 377 , 378 Boveriidae, 79, 371, iT7-ilS Bowling, 57 Box boops, 159, 337 Brachiomonas, 62, 109-110 Brachiomonas stibmarina, 108, 110 Brachionus, 331 Brady, 203 Brandt, 255, 264 Brassica, 191 Brilliant cresyl blue, 418 Brodsky, 2,2,, 34 Bruce, 17 Bryozoa, 320, 408 Budding, 44, 49, 50, 246, 292, 304, 399 endogenous, 49, 143, 308 exogenous, 44, 49, 50, 103 Bufo, 338, 392 Bufo fowleri, 337 Bugs, 142, 143, 144, 220, 276 Buliminidae, 69, 201 BuUington, 39 BuUinula, 70, 239 Bullinula indica, 237 , 239 Buonanni, 13 Bursaria, 11, 79, 374, 403 Bursaria truncatella, 374, 376 Bursariidae, 79, 371, 374-375 Butschli, 13, 15, 17, 18, 37, 60, 304 Butschliella, 76, 340 Biitschliella opheliae, 340 Buxtonella, 79, 369 Buxtonella sulcata, 369 Cabbage, 190, 191 Caementella, 73, 262 Caementella stapedia, 262 Caementellidae, 73, 262 Caenomorpha, 79, 378 Caenomorpha medusula, 377 , 378 Caenomorphidae, 79, 371, 378 Calcareous substance, 5, 25, 193 Calcarina, 69, 201 Calcarina defrancei, 202 Calcarinea, 66-67, 183, 187 Calcarinidae, 69, 201 Calkins, 9, 11, 15, 18, 21, 22, 39, 40, 41, 56,57, 58,59, 84, 89,91, 117, 129, 155, 181, 205, 282, 338, 370 Calliphora, 144 Callipus, 298 Caloneminea, 67, 187 Calonympha, 65, 165 Calonynipha grassii, 164, 165 Calymma, 255 Calyptotricha, 78, 368 Calyptotricha inhaesa, 367 , 368 Camels, 139 Camerinidae, 68, 200 Campascus, 70, 241 Campascus cornutus, 241 Campbell, 371, 379, 380 Camptonema, 71, 246, 248 Camptonema nutans, 247 , 248 Canary, 287 Cannosphaera, 73, 262 Cannosphaeridae, 73, 262 Capillitium, 185 Capitella capitata, 331 Capsa, 377 Capsellina, 70, 231 Capsellina timida, 231 Carchesium, 13, 51, 80, 394, 395 Carchesium polypinum, 56, 394, 395 Cardium, 299 Carotin, 107, 179, 180 Carp, 142, 147 Carrier of protozoan infection, 215 Carteria, 62, 110, 111 Carteria cordiformis, 108, 110 Caryospora, 73, 275 Caryospora simplex, 275 Caryotropha, 73, 270 Caryotropha mesnili, 271 Casagrandi, 214 Cash, 181, 223, 243, 244, 253 Cassidulina, 69, 201 Cassidulina laevigata, 202 Cassidulinidae, 69, 201 Castanellidae, 73, 263 Castanidium, 73, 263 Castanidium murrayi, 263 Cat, 217, 272, 274 Catenoid colony, 51 Catostomus, 147 Catostomus commersonii, 305, 311 Cattle, 17, 139, 217, 272, 289, 368, 369, 382 Caudal cirri, 29, 30 CauUery, 316, 332 Caulleryella, 75, 301 Caulleryella pipientis, 301 Cell-aggregates, Protozoa as, 4 Cell-anus, 34 AUTHOR AND SUBJECT INDEX 425 Cell-organs, 3, 20-39 Cellulose, 5, 6, 83, 96, 107, 110, 179, 184, 185 Cenolarus, 72, 261 Cenolarus primordialis, 260 Central capsule, 176, 254 Central granule, 26, 43, 246 Centroblepharoplast, 32 Centrodesmose, 47, 48 Centroplast, 43, 246 Centropyxis, 70, 238 Centropyxis acideata, 237 , 238 Centrosome, 47, 246 Cepede, 370 Cepedella, 77, 342 Cepedella hepatica, 342 Cepedia, 76, 337 Cepedia cantabrigensis , 337 Cephalina, 74-75, 291, 293, 296-299 Cephalothamnium, 64, 150 Cephalothaninium cyclopum, 149, 150 Ceratiomyxa, 67, 186, 190 Ceratiomyxa Jruticulosa, 189 Ceratiomyxidae, 67, 187, 190 Ceratium, 11, 13, 51, 61, 97, 100 Ceratium hirundinella, 99, 100 Ceratomyxa, 75, 306 Ceratomyxa mesospora, 306, 307 Ceratomyxidae, 75, 306 Ceratophyllus fasciatus, 140 Ceratopogon, 296, 299, 323 Cercomonas, 64, 152 Cercomonas crassicauda, 151, 152 longicauda, 151, 152 Cestracion, 308 Cestracion zygaena, 306 Chaenia, 77, 347-348 Chaenia teres, 348 Chaetodipteriis faber, 307 Chaetognatha, 223 Chagas' disease, 139 Chalarothoraca, 71, 247, 250-252 Challengeridae, 73, 262 Challengeron, 73, 262 Challengeron wyvillei, 263 Chatton, 43, 106 Chelydra serpentina, 218 Chicken, 146, 218, 220, 272, 273 Chilodon, 55, 78, 354, 357 Chilodon caudatus, 355, 356 cucullulus, 55, 355, 356 cyprini, 355, 356 fiuviatilis, 355, 356 uncinatiis, 56 vorax, 355, 356 Chilodontidae, 78. 344, 354-358 Chilomastix, 16, 65, 160, 415 Chilomastix mesnili, 18, 160 Chilomonas, 61, 94, 414 Chilomonas Paramecium, 46, 93, 94 Chilostomellidae, 69, 201 Chiridota, 295 Chiridota laevis, 295 Chitin, 5, 25, 83, 225 Chlamydomonadidae, 62, 107, 109- 110 Chlamydomonas, 52, 62, 109, 110, 112 Chlamydomonas angulosa, 108, 109 ntonadina, 108, 109 sp., 38 Chlamydomyxa, 66, 181 Chlamvdomyxa montana, 180, 181 Chlam'ydophora, 71, 247, 248-250 Chlamydophrys, 70, 229-230 Chlatnydophrys stercorea, 229, 230 Chlorogonium, 62, 110 Chlorogonium euchlorum, 108, 110 Chloromonadida, 63, 84, 127-128 Chloromyxidae, 75, 308 Chloromyxum, 75, 308 Chloromyxum leydigi, 50, 308 trijugum, 308 Chlorophyll, 35, 37, 82 Choanocystis, 71, 253 Choanocystis lepidida, 253 Choanoflagellidae, 63, 83, 133, 134- 135 Choanophrya, 81, 408 Choanophrya infundibulifera, 408, 409 Christophers, 153 Chromatin, 21, 45, 46 Chromatoid body, 214, 215 Chromatophore, 35, 37-38,, 82, 84- 85, 92, 97, 107, 116 Chromidia, 22, 41, 225 Chromoplast, 37-38 Chromosome, 44, 45, 46, 56, 57, 107, 246, 270 Chromulina, 60, 85, 86 Chromulina pascheri, 86, 87 Chromulinidae, 60, 86 Chrysapsis, 60, 86 Chrysapsis sagene, 86, 87 Chrysidella. 61, 93 Chrysidella schaudinni, 93-94 Chrysocapsina, 61, 86, 91 Chrysococcus, 60, 86 Chrysococcus ornatus, 86, 87 Chrysomonadida, 60-61, 84-91, 92 Chytriodinium, 62, 105 Chytriodi?iium parasilicum, 103, 105 Cil, 235 Cilia, 28-29, 33, 60, 333 Ciliata, 3, 13, 14, 20, 21, 31, 37,60, 76-81, 176, 266, 333-398, 415, 418 426 AUTHOR AND SUBJECT INDEX Cilioflagellata, 97 Ciliophora, 7, 28, 41, 53, 60, 76-81, 333^10 Ciliophrys, 31, 63, 132 Ciliophrys infusionum, 131, 132 marina, 132 Cinetochilum, 78, 363 Cinetochilum margaritaceum, 362, 363 Cingulum, 99 Circoporidae, 73, 263 Circoporus, 73, 263 Circoponis octahedrus, 263 Cirri, 29, 30, 333, 385 Cirrus fiber, 30 Cladocera, 332 Cladomonas, 64, 147 Cladomonas fruticulosa, 147, 148 Cladothrix pelomyxae, 209 Claparede, 14 Classification of Protozoa, 60-81 Clathrulina, 71, 252 Clathrulina elegans, 252, 253 Clausia, 343 Clausocalanus, 105 Clegg. 18 Cletodes longicaudatus , 404 Cleveland, 6, 167, 175, 365 Climacostomum, 79, 377 Climacostomum virens, 3T7 Clitellis arenarius, 315 Clupea pilchardus, 310 Clymenella torquata, 105 Clypeolina, 70, 236 Clypeolina marginata, 235, 236 Cnidosporidia, 8, 34, 41, 42, 53, 75- 76, 266, 302-325 Coccidia, 8, 16, 17, 45, 73-74, 266, 267-282, 284 Coccidiosis, 10, 273 Coccolithophoridae, 61, 86, 89 Coccomonas, 62, 115 Coccomonas orbicularis, 115 Coccomyxa, 75, 310 Coccomyxa morovi, 310 Coccomyxidae, 75, 309, 310 Cocconema, 323 Cocconemidae, 323 Coccospora, 76, 322, 323 Coccospora slavinae, 323 Coccosporidae, 76, 320, 323 Cochliatoxum, 79, 384 Cochliatoxum periachtum, 383. 384 Cochliopodium, 49, 70, 230 Co chlio podium bilimbosum, 229, 230 Cockchafer, 160 Cockroach, 159, 162, 170, 212-213, 220, 296, 332, 372, 412 Codonosiga, 64, 134 Codonosiga utriculus, 134 Coelenterata, 105, 147, 222-223, 341, 368, 386, 392, 398, 400, 404, 406, 408 Coelodendridae, 73, 263 Coelodendrum, 73, 263 Coelodendrum ramosissimum, 263 Coelosporidium, 76,331-332 Coelosporidiuni blattellae, 332 periplanetae, 330, 332 Coelozoic, 304 Coenobium, 110 Cohn, 14 Colacium, 63, 122-123 Colacium vesiculosum, 122. 123 Cole, 19 Coleoptera, 16, 298, 299 Coleps, 25, 77, 334, 346, 347, 412 Coleps bicuspis, 345, 346 elotigatus, 345, 346 hirtus, 345, 346 octospinus, 345 , 347 Collared Protozoa, 83, 134-136 Collection of Protozoa, 411-412 Collin, 29, 399, 410 Collinella, 77, 345 Collinella gundii, 345 Collinia, 77, 344 Collinia circulans, 343, 344 Collodaria, 72, 259 Collodictyon, 62, 109 Collodictyon triciliatum, 108, 109 CoUosphaera, 72, 261 CoUosphaeridae, 72, 261 Colonial Protozoa, 4 Colony, 4, 49, 51, 83, 107, 110-114 arboroid, 51, 90 catenoid, 51, 100 dendritic, 51 gregaloid, 51 linear, 51, 100 spheroid, 51, 87 Color of water due to Protozoa, 86, 98, 118 Colpidium, 78, 361 Colpidium colpoda, 361, 362 striatum, 361, 362 Colpoda, 13, 78, 361 Colpoda campyla, 361, 362 cucullus, 361, 362 helia, 361, 362 inflata, 361, 362 Colponema, 64, 152 Colponenia loxodes, 151, 152 Columba livia, 288 Commensal, 6, 7, 216 Commensalism, 7 Compact nucleus, 21 Conchophthirus, 79, 369 Conchophthirus sieenstrupii, 369 AUTHOR AND SUBJECT INDEX 427 Condylostoma, 79, 375 Condylostoma patens, 375, 376 vorticella, 375, 376 Congo red, 418 Conjugants, 53, 56 Conjugation, 15, 51, 53-56 anisogamous, 55 in Vorticella, 55-56 isogamous, 53, 54 Conn, 370 Contractile vacuole, 22, 36-37, 83, 176 Copepoda, 98, 105, 123, 150, 255, 320, 321, 398, 404 Copromastix, 65, 156 Copromastix prowazeki, 156 Copromonas, 63, 124 Copromonas subtilis, 52, 124 Coprozoic Protozoa, 124, 150, 151, 152, 156, 163, 205, 206, 211, 230 Coptotermes formosanus, 168, 174 Copulation, 52-53 anisogamous, 52-53 isogamous, 52 Cordylophora lacustris, 400 Coronympha, 65, 165 Coronympha clevelandi, 164, 165 Corythion, 71, 242 Corythion pulchellum, 242 Costia, 64, 153 Costia necatrix, 153 Costiidae, 64, 133, 153 Cothurina, 80, 392, 397 Cothurina crystallina, 396, 397 nodosa, 396, 397 Cowdry, 419 Crab, 270 Craig, 215, 224, 416 Craspedotella, 62 Craspedotella pileolus, 106 Craspido chilus cinereus, 330 Crawley, 332 Cretiilabrns melops, 331 ocellatus, 331 paro, 331 Cribraria, 67, 188 Cribraria aurantiaca, 189 Cribrariidae, 67, 187, 188 Crickets, 296 Crithidia, 64, 136, 142, 144 Crithidia euryophthalmi, 142-143 gerridis, 143 hyalommae, 143 Crow, 287 Crow, W. B., 115 Cruciferae, 190 Crustacea, 11, 98, 105, 150, 269, 270, 298, 299, 320, 321, 341, 344, 398, 402. 404 Cryptobia, 64, 147 Cryptobia borreli, 146, 147 cyprini, 146, 147 helicis, 146, 147 Cryptobiidae, 64, 133, 146-147 Cryptochrysis, 61, 94 Cryptochrvsis commutata, 93, 94 Cryptodifflugia, 70, 227-228 Cryptodifflugia oviformis, 228 Cryptoglena, 63, 121 Cryptoglena pigra, 121, 122 Cryptomonadida, 38, 61, 84, 92-95, 96 Cryptomonadidae, 61, 93 Cryptomonas, 61, 93, 94 Cryptomonas ovata, 93 Cryptosporidium, 73, 276 Cryptosporidium muris, 276 parvum, 276 Cryptotermes grassii, 165 hernisi, 157, 165 Crystals, 39, 207, 208, 295, 334 Ctenocepkalus cams, 144 Ctenodactylus gundi, 345 Cucumber odor of water, 10, 88 Cucurbitella, 70, 238 Cucurbitella mespiliforviis, 237 , 238 Culex, 9, 286, 287. 321 Culex fatigans, 17 pipiens, 301, 317 territans, 317 Cull, 59 Cultivation of Protozoa, 18, 414 Actinophrys, 415 Actinosphaerium, 415 Amoeba proteus, 414 Amoebae, 18, 414 Arcella, 415 Balantiduitn coli, 18, 417 Chilomastix, 18, 415 Chilomonas, 414 Ciliates, 415 Embadomonas, 415 Entamoeba barreti, 416 histolytica, 18, 416-417 Eudorina, 413 Euglena, 413 Euplotes, 415 Gonium, 413 intestinal amoebae, 416-417 Leishmania, 18, 145, 416 Lophomonas, 416 Mastigophora, 413, 414 Naegleria, 414 Paramecium, 415 Peranema, 414 Phacus, 413 Phytomonadida, 413 Plasmodium, 18, 417 428 AUTHOR AND SUBJECT INDEX Stylonychia, 415 Testacea, 415 Trichomonas, 415 Trypanosoma, 18, 416 Vahlkampfia, 18, 414 Curtis, 365 Cushman, 25, 195, 203 Cutler, 18 Cyathomonas, 61, 94 Cyathomonas truncata, 93, 94 Cyclidium, 78, 367 Cydidium glaucoma, 367 Cyclochaeta, 80, 392, 394 CycJochaeta domerqui, 393, 394 spongillae, 393, 394 * Cyclonexis, 60, 89 Cyclonexis annularis, 87, 89 Cyclonympiia, 66 Cyclonympha strobila, 17 1 , 174 Cyclonymphidae, 66, 167, 174 Cycloposthium, 79, 382 Cycloposthium bipalmatum, 55, 382, 383 Cyclops, 150, 404, 408 Cyclops fuscus, 320 Cyclosis, 14 Cyclospora, 73, 275 Cyclospora caryolytica. 275 Cyclostoma elegans, 394 Cynoscion regalis, 309 Cyphoderia, 70, 240 Cyphoderia ampulla, 240-241 Cyprinus, 142, 147 Cypris, 397 Cyrtellaria, 72, 261 Cyrtoidae, 72, 261 Cyrtolophosis, 78, 359 Cyrtolo pilosis mucicola, 359, 360 Cysts, 5, 6, 7, 8, 97, 109, 151, 162, 169, 184, 185, 207, 304. 305, 312, 319, 320, 331, 364, 366 Cystidium, 72, 261 Cystidium princeps, 261 Cystobia, 74, 294-295 Cystohia irregularis, 295 Cystoflagellata, 62, 98, 104, 106 Cytamoeba, 74, 289 Cytamoeha bacterifera, 289 Cytopharynx, 29," 34, 37, 116, 126, 335 Cytoplasm, 23-34, 36-39, 176, 204, 225, 245 Cytoplasmic color, 23 division, 49-51 binary fission, 42, 45, 47-49 budding, 44, 304 multiple division, 49-50 plasmotomy, 50-51, 304 Cytopyge, 34, 335 Cytostome, 22, 28, 29, 34, 116. 155, 335 D Dactylophrya, 81, 406 Dactylophrya roscovita, 406, 407 Dallasia, 78, 359 Dallasia frontata, 359, 360 Dallingei-ia, 64, 153 Dallingeria drysdali, 153 Dangeard, 115, 128 Dasyhelea obscura, 296, 325 Dasytricha, 79, 369 Dasytricha ruminantium, 369 Davaine, 16 Davis, 306, 309, 316 De Barv, 183, 191 Decapoda, 105, 269, 270, 298, 299, 341, 402, 404 Deer mice, Canadian, 140 Deflandre, 244 Dellinger, 223 Dendritic colony, 51 Dendrocometes, 81, 402 Dendrocometes paradoxus, 402, 403 Dendrocometidae, 81, 400, 402 Dendromonas, 64, 149-150 Dendromonas virgaria, 149 Dendrorhynchus, 75, 299 Dendrorhynchus svsleni, 299 Dendrosoma, 81, 400-401 Dendrosoma radians, 401 Dendrosomidae, 81, 399, 400-402 Dendrosomides, 81, 401 Dendrosomides pagiiri, 401, 402 Depression slide, 417-418 Desmarella, 64, 134 Desmothoraca, 71, 247, 252-253 Deutomerite, 291 Devescovina, 65, 157 Devescovina lemniscata, 157 Diaphoropodon, 70, 235 Diaphoropodon mobile, 235-236 Diaptomus, 404 Diaptomus castor, 321 Diatoms, 92, 98. 109, 195 Dicnidea, 76, 319, 323-324 Dictomyxa, 66, 181 Dictyophimus, 72, 261 Dictyophimus hertwigi, 261 Dictyosteliidae, 67, 190 Didinium, 77, 350-351, 352, 406, 412 Didiniuni nasiilum, 56, 351, 352, 412 Didymiidae, 67, 187 Didymium, 67, 187 Didymium effusum, 188 Diemyctylus viridescens, 142 Dientamoeba. 69, 221 Dientatnoeba fragilis, 20, 219, 221 Dierks, 40 Diesing, 15 Difflugia, 70, 225, 236 AUTHOR AND SUBJECT INDEX 429 Difflugia arcula, 236, 237 conslricta, 237 lohostoma, 237 oblonga, 236, 237 pyriformis. 236 urceolata, 236, 237 Difflugiella, 70 227 Difflngiella apiculata, 227, 2Z8 Difflugiidae, 70, 226, 236-239 Dileptus, 78, 352-353 Dileptiis anser, 22, 41, 353 Dimorpha, 31, 63. 132 Dimorpha mutatis, 131, 132 Dimorphism, 195 Dinenympha, 65, 158 Dinenympha fimbriata, 157, 158 Dinifera, 61, 98-106 DinobrN'on, 11, 51, 60, 89 Dinobryon serttilaria, 89, 90 Dinoflagellates, 96-106 Dinoflageliida, 34, 39, 61, 83, 84, 92, 96-106, 257 Dinophrya, 77, 352 Dinophrya licberkiihni, 351, 352 Dinophysidae, 61, 98, 100-101 Dinophysis, 61, 101 Dinophysis acuta, 99, 101 Diophrys, 80, 390 Diophrys appendiculatus, 390 Diphasia attenuata, 406 Diphasic amoebae, 205-206 Diplochlamys, 70, 231 Diplochlamys leidyi, 231, 232 Diploconidae, 72, 259 Diploconus, 72, 259 Diplocvstis schneideri, 57 Diplod'inium, 79, 382 Diplodinium bursa, 382, 383 Diplophrys, 70, 234 Diplophrys archeri, 233, 234 Diplomita, 64, 148 Diplomita socialis, 148 Diplozoa, 65, 155 Diptera, 17, 138, 139, .144, 219, 284, 286, 288, 293, 296, 299, 301, 320, 321, 323, 325, 361 Direct nuclear division, 41-42, 43, 44 Discoidae, 72, 260 Discolith, 89 Discomorpha, 79, 379 Disconwrpha pectinata, 378, 379 Discophrya, 81 Discophrya elongata, 408, 409 Discophryidae, 81, 400, 408 Discosphaera, 61 Discosphaera tubifer. 89, 90 Dissosteria Carolina, 296 Distephanus, 61 Distephanus speculum, 90 Distigma, 63, 126 Distigma proteus, 125 , 126 Ditoxum, 79, 384 Ditoxum funinucleum, 383, 384 Ditrichomonas, 65, 161 Ditrichomonas termitis, 160, 161 Division, cytoplasmic, 42, 47-51 nuclear, 41-47 Dobell, 9, 19, 43, 52, 57, 128, 165, 182, 224. 270, 274, 283 Dobellia, 73, 271 Dobellia binucleata, 271 Dobelliidae, 73, 269, 271 Doflein, 15, 19, 40, 50, 59, 84, 91, 181, 208, 282, 301, 338, 370, 419 Dog, 139, 217, 272, 274 Dogiel, 55, 175, 384 Donax trunculus, 331 Donkey, 17, 139, 140 Donovan, 17 d'Orbigny, 14 Dourine, 10, 140 Drbohlav, 18. 416 Drehkrankheit, 311 Drimobius bifossatus, 218 Drosophila, 323 Drosophila confusa, 144 Duboscq, 182 Duboscqia, 72, 321 Duboscqia legeri, 321 Duck, 218, 287, 328 Dufour, 16 Dujardin, 14 Dutton, 17 Dysentery amoeba, 214-215 Dysteria, 78, 357 Dysteria armata, 357 lanceolata, 356, 357 E East Coast fever, 289 Echinodermata, 295, 344, 363, 377, 392 Ectoplasm, 24 relation to endoplasm, 24 Edmondson, 370 Eels, 142 Egg, Protozoa parastic in, 105, 294, 307, 320 Ehrenberg, 14 Eichhorn, 13 Eimer, 16 Eimeria, 53, 73, 271 Eimeria acervulina, 273 canis, 272, 273 clupearum, 273, 274 debliecki, 272, 273 falciformis, 272, 273 faurei, 272, 273 430 AUTHOR AND SUBJECT INDEX felina, 272 maxima, 273 meleagridis, 273 meleagrimitis, 273 mitis, 273 neglecta, 274 nieschulzi, 272 oxyspora, 274 prevoti, 273, 274 ranae, 273, 274 ranarum, 273, 274 sardinae, 273, 274 schuhergi, 45, 267-269, 271 stiedae, 16, 272 tenella, 272-273 wenyoni, 274 zurnii, 272 Eimeridea, 73, 2tl-21(i Eimeriidae, 73, 269, 271-276 Elaeorhanis, 71, 250 Elaeorhanis octilea, 249, 250 Eleodes, 298 Elephant, 139 Eleutheria dichotoma, 341 Ellipsoidina, 69, 201 Ellipsoidinidae, 69, 201 Ellis, 13 Elphidium, 68, 200 Elphidium strigilata, 200 Embadomonas, 64, 151-152, 415 Embadomonas agilis, 152 intestinalis , 151, 152 Emys orbicularis, 279, 280 Enchelyodon, 77, 350 Enchelyodon farctus, 33, 350 Enchelys, 77, 350 Enchelys teres, 350, J5i trujicata, 350, J57 Encystment, 5, 6, 7, 8, 97, 364-366 Endamoeba, 69, 211-212, 214 Endamoeba blattae, 41-42, 44, 53, 212- 213 disperata, 213 majestas, 213 sabulosa, 213 simulans, 213 thomsoni, 213 Endamoebidae, 69, 205, 211-223 Endolimax, 69, 220 Endolimax blattae, 220 gregariniformis, 220 wana, 2/P, 220 ranarum, 219, 220 Endoplasm, 23 relation to ectoplasm, 23 Endoskeleton, 39 Endosome, 21, 45, 46 Endosphaera, 81, 406 Endosphaera engelmanni, 406 Endosporeae, 66-67, 187 Endomixis, 58 Enriques, 56 Entamoeba, 69, 213-220 Entamoeba anatis, 218 apis, 219 aulastomi, 219 barreti, 218, 416 belostomae, 220 &om, 217 buccalis, 216 caprae, 217 caviae, 218 cobayae, 218 co/z, 16, 215^216, 217, 218, 219 cuniculi, 217 debliecki, 217 egwi, 217 gallinarum, 218 gingivalis, 16, 2i5, 216, 217 gingivalis var. egz«, 217 histolytica, 10, 16, 18, 36, 214-215, 216, 217, 218,416 intestinalis, 217 lagopodis, 218 mesnili, 219 minchini, 219 muris, 218 Of 15, 217 polecki, 217 ranarum, 218-219 serpentis, 218 sp., 219 sp., 219 testudifiis, 218 venaticum, 217 Enteromonas, 65, 156 Enteromonas hominis, 156 Entodinium, 79, 382 Entodinium caudatum, 382, J, 335- 338 Protodiniferidae, 102 Protomerite, 291 Protomonadida, 63 64, 129, 133-153 Protomonas, 66, 179 Protomonas amyli, 179 Protoopalina. 76, 3 "6-337 Protoopalina inlestitialis, 33ft, 337 mitotica, 337 saturnalis, 337 Protophrya, 77, 344 Protophrya oiicoln, 343, 344 Protophyta, compared with Protozoa, 3, 9, 82, 95, 183 Protoplasma, 14, 20 Protoplasmic movements, 14, 185, 192. 204, 212 Protozoa and bacteria, 3, 9, 11, 12 as non-cellular organisms, 3 as unicellular organisms, 3-4, 8, 14 classification of, 15, 60-81 collection of, 411-412 colonial, 4, 49, 51, 83, 107, 110-114 cultivation of, 15, 18, 412-417 definition of, 3-4 distinguished from Protophvta, 3-4, 9 Metazoa, 4, 9 fossil, 12-13, 192, 254 geographic distribution of, 5, 6 observation of, 417-419 parasitic in algae, 98, 178, 179, 180 Amphibia, 16, 130, 140-142, 146, 158, 159, 218, 219, 220, 274, 275, 281, 289, 303, 335, 337, 338, 342, 354, 372, 375, 392, 397 Annelida, 105, 140, 141, 142, 219, 271, 278, 279, 293, 294, 295, 299, 313, 314, 315, 317, 323, 329, 330, 331, 340, 341, 342, 372 S98 birds,'l7, 18, 140, 146, 218, 220, 272, 273, 274, 287, 288, 289, 328 Bryozoa, 320, 408 cats, 217, 272, 274 cattle, 17, 139, 217, 272, 289, 368, 369, 382 Chaetognatha, 223 chicken, 146, 218, 220, 272, 273 cockroaches, 159, 162, 170, 212, 213, 220, 296, 332, 372 Coelenterata, 105, 147, 222, 223, 341, 368, 386, 392, 398, 400, 404, 406, 408 Copepoda, 98, 105, 150, 320, 321, 398, 404 Decapoda, 105, 269, 270, 298, 299, 341, 402, 404 Diptera,.17, 138, 139, 144, 219, 284, 286, 288, 293, 296, 299, 301, 320, 321, 323, 325, 361 dogs, 139, 217, 272, 274 donkeys, 17, 139, 140 echinoderms, 295, 344, 363, 377, 392 eggs, 105, 294, 307, 320 f^sh, 11, 16, 142, 147, 153, 159, 162, 221, 274, 281, 302, 303, 305, 306-313, 317, 320, 321, 331,336, 337, 349, 355, 394 fowls, 146, 218, 220, 273. 287 frogs, 16, 28, 130, 140, 141, 142, 158, 162, 218, 219, 220, 274, 275, 281, 289, 303, 335, 337, 338, 354, 361, 372, 375, 392 goat, 217, 272, 381, 382 guinea-pig, 218 horses, 17, 139, 140, 217, 328, 382, 384 Hydra, 222, 223, 386, 392 Insecta, 12, 16, 17, 139, 140, 142, 143, 144, 146, 152, 157, 158, 159, 161, 163, 164, 165, 167- 174, 219, 220, 276, 279, 284, 286, 288, 293, 296, 298, 299, 301, 319, 320, 321, 323, 324, 325 332 372 leeches, 140^ 141, 142, 219, 279, 317 man, 10, 16, 17, 18, 138,139, 144, 145, 152, 156, 160, 161, 163, 214, 215, 216, 220, 221, 274, 328, 374 mice, 140,218,272,276,279,328 mites 17, 281, 282 Mollusca, 16, 147, 210, 270, 276, 279, 298, 299, 329, 330, 341, 342, 344, 369, 408 mosquitoes. 8, 9, 286, 287, 293, 319, 361, 378 mules, 139 Myriapoda, 267, 278, 297, 298 newt, 142, 219, 337,397 pigs, 139,217,221,272,326,328, 374 plants, 136, 144, 178, 190, 191 444 AUTHOR AND SUBJECT INDEX Platyhelminthes, 295, 330, 331, 342 Porifera, 394 Protozoa, 178, 179, 403, 406, 410 rabbits, 16, 140, 217, 272, 328 rats, 17, 140, 218, 272, 282, 328 Reptilia, 140, 151, 159, 218, 275, 279, 282, 303 Rotifera, 331 sheep, 137, 139, 217, 272, 326, 328, 368, 369, 381, 382 Sipunculoidea, 271, 295, 299, 313, 314 snake, 140, 159, 218, 275 termites, 157, 158, 161, 163-165, 167, 168, 170-174, 213, 321 ticks, 17, 143, 289 Toads, 158, 303, 337, 372, 392 turkeys, 146, 273 turtles, 140, 218, 279 possessing more than one type of locomotive organelle, 29, 31, 129-132, 205-206 size of, 20, 176-177, 192, 334 Protozoology and biology, 8 cytology, 10 economic entomology, 12 evolution, 8-9, 10, 177 genetics, 9 geography, 9-10 geology, 12-13, 192, 254 medicine, 10 phylogeny, 9 pisciculture, 11 sanitary science, 11 soil biology, 11-12 veterinary science, 10 zoogeography, 9-10 Protrichomonas, 65, 159 Protrichomonas legeri, 159 Prowazek, 364 Prowazekella, 28, 64, 151 Prowazekella lacertae, 151 Provvazekia, 150 Prunoidae, 72, 260 Psammoryctes barbalus, 315 Psammosphaera bowmanni, 25 f II sea, 25 parva, 25 rustica, 25 Pseudochitinous substance, 25, 83, 192, 225 Pseudochlamys, 70, 227 Pseiidochlamvs patella, 227, 228 Pseudodifflugia, 49, 70, 234-235 Pseiidodifflugia gracilis, 235 Pseudogemma, 81, 406 Pseudogemma pachystyla, 406, 407 Pseudopodia, 25-27, 60, 83, 129, 167, 177, 178, 204, 245-246 Pseudospora, 66, 178 Pseudospora endorini, 179 parasitica, 179 volvocis, 179 Pseudotrichonympha, 66, 174 P seudotrichonympha grassii, 174 Psilotricha, 80, 391 Psilotricha acuminata, 391 Psilotrichidae, 80, 385, 391 Pteridomonas, 63, 132 Pteridomoias pulex, 131, 132 Pteromonas, 62, 115 Pteronionas aiigidosa, 113, 115 Pterospora, 74, 294 Pterospora maldaneorum, 294 Pulsating vacuole, 36-37 Pulsella, 28 Purkinje, 14 Pusule, 83, 97, 102 Pycnothrix, 77, 345 Pyc7iothrix nionocystoides, 346 Pyorrhoea alveolaris, 216 Pyramidomonas, 108 Pyramimonas, 62, 108 Pyramimonas tetrarhvnclnis, 108 Pyrenoids, 38, 82, 117 Pyrosoma elegans, 408 Pyrsonympha, 65, 158 Pyrsonympha vertens, 158 Python, 159 Pyxidicula, 70, lid 221 Pyxidicula operculata, 227 Quadrula, 71, 243 Qiiadrula symmetrica, 242, 243 R Rabbit, 16, 140, 217, 272, 328 Radiating canals. 36 Radiolaria, 12-13, 14, 15, 26, 39, 50, 52, 71-73, 176, 245, 254-263 Rainey's corpuscles, 326 Raja, 142, 308 Raja oxvrhyjichtis, 142 Rana, 338, 354, 375, 392 Rana cantabrigenis , 338 pnpiens, 307, 337 Raphidiocystis, 71, 252 Raphidiocystis ttibifera, 251, 252 Raphidiophrys, 71, 251 Raphidiophrvs pallida, 251-252 Rats, 17, 140, 218, 272, 282, 328 Red rain, 109 Red snow, 109 Red water, 98 Red-water fever, 289 AUTHOR AND SUBJECT INDEX 445 Redi, 13 Reduction division in Protozoa, 56- 57, 270 Reduviid bug, 139 Reese, 417 Reichenovv, 19, 40, 59, 91, 181, 282, 283, 301, 338, 370, 419 Reophacidae, 68, 196 Reophax, 68, 196 Reophax nodulosus, -194 Reproduction in Protozoa, 41-58 asexual, 41 51 sexual, 51-58 Reproductive cells, 113 Reservoir of contractile vacuoles, 37, 116 Reservoir hosts, 138, 221 Reticularia, 67, 189 Reticularia Ivcoperdon, 189 Reticulariidae, 67, 187, 189 Reticulopodia, 26, 235 Reticulotermes hesperns, 158 Reptiles, 140. 151, 159, 218, 275, 279, 282, 303 Retortamonas, 65, 159 Retortamonas orthopterorunt, 159 Reynolds, 223 Rhabdammina, 67, 194, 196 Rhabdammina abvssornm, 194 Rhabdophrya, 81, 402 Rhabdophrva trimorpha, 402, 403 Rhabdosty'la, 80, 397 Rliabdostyla vernalis, 397 , 398 Rhipidodendron, 64, 147 Rhipidodendron splendidum, 147-148 Rhizammina, 67, 196 Rhizammina algaeformis, 194 Rhizamminidae, 67, 196 Rhizocaryum, 76, 339-340 Rhizocarvum concavum, 339-340 Rhizochrysidina, 61, 86, 90-91 Rhizochrysis, 61, 91 Rhizochrvsis scherffeli, 90, 91 Rhizoma'stigidae, 63, 129, 130, 132 Rhizomastix, 64, 146 Rhizotiiastix gracilis, 146 Rhizopiasma, 66, 181 Rhizo plasma kaiseri, 181 Rhizoplast, 22, 23, 130 Rhizopoda, 14, 15, 66-71, 177 243 Rhizopodia, 26, 199, 235 Rhumhler, 203 Rhvncheta, 81, 408 Rhyncheta cyclopum, 408, 409 Rhynchocystis, 74, 296 Rhynchocystis pilosa, 296 Rhynchogromia, 70, 234 Rhynchogromia nigricans, 233, 234 Rhynchomonas, 64, 150-151 Rhynchomonas nastita, 151 Rhynchophrya, 81, 408 Rhynchophrya palpans, 408, 409 Ringer-egg medium, 416 Ringer's solution, 417, 419 Robertson, 290 Root-hernia, 190, 190 Rosel, 13 Roskin, 182 Ross, 17, 290 Rotalia, 69, 201 Rotalia beccarii, 200 Rotaliidae, 69, 201 Rotifera, 123, 207, 331 Roux, 372 Rupertia, 69, 203 Rupertia stabilis, 202 Rupertiidae, 69, 202 Ruppia, 191 Russel, 11 S. S. medium, 416 Saccammina, 69, 196 Saccammina sphaerica, 194 Saccamminidae, 69, 196 Sagenocene, 73, 262 Sagitta claparedei, 223 Sagosphaeridae, 73, 262 Salamander, 342 Salpa, 105 Salpingoeca, 64. 135 Salt-serum medium, 416 Sandon, 5, 6, 19 Sapotaceae, 144 Sappinia, 69, 211 Sappinia diploidea, 211 Saprodinium, 79, 379 Saprodinium dentatum, 378, 379 Sapropelic Protozoa, 35 Saprophytic nutrition, 35 Saprozoic nutrition, 4, 35, 37 Sarcocystis, 76, 328 Sarcocystis bertrami, 328 cuniculi, 328 lindemanni, 328 miescheriana, 326, 328 muris, 328 rileyi, 328 tenella, 326, 327, 328 Sarcode, 14 Sarcodina, 12, 15, 51, 60, 66-73, 90, 128, 130, 176-263, 266, 411, 418 Sarcophaga, 144 Sarcosporidia. 17, 76, 326-328 Sarcotoxin, 327-328 Sardine, 274, 310 Satellite, 296 Scaphidiodon, 78, 357 446 AUTHOR AND SUBJECT INDEX Scaphidiodon navicula, 356, 357 Scaphiopus solitaritis, 337 Schaeffer, 39, 40, 207, 208, 223, 224 Schaudinn, 15, 17, 265, 267, 283 Schilling, 106 Schizamoeba, 69, 221 Schizamoeba salmonis, 221-222 Schizocystis, 52, 75, 299 Schizocvstis gregarinoides, 299, 300 Schizogony, 17, 50, 265, 268, 299, 300 Schizogregarinaria, 75, 291, 299-301 Schizogregarines, 299-301 Schizonts, 265, 268, 303, 319 Schizotrypantim criizi, 138 Schroder, 31 Schiifflner's dots, 287 Schultzellina, 77, 341 Schultzelliua mucronata, 340, 341 Sclerotia, 184 Scolopendra, 278 Scolopendra cingulata, 298 Scoloplos miille/i, 330 Scyphidia, 80, 397 Scyphidia constricta, 396, 397 Scytomonas, 63, 124 Scytomonas pusilla, 124, 125 Secondary nucleus, 176, 205, 223 Selenococcidiidae, 73, 269-270 Selenococcidium, 73, 269 Selenococcidium intermedium, 270 Sepia officinalis, 270 Sexual reproduction, 51-58 autogamy, 57, 58 conjugation, 51, 53-56 copulation, 51-53 endomixis, 58 paedogamy, 57 Sheep, 137, 139, 217, 272, 326-328 368, 369, 381, 382 Shortt, 153 Siebold, 14, 15 Sieboldiellina, 77, 342 SieboldieUina planariartim, 342, 343 Siedlecki, 17 Silicina, 67, 196 Silicina limitata, 194 Silicinidae, 67, 196 Silicious test, 25, 86, 192, 225 Silicoflagellidae, 61, 86, 90 Silkworm, 12, 16, 302, 319, 320 Simulium, 317 Sinuolinea, 75, 309 Sinuolinea dimorpha, 308, 309 Siphonophora, 105, 147 Siphostoma, 309 Sipunculoidea, 271, 295, 299, 313, 314 Sipunculus, 295 Sizygy, 296 Skeleton, 12-13, 176, 246, 254, 256 Slavina appendiculata, 278, 323 Sleeping sickness, 17, 138 Slime molds, 183 Smelts, 320 Smith, 17 Snails, 76, 79 Snake, 140, 159, 218, 275 Snyderella, 65, 165 Snyderella tobogae, 165 Soil Protozoa, 5-6, 11-12, 225 Solea vulgaris, 281 Solenophrya, 81, 406 Solenophrya inclusa, 406, 407 per a, 406, 407 Somatic cells, 113 Sorophora, 67, 186, 190 Sorosphaera, 191 Spadella bipunctata, 223 inflata, 223 serratodentata, 223 Sparrow, 140, 287 Spathidium, 77, 350 Spathidium spathula, 33, 350, 351 Spermatozoon, 3, 52 Sphaeractinomyxon, 75, 315 Sphaeractinomyxon gigas, 314, 315 stolci, 314, 315 Sphaerastrum, 71, 250 Sphaerastrtim fockei, 249, 250 Sphaerella, 109 Sphaerellaria, 72, 260 Spbaerium corneum, 342 Sphaerocapsa, 71, 259 Sphaerocapsidae, 71-72, 259 Sphaeroeca, 64, 135 Sphaeroidae, 72, 260 Sphaeromyxa, 75, 309 Sphaeromyxa balbianii, 50, 309, 310 sabrazesi, 310 Sphaerophrya, 81, 402--403 Sphaerophrya soliformis, 403, 404 stentoris, 403 Sphaerospora, 75, 308 Sphaerospora polvmorpha, 308, 309 Sphaerosporea, 75, 306, 308-309 Sphaerosporidae, 75, 308-309 Sphaerozoidae, 72, 261 Sphaerozoum, 72, 261 Sphaerozoum ovodimare, 260 Spheroid colony, 51 Spindle fibers, 45, 46, 48 Spireme, 46 Spirochona, 81, 335, 398 Spirochona gemmipara, 396, 398 Spirochonidae, 81, 392, 398 Spirodinium, 79, 382 Spirodiniiim equi, 382, 383 Spiroglugea, 76, 323 Spiroglugea oclospora, 322, 323 AUTHOR AND SUBJECT INDEX 447 Spirogyra, 179, 180 Spiroloculina, 68, 198 Spiroloculina, limbata, 197 Spiromonas, 64, 148 Spiromonas augnsta, 148 Spironema, Hi Spirospora, 323 Spirostomuni, 36, 79, 334, 372 Spirostonium ambiguum, 35, 41, 372, 373 var. inflatum, 372 major, 372 minor, 372 teres, 373 Spirotrichonympha, 65, 168 Spirotrichonympha leidyi, 168, 109 Spirotrichonymphella, 65, 168 Spirotrichonymphella pudibiinda, 168 Spondylomorum, 62, 110, 111 Spondylomorum quaternariiim. 111 Sponge, 394 SpongiUa fluviatilis, 394 Spongomonas, 64, 147 Spongomonas itvella, 147, 14S Sporangium, 185 Spore, 8, 185, 186, 265, 302, 313, 314, 318, 326, 327, 328 acnidosporidian, 34, 326, 327 actinomyxidian, 313, 314 cnidosporidian, 302 haplosporidian, 328 microsporidian, 317-318 mycetozoan, 185, 186 myxosporodian, 58, 303 telosporidian, 266, 271, 294 Spore-membrane, 303 Sporoblast, 269, 319 Sporogony, 265 Sporont, 46, 265, 303, 304, 319 monosporoblastic, 304 disporoblastic, 304 Sporophore, 186 Sporoplasm, 57, 302, 303 Sporozoa, 17, 21, 31, 49, 50, 52, 53, 60, 73-76, 265-332 Sporozoite, 265, 266, 268, 269, 284 Sprats, 274 Stationary nucleus, 53, 55, 56 Staurocyclia, 72, 261 Staurocyclia phacostaurus, 260 Staurojoenia, 66, 172 Staurojoenia assimilis, 172, 173 Staurojoeniidae, 66, 167, 172 Stegomyia sctitellaris , 361 Stein, 15, 16, 124, 2,2>^, 380, 391, 398 Steinella, 77, 342 Steinina, 75, 298 Steinia rottinda, 297 . 298 Stemonitidae, 67, 187 Stemonitis, 67, 187-188 Stemonitis spleudens, 188 Stempellia, 76, 321 Stonpellia magna, 317, 318, 321, 322 Stephanonympha, 65, 165 Stephanonympha nelumbium, 165 Stephanosphaera, 62, 111-112 Stephanosphaera plnvialis, 111 , 112 Stenophora, 74, 297 Stenophora cockerellae, 297 Stentor, 13, 31, 36, 79, 334, 375, 403 Stentor coeruleus, 377 igneiis, 375, 376 multiformis, 377 polymorplms, 376 pyriformis, 375, 376 roeseli, 335, 376 Stentoridae, 79, 371, 375-377 Stephoidae. 72, 261 Stichotricha, 80, 388 Stichotricha secunda, 388 Stickle backs, 319, 320 Stigma, 38, 39, 83, 85, 97, 104, 116 Stiles, 224 Stokes, 15, 91, 338, 391, 398 Stokesielia, 64, 149 Stokesiella dissimilis, 149 leptostoma, 149 Stolon canals, 194 Streblomastix, 65, 156-157 Streblomastix strix, 156, 157 Strombidium, 79, 381 Strombidinm typicum, 381, 383 Strongylocentrolus, 363 Stylocephalus, 75, 298 Stylocephalus giganteus, 297 , 298 Stylocometes, 81, 402 Stylocometes digitatus, 402 Stylodinium, 61, 101 Stylodinium glohostim, 99, 101 Stylonychia, 13, 30, 80, 386, 412, 415 Stylonychia fnvtilus, 386, 387 notophora, 3'86, 387 pustulata, 386, 387 putrina, 386, 387 Stylopyxis, 60, 89 Succinia, 279 Suctoria, 7, 14, 15, 29, 49, 60, 81, 266, m, 399^10 Sulcus, 96, 98 Sun animalcules, 247 Surra, 139 Sutural plane, 303 Swarczewsky, 328, 332 Swarmers, 104, 178, 179, 185, 194, 195, 256 Swezv, 31, 98, 106, 165, 175 Swine, 10, 139, 217, 221, 272,326, 328, 374 448 AUTHOR AND SUBJECT INDEX Syllis gracilis, 331 Symbiont, 6, 163, 208, 209 Symbiosis, 6, 167 Synactinomyxon, 75, 315 Synactinomyxon tubificis, 314, 315 Synapta, 295 Synchaeta, 331 Syncrypta, 51, 60, 88 Syncrypta volvox, 87 , 88 Synura, 11, 60, 87-88 Synura uvella, 87 , 88 Systenussp., 299, 301 Tabanid flies, 139 Tachyblaston, 81, 406 Tachyblaston ephelotensis, 406, 407 Talbott, 370, 384 Tarentola, 151 Taylor, 224 Teichniann, 332 Tellina, 377 Telomyxa, 76, 323 Telomyxa glicgeiformis , 322, 324 Telomyxidae, 76, 323 Telosporidia, 49, 73-75, 265, 266-301, 326 Temperature and Protozoa, 4-5 Tenebrio molitor, 301 Tentacles of Protozoa, 29, 31, 60, 104, 399, 409 Tentaculifera, 399 Teredo, 377 Teredo navalis, 378 Ternies flavipes, 158 lucifugus, 321 Termite Protozoa, 6, 157, 158, 161, 163-165, 167-168, 170-174, 213, 321 Tefmopsis augusticoUis , 157, 173, 174 Terrapene Carolina, 218 Test, 23, 25, 83, 121, 135, 148, 149, 192-195, 225 Testacea, 22^ 25, 26, 47, 70-71, 176, 177, 195, 225-243 Tcstudo argentina, 218 calcarata. 218 graeca, 218 Tetractinomyxidae, 75, 313-314 Tetractinomyxon, 75, 313 Tefractinomyxon intermedium, 314 irregular e, 314 Tetramitus, 65, 156 Tetramitiis pyriformis, 156 rostratus, 156 Tetramyxa, 191 Tetrataxis, 68, 198 Tetrataxis palaeotrochus, 197 Tetratonympha, 174 Tetratonympha mirahilis, 174 Tetratonymphidae, 174 Tetratoxum, 79, 384 Tetratoxiim tuiifasciculatum, 383, 384 Texas fever, 10, 17, 289 Textularia, 68, 197 Textularia agglutinans, 197 Textulariidae, 68, 196 Thalassicolla, 72, 259 Thalassicolla nucleata, 260 Thalassicollidae, 72, 259 Thalassophysa, 72, 259 Thalassophysidae, 72, 256, 259 Thalassothamnidae, 72, 259 Thalassothamnus, 72, 259 Thaumatomastix, 63, 128 Thaumatomastix setijera, 127 , 128 Thaumatophrya, 81, 408 Thaumatophrya trold, 408, 409 Thecacineta, 81, 404 Thecacineta coihiirnioides, 404, 405 Thecamoeba, 225 Theileria, 74, 289 Theileria parva, 288, 289 Thelohania, 76, 321 Thelohania legeri, 9, 46, 47, 321, 322 multispora, 317 opacita, 9, 317, 321, 322 Theohaldia annulata, 361 Thomson, 154, 290 Tiarina, 77, 347 Ticks, 17, 143, 289 Tintinnidium, 79, 379 Tintinnidvum fluviatile, 378, 379 semiciliattim, 378, 379 Tintinnoinea, 79, 371, 379 Tipulid larvae, 146, 152, 219 Toads, 158, 303, 337, 372, 392 Tokophrya, 81, 404 Tokophrya cyclopiim, 404, 405 injusionnm, 404, 405 Torpedo, 308 Toxoglugea, 76, 323 Toxoglugea vibrio, 322, 323 Toxonema, 323 Toxospora, 323 Tracheliidae, 78, 344, 352-354 Trachelius, 78, 352 Trachelius ovum, 352, 353 Trachelocerca, 77, 347 Trachelocerca phoenicopterus, 347, 348 Trachelomonas, 27, 63, 121 Trachelomonas armata, 121, 122 cylindrica, 121, 122 hispida, 38, 121, 122 Trachelophyllum, 77, 347 Track elophyllum clavatum, 347, 348 Tractella, 28 Transverse flagellum, 97 AUTHOR AND SUBJECT INDEX 449 Tremalith, 89 Trembly, 13 Trentonia, 63, 127 Trentonia flugellata, 127-128 Trepomonas, 65, 163 TrepomoHiis agilis, 16Z, 163 Triactinoniyxidae, 75, 313 Triactinoinyxon, 75, 314 Triactinoniyxon dubium, 314 ■ignotum, 314 legeri, 314 magnum, 315 mrazeki, 315 Triadinium, 79, 382 Triadinium caudatum, 382, 383 Triatoma megista, 139 Tricercomonas, 65, 156 Tricerconwnas intestinaUs, 156 Trichia, 67, 190 Trichia affinis, 180 Trichiidae, 67, 187, 190 Trichites, 33, 34 Trichocera anuulata, 219 hiemalis, 219 Trichocysts, 13, 33-34, 127 Trichodina, 80, 334, 392, 394 Trichodina asterisci, 392 pediculiis. 392, 393, 406 sp., 392 Trichodinidae, 80, 392-394 Trichodinopsis, 80, 392, 394 Trichodhwpsis paradoxa, 393, 394 Trichomastix, 158 Trichomonas, 16, 28, 39, 63, 160-161, 415 Trichomonas bnccalis, 161 elongata, 160, 161 hominis, 160, 161, 415 vaginalis, 160, 161, 415 Trichonympha, 31, 66, 173 Trichonxmpha campanula, 32, 48, 173 Trichonymphidae, 66, 167, 172-174 Trichophrya, 81, 400 Trichophrya epistylidis, 400, 401 salpanim, 400,401 sinuosa, 400 Trichostomina, 78-79, 339, 358-369 Trichoptera, 152 Trigonomonas, 65, 163 Trigonomonas compressa, 162, 163 Triioculina, 68, 198 Trilocidina trigonula, 197 Trimastigamoeba, 31, 69. 206 Trimastigamoeba philippinensis, 206 Trimastigidae, 64, 133, 152-153 Trimastix, 64, 152 Trimastix marina, 153 Trinema, 71, 241 Trinema enchelys, 6, 241, 242 Tripalmaria, 79, 382 Tripalmaria dogieli, 383, 384 Triplagia, 72, 261 Triplagia primordialis, 261 Tripylea, 72-73, 255, 256, 258, 262- 263 Triton, 142, 219 Triton palmalus, 219 taeniatus, 219 Trochammina, 68, 198 Trochammina inflata, 197 Trochamminidae, 68, 198 7>ochilia, 78, 357 Trochilia palustris, 357 Trophozoite, 41, 50, 265, 266 Trypanoplasma, 147 Trypanosoma, 10, 16, 18, 28, 31, 64, 84, 136-142, 144, 416 Trypanosoma americanum, 139 brucei, 17, 138, 139 cruzi, 50, 138-139 danilewskyi, 141, 142 diemyctyli, 141, 142 dtittoni, 140 equinum, 138, 139 equiperdum, 138, 140 evansi, 138, 139 gambiettse, 17, 138 giganteum, 141, 142 granulosum, 141, 142 inopinatum, 141, 142 lewisi, 17, 50, 138, 140 melophagiiim, 137 , 138, 139 nabiasi, 140 noctuae, 140 paddae, 140 percae, 141, 142 peromysci, 140 rajae, 141, 142 remaki, 141, 142 rotatorium, 16, 28, 140-141 theikri, 138, 139 Trypanosomatidae, 64, 133, 136-146 Trypanosomiasis, 137 Trutta fario, 162 Tsetse flies, 17, 138, 139 Tuberllaria, 342 Tubifex, 295, 323 Tubifex tubifex, 295, 315 Tubulina, 67, 188 Tubulina fragiformis. 189 Tubulinidae, 67, 187, 188 Tunicata, 105, 299, 400 Turkey, 146, 273 Turtles, 140, 218, 279 Tuscarora, 73, 263 Tuscarora murrayi, 263 Tuscaroridae, 73, 263 Twist disease, 306, 31 1 450 AUTHOR AND SUBJECT INDEX Tyzzer, 283 U Undulating membrane of ciliates, 29, 30, 34, 366, 367 flagellates, 23, 28, 31, 136, 141 Urceolus, 63, 123-124 Urceolus cyclostomus, 124, 125 Unicapsula, 75, 309 Ujiicapsida miiscuJaris, 306, 308, 309 Unicellular organ isms, 3-4,8, 14 Urnula, 81, 404 Urmda epistylidis, 404 Urocentridae, 78, 358 Urocentrum, 78, 358 Urocentnmi turbo, 358, 360 Uroglena, 51, 60, 88 Uroglena volvox, (?7, 88 Uroglenopsis, 51, 60, 88 Uroglenopsis americana, 1 1 , 39, S7 , 88-89 Uroleptus, 80, 389 Uroleptus mobilis, 9, 41, 43, 56 musculus, 388, 389 Uronema, 78, 359 Uronema marina, 359, 360 Uronychia, 80, 390 Ur onychia setigera, 390 Urophagus, 65, 163 Urophagus rostraliis, 162, 163 Urospora, 74, 295 Urospora chiridotae, 294, 295 saenuridis, 295 Urosporidium, 76, 331 Urosporidiiun fuliginosum, 330, 331 Urostyla, 80, 386 Urostyla grandis, 386, 387 Urotricha, 77, 346 Urotricha f areata, 345, 346 Utricaceae, 144 V X'acuolaria, 63, 127 Vacuolaria viresccns, 127 \'aginicola, 80, 398 Vaginicola crvstallina, 396. 398 \ahlkampfia," 69, 205, 210, 211, 220, 412,414 Vahlkampfia Umax, 26, 210 patuxent, 210 \'alentin, 16 Valvulina, 68, 197 Valvulina tria}ie.ularis, 197 Valvulinidae, 68, 197 Vampyrella, 66, 180 Vampyrella lateritia, 180 spirogyra, 180 Vampyrellidae, 66, 178, 179-181 V'aucheria, 178 Ventral cirri, 29, 30 Verneuilina, 68, 197 Verneuilina propinqua, 197 Verneuilinidae, 68, 197 Veonica, 191 Vertebralina, 68, 198 Vertebralina striata, 197 X'erworn, 26 Vesicular nucleus, 21 Vipera aspis, 275 Vitality, 8, 58 Vitrina, 279 Volvocidae,4,38,62, 107, 110-114, 178 Volvox, 13, 51, 53, 62, 113-114, 179 Volvox aureus, 52, 53, 113, 114 globator, 53, 113, 114 perglobator, 53, 114 speitnatospliara, 114 tertius, 114 Vorticella, 13, 80, 334, 394, 398 Vorticella alba, 393, 394 campanula, 393, 394 longifihirn, 393, 394 nebulifera, 55-56 mdans, 393, 394 quadrangularis. 393, 394 telescopa, 393, 394 \'orticellidae, 37, 80, 392, 394-398, 406 Vivipara contecta, 408 W Wagnerella, 71, 252 Wagnerella borealis, 251, 252 Wailes, 244, 253 Wandering nucleus, 53, 55, 56 VVardia, 75, 307 Wardia ovinocua, 307 Wasielewski, 282 Wasielewskia, 205 Watson, 301 _ Weismann, 15 Weissenberg, 332 Wenrich, 128, 370 Wenyon, 154, 166, 224, 282, 283, 290, 370 Wermel, 223 West, 91, 95, 128 Whipple, 11, 19 Wilson, 224 Woodruff, 58, 59 Wormy halibut, 306, 309 Yarborough, 18, 417 Zelleriella, 10, 76, 337 Zelleriella scaphiopodos, 337 AUTHOR AND SUBJECT INDEX 451 Zonomyxa, 70, 230 Zootrophic nutrition, 35 Zonomyxa violacca, 230, 231 Zooxanthellae, 93, 255 Zoochlorellae, 247, 377 Zopf, 182 Zoomastigina, 63 66, 84, 129-174 Zschokkelia, 75, 310 Zoopurpurin, 23, 372 Zschokkelia hildae, 310 Zoospore, 185 Zumstein's medium, 413 Zoosporidae, 66, 178-179 Zygocystis, 74, 293 Zoothamnium, 80, 395 Zygocystis cometa. 293 Zoothamnium arbuscula, 394, 395 Zygote, 4, 52, 53, 56, 57, 110, 114, 269 mis BOOK HANDBOOK OF PROTOZOOLOGY was set, printed and bound by The Collegiate Press of 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