U. S. NATIONAL MUSEUM LIBRARY OF Henry Guernsey Hubbard Eugene Amandus Schwarz ost DONATED IN 1902 j— « ACCESSION No.././..4.s/..0/... fies is PCS OS/a | Se Ean U.S. DEPARTMENT OF AGRICULTURE. BUREAU OF ANIMAL INDUSTRY. ANIMAL PARASITES OF SHEEP, BY S®OPrenR CURTICE, Do V.S., M.D. PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE. WASHINGTON: GOVERNMENT PRINTING OFFICE. v 1890. - OCA ™ oe > ar + a —_ pL es | pea hs MUSEUM IAMOLLL eee 4 2 : & if 2 Ur uTis* Page. Loaminbu oi TRAST) scnicieAab cebo REGEHC Gee Doce opdge Seg BeOS TEP OSEDOeorgoodar 7 epee MENG MAT KS been spat aiatalae ocacicis fa ca-cel-s aw cceced ace Uissia cco dcs See tscemeeimninesis : 9 Parasites of the nose: Grub in the head, Gistrus ovis, Linn ..........---- s---00------ -- 22 eee 25 Parasites of the skin: Phthiriasis, Acariasis. The sheep tick, Melophagus ovinus, Linn.....-.-....--<-.----.---=---- 39 The sheep louse, Trichodectes sphwrocephalus, Nitzsch..---..----.------ 45 The goat louse, Trichodectes limbatus, Gervais, and Trichodectes climax, NAAN Cite ne ee sels seca aicinais cases acisceeras’e saclasiehcwicecascce 49 Seab insects: Acariasis, itch, scab. Head scab, Sarcoptes scabiei, de Geer, var. ovis...--.---.-------------- 53 Common scab, Psoroptes communis, Fiirst, var. ovis..---..-------.----- 56 Foot scab, Chorioptes communis, Verheyen, var. ovis.....--.----------- 65 Parasites of diverse organs: The pentastoma, Linguatula tenioides, Rud.-...--..---...---.---------- 69 ‘Immature tape-worms : Bladder worms, Tenia marginata, Batsch .....----..----- Ao Pee 72 Gidlor staprers, Tenia conus, Kuch. .25 2-0-5 a2 cseoeesia nace oon -= 83 vidas, Maenid eOhimococcus, Vii SlOD -emo-- ase ceel-c- ea esee essa ve 86 The mutton measle, Tenia tenella, Cobbold...--........--...-------- 87 Parasites of the alimentary canal and appendages: Adult tape-worms: The fringed tape-worm, Tenia fimbriata, Diesing.......----..--..---- 89 The broad tape-worm, Tenia expansa, Rud ...--....--...-----.+------ 113 Liver-flukes : The large liver-fluke, Distoma hepaticum, Linn........---..----.------ 127 The small liver-fluke, Distoma lanceolatum, Mehlis.-..------.--------- 37 The stomach worms: IND UASLOMM CONLCUN, OUGIn. 22 2a c\sscnleac cam, 2 ccsataeasies cae slew wicci) seis 138 ONG Y LUE CONLGHIUS PENG «2 522 atom aie sce sue tas Seielacas asics cesie = sie 141 Intestinal round worms: PROG MOLD VELOM ALCO: 2s apse oe arene oa ae cine coe seas css sch aes 145 ROGUES ULLCO ULES PIGU OSs 2) ot se cyeeene Mao as = als cieinia ce aeine oes. Jemisieete 146 TUL OIELE COSUS MARU Snemic ne Sane icaicvene eclcens Saeiaisls se esen= ware 149 PAS COMISRUUNLUTTOOLOES MaMa aaa, Se Sd crane cise ea isa = celsindacn ecins icicle 151 EDS OPTIONS OSs C1 Tigege lie eee en Sh ee 155 Sclerostoma hypostomum, Diesing --..-....-..--..---.----2- +--+ ------ 161 The nodular disease of the intestine, Hsophagostoma Columbianum,n.sp 165 PMIREOCEDNULUS Cpls pRUCs 9. 22) c ose sesame cele sict= ses Fes eee sasses- 2 LOL Parasites of the lungs: ROU RIC TL VAL CULALKS)v 22 oe eee k a eae se a ele eine iwiele oid a's G-1o oe seme 185 The hair lung-worm, Strongylus ovis-pulmonalis, Diesing-.-.- ---------- 156 The thread lung-worm, Strongylus filaria, Rud ..-..-. Si pews Sao raie ow eee woe COL 3 PLATE I. Wale Ville VIII. IX. X. XI. XII. XIII. XIV. XV. XVI. xeVelI XVIII. XIX. XX. XXI. XXII. XXIII. XXIV. XXV. XXVI. XXVII. XXVIII. XXIX, XXX. 2.9.48 MOM KLE sey OO-41 08 MXIT: EK. RX XVI. INDEX OF ILLUSTRATIONS. CEST ar OUIS 9! Lili la SoU Sis reat oer Sete aa oo tre fe a avarice acres PSUs. OUIS, 1) SINUSESIOL bhe head +-- -os,-22 24-188 ota ee (strus ovis, in nasal cavity and sinuses of the head ..-.---- Melophagus, ovis. PANNBUS sae)s ass eae = eee eee Trichodectes spherocephalus, Nitzsch ..---..-.--......----«-- Trichodectes limbatus, Gervais, et T. climax, Nitzsch..-.--..--- Psoroptes communis, Fiirst., var. ovis. Adult ......-.....-.- PIOrOptes COMMUMS. VAL. OVIS. YOUNG).- ~~ ean NsBUStso= alae cee cotati caniecne. case cae = Dochmins cernuus,, Crepunal 2 aaccne yee ania cel~ waters oxo sl ayonnin Sclerostoma hypostomum, Dujardin....-...---...------------ (Esophagostoma Columbianum, Curtice. (Esophagostoma Columbianum, young stages....--.---------- (Esophagostoma Columbianum, in the intestinal coats ...---.. Csophagostoma Columbianum, in the intestinal coats....---- Trichocephalusajfiiisg lsu We scnce ease esss)s oman sae ei Strongylus ovis-pulmonalis, Diesing ....-..------------------ Strongylus ovis-pulmonalis, in the lungs......----.----- PEPE Strongylus ovis-pulmonalis, in the lungs. ....-----.----------- Strongylus ovis-pulmonalis, in the lungs......---------.----- Strongylus ovis pulmonalis, in the lungs Sirougnlua floria, Rudolph... 2.2285.2.-22c-2--+ -oSs-6 202% NGONGUUUS /ULAIIA, Ie DAG UNE Sis oa narceamcinlecizin ses cam =m l= Strongylus filaria, in the lungs ee 52 110 112 124 126 136 140 144 148 150 154 160 164 174 176 178 180 184 192 194 196 198 200 210 212 214 LETTER OF TRANSMITTAL. WASHINGTON, D. C., April 21, 1890. Str: I have the honor to submit herewith a report upon the para- sites of sheep, which has been prepared with much care and will prove of permanent value to ali owners of this class of our domesticated ani- mals. The information heretofore attainable on this subject in the United States has been fragmentary and in many cases unreliable, although the parasitic diseases of sheep are among the most frequent and serious maladies by which this species of animals are affected. It has been the aim in the preparation of this volume to make the descriptions and the illustrations so plain that any one will be able to identify the parasites which he may find in his flock, and yet the sub- ject is in some of its aspects so technical that it could not be presented entirely in popular language. The technical descriptions which it is deemed necessary to insert have, however, been placed in small type, and those not interested in the characters by which the species are identified can omit such paragraphs. The symptoms and appearances presented by diseased animals and the treatment of the diseases have beenggiven at considerable length, and these will be read with interest by all who desire information on this subject. The illustrations are a prominent feature of the work, having been drawn and lithographed with the greatest care, and every attention given to make them accu- rate in their most minute details. Nearly all of these are original and were drawn from nature. The nodular disease of the intestines, together with its cause, is de- scribed for the first time in these pages. This disease is common and wide-spread, but its cause and nature were mysterious until they were discovered through the investigations of this Bureau. We have here once again a demonstration of the value of systematic, scientific in- vestigation of the diseases of animals, for the results obtained by the study of this malady are among the most interesting contributions of modern research. The facts obtained in the investigations of the fringed tape-worm and the hair lung-worm are also of more than ordinary in- terest. The subject of parasites and parasitic diseases is one of great impor- tance, and must become more prominent as the number of domesti- cated animals in the country inereases and the pastures become more 7 8 limited in comparison with the flocks which graze upon them. Under such conditions parasites multiply more rapidly, and their ravages be- come more alarming. For this reason the time has come when we must pay more attention to these organisms and study more assiduously the means of controlling them, if we would preserve that healthfulness and vigor for which the animals of this country have heretofore been noted. It is hoped that the systematic treatment of the subject presented in the accompanying volume may assist in accomplishing this object. Very respectfully, D. E. SALMON, Chief of the Bureau of Animal Industry. Hon. J. M. RUSK, Secretary of Agriculture. ANIMAL PARASITES OF SHEEP. GENERAL REMARKS. In 1782, Goeze, a distinguished German naturalist, wrote: “Among all mammals except the horse, the sheep appears to be most harassed by worms.” He thus called attention at that early period to the great abundance of ovine parasites, an abundance which have transmitted their posterity in comparatively undiminished numbers. The presentation of all the facts now known concerning these para- sites, their structure, their life histories, the injuries they cause, and the methods of prevention and treatment, together with such new ma- terial as may have been learned concerning them, needs no apology to the sheep owner, for he is alive to the fact that the majority of his losses is due to these parasites. The sheep industry of the United States embraces the product of 42,599,079 sheep, valued at $90,640,369.* De- pendent on these sheep and their products are an army of menand their families, from the flock-master and his help to the consumers of the flesh and the manufacturers of the fleece. Add to this the value of the plant, which is dependent on the sheep industry in all of its ramifications, and there results an accumulation of many millions of dollars, a value which, from a business stand-point alone, should cause the Government to foster and to protect it from every source of injury. As the whole growth of the industry is dependent on the health and vigor of the sheep, it follows that whatever tends to produce a better condition or ward off threatening disease from them is for the benefit of all interested in and dependent upon the success of the industry. The parasitic diseases — those produced by the animal parasites of sheep—are, if we may judge from observation and the letters of inquiry directed to this Bureau, the chief source of losses, and ifin any way this bulletin may result in promoting a better knowledge of these too little known pests, and in teaching facts which will lead to better care and treatment of the flocks as regards hygienic prevention of diseases, the cost and labor laid out upon the work in its various details will be well expended. Particular attention has been devoted to illustrating each species of parasite, and, so far as possible, the lesions of the disease produced by * United States Department of Agriculture, report on numbers and values of farm animals, January, February, 1889, pp. 5 and 6, 9 10 it. In the illustrations of the species certain features which present specific differences have been constantly drawn. Peculiar features of anatomy and development have also been illustrated. The entire de- velopment of any species from the unimpregnated ovum to the adult form is not illustrated, but one species may show the developing ova, another the embryo, and still another small and adult forms, and thus the entire development of many of the species can be well understood. Especial attention has been devoted to representing certain organs of economic importance, 7. e., those organs which are immediately con- cerned in injuring the tissues of the sheep. The majority of the draw- ings were made from nature by Mr. W.S. D. Haines, and the others by Dr. George Marx, both artists connected with this Department. The excellence of their work shows for itself. Where material for original illustration has been unavailable, figures chosen from the leading text-books on the subject under consideration have been copied, and due recognition of the source acknowledged in the description at- tached. For the accuracy of these drawings the author alone is respon- sible. He believes that all the anatomical details are accurate, but such is the difficulty of seeing the minuter details that some of the latter are omitted. As their presentation belongs properly to a more specific investigation than this their absence will scarcely be noticed. It has been the constant endeavor of both the artists and the author to make technically perfect drawings, and at the same time present the subject so clearly to the eye that not only a novice may, by the aid of a small magnifying glass, be able to determine the species, but that the scien- tist may also use the work profitably in subsequent investigations. The text devoted to each species is intended to contain a general description of the parasite, its life history, the way it causes disease, the disease produced and mode of treatment, both preventive and re- medial. Many of the specific descriptions are technical. To the be- ginner, who can identify the species by careful comparison with the figures, these are unnecessary, but as he advances in their study the meaning of the technical descriptions will become more apparent and useful. In a work of this character such technical specific descriptions are unavoidable. To the scientist they are absolutely necessary. Wherever possible the complete life-history of the parasite is described and illustrated; unfortunately, however, the species whose life-histories are positively known are too few. Although the life-histories of the majority of the worms seem very evident, still the evidence upon which they are based is not deemed entirely conclusive by scientists. So skep- tical are the majority of this guild that rigorous proof alone seems to satisfy them, and this is particularly the case when the views set forth in regard to either of the species are at variance with pre-existing opinions. Rigorous demonstration of the various stages in the life-history of a parasite demands that its eggs or embryos shall be fed to an uninfected Ei ek host (sheep in this case), and the parasite be found in it subsequently, at a stage of growth corresponding to the time which has elapsed dur- ing the experiment. The conditions necessary for raising embryos, for procuring uninfected sheep and for keeping them from outside sources of infection, are many and difficult to fulfill, Up to the present time, with few exceptions, infection has been secured in the experiments only by excluding or regulating certain of the conditions surrounding sheep. These conditions are such that, although the problems in each case have not been absolutely proven, there is much probability that the life- history of most species is well determined. In describing the injury wrought by the parasite and the resulting disease, technical descrip- tion has been avoided as much as possible, in order that the work may be rendered more valuable for farmers and ranchmen, who have but a limited knowledge of the terms used in medical literature. 'These de- scriptions are, on this account, necessarily imperfect from a scientific point of view, but it is hoped none the less efficient for the purpose: A careful study of the various diseases will show that the irritations set up and the lesions resulting therefrom are mainly due to mechan- ical causes, whatever be the organ attacked. Certain of the dis- eases, however, seem to be aggravated by nervous or reflex irritation induced by the parasite, while others are hastened by a loss of blood or nutritive material abstracted from the host by the parasites. The diagnosis of parasitic diseases is always determined by finding the parasite or its eggs. The quickest and surest determination for inter- nal parasites is made at a post-mortem examination. For intestinal parasites many authors recommend the examination of thedung. This method has not been verified by experience, but appears to be tedious and difficult, and a method better adapted to experts than layman. There are certain symptoms from which one may infer that sheep are infected with parasites. A large part or all of the flock is affected and the symptoms shown by the different individuals are similar. The ap- petite is generally good, but individual members present a poor, stunted, hide-bound, bloodless, big-headed, pot-bellied appearance. Other local symptoms, depending on the organs affected, are present. The most positive characteristic is to find that a number of sheep raised together are affected in the same way. From these general symptoms those de- pending on climatic changes, and irregularity or insufficiency of food and water, mustof course be excluded. The sheep owner who discovers weakness among his lambs should not wait until one of them dies before he endeavors to make a diagnosis, but should undertake to diagnose the disease in the earlier stages by sacrificing one or more of the worst affected, and thus gain time in treating and preventing the extension of the disease. By*waiting for the disease to develop he allows the lambs to grow poorer and weaker, and when action is finally undertaken it is upon patients which are, in many cases, already too weak to stand vigorous treatment, and which can in no way profit by preventive 12 measures as they should. The lambs examined can, if the meat is not too poor and watery, be used on the table without harm to the consumer. If the animals are at all feverish, as is the case in the later stages of disease, the carcasses should be thrown away. It is in the beginning of the disease that treatment, both hygienic and medicinal, is needed and produces its best results, and therefore an early diagnosis and de- termination of the malady is fully as essential as in the more virulent bacterial scourges. Though the treatment advised in a work of this character should be its strongest point, yet it is to be regretted that such is the state of knowledge of the life-history of these parasites and of the practical re- sults of medicines used in combating them under the conditions in which sheep are held on the pastures, that it is felt that this field is yet to be properly entered and worked up from an experimental stand-point. The subject appears, as yet, to be in an empirical stage. Although the best recipes have been compiled and presented, they appear to be old and hackneyed to one who has been enabled to trace the same recipes from book to book. Indeed, some of those presented, which contain inherent virtues, come from countries where sheep-ranching is unheard of, and seem to be sufficient only in the closely settled communities where labor is cheap and where time can be devoted to saving property even though the value is not great. The medical treatment of large flocks should be investigated from a broader stand-point than any yet taken. Our insufficiency of knowledge on these points arises from the small value of single animals and the hesitation of people to seek the aid of skilled veterinarians until they find that they are unable to treat the disease themselves. The great benefit in doctoring animals whose individual worth is but a few dollars lies in the treatment of numbers at a time, and in making an early diagnosis of the disease. Those who have large and valuable flocks should watch their lambs for the earli- est symptoms, and then if there is a skilled veterinarian available ob- tain his services. Oftentimes the family doctor can and will give advice that will materially assist, for his knowledge of other diseases, their symptoms and lesions, and of the use and effects of medicines, make him the most available authority in the absence of the veterinarian. Upon the hygienic treatment, 4. e., upon the care and attention the flock receives, depends in great measure its health and good condition, and the prevention of the parasitic diseases. It is out of the province of this bulletin to discuss the proper housing, food, and drink of sheep, beyond what is required for the prevention of parasitic maladies. The chief necessity as regards buildings and yards is that they should be kept clean. Periodic cleansings of wood-work ang floors should be sufficient. Whitewashirg and the liberal use of lye water for cleansing -wood-work are desirable, and in some diseases, such as scab, absolutely indispensable. In the care of yards an economic management of the manure is to some of prime importance. It would seem that a mixture 13 of this manure with lime in the compost heap, and a frequent cleansing of the yard, would be far better, so far as the sheep are concerned, than to allow it to accumulate. The lime would not only serve to kill the eggs of parasites in the manure, but would add fertilizing material to it. Manure so treated would be a better fertilizer, and would also be less apt to infect sheep when spread upon the fields. The compost heap should never be where the liquor from it can be washed by the rains into water which the sheep drink. As the manure from these yards may prove the source of infection, sheep should never be pastured on fields recently enriched with it, unless there is absolute certainty that the previous treatment of the manure has destroyed all the em- bryos of the parasites. As frequently urged in the text, every means should be taken to supply sheep with pure water. Although experi- ments show that sheep have other means of getting parasites than from the water they drink, yet this is at times a very fertile scource of infec- tion. The use of drinking-troughs into which water runs or is pumped, and rapidily running water, seem best suited to meet the requirements. The grain food should be fed from cleanly swept troughs or floors. Hay should be put in racks, as feeding from the ground is not only wasteful but tends to infect with parasites. Salt should be supplied in boxes placed where sheep can have ready access toit. The mixture of a small proportion of finely powdered sulphate of iron with the salt is allowable at times. Pastures, which are ordinarily uncared for further than to provide fences for securely confining the sheep, need careful supervision. Wet swails, bogs and swamps should either be fenced out or drained. Past- ures which are overstocked, and in which a flock of sheep is kept con- tinuously, are the most fertile sources of infection. Not only do the sheep become more frequently infected where they are compelled to eat the grass close to the ground, but the chances of their being compelled to graze on an infected area are largely increased by keeping them ranging over the same ground of limited area week after week. Old sheep stand such treatment much better than young ones. For the lat- ter, those fields which have not been pastured on by older sheep are better. The practice of feeding the sheep over fields from which the crops are removed is a good one, not only for the sheep but for the fields. These remarks, of course, apply more strictly to fenced farms and not to unfenced sheep ranges, but even on these certain portions of the range can be reserved for the lambs. The practice of allowing lambs, atter they are old enough to wean, to feed after older sheep is also a source of infection. The relation of the dog to sheep husbandry is too important to be over- looked. Were it not that the definition of: parasite excludes such ani- mals as can be considered beasts of prey, the dog would be placed at the head of the list of parasites as being the most destructive. Though this be unmistakably apparent to a large majority of sheep-owners, 14 there are many who believe that the dog is man’s most faithful friend and that he is of great use even on a sheep farm. It is unfortunate for the dog that the mass of testimony on this subject is against him. It is not from the stand-point of the dog as a beast of prey, how=ver, that this work is written, but it is from the more technical stand-point of the dog as a carrier of parasites dangerous to sheep and man. In the list of parasites of sheep there are at least four which are common to the dog and sheep, viz: Tenia marginata, Batsch; T. coenwrus, Kiich.; T. echi- nococcus, V. Siebold, and Linguatula tenioides, Rud. The last is rare, and in justice to the dog should not be used against him, although it may subsequently afford as damaging evidence as the other species. By referring to the descriptions of the other three species it will be found that dogs harbor in their intestines the adults of these species, and that they scatter the eggs of the parasites broadcast for the infec- tion of sheep. Thus each dog, harboring one or more, is a constant menace to the health and lives of the flocks in the neighborhood. Nor is this all, for man himself can be infected by at least two of these spe- cies— Tenia echinococcus and T. marginata—in their cystic stage. The former of these species produces a disease of slow development, but one which is nearly always fatal in results. To prevent these diseases the precautions prescribed in the text must be closely adhered to. _ r Py er. : ay na ne as ; POLL. GHEE Sr age 8 is ; - b f, a A oT ® wei i a ae Coma a se : at, 7 P ‘Thad 7 vs @ 1 M Ty \ i i] ray bb i H Yr core f _ tot ia , he sy tig Ay a aA . . \ yk ’ a i ’ ff y = sd : “ Ret Shea! ah j as ee) +4 “i 2 1 : 1 aD yee . ' al p a te in yak a ae ou : ra +) af : of ‘ 17 hea ty giyih PER Ay the et wi ge ne. 1% xtiny te SRO Ae le, 2 ac { My i need Cah i c ' hi "ise fis Peas bate - vs Car | a 7 on yb ae ay ae Pe ite rae Med) « ' i i iy fiaa® a v re ed ye ‘ 1h on oe ‘ i) “Par ike Av det Ate gt + ; ig Tare te avi > a \ Celi wed on Sal eye ‘a ye ine shy No Te ern AP eros ey) ts 4) i) ae le eek ae é oat 4F + he earn oer ea! oe PET ee ole Ni a he yar Milf oy hae TRG ke pa sift } ck r GhevueA coy yl a ot bay he fo ’ *, ag ; ah ra ey =. Pr AREA RIES fel Gy Hey pe pa? Mie hy i Mains {ORG . id “ke MPS be Ge 0 ras ‘agit it i? aiuil na Lie f ethyl! rh xh bt ‘ : bite < gal Mee rahe Abt. 14\ is acy 4 Waly fa Ars Nong eis? 15 iv it 14 | , i «ie? Gone WE aaee RE CP DREER TOE htt Keun SRS . rte 2 Leh, AME a3 ket a + 38 (ESTRUS OVIS, Linn. PLATE III. Fig. 1. Section of head of sheep made a little to the right of mesial plane: a, a, a, a, a, section of bone surrounding b, the brain, and ¢, the nasial cavity ; d, the lower jaw bone; e, nostril; f, opening of tear duct; g, g, g, turbi- nated bones; h, the posterior opening of the nasal cavity, and near the opening of Eustachian tube; ¢, placed on the turbinated bone over a grub in the groove leading to the frontal sinus; k, the frontal sinus; /, the nasal sinus; m, the thin perforated plate of bone called the cribriform plate; m, n,n, larve of @strus ascending the nares and wandering about its surface; i, one ascending to the sinus; k, opposite three, nearly mature larvz in the sinus. Figure reduced to three-fourths of natural size. Fig. 2. Outline drawing of the skull surrounding the frontal sinus after removal of part of the turbinated bone, lettered as in Fig. 1; 0, 0, straws passed through the channels connecting the nares with the sinuses, marking the path by which the Jarva reaches the sinus ; p, cut ends of the removed bones. “WAUVT SOULS AG GHAGVANI GVAH SdHGHS AO NOILOUS TVISEW a UML eR THASNBOC YLT oF gy uaoy y ‘jap ‘samp THE SHEEP-TICK OR LOUSE-FLY--PHTHIRIASIS. MELOPHAGUS OVINUS, Linn. Plate LV. One ot the best known of all the external parasites of sheep is the sheep-tick, Melophagus ovinus, Linn. This pest isa very common one in the Eastern States, and although it seldom causes any serious damage either to the sheep or to the wool, it is at all times an annoyance, and occasionally causes decided losses to the flock-master. This tick, like a majority of the parasites of the domesticated animals, was introduced into this country from Europe. The name “ sheep-tick,” though not a misnomer, as every one knows what a sheep-tick is, is misleading. So much do they resemble the true ticks that they are often classified together. The most superficial study will, however, serve to show their differences. Description.—The sheep-tick is a wingless fly having but six legs, whereas the true ticks are more closely related to spiders, and have ight legs in their adult state. The adults are less than a quarter of an inch long, and have a short, flattened, bristly, leathery body. The head is slightly wider than the thorax, into which it is sunk. They have very short antenn, which are sunk in sockets in the face; the proboscis is tubular, and is protected externally by two flat, elongated bristly pieces, the labrum; its end is armed with teeth. The thorax or linb-bearing portion of their bodies is nearly square when looked at from above. It is composed of three pieces, the middle being the one seen on the back. The legs are very stout, covered with bristles, and each is provided with two strong, sharp claws. The last joint of each foot bears a pinuiform or feather-like organ whose office is as yet un- determined, but is probably that of coiling around hair for better pre- hensiom. There are no wings. On either side may be seen two small, bristle-covered, round spots at points where the wings should be attached. At the posterior outer corners of the thorax are two little projections which remind one of balancers. The abdomen, usually jarger in females than in males, is flattened and bag-like, and is as large or larger than the rest of the body, especially after the louse- fly has eaten, when the red blood sucked from its host may be seen through its skin. Its skin is tough, unsegmented, semi-translucent, and permits the abdominal organs to show through. On each side there are seven stigmata or breathing pores. The anus is situated on 39 40 the ventral side and just behind the genital orifice. The sexes resemble each other, but may be separated by their size and by the form of the external genital apparatus. In habit these parasites resemble lice living among the hairs of the fleece, whence the name, louse-fly. They seldom remain attached to the skin longer than a sufficient time to fill up with blood; this they suck up through the proboscis with which they perforate the skin. They try to evade capture by running into the wool, and when caught cling tena- ciously. , Life history.—The family of flies to which this parasite belongs is truly wonderful, in that they bring forth their young as puparia. The puparia of Melophagus are laid as flat, ovoid, chestnut brown, glistening seed-like eggs, which are nearly one-third as large as the abdomen of the parent, and contain an imperfectly developed larva within them. The egg cases or pupa are marked by two rows of seven dots each on one surface, a slight depression, indented by two dots in one end, and a slight elevation at the other. The two dots are at the anal end. A dissection of one of these, taken from a female, shows the pointed end to be connected with a membrane, and to be the end through which the larva obtains food. Some authorities say that each female produces but one or two of these puparia; others say that they can lay about eight or nine during their life-time. They lay one at atimein the wool. A portion of each puparium will be found to be covered with a dry, dark substance, which came from the parent when the puparium was laid, was sticky, and glued it to the surrounding hairs. This prevents the pupa, which becomes hard, dry, and glassy, falling from the wool. The insect emerge, with adult characters from the pups cases, through an opening in the end of the case made by a round lid splitting off, and wanders into the wool. Some of these eggs collected in the course of our investigations hatched within four weeks at ordinary temperatures. Occurrence.—These ticks, or their young, may be found on the sheep at all times of the year, but appear to be most numerous in spring. They are particularly noticeable at shearing time on the old sheep after they are deprived of their shelter. At this time those that can.do so take refuge in the longer wool of the lambs, and prove veritable pests. The others perish either from being eaten by the sheep, carried away in the wool, or dropped to the ground. They frequently become attached to the clothing and persons of people with whom they come in contact, but they prove but a slight source of discomfort, as they are easily caught and killed. It is not at all probable that they can exist many days apart from the sheep, as they are unfitted by structure for any other habitat. Their food consists wholly of the blood which they suck from the sheep. They depend also on the sheep for warmth ; in warm spring days they may be found crawling near the ends of the wool, while in the colder days they will always be found either engaged in Al feeding or resting at but little distance from the roots of the wool. A dozen or more of these ticks, which were moderately well fed when taken from the sheep were, with some wool, placed in a cotton-stoppered bottle and kept in a room with a temperature varying between 60° and 80° Fah. They all died in less than four days. The leanest succumbed first, in abont two days, while those that were better nourished grad- ually grew smaller and thinner, and lived little longer than the third ‘day. Others placed in wool over the damp soil of a geranium in a flower-pot died within four days. On the other hand, some young ones which were hatched out in a bottle were kept for nearly two weeks, or until their daily feeding was neglected. To feed them they were placed on the back of my hand. By this means I could, with a lens, watch them bore into the skin and see the abdomen slowly enlarge as they drew in the blood. They had some difficulty in penetrating the thick skin, but usually succeeded by slipping their tube into a hair follicle, At first no itching or irritation was felt, except a slight twinge when the bills first penetrated the skin ; but little swellings came on a day or two later which itched for over a week. The itching was far more per- sistent than with mosquito bites. They must in this way cause lambs much discomfort. It was at first thought that a fluid could be seen running from the parasite to the hand through the bill, but no more was thought of it until the elevations began to rise and itch; then it ap- peared certain that the little pests had secreted a poisonous fluid. The oftice of this secreted fluid is probably to assist the flow of blood by keeping it from clotting. The above experiments show that the parasite spends its whole life on the sheep. Source of contagion.—The fact that this parasite passes its whole life on the sheep, and that it produces but few young, are very important con- siderations in efforts for exterminating the pest and preventing a new infection. They indicate that if all are killed the sheep will not again he infected except from other sheep. Disease.—The injury sustained by sheep from these parasites varies according to the number present. It arises from the itching and pain inflicted by them when obtaining their food. A few cause but little annoyance, and, were it not that these may become the source of future multitudes, would be scarcely worth noticing. To lambs the annoy- ance is particularly aggravating, as their skin is tender and the number of parasites attacking them after shearingis unusually large. In older sheep the irritation is the more noticeable towards spring. At thistime the parasites are more numerous and the animals bite and scratch them- selves oftener. - Medical treatment.—The well-known means of ridding the sheep of these pests are the tobacco or other mixtures used for scab-dips. The best time of the year to dip is at shearing time. Then the older sheep can easily be handled and cleansed. The dipping should not be delayed 42 long after, for each additional day is one of torment to the lambs. The lambs also should be thoroughly dipped. One dip is said to be sufficient to kill the old parasites. However,a few of the pupz may remain in the fleece of the lambs. They should be thoroughly examined two or three weeks after, and if there are any present they should again be dipped. All the precautions taken in dipping sheep should be carefully ob- served. The shorn wool should be stored where the young ticks which may hatch from the pupa cases can not crawl back to the sheep. How- | ever, they seem to have great difficulty in crawling, and may not be able to go far. An experiment in which some of the pups became wet with moisture from other ticks in the same bottle demonstrated that they would not hatch, and indicates that the sheep bath will very likely kill the inclosed larvee. In The American Agriculturist, October, 1889, page 490, Mr. Joseph Harris advises fall dipping for these pests. This is a good plan if the sheep have become infested with ticks after the spring dipping by some inadvertence of the master. He advises the use of tobacco, carbolie¢ acid, and kerosene emulsion dips. The carbolic acid dip is composed of a pound of soap and a pint of crude carbolic acid to each 50 gallons of water. Dissolve the soap in a gallon or more of boiling water, add the acid and stir thoroughly. Keep the mixture well thinned, and do not let it get into the mouths, nostrils, or eyes of the sheep. Hold each sheep in the bath not less than half a minute. The formula for kerosene emulsion is as follows: Churn fresh skimmed milk and kerosene together in the proportion of 1 gallon of milk to 2 gallons of kerosene, either in a churn or by using a force- pump until an emulsion is made. The method of using the force-pump is to set it in the vessel containing the mixture and turn the stream back into the same vessel. The emulsion will form quicker if boiling hot milk is used. Tor dipping use 1 gallon of the emulsion for each 10 gallons of water required. Mr. Harris seems to think 20 gallons, with a reserve of 10 gallons, sufficient ; but he was evidently thinking of a very few sheep. He did not use this emulsion, but a variation made with soap, as follows : Boil a gaSlon of water, dissolving a pound of soap in it; add 2 gal- lons kerosene; churn the mixture until it emulsifies, or until all the oil is “cut.” Use 1 gallon of emulsion to 8 of water. Mr. Harris ad- vises dipping twice with an interim of two weeks. Fifty gallons ot the dip will suffice for fifty sheep. Seventy would probably answer for one hundred; but much depends upon the amount of waste on account of the liquor being carried off by the fleece. The recipe is very easily modified for ranching purposes. The emulsion has already been advised for cattle lice in Bulletin No. 5, Iowa Agricultural Station, p. 184, May, 1889, and for cattle ticks in Insect Life, Vol. II, No. 1, p. 20, U. S. Department of Agriculture, July, 1889. Though the efficacy of this remedy against the various 43 kinds of insect parasites of domestic animals has yet to be tried in de- tail, its importance in this field has already been demonstrated. Preventive treatment.—The sheep should not be turned into the old pens or pastures until a week after the first dip, by which time it may reasonably be supposed that all parasites on the ground have died. To avoid the chance of any recently hatched parasites getting from the ground to sheep in places where the sheep rest, it is best to scrape out and cleanse the pens. Animals recently purchased should always be dipped before being added to the older flock. By following out a thorough plan of treatment, and by carefully guarding the sheep from re-infection, the flockmaster should be able to rid his flocks of this pest in a single season. Fig 44 MELOPHAGUS OVINUS, Linn. PuaTE IY. 1. Female sheep-tick: 1a, larva case, each natural size. . 2. Male, dorsal view, X8: a, head; b, thorax; c, abdomen; d, limbs; e, oval bristle-covered disks, which correspond to the points of attachment of wings in other flies; f, rudimentary Halteres or poisers. g. 3. Male, ventral view, X8: g, h, andi, the three segments of the thorax; k, the external genitals. . 4. Female, dorsal view, <8. . 5. Larva case, X8: a, cephalic end; b, two rows each of seven shallow indent- ations. . 6. Foot: a, the two claws between which hangs b, the pinniform prehensile organ; ¢, the tarsi, whose last joint d supports the prehensile organ; e, distal end of the tibia. : . 6a. Prehensile organ, X60: a, the sesmented muscular portion included within the tarsus; b, the flexible grasping portion. .7. Front view of head: a, the compound eyes; b, the antennze sunk in eup- like cavities; ce, the labrum which protects the sucking organ. g. 8. The sucking apparatus: a, the labrum; ), the orifice from which the tube protrudes; c, the sucking tube. .9. End of the sucking tube, 120: a, teeth by which the tube cuts its way through the skin; b, rod upon which the teeth are set; ¢, tube which has lateral orifice in it. Other details not shown. . 10. External genital apparatus of female: a, spine-covered cap which fits over b, the genital orifice above; ¢, two clusters of spines which seem to be for clasping; d, the terminal of the seven pair of stigmata or breathing pores ; é, anus, . 11, External genital apparatus of male: a, the two lateral of the three chit- inous styles which surround the projecting intromittent organ; b, two clusters of spines which seem to be claspers; c, stigmata. g. 12. Larva case, X6: a, case with the broken operculum inside ; b, cephalic end, showing line where the operculum splits off and the remains of a cen- tral orifice through which nourishment was obtained by the embryo from the parent; c, caudal end showing the two dots corresponding to the two terminal stigmata. . 13. Larva case with larva, X6: a, ventral view; b, dorsal view. PLATE IV A.Hoen & Co, Lith, Balbo ce Haines, del. MELOPHAGUS OVINUS, (The Louse-fly.) THE SHEEP-LOUSE—PHTHIRIASIS—LOUSINESS. TRICHODECTES SPH ZROCEPHALUS, Nitzsch. Plate V. The little red-headed sheep-louse is not very abundant in this coun- try, and easily escapes detection. It is, nevertheless, of sufficient economic importance to engage our attention. The genus Trichodectes, to which this parasite belongs, is classed by scientists in the order Mallophaga, to which order the bird-lice belong. They are said by Packard (Guide to Study of Insects, p. 554), to live upon the hairs of mammalia and feathers of birds. Description.—The sheep-louse is quite small, about 1™™ or one- twenty-fifth of an inch in length. The female is slightly longer and larger. It is characterized by its reddish head and the pale, transverse bands which cross the abdomen. Neumann describes the species as fol- lows: Its head is wider than long; truncated in front, the antennal band making the turn of the forehead which carries long hairs on its border. The antenne are hairy and a little longer in the male than in the female. The abdomen carries sub-quad- rangular median spots. The general color is whitish; the spots and head are ferru- ginous. Length of female 1.6™™, and male 1.4™™, This general description is very good, but would hardly serve to dif- ferentiate this species from others without figures and comparative descriptions. Entomological anatomists enter into very minute details of description for determining these species, but a comparison of speci- mens found with the figures in Plates V and VI will assist the farmer more than a long technical description. As yet the only form recorded from sheep in this country is the one species, Trichodectes sphwrocepha- lus, or T. ovis, which is a synonym. The following appear to be the most marked differences between this and other species: The species is generally smaller than others. The breadth of the abdomen is relatively narrower, and that of the male seems to be more obtuse. The dorsal sutures on the head (see Plate V, Fig. 2 e, e), are fainter in the middle. The-front of the head is more convex. The brown markings on the head are all relatively fainter; those on the back of the male and female increase from the first to the fourth and then decrease to the last in a gradual manner. The claws of both anterior and posterior feet are more nearly of the same size. The eggs (Figs. 6 and 7) are midway in size between those of the two species figured on Plate VI. These eggs have a cap marked by vertical strie, which constitute a generic charac- 45 46 ter. The markings on the under side of the head and the form of the caudal end of male and female seem to differ from others, but these differences are unessential for the present description. The form that most nearly approaches it in general appearance is the Trichodectes pilosus, Giebel, from the horse, but the latter is a relatively larger spe- cies. The species is to be found on poorly nourished young sheep in places where the wool is scanty. A favorite place is between the legs and body, just under the shoulder. Coarse-wooled sheep are more afflicted with them. ; The life history of these pests is very simple. The adults lay their eggs on the wool fibers at their base, and a glutinous material sticks them there (Plate V, Fig. 6). The eggs hatch out in the wool, and the young louse emerges by pushing off the cap (Figs. 7 and 3). The young then grow to be adult. It is most probable that sheep can only get the lice from other sheep, as another host of Trichodectes sphwrocephalus is yet unknown. The presence of these parasites may easily be learned by searching for them or their eggs. Sheep affected manifest their presence by scratching themselves with their hind feet or by rubbing against stationary objects. Disease.—The injury wrought by this parasite is caused by its life- habits. The injury effected by species of Trichodectes is not as de- cided as that caused by those of Hamatopinus, the genus to which the true lice belong. The mouth parts of the latter are so arranged that it can live on the blood of its host, and in biting through the skin it causes an itching sensation and a wound. The Trichodectes, however, are not fitted for penetrating so deeply, and appear to go but little deeper than the epithelium. They can probably bite through to the young growing tissue, for animals which are severely afflicted with these pests have a roughened, scabby skin, which would not be the case if the parasite only lived on the hairs and epithelial débris. The pres- ence of these parasites on the skin not only gives discomfort to the sheep, but causes the skin to thicken, become rough and covered with little dry, black scabs, and the wool to become short, dry, gnarly and worth- Jess wherever the pests attack the skin, ee ie ea Ne | AN ate 48 TRICHODECTES SPH AROCEPHALUS, N. PLATE V. In Plate V, figs. 1, 2, 3, 6, and 7, and in Plate VI, figs. 1. 2, 3, 5, 11, 12, 18, and 15 are equally Pelee ged, ond present relative differences in size and ened Shen parts are also enlarged similarly for the sake of comparison. Fig. 1. Male, natural length indicated by line. Vig. 2. Female, natural length indicated by line: a, head; b, antennex; ec, face; d, cheeks; e, e, dorsal sutures; f,f,f, legs; g, prothorax; h, metathorax; i, abdomen; k, dark transverse bands; J, line of hairs on each segment; m, m, stigmata or breathing pores; n(fig.1), male genital orifice; 0, female genital orifice; p, female claspers. Fig. 3. Young specimen just emerged from shell. 5 Fig. 4. Male antenna. Fig. 5. Female antenna, = vo Fig. 6. Egg soon after being laid: a,cap with peculiar rod-like structure; b, line at which the cap is to cleave off. Fig. 7. Egg shell which has lost its embryo and cap: b, b, wool fibers. Fig. 8. Anterior leg: a, coxa; 0, trochanter; c, femur; d, tibia; e, tarsi and claws. Fig. 9. Posterior leg. Fig.10. Head, ventral side: a, a, antenna; b, b, ventral continuation of dorsal sut- ure; c, ¢, ventral suture; d,d,mandibles; e, maxillw showing through the chitinous gular plate; f, the labrum. Fig. 11. Tail end of male, dorsal view: a, the last segment; b, the genital orifice ; c, chitinous, hook-like appendages of the genital apparatus. Fig. 12. Tail end of female, ventral view: a, the last segment; b, the genital and anal orifice ; ¢, the claspers. . PLATE V M ie Se ‘ PTT ar re Aan rae: A.Hoen & Co. Lith. Baltimore. Haines, dele TRICHODECTES SPH #ROCEPHALUS, (The Sheep Louse.) = GOAT LICE. TRICHODECTES LIMBATUS, Gervais. Plate VI, Figs. 1-8. Description.—Trichodectes limbatus, Gervais—the Angora louse—re- sembles 7. climax closely, but differs in specific details. All the brown markings on T. limbatus are darker and wider; the head is slightly more indented in front; the dorsal suture (Plate VI, fig. 2 e, e,) is more pronounced; the head is wider in proportion toits length. The banded margin of the abdomen is wider. The greatest difference lies in the disproportion of size between the male and female of ZT. limbatus, and the character of .the transverse bands of the abdomen of the male; the abdomen of the male being shorter is relatively wider in proportion to its length, and has a quadrangular appearance. The first band is nearly straight and one-third shorter than the three succeeding, which are of nearly equal length and convex anteriorly, concave posteriorly. The fourth and fifth segments bear a second narrow band near the posterior margin. The egg of this species is larger than that of T. sphwroceph- alus or T. climax. The marked differences shown between the bands of T. climax and T. limbatus was a constant one in all males examined. This feature, in connection with the difference in size of the eggs and the many minor differences of form and color, seem to be specific. The males of these species seem to offer the most tangible characters for separation. When- ever other species of this genus are described particular attention to the males should, on this account, be given. The females seem to ap- proach each other more closely. Occurrence and disease.—The goat louse is common, and. causes more trouble to goats than the little red-headed louse does to sheep. When present it occurs among the coarse hair along the back and sides of the goat. It causes much discomfort and scabbiness of skin. If the ani- inals are severely infected they become poor and thin. The Angora goat louse caused, in the single flock in which it was seen, not only a severe scabby skin disease, but a loss of fleece. The whole back, sides, and head seemed to be completely covered with the parasites, young and old, and nits. Treatment.—The disease caused by these parasites is of that class which is preventible, and it is inexcusable if it be allowed to continue. ‘The history in each ease is that of infection from other sheep, goats, or Angoras, as the case may be. As the parasites spend their whole lives on these animals they may be killed on them and not be expected to 23038 A P——4 49 50 come again except from other animals of the same kind. Yards, where any of these animals are kept, should be sprinkled with lime and the walls washed with diluted lye, or whitewashed before the animals which have been treated are returned. This will ensure safety from any par- asites which may have fallen to the ground where the goats have lain. The treatment should be thorough. As these animals are small the best method is to immerse them in tobacco water, thus insuring the de- struction of every parasite and nit, even those on the nose, by immers- ing them while holding the nostrils. If the hair is long on the Angora they should by all means be sheared. If it is not desirable to dip them, the selected remedy may be sopped on the skin and wool and thoroughly rubbed in so as to wet the skin. : Medicines may be applied in three forms: in powders, as pyrethrum or Persian insect powder, and tobacco dust; in ointments, as oil or lard, with some added ingredient, and in baths, as the tobacco or arsenical dips. Of these the first is the more objectionable and the least valuable, The second is better, but not entirely successful. The third is the one which should be used in the majority of cases, as it is the most certain. ‘The following recipes are among tliose in use, and are recommended by various authorities : A decoction of stavesacre seeds, 3 ounces to 2 quarts of water, to be thoroughly rubbed in. (Neumann.) A decoction of stavesacre seeds, 1 ounce to 1 quart of water or vine- gar, or half water and half vinegar. (Finlay Dun.) In powders, tobacco, pyrethrum, stavesacre and sabadilla may be used, but the last two are not advisable. Benzine 1 part, soft soap 6 parts, water 20 parts, or petroleum (kero- sene) 1 part, sweet oil 10 parts. (Neumann.) Schlegs’ mixture is recommended in Germany for its efficacy and harmlessness when prudently used. Arsenious acid one-half ounce, potash one-half ounce, water 3 pints, vinegar 3 pints. (Ziirn.) The most efficacious remedies are the tobacco, or the tobacco and sulphur dips, advised for scab. For flocks of large numbers, nearly all other recipes are unavailable, Mercurial salves should not be used. Ziirn advises tobacco 1 part, water 20 parts, or water 20 parts and vinegar 10 parts, to be made into a decoction, and vinegar added after cooling. The kerosene emulsion may also prove a valuable remedy. It should be applied as directed for exterminating sheep- ticks, o or by means, of a force-pump and spray-nozzle. TRICHODECTES CLIMAX, Nitzsch. Plate VI, Figs. 11-18. The common goat, Capra hircus, L., is quite commonly infested by a Species of louse which has heen identified by the writer as Trichodectes climax, Nitzsch, and the Angora goat, Capra hircus, yar. Angorensis, by 51 one which seems to be Trichodectes limbatus, Gervais, or T. climax, var. major, Piaget. The name applied by Gervais is accepted, for the differ- ences between the two appear to be specific and not varietal. Description.—The characters of Trichodectes climax are: Head wider than long, quadrangular, presenting a wide but shallow indentation in front, at which the two antennal bands stop; antenn hairy, a little longer with the male than the female; the first joint is larger and shorter than the others ; the second longer than the third; the abdomen bears median spots, the width of which diminish as their length in- creases. The last segment of the male carries two hairy cushions. Head and thorax, reddish-brown ; abdomen, pale yellow ; spots, brown- maroon; bands, blackened. Length, female, 1.6™"; male,1.3™"™. (Neu- mann.) The female of this species is broader and the male a little shorter than in the corresponding sexes of T. sphcerocephalus. The dorsal sutures of the head are much darker and plainer; the edge of the head and ad- domen are margined by a pronounced dark band. The differences between the anterior and posterior feet are much more decided. The dark bands of the back of the abdomen of the male seem to offer the best characteristics, viz: They gradually increase in length to the fourth, when they begin to narrow. Beginning next the thorax the first band is narrow; the second, third, and fourth are wider; the succeeding are narrower ; posterior to the line of hairs on the second to the fifth seg- ments are extra narrow bands, which are about equal in width. The egg of this species is shorter and narrower. TRICHODECTES LIMBATUS, Gervais. PLATE VI. Fig. 1. Male, natural length indicated by line. Fig. 2. Female, natural length indicated by line: a, head; b, antenne; ¢, clypeus ; d, cheeks; e, e, dorsal sutures; f, f, f, legs; g, prothorax ; h, metathorax ; i, abdomen; k, k, dark transverse bands; J, 1, lines of hairs; m, m, breath- ing pores; n, male genital orifice; 0, female genital orifice; p, female claspers; g, male genital hooks. Fig. 3. Head, ventral view: a, antenne; b, mandibles. Fig. 4. Posterior end of female, ventral view: a, genital and anal orifice; b, claspers, Vig.5. Egg: a, the cap; b, the line where it splits off. 6. Antenna of female. e Fig. 7. Anterior leg: a, coxa; b, trochanter ; c, femur; d, tibia; e, tarsi and claws. 8. Posterior leg. Trichodectes climax, N. Figs. 11 to 18. Numbered and lettered for the same parts as Fig. 1-8. PLATE VI Ss. ee a TCt—‘(—C A.Hoen & Co. Lith, Baltitnore, TRICHODECTES LIMBATUS, TRICHODECTES CLIMAX, Ge (The Angora Goat Louse.) (The Common Goat Louse.) 7 ue Ve a Me THE ITCH OR SCAB INSECTS—ACARIASIS—ITCH—SCAB. - SARCOPTES, Latr.; PSOROPTES, P. Gerv.; CHORIOPTES, P. Gerv. Of all the diseases caused by external parasites those due to the seab- making insects are of the first importance. The losses due to them are very heavy, and are exceeded by those of no other external parasite, and equal those of the most destructive of internal parasites. Owing to the means used in preventing flocks from becoming infected, and to the extermination of the pests by the proper use of efficacious remedies, these losses are annually becoming reduced. It is to be hoped that in the near future, through the exercise of proper sanitary laws, this most tractable of all the parasitic diseases may be completely exterminated in our country. Scab is a disease due to the presence of minute insects which lead a parasitic life on the skin of their hosts. It is caused by the inflamma- tion they excite in penetrating the skin, that they may procure food for themselves and young, and suitable conditions under which the eggs may be deposited and hatched and the young matured. The disease is thought by some to be aggravated by a poisonous fluid secreted by the insects, which adds to the intense itching. The malady proceeds step by step with the growth, propagation and decay of the innumerable insects which result from the acquisition of a single fertile female or a few pairs of individuals, and the spread of the disease, therefore, coincides with an increase in the numbers of the par- asites, while the limitation of the disease follows their extermination. There are at least three different species of scab-forming insects, parasitic on sheep, and each species is not only specifically different from the other, but the disease caused by each is different. This is due to the variation in the anatomical structure and habits of lifein the several species of these pests, which causes them to attack the skin in different places and by different methods, and hence gives rise to the various symptoms common to each disease. These insects are known as Acari, and the diseases they cause as acariasis. The various species parasitic on sheep are Sarcoptes scabiet, de Geer, var. ovis; Psoroptes communis, Fiirst, var. ovis; Chorioptes communis, Verheyen, var. ovis. Of these the Sarcoptes causes scab of the head; Psoroptes causes common scab, and the Chorioptes foot scab. The life history of these parasites is in general very similar. They attack the external skin of the animals in which they live by biting it. Soon after scabs are formed. Under these scabs the insects lay their 03 54 ovoid eggs. After two or three days these eggs hatch, and in fifteen days - the progeny become adult. Each adult female is estimated to lay about fifteen eggs, two-thirds of which produce females. When hatched the young invade new territory and lead the life of their parents. The ex- tension of the invading hosts is due to their migration and rapid propa- gation. The disease usually spreads as a constantly growing patch. The infected sheep sometimes scatter the scabs by scratching; these, in turn, become new centers of infection. The multiplication of the invading pests ceases only at the death of the host, or when they are killed by the use of proper remedies. To illustrate the rapid increase of the Sarcoptes, Gerlach, a scientist, computed that in three months a single female would produce 1,500,000 progeny. He esti- mated that each adult female laid fifteen eggs, of which ten were females, and that the eggs became adults in fifteen days. The result is shown in tabular form as follows: ~ eniales: Males. First generation after 15 days produces.. -. 10 5 Second “ 30 ines tak 100 50 -Third ‘S Pa 2 EGA) Sa fe Sey 1, 000 500 Fourth ‘ sire XO) ue =eee) 2L0;000 5, 000 Fifth sf sctC pa ae Or 222. 1005000 50, 000 Sixth $ se gO Oe gs .---1, 000, 000 500, 000 This table presents a very moderate estimate of the rate of propaga- tion. A microscopic examination of minute particles of scab shows them to be teeming with young and old parasites, and would seem to confirm the estimate given. As but few of the parasites may be trans- ferred to a healthy animal, it is evident that up to the second month but little advance in the disease will be noticed, but after that time the tenfold increase every two weeks produces an enormous number of the parasites and causes the disease to advance with wonderful rapidity. THE HEAD SCAB. SARCOPTES SCABIEI, de Geer, var. OVIS. Description.—The insects which cause this variety of scab are almost invisible to the unaided eye, and are among the smallest of the scab- making insects.. They are known as Sarcoptes scabiei, de Geer, var. ovis. They may be recognized by their rounded or somewhat oval bodies, their small heads, which are furnished with a viting apparatus, and by the adult having four pairs of legs. The young have but three pairs of legs. Other anatomical characters, which are different in differ- ent species, are present, but for the flockmaster these are unessen- tial, as the species can be separated by biological characters which are plainer and easily understood. Disease.—Head scab begins on the upper lip, and about the nostrils ; more rarely it may show itself for the first time about the eyelids and 55 ears. In these places there is less hair and grease, affording the pests better opportunities of getting at the skin. From these starting-points the scabs spread over the forehead, cheeks, eyelids, and occasionally over the space under the jaw. In badly infected sheep the disease may sometimes extend to the fore limbs, under the belly, around the joints, and especially between the foids of the knees, hocks, and pasterns. Sheep with coarse dry wool are more likely to suffer this extended invasion than those with fine, oily, and soft wool. Long wool seems to offer a barrier to its progress, for the invasion of parts covered by short wool is much more rapid. The demarkation between the invaded parts of the head and the healthy wool-bearing portions is quite abrupt. In coarse-wooled breeds the disease may rarely cover the entire body. The first indication of the disease is shown by the sheep in rubbing or scratching its head. The intensity of the itching is manifested by the violence of the sheep’s action. The first that can be seen on an infected spot is little elevations with soft centers. These elevations break of themselves, or through the rubbing they receive, and from them runs a watery fluid that in drying forms little hard bunches which stick to the skin and adjacent hairs. These little elevations are made by the parasites, which sink themselves into the skin. Here the parasites find suitable food, grow and produce their young. These migrate and pene- trate into the skin as did their parents. Thus the disease spreads slowly as the parasites increase. Finally, as they become more numer- ous, they cover the invaded skin with a thin layer of scabs. As the disease advances the little scabs not only run together, forming one mass, but they become thicker, whitened, and hard. Later they run together over the nostrils, lips, face, cheeks, forehead, eyes and ears, and form a dry, hard, thick, scabby mass. By repeated rubbings this scab breaks up, and the skin tears, cracks, and bleeds. Later the wounds heal and scars are formed. When the scabs cover the eyelids the latter close up and the animal becomes practically blind, being un- able to find its way or to see food. The insects are to be found in the moist layer underlying the scabs. Source of contagion.—The insects which cause the disease have been derived from other sheep with which the recently infected flock may have come in contact, or which may have left a few parasites on some brush or stick, or in some trough with which the uninfected flock came in contact. The methods of infection are various, but he who under- stands that these parasites always come from some where else, and always from some infected flock, will soon learn what to do to prevent his sheep from becoming infected. The variety of Sarcoptes parasitic on sheep is similar to the variety living on goats, and it has been ex- perimentally proven that each variety may be transferred and will live on either animal. Some of the varieties living on other animals may be transferred to sheep, but they do not thrive. It is not at all prob- able, es that sheep are infected from other animals than sheep. + 56 Diagnosis.—Head seab can not well be confounded with any other - variety of scab. The seat of the disease and the presence of the para- site, which is scarcely visible to the unaided eye, are sufficient to defi- nitely diagnose the malady. Prognosis.—This variety of scab is one of the most amenable to treat- ment. Being mostly on the head it is easy to reach with remedies. If treated it will prove of little loss to the flock-master, whileif allowed to take its course it will continue for a long period, gradually growing worse and rendering the patient more and more unsightly and ill-fa- - vored. It can cause severe inflammation of the eyesand ears. It can hinder the fattening of the animal and cause extensive alterations of the tissues of the skin. By affecting the health of the sheep, it will not only decrease its weight but materially lessen the amount of wool pro- duced. Medical treatment.—The worst feature of treating the disease is, that treatment for a complete eradication seems to be extreme and out of proportion to the end to be attained. Curative treatment always yields good results when the application is rational. In the early stages of the disease, when the scabs are just formed, simple applications of scab dips or ointment are all that are needed; in cases of longer standing it will be found necessary to first soften and loosen the scabs with some kind of grease or oil, and then to remove them with some alkaline solution orsoap. The thin oils (sweetoil) that penetrate are the best. The wool adjacent to the scabs should be cut away so as to allow the remedies to get at the newly affected portions. COMMON SCAB. PSOROPTES COMMUNIS, Fiirst., var. OVIS. Plates VII and VIII. Common seab is caused by an insect known as the scab-mite or itch insect— Psoroptes communis, Fiirst., var. ovis. This insect is much larger than the Sarcoptes, which causes head scab, being’ visible to the unaided eye. . Disease.-—Of all the diseases of sheep in this country, scab is the most feared by the flockmaster. So insidious is its attack, so rapid its course, so destructive its effects, and so difficult is it to exterminate that it has justly earned the distinction of being. more injurious than any other disease caused by external parasites. Scab alone, of the par- asitic diseases, has become the subject of legislation in most countries, and yet, if proper precautions were taken and a rational treatment fol- lowed, this disease could soon be completely eradicated. Early symtoms.—Attention to the disease is first attracted by the in- fected sheep scratching, biting, and rubbing themselves. The coats of the animals look rough, taggy, and felted. The itching is always 57 most violent when the sheep have been heated by driving or warming in a stable. Pathology.—By separating the wool and examining a recently infected spot, there can be seen some minute elevations, which differ from the surrounding skin in being slightly whiter or yellower, and which have been produced by the bites of the pests. The insects themselves can be found among the hairs at but little distance from the bites. As time passes and the insects multiply in numbers these elevations become more and more numerous, and closer and closer together, until they finally unite over a considerable extent. From the summit of each eleva- tion or papule, a watery, serous fluid exudes and accumulates, which transforms them into vesicles and pustules, and which in drying cover them over with a thin crust. Ina few days the whole surface is cov- ered with a yellowish, greasy, scaly layer, under which the parasites are hidden. As the disease proceeds this layer gradually increases in thickness by an increase of the serous exudate, and in circumference by the extension of inflammation produced by the ever-multiplying par- asites which live beneath it, forming scaly crusts. These crusts, in be- ing torn out, mainly by the rubbing with which the sheep endeavors to allay its intense itching, carry with them the tags of the wool, the loss of which is an early symptom of the disease. At a later period the crusts are replaced by another set of thicker, firmer, adherent scabs, which are still further enlarged by the outward migration of the para- sites. As they abandon the center of the scabs these are again replaced by a peeling off of the external layers of the skin, which gradually heals, while the disease slowly progresses at the outside: The complete cure is very slow, and the skin remains thick and folded for a long time. In sheared sheep the skin becomes covered by a thick, dry erust, like parchment, while beneath it remains much swollen. Late symptoms and diagnosis.—The fleece of scabby sheep presents a characteristic rough look. In places the wool is stuck together in masses; in others it fails, while in others, which are apparently sound, it can be easily plucked off. The rubbing and scratching indulged in by the sheep not only tend to tear away the wool but increase the irritation of the skin, which may become intensely inflamed and swollen and finally end in a superficial death of the part. Unlike Sarcoptes, the Psoroptes seeks the longest, thickest wool. It begins its attack along the back and extends to the neck, flanks, and rump. The Psoroptes are-rarely found in the region of the chest and abdomen. They are collected in masses on circumscribed surfaces. The scabs they produce constantly increase at their edges, and their number depends on the number of places invaded. Owing to the closeness in which sheep con- gregate and to their violent scratching the parasites become very gen- erally scattered and finally the scabs may run together. While few of the parasites are present in the older diseased parts, at the edges of the scabs they can be found in swarms, They look like 58 Be little white points with a brownish extremity. If picked up by the point of a knife or a sharp stick and placed on the hand they will be seen to move. The six-legged young, the eight-legged adults, the sexes, couples joined together, and the eggs of this interesting insect can easily be identified by the aid of a low-power magnifying glass. Prognosis.—The disease is favored in its advance by the seasons in which the wool grows longest, and in which the sheep are brought into closer contact in sheds. Autumn and winter are the most favorable for its spread and rapid advancement. In summer, and especially after © shearing in spring, the disease makes little, if any, headway until the wool has grown to a considerable length. Age, temperament, state of health, energy, and race of the animals, the length, fineness and abun- dance of fleece, and the hygienic surroundings have much influence on the advance, progress, and termination of the disease. The young, the weak, the closely in-bred, the long coarse-wooled sheep, and those sub- jected to bad climate, to unhealthy localities, to poorly constructed, illy- ventilated sheds, are all .more subject to the rapid advances of the disease. On the other hand, healthy, well-fed, well-housed sheep may withstand the ravages of the disease for months. When left to itself scab causes severe disturbances of the functions of the skin, and on account of the intense itching brings on fatigue, through loss of rest and sleep. Marasmus and cachexia preceding, death may come to weak, ill-nourished subjects in two or three months. The mortality due to scab varies much, depending on the season, gen- eral health of the flock, food, shelter, and a variety of other factors. It is most disastrous in autumn and winter among sheep poorly fed and housed, and of weak constitutions. Many other diseases may intervene and carry off the weakened animals. The death-rate is not the only occasion of loss, for whether the shepherd keeps his flocks for mutton or wool he will find a loss in either, depending much on the severity of the dis- ease. Ewes weakened by the disease will remain infertile, abort or pro- duce but weak and feeble lambs, which will either die or scarcely be worth the rearing, To this loss must be added the decreased value of the wool obtained from the first shearing after a recovery from the at- tack, due to the mixing of the ends of the old wool with those of the new, known as the double-ended wool. This mixture lessens the value for manufacturing purposes. Source of contagion.—Remembering that common scab is caused by insects which the infested flocks are continually spreading broadcast by dropping tags of wool by the wayside, by leaving them attached to brush, by rubbing posts and fences, it is easy to realize that there are many methods of transmitting the malady. Experiments with these insects have shown that they can live at a moderate temperature on a piece of scab from ten to twenty days; that they may live after being subjected to intense cold; that they die more rapidly when they are in contact with animal matter at freezing temperature, and that they die 59 soon if they remain exposed to alternating high and low temperatures. These experiments show that the Psoroptes can live about the sheep sheds, yards, corrals and fenees during twelve or fifteen days, at least, after they have separated from the sheep. Although this species of parasite is but a variety of the Psoroptes communis, of which the Psoroptes parasitic on horses is another variety, the latter has not yet been made to grow on sheep experimentally. It is not probable that either of the varieties parasitic on cattle or rabbits would thrive on sheep. That is to say, so far as is now known, sheep are infected with common scab from other sheep, and can not acquire it from other animals. On the other hand, the ovine variety of Psoroptes has not yet been found to growon other species of our domestic animals. Differential diagnosis.—Psoroptic, or common scab, is different from Sarcoptic or head scab, in that the former chooses to live where the fleece is longest, and the latter where there is little or none at all—the one on the back and sides, the other on the head and occasionally on the nether parts; the one is almost invisible to the naked eye, and the other is plainly seen, though small. The itch due to other parasites, such as sheep ticks and sheep-lice, can be easily separated, because they are large and can be found in the wool. Sheep are sometimes subject to an inflammation of the sebaceous glands. In this, however, there will be no parasites of any kind found. ‘Prognosis.—Scab, as has been said before, is one of the most dreaded diseases of sheep. For the flockmaster who has but few sheep, say fifty or a hundred, the task of treatment and eradication of the scab from the flock is no easy affair; but for him who owns from five to twenty thousand the difficulties to be met are enormously increased. Though the disease may be easily treated as far as a single sheep is con- cerned, still the treatment would only be palliative and would not as- sure the flockmaster that the disease would not break out again. Treatment, therefore, of a flock in which scab has appeared must be applied to every individual exposed and to the corral and sheep-pens in which they have been lodged, and is not only a serious time-conusum- ing affair, but a most expensive one. Treatment.—This is of two kinds—preventive and curative. The preventive treatment is undertaken before, during, and after the curative. Indeed, if the flockmaster exercises proper care his flocks will never require the curative treatment, for the disease always comes from transference of the insect. Preventive.—An infected flock should be quarantined so that it Shall not transmit the disease to other flocks, and should be kept from public highways where other flocks may pass, until it can be thoroughly cleansed and cured. The sheds, yards, and corrals where they have been kept should also be cleansed, so that they may not transmit the disease. After treatment begins the sheep should be transferred to a temporary uninfected yard, so that the old yard may be thoroughly 60 disinfected by carting away the soil to some safe spot, by washing all the wood-work as high as a man’s head with a solution of boiling lye,* and afterwards covering it with a coat of whitewash. All old pelts which could harbor the insects should be burned. Every possible se- creting place for the insects should be overhauled. After a thorough cleansing the yards should be left vacant for three weeks. After the dipping the sheep should be driven into fresh, clean yards, and not into such as have not been sufficiently cleansed. If possible they should be kept from infected pasture ranges for three weeks, by which time all parasites which may have dropped from them may be considered as dead. Sheep which have been dipped in any of the tobacco preparations can be, so it is stated, driven on the ranges im- mediately after dipping with impunity, as the tobacco odor keeps the insects away. Any sheep which may have died on the range should either be buried deeply or burned. In dipping extreme care should be taken by all who handle sheep not to transfer the pests from animal to animal. Medicinal.---There are two methods of treating sheep for scab. The one of rubbing poisonous ointments and oils into the fleece by the hand is the oldest and least used. It is slow, tedious, and unreliable, and has been superseded by better methods. The other consists in immersing sheep in watery mixtures which will kill the parasites. This method being cheaper, quicker, and more effective, is the one in general use in this country. The formule used and the methods of applying them vary in different portions of the coun- try according to the needs of the sheep-owner. In the East, tubs large enough to hold sufficient of the dip to com- pletely immerse the sheep, and kettles or cauldrons of a capacity to heat the required amount are used, but in the range country of the West, where thousands of sheep are to be treated, especially made dip- ping pens and tanks through which the sheep may be driven, and large boilers made for the purpose, are used. Each method is adapted to the needs of the respective localities. Although some dips are fairly effect- ive when applied to sheep with their fleeces on, the dipping should, as a rule, be preceded by shearing. This rule should be violated only on account of season. If any of the flock are infected all should be sub- jected to treatment, otherwise the disease will be carried along and | break out from time to time. The shearing should take place in a shed where all the wool can be eared for, and either poisoned or destroyed, or so safely stored that it could by no possibility seatter the insects. Any treatment undertaken without being preceded by shearing can at best be considered as pailiative. The object of the treatment is to kill the parasites and their eggs. The parasites are killed by the direct application of a poisonous dip. The eggs have a thick shell which often resists the effect of the poison, | * Use 1 part of potash to 200 of water. 61 and the young parasite emerges in due time. They are then subjected to asecond dip some six or ten days afterwards, at which time it is pre- sumable that all the eggs have hatched and none of the young have be- come adult. If the second dip is delayed much longer than twelve or fourteen days, some of the newly hatched larvie may have become adult and laid eggs, which may in turn hatch larvee, and become new centers of infection. All dips, to be effective, contain some ingredients which are poisonous to the parasite. This poisonous element may also, if used in too con- centrated a solution, be poisonous to the sheep, but this is to be avoided by using the dips in the exact proportions of the formula given and maintaining these proportions throughout the treatment. In addition to the poisonous element, a dip may contain other elements, as water to — dissolve and to dilute the poison ; also such a substance as alum or soda to combine with the poison, as arsenic, to make it more soluble; or it may contain an alkali, as soda or potash, to soften the scabs when ap- plied ; or it may contain substances which are empirically added because they have been experimentally proven of service. The chief poisons used in the dip are tobacco, arsenic, and earbolic acid. Of these, tobacco is the favorite, because its use has not been followed by the fatality that has in times past followed the use of arsenic. Carbolic acid is too expensive to be used in large quantities, but is an excellent: ingredient when only a few sheep are to be dipped. The addition of tar to these dips is excellent, as the tar water is not only good for the wounds but serves an excellent purpose of driving away the flies. The quantity of dip required for each sheep is variously estimated at from 1 quart to 1 gallon. For small numbers of sheep, say fifty or one hundred, the larger amount 1s necessary, but for large flocks, 1 quart for shorn and 2 for unshorn sheep may be allowed. It is always best to have more of the ingredients on hand than is necessary, so that they may not be used up before the dipping is finished and thus delay the business. To make the dip more effective the solution should be ad- ministered quite hot. The most desirable temperature is from 100° to 110° Fah., which is a comfortable one for the sheep, whose internal temperature is about 103°. The warmth enables the dip to penetrate the oily wool better, makes the parasites livelier, and proves far more efficient. Instead of treating the scab by one application some authorities ad- vise the use of a preliminary dip of alkaline water to soften the scabs, or_of oil or glycerine well rubbed in for the same purpose. This is to be followed in two or three days by a poisonous dip. Nearly all advise that the scabs should be rubbed with a stiff brush while the sheep is being dipped. The Australian or Rutherford dip, which has been very successful in the hands of large flockmasters, is as follows: Take of tobacco and 62 flowers of sulphur 1 pound each, to every 4 gallons of water to be used. The tobacco should be steeped in a portion of the water two or three successive times so as to extract all of the juice. The leaves-or stems may be used; of the latter three times the weight is required as is needed of the former; a press or wringer is convenient to squeeze out all of the liquor from them. The sulphur should be mixed with some of the tobacco water and stirred until it is of creamy consistency. These ingredients should be added to the required amount of water. During the dipping this mixture should be constantly stirred and a lit- tle fresh water added from time to time to replace that lost by evapora- tion. This dip, to be more effective, should be heated to between 100° and 110° Fah. in summer, and 110° and 120° Fah. in winter, never being allowed to fall under or exceed these limits. The sheep should remain immersed in it from sixty to ninety seconds, and the head should be completely immersed at least once. When sheep with heavy fleeces are dipped it will be found necessary to separate the fleece with the hands, that the fluid may permeate better. Hight or ten days after the first dipping the treatment should be re- peated. Sometimes a third and more rarely a fourth dipping is neces- sary. When the iast two are required it is most often due to care- lessness in preparation, or a failure in the strength of the first dips. Sometimes it may be necessitated by the rain having washed off the first solution soon after dipping. _Australian sulphur and lime dip: Take of flowers of sulphur 100 pounds, of quicklime 150 pounds, water 100 gallons. Mix and stir while boiling for ten minutes, until the mixture assumes a bright red color, then add 3 gallons of water. Hold the sheep in the mixture until ‘the scabs are thoroughly soaked. Immerse the head at least once. Use the dip at 100 to 110° Fah. Dip twice at an interval of two weeks. In the American Merino, 1887, Stephen Powers gives an excellent description of sheep-dipping on a large seale, and the following recipes in use in various sections of the United States: Texas and New Mexico: Thirty pounds of tobacco, 7 pounds of sulphur, 3 pounds of concentrated lye, dissolved in 100 gallons of water. Nevada: sulphur, 10 pounds; lime, 20 pouuds; water, 60 gallons. California: Sulphur, 4 pounds; lime, 1 pound; water, enough to make 4 gallons. Kansas: Sulphur, 22 pounds; lime, 7 pounds; water, 100 gallons. : Sulphur and lime is probably the cheapest recipe, but the lime is apt to injure the staple; still this recipe appears to prevail over all others in the scab-infested regions. Probably tobacco and sulphur form the best combination known for the treatment of scab. Toevery hundred gallons of water there should be used 35 pounds of good strong tobacco (if stems or other inferior parts are used there should be more), and 10 pounds of flowers of sulphur, This preparation used at a temperature of 120° Fah., will kill all acari ticks and lice, and leave the waol in a healthy con: dition, To insure thorough work apply a gecond time in ten days or two weeks. 63 Walz’s dip, one of the oldest recipes, is as follows: Take of fresh slaked lime 4 parts, carbonate of potash 5 parts, mix and boil in barn- yard water; add animal oil 6 parts, tar 3 parts; dilute with barn-yard lees 200 parts, water 800 parts. To-day this recipe is more curious than useful; one of the ingredients is not on the American market, and an- other is offensive. Veterinarian Clok, in his Diseases ef Sheep, 1861, reports this mixture as being too weak for old cases, and recommends the following modification: Take of freshly-burned slaked lime 6 pounds, add potash 6 pounds, and water 10 quarts; boil an hour, stir- ring occasionally. Add pine-oil 8 pounds, and tar 2 quarts, stirring the mixture thoroughly. Make an infusion of 20 pounds tobacco in 130 quarts of water; add the lye already made and stir. This quantity suf- fices for one hundred sheep. Apply by immersing the sheep, separat- ing the wool and breaking the scabs. Repeat in eight or ten days. Law’s recipe (Farmers’ Veterinary Adviser) is a very good one: Take of tobacco 16 pounds, oil of tar 35 pints, soda ash 20 pounds, soft soap 4 pounds, water 50 gallons. This quantity suffices for fifty sheep. The tobacco should be steeped; afterward the other ingredients should be added at 70° Fah. Zundel’s dip is available, but Dr. Kaiser (Kuhrverfahren bei der Schaf- rdude, 1883) reports that it is too weak in cases of long standing. It is: said to leave the wool clear and white after using. For every one hun- dred sheep take crude carbolic acid 3 pounds, caustic lime 2 pounds, pot- ash 6 pounds, black soap 6 pounds, and water 70 gallons; mix and boil. Dr. Kaiser has obtained excellent results from a modification of this recipe. Take of tobacco 5 kilograms (134 pounds), infuse it in 250 liters or 66 gallons water; dissolve in it 3 kilograms (8 pounds) soda, add 145 kilograms (4 pounds) freshly burned and slaked lime. Dilute 3 kilo- grams (8 pounds) black soap (soft soap will do) with hot tobacco broth and add it to the rest; then add 14 kilograms (4 pounds) crude carbolie acid, which contains at least 50 per cent. of the pure acid. Mix. This quantity is sufficient for one hundred sheep. Gerlach’s dips, which are administered at two different times for a single treatment, are cheap, but owing to the time and labor to be ex- pended in performing an operation twice which in other instances is done but once, is much more costly than those which require but one application. Take of potash 2 parts, burnt lime 1 part, water 50 parts. Mix. Use this dip for softening scabs. Follow it-in two or three days by the fol- lowing: Make an infusion of tobacco 34 pounds in 66 gallons water, by slowly steeping the tobacco in a portion of water and finally adding it to the remainder. Repeat the dip in from six to ten days. Roloff’s dip, for a mixture sufficient for one hundred sheep, is: Take 7.5 kilograms (20 pounds) of tobacco, steep it with 250 liters (66 gal- lons) water for half an hour, heat it to 309 R. (952 Fah.) and add 1 kilogram (24 pounds) each of pure carbolie acid and of potash, 64 A cheaper and fully as effective dip of similar formula is the follow- ing: Mix an infusion of 15 pounds tobacco with 1 kilogram (24 pounds) carbolic acid and 5 kilograms (13§ pounds) wood tar, pour it into 250 pounds (66 gallons) water at 40° R. (125° Fah.), in which 3 pounds soda has been dissolved. Use it at a temperature of 80° or 90° Fah., and repeat in six or seven days. ; There are three arsenical dips favored by European authorities, the jast of which might be used while exercising proper care and precau- tion. The solution should always be kept as dilute as the formula cails for. The sheep should not be allowed to drain on the grass, but should be kept up until nearly dry, and the laborers who dip should grease their arms with linseed-oil before beginning work. Tessier’s dip, the oldest, was proposed in 1810. To make a mixture for one hundred sheep, take arsenious acid 3 pounds, sulphate of iron 20 pounds, and water 190 pounds; boil. Tessier’s dip causes a discoloration of the wool, which can be removed by washing with soap, but it.is on this account more or less objectiona- ble, and to overcome this objection Clément has modified it as follows: Arsenious acid, 1 part; sulphate of zine, 5 parts; water, 100 parts. The water is put over the fire, the medicinal substances added, and it is allowed to boil for eight or ten minutes. After the temperature has fallen to the proper degree it is ready for use. The sheep is entirely submerged in the liquid, with the exception of the head, the udder of ewes suckling their young having been previously covered with some fatty substance to prevent the action of the astringent on the skin and on the secretion of milk. ' Matthews dip: Take arsenious acid 1 part, alum 10, and water 100 parts. Scheurle and Kehm’s dip: Take arsenic 1 part, alum 12, and water 200 parts. This latter is weaker than the former, and therefore safer. Moreover, it is claimed to be as effective. The sheep dips that are put upon the market are objectionable for three reasons: First, their formulas are not given; second, the preparation may be valueless, or if not valueless of insufficient strength; and third, the preparation may cost more than it is actually worth. Should the dip be put up by reliable houses, and have their formulas printed on the outside of the package, the prepared article might prove better compounded and absolutely cheaper than the flockmaster could pre- pare it. : Police sanitation.—It is not sufficient that the flockmaster thoroughly cures his flock, disinfects his sheds and quarantines his place. Another duty awaits him, and that is a public one. All flock-owners should unite and assist the State in improving and carrying out its sanitary laws. Nearly all States have laws regarding the suppressing and quarantining of sheep infected with scab, but they seem to lack in stringency and are therefore inadequate. Laws compelling strict quar- 65 antine and public supervision of the treatment, at the expense of the owner, even though it is undertaken by the State, are demanded for the complete eradication of the disease. With such laws no one could long harbor on his premises a disease which constantly threatens the flocks of his neighbors with destruction and their owners with financial ruin. FOOT SCAB. CHORLOPTES COMMUNIS, Verheyen, var. OVIS. This variety of scab, which is due to Chorioptes communis, Verheyen, var. ovis, is of rare occurrence. It has been noticed and studied in Ger- many by Ziirn. The seat of this disease is in the feet and limbs. The disease pro- gresses very slowly from the feet, and little by little invades the upper parts of the limbs and adjoining parts. Itis not readily communicable to other sheep and spreads slowly. In the beginning this variety of scab is characterized by the redden- ing, followed by au abundant scaling of the skin, and later by yellowish white crusts. The animals stamp, scratch, and bite.the parts, showing anintense itehing. As the disease progresses the crusts become thicker; cracks may form in the folds of the pastern and the limbs become quite unsightly. The parasites swarm beneath the crusts, and when found form a certain symptom of the character of the disease. Foot-scab is not a serious malady, as it readily yields to treatment and is of slow extension. Any of the remedies proposed for the treat- ment of common scab may be used with good effect. 23038 A P——--5 bh PSOROPTES COMMUNIS Fiirst., var. OVIS. PuaTE VII. Fig. 1, Adult male, dorsal view: a, head; bb, legs; ¢c¢, suckers. Fig. 2. Adult male, ventral view. Fig. 3. Adult female, dorsal view. Fig. 4. Adult female, ventral view. NotE.—Figs 1 to 4, Plate VI, and Figs. 1 to 3, Plate VIII, are cqually magnified. PLATE VII Haines, del A.Hoen & Co. Lith. Baltimore, , del, | : PSOROPTES COMMUNIS, Var OVIS, 3 ~ (The Common Scab-Mite.) iat i dyes No yeurp 68 PSOROPTES COMMUNIS Iiirst., var. OVIS. PuaTE VIII. Young female before moulting for the last time. Egg drawn from a specimen which was inside an adult female. Young six-footed larva. a, open, and b, closed sucker of Psoroptes from ears of rabbit; ¢, the rod which connects the membrane on the end with the muscles which close the sucker. Two views of the mandibles. The lateral spurs, a, a, point outward (Megnin). Head and anterior limb enlarged; ventral view: a, mandibles; b, antennx; c, maxille; d, membrane joining the antenna ; e, ¢, e, joints of the limb; J, the claw ; g, the ambulacrum or sucker, Male and female of Psoroptes communis var. equi (Megnin), PLATE VIII A.Hoen & Co. Lith. Baltimore, PSOROPTES COMMUNIS, Var OVIS, (The Common Scab-Mite.) THE PENTASTOMA. LINGUATULA TANIOIDES, Rud. See Plate XVII, figs. 1-6. Linguatula tenioides is also known under the names Linguatula rhi- naria, Pilger, and Pentastoma tenioides, Rud. In describing this parasite, Neumann’s excellent description in Traité des Maladies Parasitaires, page 491, has been taken as a guide. The species is probably present in this country, as in two instances the larval form known as Pentastoma denticulatum has been found. The larvze were found by Dr. F. L. Kilborne, of this Bureau, in a rabbit, some time in the summer of 1887, and once by myself in another rabbit in 1888. This curious parasite is classed among the Arachnids, being more closely related to the spider and mite family than to any other. ‘The order Linguatulide, to which they belong, is thus defined : Endoparasitic arachnids with elongate, vermiform, annulate body. Mouth want- ing jaws in the adult state, and surrounded by two pairs of hooks representing rudi- mentary feet. No heart. Respiration cutaneous. In it are two genera: (1) Lingua- tula, Frohlich, which has the body depressed with dorsal face rounded and with the borders crenulated. The cavity of the body forms diverticula in the lateral parts of the rings. (2) Pentastoma, Rud., which hasa cylindrical body and the cavity of the body continuous. It is not represented in our domestic animals, unless it be a lar- val form found once in the peritoneal cavity of a dog. Description.—The species met with in the domesticated animals has the following characters: Body white, lanceolate, very elongate, worm-like, depressed dorso-ventrally with the ventral face nearly plane and the dorsal face convex. Anterior extremity rounded, large ; posterior extremity attenuated. Cephalo-thorax short, solidified in all its width to the abdomen, from which it is scarcely distinct, and which forms by far the larger part of the body. Integument showing about ninety rings, larger in their middle ; these make the borders of the body crenulated. Hooks acute, re- curved, twice-jointed, the basal joint attenuated in its deep part. These hooks, each retractile in a pocket, are moved by muscular bundles which act in opposite direc- tious. Mouth sub-quadrangular, rounded at the angles; digestive tube simple, rec- tilinear; anus terminal. Male, white: length from 18 to 20™™; width, in front, 3™™; behind, 0.5™™, provided with saccular testicles which fill the body cavity even to the anterior fourth. Female, whitish grey, often rendered brown by the eggs along the median line where the integument is thin and semi-transparent; length from 8 to 10°; width, in front, from 8 to 10™™, and behind, 2™™, Eggsovoid; length, 0.09™™; width, 0.07™™, : Tafe history.x—The female Linguatula tenioides lays its eggs in the nasal cavities of the dog. These are scattered on the ground and grass 69 70 where they lie until eaten by some herbivorous animal. The shell is then dissolved from around the embryo, and it bores through the walls of the stomach or intestine into the mesenteric gland, liver, or lung, where it encysts itself. In its first stage of active migration the larva resembles the Acari (Plate XVII, Fig. 4). It has an ovoid body, flat- tened on the ventral face, rounded on the dorsal. Its posterior extrem- ity is narrowed and dentate. It is furnished with two pairs of articula- ted, two-clawed feet, and at its anterior end by a perforating apparatus formed of a median stylet and two re-curved hooks. Its length is 0.138"; its width 0.06™™, Having arrived at the mesenteric glands, the liver, or the lungs, as the case may be, the embryo loses its feet and is transformed into an im- movable pupa (Fig. 5), without segments, hooks, or hairs, measuring 0.250 to 0.300" long, and 0.180™™ in width. It emerges from this cyst transformed into another larva by a series of successive moults (see Fig. 6). The body is elongate, Jarger forward, and is divided into eighty to ninety rings bordered behind by a series of fine spines. The digestive tube is large, the mouth is elliptical, and surrounded with four characteristic hooks and with accessory hooks. The larva is agamic, its genital organs being rudimentary and rep- resented only by a little granular mass in the posterior part of the body. ‘Towards the sixth or seventh month the larva is completely developed, measures 6 to 8™™ long, and is in the stage called Linguatula denticulata. These larve having escaped from the cyst, fall into the serous cavities and remain there for some time. They eventually escape, but the precise method is unknown. Next they are seen in the nasal cavities of dogs. Exceptionally, so it is said, they are found in the nasal cavities of sheep and cattle, into which they have wandered. These larve can acquire their full development only in the respiratory passages. Once installed in the nasal cavities they develop into egg-bearing adults. The males wan- der and can be found at* various points of the cavities, but the females are more sedentary, and are never found in the ethmoidal cavities. After the death of the host they may travel into the pharynx and larynx. They exceptionally introduce themselves into the frontal sinuses. They are generally found at the bottom of the nasal chamber. : As the adult stage is not usually found in sheep, and as its occurrence is problematical in this country, the disease it causes will not be con- sidered in this volume, Disease.—The young state, Linguatula denticulata, found in eysts within the glands, etc., are said to be particularly frequent in sheep in Europe. Sheep in which the parasite affects the mesenteric glands are generally less fat; their flesh is paler, and they are apparently predis: posed to anemia. These glands show no evidences of the parasite at first, but later they grow browner, smaller, and are crossed by galleries filled with larvae. These cavities are separate at first, but finally com- municate; the substance of the gland is destroyed and transformed into a brown tumor, in the middle of which are the Zinguatule. From these: the parasites often escape through openings with irregular borders; at other times the surface is covered by dark, irregular spots, fibrinous de- posits, and false membranes, which indicate a recent departure or a de- (2 struction of the embryos. At last the tissue is found thickened, indu- rated, and offers here and there tuberculoid grains formed from the old nests of Linguatule. These altered glands are destroyed and are of no further use in nutrition. The larvee create further troubles in their mi- grations, but so little is known about these parasites that little can be said. There is no treatment. Prevention is also difficult. If it should be learned that we have these parasites here in considerable numbers the best remedy would be to remove the dogs, which are certainly the cause of large numbers being scattered in Europe. IMMATURE TAPE-WORMS—BLADDER-WORMS. Plates IX, X, and XI. Besides the adult tape-worms found in the intestines of sheep, there have been four other species described which infest various portions of these animals in their immature stages. These species are Tenia mar- ginata, Batsch, T. coenurus, Kiich., T. echinococcus, v. Siebold, and T. tenella, Cobbold. The forms found in sheep were first described as . Cysticerci, and have since been known as Cysticercus tenuicollis, Coenurus cerebralis, Echinococcus and Cysticercus ovis, respectively. All these species resemble each other in their anatomical structure, their growth, and their life history. They differ in minute structure, in invading different portions of the sheep, and in the effects they produce on the animal. . Tenia marginata is more common in the United States, and T. coenurus next. Neither of the other two species have been found in sheep in this country. TANIA MARGINATA, Batsch. Plate IX. Tenia marginata occurs in sheep as a little semi-transparent bladder filled with liquid, varying from a very minute size to a bag an inch or more in diameter, but usually having a diameter of a half or three- quarters of an inch. Occurrence.—This tenia, in its cysticercal stage, is usually found be- tween the layers of the serous membrane which form the omentum, or ‘*caul” of the abdominal cavity. It may be found in the liver, espe- cially within a week or two after the infection of the sheep by it. A very common place to find it is between the folds of serous membrane which suspends the intestine in the pelvic cavity. When one of these little fluid-sacs are found it may be cut out, with the surrounding tissue for examination. Afterwards great care should be taken in dissecting the serous tissue, which forms an outer sac, so that the cysticercus within shall not be cut, its contents allowed to escape and its walls to collapse. Description of cystic stage.—The smaller bladders are apparently com- posed of a semi translucent whitish membrane, at one end of which may be seen a whitish thickening. As the bladders grow the walls become slightly thicker and thespot at the end becomes much larger and pro- jects in the form of a knob. 72 73 When the animal is placed in a saucer of lukewarm water immedi- ately after its removal from the slaughtered sheep and examined, it can, by the aid of a low-power lens, be seen to possess considerable peristaltic movement. This movement is produced by bundles of muscles lying at right angles to each other, which may be seen appear- ing as a faint striation on the surface. The little knob end of the bag is its essential part, and contains what is to develop into the future tania. Sometimes the animal will extend this knob into a cone, and finally thrust out of its center the very tip of the cone. By careful handling this so-called head end may be squeezed out by the fingers. The tip, when examined by a magnifying glass, can be seen to possess four cup-like spots, with a little glittering circlet of hooks between them at the very apex of the cone. Life history — When these cysts have attained their hooks and cups in a well developed condition, they are ready for transplanting into another animal or host. The cysticercus completes its development in about eight weeks. It may live a long time after this, and its cyst enlarge, but the modifications it may undergo are unessential. The host within which the cysts or cysticerci generally develop is the dog. They may, however, also develop in other carnivora, such as the wolf or coyote. Their emigration is a passiveone. They remain encysted where they are found until the sheep is slaughtered and the dogs eat the offal, or until the sheep is killed by a dog or wolf and its liver is torn from its place and devoured, together with any of the cysticerct which may be attached. Uaving gotten into the intestines of the host the parasite completes its development, becomes adult, and finally produces young, which pass from the host along with the ejecta of the intestines. The young at this stage are egg-like. They are very small and hardly visible to the naked eye. When viewed with a glass they are seen to be a minute, jelly-like mass, furnished with six hooks and sur- rounded by at Jeast three membranes. The outer is thin and filled with fluid; the inner two more closely surround the embryo, and confine be- tween them an oily material which serves to protect it when exposed to the atmosphere. After passing to the ground these embryos in some way, possibly by adhering to food or by floating in drinking water, make their way into the sheep. When they arrive in the abomasum, or fourth stomach, it is supposed that the gastric juice digests the membranes surrounding the embryos and they then begin their active wandering. At this stage they penetrate the walls of the fourth stomach and make their way between the walls of serous membranes to the place where they finally find lodgment. This active migration must often be converted into a passive one after the embryo has made its way through the mucous coat of the stomach, for when the embryos have been fed in large num- bers to the sheep in the course of the experiments of different investi- 74 gators the liver has been found to be filled with multitudes of them. One investigator has found them in the minute branchlets of the portal vein, which conducts the blood from the stomach and intestines to the liver. Now, in order to appear in the liver and in the portal vein in such numbers the embryo must make its way into the little branches or capillaries which collect the blood at the stomach, and then be washed by the blood current into the liver. When they become lodged in the liver they again migrate actively and tunnel through the mass of the liver in alldirectious. The little channels are made slowly. They begin as a minute point, and become gradually larger as the parasite increases in size and changes its position. About the ninth day after the embryos have been swallowed some of the parasites may be as large as a flax- seed; most of them will be smaller. They will then be little oval water- bass, with a whitish thickening at the end. Some of the parasites seem to pass the entire length of the intestine before they penetrate the walls; but when they reach the rectum they pass through, and, becoming lodged between the layers of serous mem- brane, develop there. This probably accounts for the presence of the considerable numbers which are found in the pelvis. The destination at which these parasites arrive has its influence on their development. When they have migrated to a point between serous tissues which may be easily spread apart, and offer little resist- auce to the growing parasite, a certain proportion of them seem to thrive and arrive at a stage in which they may continue development by the proper exchange of hosts. If this exchange is not effected the parasite may remain unharmed for a long time while awaiting this opportunity. Should they die ‘from any cause a slow change in the appearance of the parasite is noticed. The fluid it contains becomes milky and limy. The serous sac surrounding it becomes thicker; finally such changes have occurred that in place of a soft sac a round, hard sphere of lime covered by a thick membrane may be found. The re- mains of the parasite may still be seen by careful dissection between the cover and the limy deposit. But when, on the other hand, they arrive at the liver they seem to have reached a place of destr eeu for if they do not kill the iuvaded host within two weeks, a period long before they could continue their life in another host, thesame degenerative processes seem to affect them, in their earlier stages, which destroy. the older individuals in other or- gans of the body. This seems in part due tothe pressure which the liver cells and capsule exert upon them. These statements seem substanti- ated by the presence of either scars or calcareous nodules in the liver and of no large cysticerci, except where the loose serous membrane may have permitted their growth. These parasites have occasionally been observed in other parts of the system than those mentioned, as in the lungs, heart, and muscles. Disease.—The harm that Tenia marginata does in its young stage depends much on the degree of infection. In experiments animals have 75 been killed in from nine to twelve days after feeding. In such cases the sheep usually die of hemorrhage from the liver and peritonitis. This is caused by the perforations of the serous covering of the liver due to the parasites. These experiments show that the parasite is injurious to sheep. ‘The presence of a few well-advanced cysticerci in nearly all of our sheep also shows that though the parasite may be injurious in its young stages, the sheep rarely succumbs to them in their period of inva- sion. After a period of about twoweeks the sheep seem to have no dis- comfort from them. Sheep may be invaded by the tania at almost any time of the vear. The winter season, when the embryos which have been scattered by the dogs become frozen, seems to be less favorable. If the dogs have access to the sheep-pens ev en this season will not delay the infection. Lambs and yearlings appear to be most subject. Three months’ lambs are the youngest in which the cysticerct have been found. Experi- ments in attempting to produce the cysts in old sheep by feeding gen- erally*fail. Young sheep furnish the best specimens, while in five or six year old sheep the cysticerci seem to have degenerated into calea- reous nodules. The adult tenia live in dogs. Soon after the cyst is swallowed the tissue is digested from it, and the large, watery bag, which has prob- ably already lost its fluid in the mastication of the food, disappears. The head remains, and passing from the stomach into the intestine at- taches itself by its hooks and cups, which serve as suckers. Here the parasite, bathed in the intestinal fluids which nourish it, proceeds with its development. In a day or two it lengthens and begins to show cross lines, which indicate the points where the division into segments is to occur. Later the segments appear and the worm gradually ma- tures the organs of reproduction in them. After ten or twelve weeks have passed, the parasite begins to lose its end segments, which have fully developed embryo in them, and are ready for the infection of sheep. Description.— Tenia marginata, Batsch, or Tenia cysticerci tenuicollis Kiich., is the largest of the tenia infesting dogs. It is usually, when mature, about a yard long. Large specimens may be stretched, when fresh, until they are 24 yards long. The greater number of specimens are, when contracted, under a yard long. The width of the worms also depends on their degree of contraction, the more contracted specimens being the widest. The average of relaxed specimens is about two-fifths of aninch. The same specimens, when alive, might contract so much as to measure three-fourths of an inch. The width of the worm gradu- ally widens from its bead for four-fifths of its length, and then contracts slightly totheend. This species is moderately thick, measuring a little over a twenty-fifth of an inch where thickest. When first taken its ap- pearance is white and opaque, but when kept in water it becomes par- tially transparent. It then resembles a whitened, pliable band of geia- tine. At its small end is the so-called head, which is separated from the 76 body by scarcely any constricted neck. The head is quadrangular, is about one-twenty-fifth of an inch in diameter, and has a circlet of from thirty-two to forty hooks at its apex, and four moderate sized suckers. ‘The specimen figured contained twenty-eight. These hooks and suck- ers serve to anchor the parasite to the intestinal walls. The neck is short, and at a little distance from the head shows the division into seg- ments which become plainer and plainer towards the end of the body. The segments are at first very short and broad, but gradually lengthen- ing become square where the animal is widest. when relaxed, and about twice as long as broad at the end. The terminal segments measure about one-fourth of an inch wide and one-half inch long. There is no ali- mentary tract, the office of absorption of food being filled by the skin. Motion is effected by muscular bundles situated beneath the skin, which give a variety of vermicular movements. Fig. Fig. Fig. Fig. o Fig. Fig. Fig. Fig. Fig. Fig. Fig. 110 TANIA FIMBRIATA, Diesing. PLaTE XII. 1. Adult, natural size. From contracted alcoholic specimen. 2. Head, edge view, X6. 3. Head, side view, X6. 4. Head, top view,*x6. 5. Portion of segment: a, genital pore; b, cirrhus pouch; ce, seminal appara- tus; d, the efferent tube; e, the rudimentary uterine apparatus; f, vagina; g, the receptacle of the semen; h, fimbrie. 6. Portion of segment more mature than Fig. 5: a, genital pore; b, cirrhus pouch ; d, efferent tube; e, the uteri. 7. The uteri enlarged. 7a. The uteri still further enlarged, showing the contained embryo. 8. A half-grown tenia, showing the fimbrix, <2. 9. Fragment of tenia from near head, showing the lateral excretory vessels. 10. Terminal portion of adult, x2: a, segments which have lost their contractil- ity; b, separated segments. 11. External reproductive apparatus, x40: a, genital pore; b, cirrhus pouch; c, penis. 12. Adult segment showing the symmetrical arrangement of the reproductive apparatus: a, a, genital pores; b, b, uteri; ¢, c, fimbri. 13. Embryos as they exist in the uteri: a, a, envelopes; b, b, embryo. 14. Embryo showing envelope and its six hooks. 15. Youngest tenia found. Natural length indicated by lines at their sides. All specimens except figures from 1 to4 and 15 were drawn from fresh preparations. Teepe Bae Nt GBRerY PATI Pyotr erect sree eyreweagsny, ua PMR AMA PLATE XII J} Mus = TAENIA FIMBRIATA, (The Fimbriate Tapeworm.) A.Hoen & Co. lath. Baltitnore. Torn s5 f , Tay Yor! ’ J TAENIA FIMBRIA'TA, Diesing. PLATE XIIJ.—Diesing’s original figures. Fig. 1. Adult, natural size. Fig. 2. Head, side view. Fig. 3. Head, top view. Fig. 4. Segments near head. Fig. 5. Segments further removed from head. 5) Fig. 6. Some still more remote. Fig. 7. From near end. 5 PLATE XIII 4 a nA } AAPA £ ERT ot pac eee oR se avai aatatanta ata avaata stave’; a "aatay AAAANAL IAIN NGREGRSE: AAMAS es ai ls A Munanunnaainaiui sa) A.Hoen & Co. Lith. Baltimore, TAENIA FIMBRIATA. THE BROAD TAPE-WORM OF SHEEP. TANIA EXPANSA, Rud. Plates XIV and XV. Tenia expansa, the Broad Tape-worm, is one of the best known of the internal parasites of sheep, because of its flatness, length, and large size. In summer and fall it is quite abundant. The amount of pecun- iary losses occasioned by its ravages depend upon the season and its abundance in affected flocks. It was introduced into this country from Europe along with the imported flocks which harbored it. Since then it has been parasitical on our flocks from generation to generation. It is now distributed from the wooded hillsides of New England to the grazing lands of Georgia, over the fertile prairies of Ohio, Illinois, Iowa, and Nebraska, and the boundless prairies, basins, and mesas of Colorado, Utah, California, and Oregon ; in short, over every sheep-grazing local- ity in the United States. Reported outbreaks from this vast extent of country are comparatively few and scattered, but are sufficient to warn us that when the pastures become narrowed, older, and overstocked, we may expect the saine trouble with this and other parasites as has been experienced by sheep raisers through all time in the more densely pop- ulated districts of other countries. Description.—The entire worm measures in length about 5 yards, and in width from one-twenty-fifth of an inch at the head to a half or three- quarters of an inch at the tail. Its thickness is from one-tenth to one- twelfth of an inch. These dimensions vary greatly, depending on the contracted condition of the worm when measured and on its state of pre- servation. Adult specimens taken from sheep may average less than 4 yards, or may slightly exceed 5; but they never, in this country at least, attain that gigantic measurement of 100 feet ascribed to them by Eu- ropean observers. The head is somewhat larger than the neck, and measures one-twenty-fifth of an inch in width. It is smooth on the end and has its four suckers directed anteriorly. Its neck, or that portion of the worm immediately succeeding the head, which is unsegmented, is shortor lacking. The body of the worm is apparently made up of a series of very short but extremely wide joints, which vary in length and width in the successive portions of the body. The first rings of the tenia are very short and narrow; the others are longer, but are always broader than long. Those segments which are about two thirds the entire length 23038 A P——8 413 114 from the head are the longest. From these to the end they become grad- ually shorter and wider. In width the segments gradually increase from the head to theend. When first collected the texture of the worms is usually opaque and white, and it is only by allowing them to stand in rater that they become transparent enough for study. It can then be seen that each segment is bilaterally symimetrical—that in each half is an independent set of genital organs. These become apparent ata little distance from the head, but show in their best development about half the entirelength from the head. From this point on the segments be- come more and more opaque tothe end. The genital organs first appear as a little horizontal line on each side ;. gradually a little rosette grows at. the end of each line; these disappear and the segment becomes filled with the young eggs or embryos, which form the opaque mass. The ex- ternal genitals consist of around pore on either side of each segment, in which is a minute dot, the opening of the vagina, and an exserted in- tromittent organ. The apparatus is called hermaphroditic, 7. ¢., each half of the segment is capable of fertilizing itself; but it is likely that cross fertilization also occurs. Fertilization occurs about where the dots which line each side of the worm appear plainest. From this point on the eggs are developed into embryos until the end of the worm is reached, when the segments are prepared to retain vitality as indi- viduals for some time after being ejected with excreta to the ground or water. Besides the reproductive apparatus there are two so-called excretory canals, one on each side of the worm, running the entire length. I have not observed cross-canals, such as occur in the armed tenia, as in T. marginata. There is no alimentary canal. The nervous system is very rudiment- ary, consisting of little more than bundles of nerve fibers. The suck- ers are each supplied with their special fibers, connected together, and each segmentis supplied by two long nerve bundles which run parallel to the excretory vessels on either side. Absorption of nutrient material or feeding takes place through the surface of the segments. The young exgs or embryos are polyhedral by pressure, and measure about 0.05 to 0.07™" in diameter. They have usually two envelopes, between which a considerable amount of oily material is held. They may have three such. Around the embryo is a pear-shaped apparatus whose small end is surmounted by a cap with shredded periphery. The embryo itself is contained in a cavity in the large end of the pyriform covering, and when alive can be seen moving around init. The em- bryo seems to be a highly refrangent mass of protoplasm provided with six hooks, and does not look essentially different from the embryos of other tape-worms. The cap with shredded edges is the remnant of a mass which originally included and covered the embryo and its balloon- like expansion. No attempt has been made by the writer to work out its earlier embryology. 115 The next stage of the embryonic tenia found was taken from a lamb. In this stage the young worm (about 2" long) is well outlined. It had a head with four suckers and a short unsegmented body. The next step in the development showed the body segmented. In one or two speci- mens I have seen a little loop with its convex end projecting towards the outside, but have not yet been able to determine its significance. Between these stages and the adult the different steps of development are easily filled in by a study of a single worm. Occurrence and distribution.—Although there is a periodicity in the appearance of the broad tape-worms among lambs, causing at times epi- zootic outbreaks, the worm may be found throughout all months of the year in localities where it occurs. No section of the United States seems to be entirely free from it. They have been found in winter, in spring, in summer, and in the fall, in the intestines of lambs examined at the abattoir. They are not so frequent in winter and early spring as at other times, but seem to be more abundant in some localities than in others, though this may be due to unequal opportunities of observation in all places. A less number was found in the West than occur in the East. Conditions of climate and soil also seem to have some influence on the appearance of the tape-worms. Damp, warm climates and heavy, moist soils appear to be more favorable to their preservation while onthe ground. But none of these factors would seem so favora- ble to the growth and life of the tenia as holding the sheep on over-fed pastures, as demonstrated by experiments elsewhere related. Differential description —Tenia expansa differs from T. fimbriata in the method of shedding its segments. Instead of maturing a few of the segments at a time and shedding them, as the latter do, whole sec- tions ripen and pass away, so that an examination of a sheep which has been observed to pass proglottides during a past week will reveal but little more than the head of aworm. The exact length of time that is consumed by the worm in maturing, so that it all passes away, is undetermined, but it is nevertheless an important factor in the disease, for after the worm is passed the lambs begin to recover. From what was learned and seen of the disease the opinion was formed that the worms do not retain their adult size more than a month. The heads, which are left, develop slowly and form new adults. They may not cause so much disturbance at this time, however, for the lamb becomes older and better able to withstand them. The rate of growth of the broad tape-worm is very rapid as compared with that of Tenia fimbriata. This is easily demonstrated by the fact that T. expansa are found 2 to 5 yards long in lambs from two to four months old, while 7. fimbriata are scarcely as many inches long in lambs of the same age. If we suppose the lamb to become infected during the first month of its life, the age of the tenia in the above lambs would not be over three months, which would give an average growth of nearly a yard per month. This enormous increase in size is an important factor 116 in rapidly developing disease in the young lambs. The Tenia fimbri- ata, on the contrary, slowly develops a disease which culminates in older lambs. Life history.—The life history of Tania expansa is only incomplete in that portion of its life which it passes outside of the host. Just exactly what happens to the embryo-containing egg, between the time that if escapes until it is again found in sheep as a little head with four suckers and a short tail-like appendage is not known, but from our present knowledge may be inferred with a tolerable degree of accuracy. No one has yet been able to either develop these embryos in water or to feed them and produce an infection in sheep. So it has been sup- posed by reasoning from the life history of other forms of tania, that these embryos must pass a portion of their development in some of the minute animals which inhavit the grass and water of sheep farms, From my own studies, although I have not yet been able to produce tape- worm disease by feeding the embryos, I think that the above view is fallacious, and that these embryos need not pass any of their existence in other invertebrates. Dr. F. A. Ziirn (Die Schmarotzer, p. 191, 1882) is authority for the statement that “the disease is also present in sheep which have been fed entirely in the stalls, though more especially among the younger and youngest of a herd which are sent tu the pastures.” Experiment to demonstrate method of infection—About the middle of May, 1888, six lambs, from three to four months old, were bought on the market and added to the flock at the Experimental Station of the Bureau. This flock was kept in a small stable with an adjoining hill- side yard. They were fed on clover and grain from the market, and the water was drawn froma well near at hand. The vard was sufficiently large to be grassy, but they soon ate it down to the roots. In one cor- ner of an adjacent pen was an iron trough, kept full of water. After — a rain the water might have stood in the yard for a day or two ina small puddle, but there was no so-called permanently standing water which could have harbored insect life. There were already on the place three lambs, with their mothers, which had been raised there that season. . May 16.—Two lambs were fed by drenching with the embryos or eggs of Tenia ex- pansa. May 22.—An iron trough was prepared with a grass bottom, and then filled with water. A quantity of segments of JT. expansa were scattered in it, and at first only two of the lambs were allowed access to it. Afterwards, all were allowed to go and drink out of it. June 11.—Slaughtered one of the lambs, which had been drenched with 7. expansa embryos May 16, and had since been held in the yard with the trough prepared on May 22. No tenia were found. The experiment was therefore of negative value. After these dates the lambs were neglected, so far as feeding experi- ments were concerned, until fall, June 21.—One of the experimental lamba, which had previously been fed with ripe segments of TZ. expansa, was killed. It wasin poor candition, No tenia were found 117 in it, but numerous sears of 7. marginata furrows on the surface of the liver. It was also found that numerous white patches, which were scattered along the mucous coat cf the small intestine, were due to a species of coccidia. As the latter disease has not been seen since that time, and as there was a possibility that the lamb had be- come infected with the coccidia from the dirt thrown out of neighboring rabbit pens, where the disease was abuncant, it has not since been studied. The results, so far as T. expansa is concerned, were negative. October 10.—A ewe lamb was examined which had died some hours previously ; but one cysticercus was found. October 13.—A young buck lamb was examined, which was bought in May with his mother, soon after birth, from a neighboring slaughter house and was one of those which is referred to as raised on the place). There were found a quantity of young teniae, many adult and young of Strongylus contortus, a few young Dochmius, and a few Trichocephalus. ‘This lamb was one of the two that was drenched with eggs on May 16. He had pastured with the others, which it was subsequently learned had adult tenia, and which had been purchased supposing them to be infected. October 9.—A buck lamb was examined, one of the six purchased in May. Old cicatrices of Tenia marginata were found in the liver, six Cysticerci of this species, two adult and six young Tenia expansa, a quantity of young and old Strongylus con- tortus, and a few specimens of Trichecephalus. October 16.—A buck lamb, another of the six, was found to be infested by a quantity of very young tenia, also by young and old Strongylus contortus, Dochmius, and Tri- chocephalus. October 17.—Another of the six animals bought in May was found to contain young and adult Tenia expansa, Strongylus contortus, Dochmius, aud Trichocephalus. January 3, 1889.—A lamb slaughtered for examination was found to contain three Tania expansa, one Cysticercus, and many specimens of Strongylus filicollis. The period which had elapsed from the time that these lambs had been received on the place, to the period when the majority were examined (from May to October), was about five months. Those first killed gave negative results, probably because they were examined too soon after feeding. ‘The lot examined in October gave very positive results. The worms found in them varied from very young to adult. The smail- est and youngest are those shown on Plate XV, figs. 8,9, and 10. These were not fed to the sheep, for lambs which had not been fed were in- fected ; but the majority of the young tape-worms were acquired and developed after the sheep came under the experiment. This is amply proven in the case of the young buck bought and put with its mother in the experimental yard before the former was two days old. That the time of development of the adult worm is less than four months was also proven, from the fact that other lambs, less than four months old, ex- amined in May at the slaughter house, contained aduit tape-worms. The lambs, therefore, acquired those parasites on the place. The ques- tion of the necessity of an intermediary host is also settled by this ex- periment, for none of those invertebrates, which are usually suggested as being the intermediary bearer, were present at any time; nor were the conditions which are essential to the life of many such invertebrate hosts present. The pasture was and is a very dry hillside yard, from which the grass was eaten very close by the sheep. There is another phase of the question which is stillin doubt. Early 118 in the experiment segments of tape-worms were placed inan iron trough out of which the sheep drank, or could have drank all summer long ; and there might have been times when, for a day or two, alittle puddle of water could have collected after a rain. In these, more especially the former, the development of the parasites could have proceeded until they were taken up by the lambs. The point in doubi is, whether the lambs got their embryos from the water or from the yard while grazing. lam inelined to believe the latter, for they acquired other species of worms which were not placed in the iron tank, and these were also in various stages of development. Still another feature inclines me to this view. If the lambs had been infected from the iron tank they would very likely have been infected by a large number of tenia, all of nearly equal size; but they were not. Direct infection has been tried before, but only negative evidence obtained. The failures prob- ably arose not only from expecting results too soon, but also from not preparing the infecting material properly. Since writing the above, two lambs have been examined, which give additional data : August 10, 1889.—A five months old lamb was examined, which had been born at the experimental station, and kept there under the same conditious as the other lambs, i. e., water supplied from a pump and pasturage from the yard and lane near _the sheep pens. This lamb contaiaed two adult Teniae, and Slrongylus contortus, S. jilicollis, S. ventricosus, Dochmius cernuus, Trichocephalus affinis, and Cisophagostoma Columbianum, in all stages of growth. The last species did not show adults. August 10.—Examined a lamb eleven weeks old, which had been bought with its mother from a neighboring slaughter house when two days old. The lamb had been kept under the same conditions as above. There were found one adult Tenia (shed- ding proglottides carrying well-developed six-hooked embryos) and all the other species enumerated above, but not in the same abundance. Each of these lambs showed that the infection had been continuous. ‘The elder of the two yielded a greater number of S. filicollis than any sheep hitherto killed, and led me to think that this species may have been productive of more trouble than had hitherto been suspected. The above experiments were planned with an aim to obtain infection within a limited area, and under conditions which could be controlled, deeming it better to obtain infection under such conditions, though there be a number of them to complicate the question, than to restrict the conditions and not get an infection. The presence of the adult tenia in the comparatively young lamb of eleven weeks shortens the limit of time of complete development of the tenia, The tenia was about two yards long, and had developed inside of three months. A reason for the early infection of this lamb was that its mother died and left it to shift for itself. These experiments con- clude the series for determining whether sheep necessarily get the worms from drinking water or from the pasturage. Summary.—The life history seems from the above to be a compara- tively simple affair. The embryos pass from sheep to sheep and develop into adults, which reproduce young for infection of other animals. 119 Whatever changes the embryos may pass through outside the sheep ean have little to do with the case as far as a knowledge of prevention of infection goes, for but very few of the conditions under which these sheep were kept can be improved by the flock-master. Disease.—The tape-worm disease can be diagnosed by finding the lit- tle white oblong tape-worm segments which are voided from the sheep and stick to the moist pellets of dung.’ They may also be found adher- ing to the wool and dirt around the tail. But this is only after the tape-worms have become adult and have begun to shed segments. Though sheep often harbor tape-worms and give no evidence of their presence until after slaughter, there are other cases in which their pres- ence is only too evident to the flock-master. The first indications of the disease are usually unobserved, because of the slow growth and of the comparatively small number of parasites that may be developing, The time of growth occupies about two or three months from infection. The number of individuals may be from two or three to a hundred, but it is unusual to find more than a halfdozen adults together. As many as fourteen adulis were found in a lamb four months old. When young they occupy but small space, need little food, and cause few vermicular contractions. In the earlier stages it is plain that they cause but little trouble, but when they grow so large that they seem to fill the whole of the small intestines they cause the sericus disturbances ascribed to them. These disturbances may be to a certain extent those arising from a re- flex irritation of the sympathetic and spinal nerves, but most of them seem to be due to the indigestion which the worms produce. The worms obstruct the intestinal canal by their great mass, irritate it by their ver- micular contractions, cause excessive secretion of intestinal fluids, non- assimilation of food, and abstract nutriment from the intestinal con. tents for their own growth. The lambs become poor and hide-bound; their flanks may either be distended by gas in the bowels or be tueked up from gauntness. In the progress of the disease the animals become evidently weaker, the mucous membranes paler, and the fleece dry and harsh from the loss of its yolk. The animals walk with a tottering gait. They often eat more and drink oftener than those less affected. In the severest cases the lambs grow extremely weak and poor, diarrhea becomes more and more pronounced, and at last they die through sheer exhaustion. While suffering from these worms they are more susceptible to the at- tacks of other parasites, and other diseases supervene and hasten the death of the already weakened animals. Prognosis.—Though the tape-worm disease in its mildest form is very destructive to lambs and yearlings, yet if would seem that if they are able to pass safely through @ certain period they are very apt to re- cover. In 1887, in the examination of two wethers which two weeks before had been passing proglottides, or segments, in abundance, and 120 from which it was expected to secure specimens for illustration, only a small piece of the worm was found, all the rest having passed away. Occurrence of the diseuse.—The worm, though present throughout the year, is more abundant in the locality of Washington during May and June than at any other season. This fact was doubtless somewhat de- pendent on the age of the lambs examined, which were about three or four months old at that time. In Colorado an outbreak was heard of in a flock of Merinos which occurred annually about July and August, after which time the lambs would improve. The disease is more prev- alent in the summer season, and causes the greatest damage in lambs less than six months old. if the young animals can be carried beyond this age they seem to be either better able to withstand the ravages of the parasite, or to have reached a season unfavorable for its develop- ment. Duration.—The broad tape-worms do not last long in theiradult state, but after maturing nearly all their segments are shed at once. Trom the time that the segments are shed the afflicted lambs will begin to receive and rapidly lay on fat. The disease leaves no traces other than debility in the early stages of recovery. Preventive treatment.—Treatment for the prevention of this disease is that suggested for general prevention of parasites and an observance of those measures which promote good heaith in the flock. Do not overstock pastures. Give good, pure water. When possible, put the lambs on new pastures. Feed some grain, put salt where the animals can take it daily, feed hay from racks, and grains, salt, and water from tioughs. The medical treatment promises better results than that for Tenia fimbriata, since the T. expansa is never found wedged into the gall duct cr pancreatic duct, as is TZ. fimbriata, but is found lower down in the small intestine, from whence it can be removed. Many of the popular tape-worm remedies are said to be efficacious, butas the disease is dif- ficult to diagnose until the worms begin to shed their segments much damage is done to the heaith of the lambs beforetreatment begins. On those farms and ranches where it appears periodically the lambs should be treated as soon as they begin to show symptoms. Even then com- plete cure can not be attained, for the lambs will continue to pick up eggs as in the first instance. For safety all sheep in the flock should be dosed, especially if all are to occupy the same pastures as those affected. Ziirn (Die Schmarotzer, ete., p. 191, 1882), says that treatment is practical when the disease is recognized before the lambs and yearlings are reduced to a cachectic condition. Although those far reduced in strength may not survive a medication, still they should be dosed in order that the parasites may be expelled. Otherwise the sick not treated should be yarded by themselves or killed and buried, so that they may not scatter eggs for further infection. Before giving the sheep any 121 worm remedies they should be prepared by withholding food the night before and not watered on the morning of treatment. The dose should be administered at one time, allowing every animal to swallow it slowly if fluids are given. They should not be turned out after dosing, but should be watched during the day to see if the worms are voided. If the worms are not passed off the dose should be followed by a cathartic on the next day. If it is certain that the sheep have tape-worms and none appear, the animals should be redosed with increased quantities on the following day. Of course particular attention must be paid to the purity of the drug given. After the sheep have been driven out the yard should be elammead by removing the surface earth. This dirt should be placed where it can not be washed on to the grass to which the sheep have access; or, it may be thoroughly disinfected, burned, or buried. Cleansing the yard may save a reinfection. Ziirn (0. ¢., p. 192) details experiments made by Schwalenberg, in which wormseed, Persian insect powder, petroleum, Chabert’s oil, ka- mala, kousso, and koussin were tried. The last three gave good results. In the first experiment 3.75 grams kamala (about 1 dram) were given to each lamb. This dose caused diarrhea and removal of the tape-worms in forty-eight hours. The lambs remained poor for a long time, in spite of good care. In the second experiment 7.50 grams kousso (nearly 2 drams) given each lamb gave good results. Koussin, also known as teeniin or brayerin, in 12 centigram or 2-grain doses, gave better results. The tape-worms wereexpelled. The treated animals remained cheerful, retained their appetites, and improved in condition. _ Pierie acid, 10 to 20 grains, made with meal and water into a pill, is also recommended for lambs. This quantity is sufficient for one dose, and should be followed by a cathartic. Epsom salts in 4-ounce doses is a good saline cathartic, or 4-ounce doses of the bland oils, adminis- tered slowly, may be used. The powdered male-fern root, in 2. ounce doses, is recommended, or the «theric oil of male-fern in dram doses. The latter is the best. It can be given in combination with from 2 to 4 ounces of castor oil. Dr. H. Piitz (Seuchen wnd Herde Krankheiten) recommends dosing in the morning, and withholding all food the night before giving the medicine, and on the following morning to give a cathartic. This may be unneces- sary, however, when the male-fern has been given with castor oil. Froéhner (Thierdrztliche Arzneimittellehre, 1889), gives the following recipes for lambs with tape-worms: Take of koussin 3 grains, and of sugar 10 grains, mix, and give at one dose. The dose of tansy is from 2to6drams. It forms one of the chief ingredients of Spinola’s worm cake, which is fed to lambs as a preventive medicine against worms. The recipe, sufficient for one hundred sheep, is as follows: Take of 122 tansy, calamus root, and tar each 24 pounds; of cooking-salt, 14 pounds; mix these with water and meal, make into cakes, and dry. This is an old and oft-repeated recipe, but I can not vouch for its efficiency. Powdered areca nut may be given to lambs in from 1 to 3 dram doses. If it does not produce a stool in three or four hours it should be fol- lowed by a cathartic. Ground pumpkin seeds are in repute with some, but it is difficult to induee sheep to eat the required dose. Tellor (Diseases of Live Stock, 1879, p. 383) recommends salting liber- ally, and giving once a week the following saline tonic and bitter-lick as a preventive against worms: Take of common salt 2 pounds, sul- phate of magnesia 1 pound, sulphate of iron and powdered gentian, each half a pound, and mix with ground feed or fodder sufficient for seventy-five to one hundred sheep. This recipe is a very satisfactory one for improving the appetite and health of the sheep, but probably Gan not be depended on for keeping the worms away. Fer tape-worm in sheep the same author recommends: Powdered areca nut, one-half to 1 dram; oil of male-fern, 10 to 20 drops; give in molasses and water, and follow the next day with a purge. For purges he gives two recipes: Sulphate of magnesia, 2 ounces; warmwater, 1 ~pintin one drench; or, castor oil, 3 ounces; calomel, 12 grains; mo- lasses, 3 ounces—for one dose. After the sick lambs have been treated, care and attention should not be relaxed, for it is of the utmost importance that they regain their strength and vigor before the cold weather sets in. The best pasture, an extra feeding of hay, and some roots and grain in judicious quanti- ties, should be allowed them. ‘he feeblest should be kept by them- selves, Where they can get plenty of food and water without entering into competition with the stronger. This treatment should be kept up until they are fully able to hold their own. nny una a Pe re # bas pate BRITS KCK ; ry sk ro hi EE el LP ‘\yentely ud Bert as y Y batsas 3 shanti sy Waviok gyeershy Ali wees can ents Ale a} OYS W SD NT 19-56 7 Oe . win iy FUMIE Tt oe ins ssa vie 13% a cata wih} 1h Bien a3 wieK We a % tay De Tae ieee Brie she Moov soe th | fia ph ani “ % hbase BBG altel Kaka wen, Metre a Pavitsod 8S he ait A ye ea ae api SEG aitie Fs, ty $3} Taito... ¢ Nigh ay $} ited ate chetier te, asa Jah egnelan oe quleigier in SSIES ¥ hae Roth st ibectne ) eed ps) ured i, igi Aa ae) Mite ai Gerrans SBE bys eon bk ; - “TB aed ripel 3 py a SR TRE: at + tee bette ‘ She sat on sate Lagi: al bl ney By A ee te tidig eerie yagi [deg re outs eed = wut sel ig 124 TANIA EXPANSA, Rud. PLATE XIV. Figs. 1 and 2. Young tape-worms, natural size. Fie. 3. Head end of tape-worm, drawn to show vermicular contractions when living. Fig. 4. Head, top view: a, a, the suckers or cups, by which the worm attaches itself to the intestinal walls. Fig. 5. Head, side view : a, a, suckers ; b, b, folds in the neck; c¢, ¢, the first segments. Fig. 6. The large end of a young tape-worm: a, a, segments which are not mature enough to drop off; b,b, segments ready to pass away from the worm. Fig. 7. Segments, or proglottides found, separate from the worm. Fig. 8. An adult tape-worm, drawn in sections at regular intervals apart: a, head. Fig. 9. A fragment of another worm, which is not only slightly larger, but whose segments are shorter and broader. The specimen shown in fig. 8 could have assumed very much the same form when alive as is seen in fig, 9. PLATE XIV Foy L7Bliey, at, e Te inys, <8 VA o3. eee TN aa. “Wan, A.Hoen & Co, Lith, Baltimore. TAENIA EXPANSA, (The Broad Tape-Worm.) a eat ’ al ei. ae re Oe 0 = : WEA nS ry - rate ced! ary Var A —= pangs 16:9 RATS EWP H pwr, (as 4 aa r 1 Fae] hs ) y or RNG 9 A> Seyi Dee Thar, eee ’ % eee i oats “Ee aie MN DS ieee aan eel | ‘ zx “d at 4 ’ Dad . 5 @ Pee wees d abrs 2: velit Hie the ae tp as So Saetrt Seria ; nf ite oe : Bak, ; d d 3 j a6 ;, Vig . , Me oa, ot bay COGN Sa ' tr = . ss mr - 3 an : ia os MDS: . getty lie : “Site Fieeet Aram ee Me Gey. . J a te | I : " ; - 2% r. Ty) (haat TP Lo ee. te eee > 2 A a 3 G * : 4 tah Pee ao he, 90 ane . vet) re 1g i Z £ L’ a a a >» - ss howe SPS 7 * ‘ : p Pi . d - 1 ae Rate 1. 2. 3. 4. 5. for) f. 8. . 10, 126 : TANIA EXPANSA EMBRYOS. ERT ee Vie Embryos magnified and tlattened under cover-glass. A single embryo and its enveiopes somewhat flattened. The same greatly flattened: a, the thick, oily mass between the inner and outer covering, The same with outer envelope ruptured: a, the outer envelope; 0, the in- ner; ¢, oil globules; d, the embryo and its pyriform apparatus. Embryo, with three envelopes. Embryo escaped from ruptured inner coat: a, the fringed cap-like covering; b, the bladder-like sae protuding from it; ¢, the six-hooked embryo. A younger embryo, inwhich the bladder portion has not burst from the cap; a, the cap; b, the embryo. Three young tenia which show no trace of segmentation. A young tenia which is beginning to segment. A head of young specimen showing a peculiar loop in it, Lith. Baltimore, A.Hoen & Co, TAENIA EXPANSA (Young Stages.) ail ; ? N rs a M4 = Is pate Poet’ ‘> oon. May gm f » ba rape wit HE OLIVER: | LUKE—LIV ER-ROT, DISTOMA HEPATICUM, Linn. Plate XVI. The liver fluke disease, which causes so much loss in Great Brit- ain and on the European continent, is comparatively unknown in this country ; so rarely, indeed, is it discovered that most authorities on the management and care of sheep seem never to have seen it. That it has occurred in this country, and that it is present in certain portions of it, is tolerably certain, for good observers have recorded it at various times. Henry Stewart, in the Shepherd’s Manual, 1882, page 223, says that flukes were found in a flock of Southdowns at Babylon, Long I[siand, and also in Cotswold, Leicester, and native sheep, presumably at the same place. In the Tenth Census Reports of the United States, Vol. IT, flukes are said to occur in Texas and California. In the latter State they have been seen by Prof. E. C. Stearnes, of the Smithsonian Insti- tution. The disease occurs so infrequently in this country that the writer has seen but two cases of it, and both of these were in cattle. For a de scription of the malady we will therefore have to depend upon writers in those countries where it occurs more frequently than it does here. Description.—Body flattened, leaf-like, pale brown, irregular, the adult from 18 to 31™™ Jong, from 4 to 13™™ wide, oblong, oval or lanceolate, larger and rounder in front, where it is abruptly contracted in such a way as to present a conical neck; attenuate and obtuse behind. Skin bristling with numerous little points directed backward. Oral sucker terminal, rounded. Ventralsucker large, projecting, with a triangular opening situated about 3™™ behind the first. Intestine with two rami- fied branches visible through the skin and of a deep shade. Penis projecting in front of the abdominal sucker, always recurved. Vulva very small, situated at the side of the male orifice or a little behind. Eggs brown or greenish, ovoid; length from 0.130 to 0.145™™ ; width from 0.070 to 0.090"™, (Neumann.) Occurrence.—This parasite has been found in the livers of sheep, goats, cattle, camels, and certain wild ruminants. It has also, been -found in the horse, ass, pig, elephant, rabbit, and man. It lives in the biliary ducts of the liver, and, according to Kiichenmeister, feeds on blood drawn from the mucous membranes of those passages. The par- asite does not appear to be equally abundant at all times in Europe, but seems to develop at various periods in sufficient numbers to cause epizootics. A number of these outbreaks, compiled by Neumann, 9. ¢., p. 127 128 463, demonstrate no periodicity or law by which future outbreaks may be ieooted or predicted. Sheep-owners and veterinarians are agreed that damp, wet seasons, and damp pastures are favoring conditions for the development of the parasite and promotion of the disease. The life history of the parasite has been determined by Leuckart in Germany, and a little later, but apparently independently, by A. P. Thomas, in England. The former published his observations in Zoolo- gischer Anzeiger, December 12, 1881, and October 9, 1882, and the lat- ter in the Journal of the Reeal Agricultural Society of England, Vol. XVIII, part 2, 1882, and Vol. XLX, parts 1 and 2, 1883. These authors have idsonibed most of the stages in the life history of the parasite, leaving but little to be said in addition. The egg of the fluke passes from the biliary passages through the in- testine to the ground (Plate XVI, Fig. 2a). Those that fall in favorable places develop (Fig. 2b) and finally break the little lid off the end of the shell (Fig. 2c) and escape. This happens in summer and occupies from three tosix weeks. At this stage (Fig. 3) the whole body is covered with fine cilia (hairs), which enable the embryo to swim about in the water. At one end of the embryo is a little projection which can be thrust out and withdrawn, and is the apparatus by which it bores into its second host. If it does not meet one in a day or two it dies. If it meets a water snail (Fig. 6 and 6a), it is not slow to penetrate into the body, where, according to Leuckart, it lodges in the respiratory cavity. Here it encysts itself (Fig. 4), contracts into an oval mass, and rapidly grows. The name sporocyst has been applied to this form. The con- tents of this sporocyst split up into a number of bodies (Fig. 4), usually from five to eight, which develop into rediw (Fig. 7). Their length at this stage is about 2™™, or one twelfth of an inch. These are ex- cluded from the sac one by one through a rent. Now each redia, in its turn, develops from fifteen to twenty cercarie (Fig. 8) within it, which are evacuated in turn through an unpaired orifice situated under the neck of the redia. The cercarize are the forms that escape from the snail, and are scattered by it in its wanderings. The cercaria, after a time of active life, loses its tail, which it has developed, and again en- cysts itself. (See Figs. 11 and 12 and Fig. 10.) The contents of the cyst still more resemble the future fluke, and it is at this stage that the sheep swallows it with grass. Itthen breaks from the eyst, arrives at the stomach and duodenum, to finally make its way into the biliary canals and grow into another adult hermaphrodite, capable of giving rise to other generations of young. According to Thomas the eneysted embryo (Fig. 4) may give rise to daughter rediz or to cercariz, the former to develop in the summer and the latter during the cold season, The epitomized life history is first the egg; second, the eine which encysts in a snail; third, five te eight rediz, developing from the eystia 129 larva; fourth, fifteen to twenty cercarie, developing trom each redia and escaping from the snail; fifth, the encysted cercariz, which after havivg been swallowed by a lamb develop into adult flukes. This life history is fully as wonderful as any occuring in nature. Ac. cording to it, at least seventy-five young flukes under favorable sur- roundings could develop from a single egg. As the proper conditions are scarcely ever fulfilled, there are but few of those which meet with all the requirements for development. The disease created by these peculiar parasites is known by many names, the most popular of which is Liver Rot, a term expressive of the chief patholdgic symptom. Aqueous Cachexia, Rot, Rot Dropsy, Sheep- Rot, Liver-Disease, Liver Fluke, Jaundice, Yellows, Verminous Phthisis of the Liver and Ictero-Verminous Cachexia, are other names for the disease, each being expressive of some of its symptoms. The symptoms, according to Neumann (Maladies Parasitaires), to whom the writer isindebted for the greater part of this article, may be divided into four periods, viz: (1) Period of immigration.—This is the period in which the parasite invades the liver. In this stage the flukes are small and do not cause excessive disturbances. This period lasts from four to thirteen weeks. It is probable that it lasts as long as the weather remains favorable for the development of young flukes and sheep are kept on infested pastures. (2) Period of anemia.—This ordinarily coincides with the months of November aud January, or after the lapse of thirteen weeks from infec- tion. The sheep are less lively; the mucous membranes about the eyes, the nose, and the gums, the internal surface of the ears and the skin, are all paler than in well sheep. The appetite is still good, and the animals have a tendency to fatten, caused, according to Simonds, by a better assimilation of food from the increased flow of bile stimulated by the young flukes. This fattening stage has been taken advantage of in England by a dealer (Bakewell), who purposely exposed the lambs he wished to market early to the disease, that he might send fat lambs into the market five or six weeks ahead of his neighbors. Sometimes the appetite diminishes, thirst increases, and rumination is irregular. The conjunctiva, the mucous membranes of nose and mouth, and the skin are white, slightly tinged with yellow. There is a slight cedema (puf- finess); the skin is looser, feels pasty and soft to the touch where bare; the conjunctiva is infiltrated and puffy and the eye partially closed ; the wool becomes dry and brittle, is easily puffed off, and sometimes falls off of itself. Weakness appears more and more marked. There is sometimes fever and quickened breathing. Palpation and percussion indicate ascites. The droppings are normal, but contain at the end of this period numerous fluke eggs. Death may result in this stage from apoplexy. 23038 A P-—9 130 (3) Period of loss of flesh.—The sheep begin to become leaner at the end of the third month after the immigration of the larvae, or about the beginning of January. The malady is then at its height. The animal becomes gradually leaner; the mucous membranes and the skin are bleached, and lose the yellow tinge. The temperature is variable and is highest in either the morning or evening. Respiration is feeble and frequent. The appetite keeps up, and the feces present nothing in particular except fluke eggs. The urine is nearly normal. The ani- mals are listless and dejected, carry their heads iow, and give way when pressed on their backs. There are frequent abortions. Nursing ewes have a clear, watery milk, very poor in nutritive elements. ‘Their lambs are weak and thin, and usually die unless they are put to another nurse. The cedema becomes localized and increased in dependent parts. It is dispelled by walking and comes again in rest. The space under the jaws and along the trachea is a frequent seat of puffiness. This disap- pears during rest and comes on during feeding. It is often absent with adults in hot seasons. In the three weeks which follow the ani- mals become still poorer despite abundant feeding, and there is gener aliy diarrhea, edema, jaundice, and pain on pressure over the liver. Hither death occurs at this period, or the animals improve and enter the next period. (4) Period of emigration of the flukes.—This is the period of convales- cence and of spontaneous cure. All the symptoms grow less and finally disappear, but the cure is never complete, the changes which have taken place being irreparable. The recovery of affected sheep is exceptional. Duration of disease.—The flukes are said by some authors to remain nine months in the liver, by others fifteen months. After this time they make their way into the intestine and are evacuated with the exere- ments. Thomas says that he has seen the sickness last six years, and Neu- mann seems to coincide with Perroncito, that the flukes have little ten- dency to quit their hosts. The question of reinfection of the same ani- mal would leave it doubtful whether such long period of infection were all due to the same parasites or to renewed generations of them. The duration of the disease, which, as a rule, is variable, depends en- tirely on the degree of infection and the treatment, hygienic and me- dicinal, which they receive. It ordinarily lasts about six months, but exceptionally may have an extremely rapid course of a few days, death being caused by an acute inflammation of the liver, set up by the para- sites, and oceurring in from seven to nine days after the first appear- ance of the disease. Weakened by the fluke disease, the animals are more susceptible to other maladies, and these may destroy them before the primary disease has run its course. Diagnosis.—There is little difficulty in diagnosing liver-rot in the stages at which it is first noticed if the flock-master sacrifices one of the worst affected sheep. Although he may think that it hardly pays to 131 kill a sheep to find out what the trouble is, he will subsequently learn that a little loss in the beginning leads to a great saving in the end, and therefore becomes an investment. In fluke disease not one or two lambs only are infected, but all the flock that have been feeding together. If the flock-master has a micro- scope he can detect eggs of the fluke in the droppings, but this ean only be found after the fluke has matured and the disease has well advanced. Besides, it requires some skill to make the required examination. So numerous are the eggs and so characteristic is the shell with its little cap, however, that this method forms an important element in diagno- sis. The droppings should be moistened with water and thoroughly picked to pieces, then spread evenly on a piece of glass and covered by another thin glass. The mass should be closely examined with the aid of a microscope magnifying from 70 to 80 diameters. This operation should be repeated a number of times if eggs are not found. The ex- amination of the liver is the best means of diagnosis. When the gall ducts are cut open the young flukes will be found in them. They usu- ally occur in smaller or larger nodular swellings. The structure of the liver is also characteristic, presenting a dark, soft, rotten appearance. Young flukes can be found by cutting into this organ and washing it in water. After allowing everything to settle, pour off the top and repeat the operation until the contents of the dish can be distinguished. When spread out on a flat-bottomed dish the flukes may be easily distinguished by the unaided eye, or, if very young, by the help of a small lens. If the sheep has been killed the flukes will be seen to wriggle and curl, for they die slowly in water ordinarily warin. Prognosis.—The disease is very tenacious, and when once on a farm is difficult to extirpate. Many farms in infected localities are rendered useless for sheep raising by these parasites. When a flock becomes infected it is not to be expected that the disease will be stopped until it has caused extensive damage, aud that only the most prompt and effective measures will save any of the afflicted animals. Pathology.—The disease is seated in the liver, and all the symptoms and changes observed in other parts are directly dependent on those occurring in this most important organ. The different periods into which the various alterations have been divided are directly dependent on the periods in the life history of the flukes. For our present purpose, however, it seems advisable to give but the most brief description of these pathologie changes. When the flukes first invade the liver they cause an inflammation, which is shown by a thickening of its mass. It becomes softer, and the surface, which should be smooth and glistening, becomes rough. These changes increase as the days go by, and the liver becomes softer aud thicker. The surface becomes covered by thready fibers, as well as much rougher; the abdomen contains more or less dark-colored serous Huid; young flukes from one-tenth to one-fifth of an inch long 132 can either be found in serum-filled cavities of the liver or attached to the outside, or perhaps free in thé cavity. Still later, the liver shows places puckered up, which are caused by the reparative process and the contraction of the newly-formed tissue. There will be numerous chan- nels beneath the serous membrane visible to the unaided eye. The bil- iary canals will be found thickened and enlarged at places to the size of a hazel-nut, or even larger. In these dilatations are flukes of con- siderable size, surrounded by a greenish black, sticky mass. Some- times hard limy fragments are found in them. The substance of the liver becomes very rotten, and crackles under pressure by the finger. When the flukes migrate healing. takes place to some degree, but the liver will never Jook healthy. It will grow considerably smaller and become much whiter, due to the connective tissue changes which take place. Preventive treatment.—Thomas has formulated rules of prevention against this parasite, which are founded on its life history and seem to be eminently practical. He says: (1) All eggs of the liver fluke must be rigorously destroyed. Manure of rotten sheep or other infected animals must not be put on wet ground. As the liver and intestines contain eggs, these, too, must be destroyed or put in the compost heap. The manure of affected animals should not be stored where there is a drainage from it to the neighboring grass. It should be mixed with lime and salt before being spread on meadows or cultivated fields. (2.) If sheep are infeeted, let them be sent to the butcher at once, unless they are specially valuable and are not badly affected. If kept, they must not be put onto wet ground. The above advice is preferable with all common stock; and the ex- ceptions, when medicine should be tried, are very few. Stock should be very valuable to repay the expense of care and treatment in face of the large percentage of death which occurs in this disease, and the ill condition of the remnant after recovery. (3.) Care must be taken to avoid introducing eggs of the fluke either with manure or fluked sheep, or in any other way. Rabbits and hares must not be allowed to in- troduce the eggs. The most prolific source of introducing parasites is in the introduc: tion of infected sheep, and purchasers should learn all they can of the history of the animals they buy, and not purchase from diseased flocks. (4.) All heavy and wet ground must be thoroughly drained. _ Draining is of advantage in many ways. It makes tillable land of what was before useless, either for pasturage (as shown by its infecting the flocks with a fatal disease) or for cultivation. (5.) Dressings of lime and salt (or both) should be spread over the ground at the proper season to destroy the embryos, the cysts of the fluke, and also the snail which acts as host. After draining, such fields should be cultivated and suitable crops raised on them. (6.) Sheep must not be allowed to graze closely, for the more closely they graze the more fluke-germs will they pick up. 133 This rule is advisable wherever the sheep may pasture. Sheep on over-stocked pastures do not get enough grass, and become more in- fested with worms from having to eat close to the dirt. (7.) When sheep are allowed to graze on dangerous ground they should have a daily allowance of salt and a little dry food. Exigencies can be conceived in which sheep may be allowed to pas- ture on infected ground, but, in view of the fatality attending the malady, it would seem more profitable to sell the animals while they are still in good condition than to expose them further to these parasites. Lime and salt are the two cheap preventives against this parasite. The former, mixed with manure, increases its value as a fertilizer. A solution of three fourths of 1 per cent. of salt in water has been found by experiments in the laboratory to kill fluke embryos. This weak so- lution might prove too weak in the field, when the salt would be still further diluted by dew or rain. Perroncito has shown that the encysted cercarie and the larve encysted in Limnea palustris die in 2 per cent. salt solutions in five minutes; in 1 per cent. solutions they die after twenty or thirty-five minutes; 0.65 per cent. solutions kill in about the same time; in 0.25 per cent. solutions the worms live after twenty hours’ immersion. The weakness of the brine necessary to kill the parasites in the labo- ratory points out that a small proportion of salt mixed with the lime would be very advisable. Salt was first advised from a knowledge of the fact that sheep never became infected with flukes on salt marshes. Stronger solutions of salt also kill the snails, which are the hosts of the embryouic fluke. The time of year for scattering the lime or salt on the fields is the first part of June, July, and August. Neumann advises mixing two teaspoonfuls of salt for each sheep with the ground grain they eat. Perroncito advises the addition of one-half of 1 per cent. salt to the water they drink (about a heaping tablespoonful to each gallon of water). Aithough the flockmaster can never completely cure his sheep, he may, by judicious medication, so improve the condition of the con- valescent animals that they will take on considerable flesh. Many vegetable astringents and tonics have been tried, with more or less profit, but it is to the mineral astringents that we look for the best re- sults. Sulphate of iron and common salt, dissolved in the drink or mixed with the food, are among the best and cheapest. Medicinal treatment.—Some experimenters have endeavored to kill the flukes, and have met with varying success. The remedies tried have been extract of male-fern, given with turpentine or benzine, castor oil, etc. For proportions of these remedies see remedies for Tenia ex- pansa. Mojkowski, according to Neumann, has obtained encouraging results against the distomatosis (the fluke disease) of sheep with naph- 134 thaline, given twice a day during a week, in from 10 to 15 grain doses, alone, or mixed with powdered gentian. The following recipes, to be used as licks, may be useful in small flocks : Take of sulphate of iron, 2 ounces; calamus root, 1 pound ; of crushed oats and roasted barley malt, of each, 20 quarts. This quantity is sufficient for one hundred sheep. Other mixed grain may be substi- tuted for the barley-malt and oats. Or, sulphate of iron, 1 ounce, and powdered juniper berries ‘and gentian root, of each, 1 pound. Mix with 20 quarts of grits. etey teas OL eft 1 tab wie eee. D ls estan AIP} 3 ty wAaee 5 WoL Sate vty What Ny bene ead shit rent uk enh af Aue ) ,) nl , y or a AY’ ion Ta a 4 ah in i a. "eR ; : (303 a maise J Sint ec Dar pal wee a ws i . tae Me ad BA Faget Poi Ata load tt alee rece pe ope Nee Mich f “i be. f gp lud let Fre Ab: YR ttre ptt a thie Lire ay Cty mek ay 98 4 , ‘ we s » 4 ea : ¥ “et 3 ‘ety ¥ ANS) ‘ me : wipe, T yo aie ris Suto bib a0 is a Woe gut iets Sth. anu ee sah rae ids wa PN aN TY 2 ge ae Taek ty A wT hg SUE OA et ohisied fas cee 5 i: . aaa Eaton das 4 = BPS) Ae VO melee Sey, 1, ; ; 3 f ae niete te Kheon’a ‘eg > Rape Eye! sve tb LWA ee ay sate ‘ ; Mu > foal ae 11 Feb ty hs Wh ee oe ray at peel ts Ba Phy Nbtts ar Jes ’ 1” wip * 5 ty Bet ae « : : SL See Ean i ye i Ah y . he (rt Wietihen c ll ie Bigs i: Pig.” 2. Fig. 3. Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Lae Fig. 10 Fig. 11 Fig. 12. Fig. 13 Fig. 14 Fig. 15 140 LINGUATULA TENIOIDES, Rudolphi. PrATE XeVLL, Male, natural size. (Cobbold.) Female, natural size. (Cobbold.) Egg with contained embryo. (Leuckart.) . Embryo escaped from egg-shell. (Leuckart. ) . Pupa nine weeks old: a, anus; b, mouth. (Leuckart.) . Linguatula denticulatum. (Leuckart.) AMPHISTOMA CONICUM, Rudolphi. . Piece of the rumen of a cow, showing the parasite attached between th papilla by their large posterior sucker: a, an isolated individual, natura size. (Raillet.) . Dorsal view, X2. (Blanchard.) . Lateral view, <2. (Blanchard.) . Egg of an amphistoma, X80. (Cobbold.) DISTOMA LANCEOLATUM, Mehlis. , Ciliated embryo. (Leuckart.) Early stage of development, in which there is no digestive apparatus (Ercolani.) . Another stage: a,a, groups of cells representing the future testicles. (Ereo lani.) . Stage showing the testicles plainer, a,a; b, the rudimentary cirrhus pouch and c, the digestive system. (Ercolani.) . Adult, natural size figure by itsside: a, pharynx; b, esophagus; ¢, branche: of intestine; d, ventral suckers; e, e, testicles; f, f, deferent canals; g, cir rhus pouch; h, ovary; i, albuminous glands; k, uterus; J, vagina. PLATE XVII Ae hint stoi nh HEU: sp pidalen eat nt ei HEHE pint ag 1 iD ih TTY Leer SOT ST ‘VOTED TEAM REET LL ‘DIVERTED (RELA) ABLE Roan )OSETETEONNY ON LEY MA ‘RL en NSN TE Hi) Pty Ory LE Loy, AMMO MST) EL) SLD: Hae a THN rat pee Sn ne PUMA nT A EE OUT TEs im FT ecu EHH Lette La OPIN TTY Liao Derren tn aa A.Hoen & Co. Lith Bolnraere 3 LINGUATULA TAENIOIDES. AMPHISTOMA CONICUM. es ; DISTOMA LANCEOLATUM. : THE STOMACH ROUND WORMS. STRONGYLUS CONTORTUS, Rud. Plate XVIII. Strongylus contortus, or the twisted strongyle, is an inhabitant of the fourth stomach of sheep and goats. Though in the majority of flocks it produces but little if auy disturbance, yet there are times when, in connection with other species, it causes disease which may carry off numbers of lambs. In the southwestern States and Territories the disease has been called lombriz, a corruption of the Spanish word lombrici, meaning worms. The later writers seem to be inclined to attach a specific meaning to this word, while the Mexicans, who used it, merely intended to say that the lambs died of worm disease. Descriytion.—Female, 18 to 30™™ long; male, 15 to 20™™ long; body reddish; female warked by a double spiral white line, thicker toward the caudal end. The skiu shows eighteen longitudinal lines. The mouth is round and without visible lips or papilla. The neck has two barb-like side papillee; unicellular glands scarcely visible. The male is about two-thirds as long as the adult female, and shows no spiral line. Bursa deeply bilobed, with a small dorsal lobe attached to one of the pair. The lobes are somewhat longer than broad. The ventral costz are separated ; the lateral are double and separated ; the dorso-lateral is attached to the lateral group near its base; the dorsal costw support the dorsal lobe and each branch is double; the tivofold character is indicated by a little notch. The lateral cost are irregu- larly divided, many variations being observed. Spicula two, embracing a chitinous piece between them. They are short, cylindrical, barbed on one side near the end, and have blunt tips. Female: Vulva 3™™ from the tail and covered by a nipple- _ like projection, 0.5™™ long; the latter has thin borders, and is concavo-convex, to fit the body when pressed against it. Uteri two, each opening into the common vagina ; one is anteriorly directed and the other posteriorly, with a short loop between it and the vagina. The ovary of the posterior uterus is reflected anteriorly to rejoin its fel- low, and together they wind spirally around the dark-colored intestine. The ovoid eges are laid in the gastrula form, or after they have passed through the segmenta- tion stage; length, 0.070 to 0.097™™; width, 0.043 to 0.054™™, Occurrence.—This worm may be found in all stages in the fourth stomach or abomasum of sheep. When collected immediately after death from a slaughtered sheep they may be detected adhering by their heads to themucous membrane. They are then of a reddish color, which may be because they feed in part upon the blood of the victim. The life history of Strongylus contortus seems to be apparently simple. _ Among a number of lambs kept at the Experimental Station in 1888 _ were two or three which had been raised there. A post-mortem exami- 141 142 nation of one of these, with four other lambs which had been at the Station for the five previous mouths, revealed numbers of Strongylus contortus in all stages of growth, and of Dochmius cernuus, Trichoceph- alus affinis aud Tenia expansa. These lambs were supplied with well wa- ter, and were allowed torun in a small, dry, grassy yard connected with a stable. The presence of these species of all sizes in the former grou) of lambs showed that they acquired them on the place, and that their development was direct; that is, they did not pass through a secondary host in passing between the sheep and thelambs, for all of the conditions were under inspection. The grass in the yard became very short, and probably it was because the sheep ate it so close to the ground that they became more infested with worms than sheep ordinarily do. The his- tory, therefore, is probably as follows: The eggs fall to the ground; they are eaten by other sheep along with their feed, and they then ar- rive at the stomach and develop there. The disease they cause can not easily be distinguished from that pro- duced by other intestinal parasites. In the worst cases, besides a gen- eral lack of tone and good health, there is weakness, paleness, some fever, diarrhea, etc. In fatal cases death is said to occur within a very. few days after the illness is observed; but, as the parasites develop slowly, itis probable that no symptoms of illness are apparent until after the lambs have been ailing for some time. A positive diagnosis is to be made only by a post-mortem examination. The little worms, if present in large numbers, will appear like masses of threads lying in the stomach. If the sheep has been killed for examination, the worms will be seen wriggling and squirming in all directions. Treatment.—Various remedies are proposed, but of those available an emulsion of milk and turpentine, prepared by shaking the mass well, seems most practicable. Add 1 part of spirits of turpentine to 16 parts of milk, and give from 2 to 4 ounces of it to each animal, according to age of patient. One dose should be sufficient ; if not, repeat it in three or four days. Or, take of linseed oil, 1 ounce; turpentine, one-half ounce, shake well and give as onedose. Quantities sufficient for any number of sheep may be made up in these proportions. The following recipe is from Finlay Dun’s Veterinary Medicine: Common salt, 3 pounds; powdered ginger and niter, halfa pound each ; dissolved in 3 gallons of warm water; add 24 ounces of turpentine when nearly cold. The dose for iambs between four and six months’ oldis 2 ounces. The entire quantity is sufficient for one hundred and sixty - lambs. For delicate lambs, which are coughing and purging, the same writer recommends oil of turpentine, powdered gentian, and laudapum, 2 ounces each, all to be dissolved and stirred in 1 quart of linseed tea or lime water. This quantity is sufficient for ten or twelve doses. Ziirn recommends (after Rabe) the picrate of potash, because it is less irritating to the patients. The dose for.a lamb is from 24 to 5 grains; for an adult up to 20 grains. It can be given dissolved in water. 143 Dr. H. J. Detmers, in a report to the Commissioner of Agriculture, 18383. on the diseases of sheep in Texas, recommends the use of tartar emetic as follows: A half pound of tartar emetic is to be dissolved in 12 quarts of water, and from 1 to 2 ounces of the solution, containing from 5 to 10 grains of the remedy, is to be given each patient, depend- ing on its size. He recommends dosing out of a small 2-ounce vial, and in small swallows. Good, nourishing food, and a dry yard in summer, or a healthy, well- ventilated stable in fall and winter, are advisable. In giving medicine, drench from a horn, a spoon, ora stout glass bottle. Bottles are always liable to break. Let an assistant throw the sheep onto its haunches and hold it between his legs, back toward him. With the lower jaw seized in his left hand, from the left side, he can either seize the upper jaw or pull out the cheek-pouch with his right. The medicines are best administered while the sheep are thirsty. Small doses may be diluted, but a dose of 4 or 6 ounces is more apt to run directly into the fourth stomach than larger doses; otherwise, some of the latter might be diverted into the second stomach and fail of an immediate effect. - The following recipe was recommended to the readers of Field and Farm, August 7, 1889, as a preventive remedy for worins in sheep. Mr. G. B. Bothwell, of Breckenridge, Mo., who used it for fifteen years with success, is its author. Salt, 1 bushel; air-slaked lime, 1 peck ; sulphur, 1 gallon; pulverized rosin, 2 quarts; put in trough with cover, where sheep can have free access. When sheep become thoroughly infested with worms death is almost sure to follow, but the above, if kept before the sheep, will surely act as a preventive. A more complicated arsenical recipe for worms, the source of which is unknown, is as follows: Take of arsenic, washing soda, and carbonate of soda, each 1 ounce; put them into 2 quarts of hot water; boil, and stir for one-half hour, then add 10 quarts of cold water. The dose for a lamb, after weaning, is one-third of a gill. If the lamb is not very sick give but one dose, but if badly affected repeat in nine days. Fig. 1. Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6. Fig. 7 Fig. 8. Fig. 9. 144 STRONGYLUS CONTORTUS, Rud. PLATE XVIII. Adult female, X6: a, head; b, ovaries wound around the intestines; ¢, ¢, uteri; d, a large papillie, just in front of and covering the vulva; e, anus. . Adult male, x6. . Head: a, two barb-like papille ; b, mouth; c, esophagus; d, intestine. . Eggs, highly magnified: a, eggs before they have left the ovaries; 6, eggs showing nuclei; ¢, eggs after they have passed through the oviduct; d, egg with one cell; e, with two; f, with four; g, with eight; h, with many; 1, egg as it is laid. . Skin, showing nine of the eighteén longitudinal lines. Portion of female: a, the intestine; b, b, the ends of the ovaries. . Caudal end of female: a, the anus; b, the vulva; ¢, vagina; d, d, uteri filled with eggs; e, oviduct; f, f, ovary; g, intestine. Spicula, enlarged. Bursa, expanded to show cost: a, ventral; b, ventro-lateral; ¢, lateral; d, dorso-lateral ; e, dorsal; f, spicula. .10.G roup of adult males and females, natural size. ig. 11. Caudal end of male: a, bursa; 0b, spicula; c, seminal reservoir; d, intestine. PLATE XVIII Balnntore A Hoen & Co. bith STRONGYLUS CONTORTUS, (Tne Twisted Stomach Worm.) ’ Geo. Marx, del. J _ INTESTINAL ROUND WORMS. Sheep in this country harbor at least six species of round worms, parasitic in the small and large intestines, which their ancestors brought with them from Europe. They are: Strongulus filicollis, Rud.; Strongy- lus ventricosus, Kud., both found in the duodenum ; Dochmius cerniwus, Creplin, found in the small intestine; Ascaris lumbricoides, Linn., also found in the small intestine; Trichocephalus affinis, Rud., found in the cecum; Sclerostoma hypostomum, Diesing, found in the large intestine. A seventh species, Gsophagostoma Columbianum, Curtice, is found in the large intestine and is probably indigenous to this country. Of all these the last species produces by far the most injury. Dochmius cer- ‘nuus is next in importance. The injury inflicted by the others may, at times, and in conjunction with other parasites, be considerable ; but disease which may be ascribed to either species alone has not yet been reported. From personal observations it is believed that the number of individuals in each sheep are usually too few to ever cause extensive loss, and that their greatest harm is from the little discomforts which they may add to those produced by the more destructive parasites. At certain seasons of the year some of the above species are abun- dant, while at other times but few individuals may befound. Strongy- lus filicollis and S. ventricosus are usually found associated together, but are so Small that they can easily be overlooked, or if found may be re- garded as the young of other species. Dochmius cernuus is about an jnch long, and being large is readily detected. Ascaris lumbricoides is rare, having been met with only a few times by helminthologists in any country, and in but one lot of sheep by the author. Trichocephalus affinis is usually found in young sheep, but is met with in comparatively small numbers. Sclerostoma hypostomum seems to bé a rare species in the East, the single instance in which it was met with in these investi- gations being in examining an old sheep in Colorado. (Msophagostoma Columbianum seems to take the place of the last-named species in the Kast, and is found most abundantly in spring and summer in its adult state, although it is present throughout the year. The most favorable time for collecting most of these species has been in late fall and win- ter. The quantities in which the various species may be found vary with the season and the flock examined, so much so that no accurate statements of percentage of occurrence or of distribution ean be made. The symptoms which these worms produce are those of general debil- 23035 A P——10 145 146 ity and indigestion. They are caused by the irritations set up in the intestines by the worms. It is found as a rule that a weakly sheep is attacked by more than one species of parasite at a time, and, conse- quently, it is difficult to learn the symptoms produced by either of them acting alone. Then, too, it should be remembered that symptoms are sometimes incorrectly attributed to parasites when they really result from diseases due to entirely different causes. Even the fattest sheep harbor a few parasites, and some of them many more than one would suspect from their apparent good health. The treatment should be directed toward keeping animals in good health and in preventing them from acquiring parasites by providing them with pure water and pastures which are not overstocked. Medic- inal treatment will rarely be attempted for any single species of these parasites. A remedy which wouid prove effective for any one of them would do for all. Their treatment will therefore be embraced under that for Dochmius cernuus. = STRONGYLUS FILICOLLIS, Rud. Plate XIX. Description.—Male, 8 to15™™; female, 16 to 24™™, Body very small; cephalic end thread-like and tortuous ; caudal end, especially of female, thick and straight. Skin marked by longitudinal lines standing at about equal distances apart. Head very small, subspherical, continuous, with a swollen cylindrical neck; the length of the inflated portion is about one-fourth that of the cesophagus. Four head papillz visi- ble; the lateral papillee are probably present, but can not easily be made out. Mouth terminal; apparently without chitinous armature. Ciesophagus linear spatulate ; unicellular gland ducts present. Position of ventral cleft not determined. Male: Filiform and uniform in size throughont its length; bursa strongly bilobed ; the membrane being well filled on the dorsum but absent on the ventrum ; can not be spread without tearing; cost generally symmetrically arranged, ventral slightly separated; ventro-lateral either joined to lateral or ventral; lateral scarcely sepa- rated; dorso-lateral joined to the dorsal, dorsal notched and with the dorso-lateral form a stem, the two pairs uniting to form the dorsal stem; the lateral cost~ are the jongest. Spicnla 1.5™™ long, cylindrical, very slender and dark colored; their points are tipped with an oval inflation of the membrane and are more or less firmly attached. ‘ Female: Tail obtuse; vulva situated about one-third of the entire length of the worm from the tail; body of the egg-bearing female enlarged in front of the vulva by the swollen and crowded uterus. Uteri directed each way from the vagina, aud filled with comparatively few and large eggs in all stages of segmentation. Eggs 0.17™™ long, 0.08™™ wide, ovoid ; laid in the morula or gastrula stages. Embryo vot observed. This species occurs with Strongylus ventricosus in the upper end of the small intestine of sheep and lambs. It is often mistaken for the young of other species, and has been identified as a variety of Strongylus contortus. It is needless to observe that it is specifically different from any other nematode found in sheep; a glance at the plate illustrating the species is sufficient proof of this. It is quite abundant during fall er ee 147 and winter. European observers seem to find it rather infrequently. The species appears to be a comparatively harmless one. It is probably the young of this species which Wed] found associated with Twnia expansa, and named Trichosoma papillosum. Wedl characterized it as having a double uterus and the mouth furnished with four papille. Neither of these characters is inconsistent with Strongylus /filicollis, while the fact that Wedl’s species, with a double uterus, was classified in a genus which has a single uterus and spicule indicates an error. 148 STRONGYLUS FILICOLLIS, Rud. PrArnckcikxe . Adult male, natural length indicated byline: a, head; 6, bursa and spicula; c, worm enlarged twice. . Adult female, natural Jength indicated by line: a, head; b, vulva; c¢, anus; d, worm enlarged twice. . Head: a, mouth surrounded by four papille; b, esophagus; c, inflated skin surrounding head and neck. . Skin: shows nine of the eighteen longitudinal lines. . Cephalic end: a, the head; b, the esophagus; ¢,¢, the unicellular gland ducts. . Bursa: a, the spicula; b, their knobbed tips. . Portion of the spicula enlarged. . Ovary of female with inclosed eggs showing segmentation. . Bursa spread ont: «, ventral cost ; b, ventro-lateral; ¢, lateral; d, dorso- lateral; c, dorsal. ys , PLATE XIX A.Hoen & Co. lith. Baltimore. STRONGYLUS FILICOLLIS (The Thread-Necked Worm.) a ; ane a, N yu)? = ~ hy ‘ de ed Seeder. | : - ” f > * . « ; * r= 7 * a is : r 11k pd eee 149 STRONGYLUS VEN'TRICOSUS, Rud. Plate xx. Description.—Male, 6™™; female, 13™". Body very small and comparatively stout. Males and young females usually spirally coiled; body of old female straight, with cephalic end coiled. Skin transversely striate, marked by fourteen longitudinal lines; the five larger standing at equal interspaces on the dorsal and ventral sur- faces, the two smaller standing close together on the sides. The crossings of the strive and longitudinal lines make pits which are quite characteristic. Head little larger than neck, but hemispherical and continuous with the cylindrical inflation of the neck. No head or neck papille visible. Mouth terminal, very small and round. The end of the head is furnished with a hemispherical cap-shaped chitinous piece. Other oral armature apparently absent. Inflated portion of head about one-fifth the length of esophagus. Unicellular glands not apparent. Male about one-half the jength of female; bursa conical and bilobed, the ventral membrane being narrow, the dorsal wide; ventral costie not separate, smaller than the ventro-lateral, which is stout; lateral widely separate and apparently formed of three nearly equal costie ; dorso-lateral slender ; dorsal notched at the end and giving off laterally a very short side branch. Spicula 0.36™™ long, short and stout, and margined by a fringe-bearing sinuous membrane. They are tipped by a soft pad-like expansion of the membrane. Female characterized by a swelling at the vulva, which gives the species its name. This character is more pronounced in older specimens. Vulva from two-ninths to one-third of the entire length of the female from the tail. Uteri directed anteriorly and posteriorly from the vagina. Ova 0.13™™ long, 0.07™™ wide, comparatively large, and found in all stages of segmentation. Embryo not observed. This species is found in association with Strongylus filicollis in the upper part of the small intestine of sheep. It can be separated by its smaller size, its spiral twist, and the markings of the skin. It is best found in fall and winter. The species was originally described from specimens taken from cattle, and so far as known has never before been noticed as being found in sheep. The female in its adult stage re- sembles the small specimens of S. filicollis. It is apparently the cause of little or no disturbance, although from the appearance of its mouth parts it might seem to be more injurious than S. jfilicollis. 150 STRONGYLUS VENTRICOSUS, Rud. PLATE XX. Male, natural size indicated by line and smull fignre of worm: a, head; 3, bursa and spicula. Female, natural size indicated by line and small figure of worm: a, head; b, genital orifice. Head: a, mouth; bb, chitinous cap surrounding it; ¢, cesophagus. . Portion of skin showing eight of the fourteen lines: a a, the two lateral lines: b b, the dorgal and ventral lines. The dots indicate depressions where the longitudinal and the latitudinal lines cross. Cephalic end: a, head; b, cesophagus. . Spiculum: a, its chitinous portion; b, the protractor muscle; ¢, the fringe edging the membranous portion; d, the distal end covered by membrane, Female, natural size indicated by line: This female is more characteristic of the species than that of Fig. 2, but is not quite mature. Bursa with spicula. Bursa spread out: a, ventral cost; b, ventro-lateral; c, lateral, of which there seems to be an accessory branch; d, dorsal-lateral; e, dorsal, which also has an accessory branch. ' Baltimore. cee tae PLATE XX A.Hoen & Co, Lith, Ne RUE SE att ayy yor 7 STRONGYLUS VENTRICOSUS (The Ventricose Worm.) s soostiocs , pea EReT ETT eee PT CETPeESE || STTEFHTE sasetet Le THE LARGE ROUND WORM. ASCARIS LUMBRICOIDES, Linn. Plate XXI. Description.—Male and female 150™™ each ; in the specimens figured 120 each. Body very large and thick, obtuse at each end, of a yellowish color, skin marked by rings. The site of the vulva is marked by a smooth wide band about one-third the entire length from the head. There are three longitudinal bands; the two wider are nearly lateral; the third is ventral. The head end is abruptly terminated in three well- formed lips; the dorsal possesses two papill:e near its base and the two ventral one each. Each lip consists of a chitinous support covered by cuticular membrane. The tail of each is obtuse. The description after Schneider (Monographie d. Nematoden, p. 36) is as follows: ‘Lips nearly equal, their form changing from semi-circular to quadrangular. Teeth very fine. The lobes undivided. .The azygos lobe has a rounded point, and reaches with its anterior end to the front of the saddle. Cuticularrings longitudinally ribbed, Vulva 40 to 65™™ from the cephalicend. Vagina 11"™ long. Tail of the male flat on the ventral side. Only behind the anusis the skin broadened into a bursa; sixty-nine to seventy-five papillz on each side; the first seven pairs of these papillz stand behind the anus; the second pair stand nearer tne ventral line than the first and third; the fourth and fifth pairs and the sixth and seventh pairs are united into double papille. (See Fig. 7.) The succeeding stand first in a single row, then in pairs forming a double row; and on the whole they are very irregular. An unpaired papille stands in front of the anus. Spicula two, each a single tube, with its point terminating bluntly and irregularly in front. “‘This parasite occurs in the small intestine in man and swine, and sometimes forces its way into the gall ducts, stomach, cesophagus, nose, and lungs.” In one flock of sheep only has the author found this parasite. In this flock it occurred in six animals, a majority of those examined. That it is not a common parasite is attested by the writings of various Euro- pean helminthologists. A few of the latter have described a special species (Ascaris ovis), from the sheep, but as it is infrequently found it seems to be an inconstant parasite or an adventitious one, i. e., it is probably a coustant parasite of some other domesticated animal, and occasionally only becomes parasitic on sheep. Besides, the specimens figured always seem to have been immature, and do not differ from Ascaris lumbricoides of the same size and age. In the single flock in which this worm was observed all the specimens found were:immature. The vegetative organs of these specimens differ in no essential point from those of Ascaris lumbricoides as figured by various authorities. In addition, a close comparison of these specimens 151 152 with equally immature Ascaris taken from pigs gave no determinable differences. These remarks presuppose that A. lumbricoides of man and A. swilla of swine are identical species. The description seems to be incomplete, but as the species is neither peculiar to nor commonly found in sheep no attempt is made here to enlarge it. The species can easily be determined by a comparison with the figures. Sheep probably acquire this parasite while pasturing after swine. As few are infected, little harm is accomplished by the Ascaris. It is more abundant in summer and fall than at other seasons. ' AN 7 4 id, : Pe at ah col eer LEER teh Le SPT 8 Pie SR BO aa ai mes ; ‘ . ; A Th OS OR Coat ee ae SRT eae Pe Sf oe oe. mii ae AE ie Buti CuitSy, Lat, » igtc®? id peat ee Or ctl tet i ; OS IER tek t jn “ir iM f mal r a : 4 ’ - he i ces re Tov Mey bat? e ae ested IE A by f * US Sa 7 ak : , * vida I be wey , P Ye aging @ Aria Se y Moo ‘ * N ‘ te \ vj my ” as Se . n as ig. 10, ig. 11. EE Tl ed 154 ASCARIS LUMBRICOIDES, Linn. PEATEs . Adult male, natural size. . Adult female, natural size. . Top view of head enlarged; a, dorsal lip with two papille; b, b, ventral lips with one papillz each. . Head, ventral view. . Head, dorsal view. . The lips greatly enlarged and flattened: a,a, Heetilads b, b, the serrated edge of chitinous support. . Tail of male, ventral view: a, anus; 1, e 3,4 and 5, 6 and 7, the post- anal aii. 8, the unpaired pre-anal; 9,9, 9, other papillae. . The two spatulate spicula: 8a, one of these enlarged. . Portion of female: a, the genital opening; b, the ventral line; c, one of the two lateral lines. Tail of female, lateral view. The same, ventral view. PLATE XXI = i hs A.Hoen & Co, Lith. Baltimore. ASCARIS LUMBRICOIDES, (The Common Round Worm.) 155 DOCHMIUS CERNUUS, Creplin. Plate XXII. Description.—Female, 20 to 26™™ ; male, 13 to 17™™, Body very dark colored when + fresh; whitened when preserved; attenuate towards the ends. Head curved, the mouth being directed dorsally. Mouth round, smalJler than the oral surface, and opens into an ovoid dark-colored capsule. About the opening stand four teeth, two on each side, their base being sunk into the capsule and their free edges projecting into the cavity. The ventral are the larger, thicker, and more opaque; their edges form an unbroken sinuous line. At the caudal opening of the capsule are one pair of ventral and a single dorsal tooth; the latter is conical, very large, and risss to near the mouth. In the pharyngeal opening are six very small club-shaped, spinous, chitinous appendages of the cesophageal supports or rods; they seem to be jointed. There are six papille—dorsal, lateral, and ventral pairs. The lateral may give off a branch on the dorsal side. There are two lateral neck papille, nearly opposite the middle of the esophagus; the ventral cleft is situated a little anterior to a line con- necting the latter. Unicellular neck glands quite plain. Male: Bursa funnel-shaped ; will not spread without tearing ; costa unsymmetrical as to form; ventral pair not separated ; lateral, widely separated; dorsal notched ; dorso-lateral unequal in length and differently attached to the dorsal stem. Spicula 0.6™™ Jong, aculeate, fenestrated, and provided with a narrow membranous margin. Female: Vulva about three-fifths of the entire length of the body from the end of the tail. Vagina opening at right angles to the side of the body. Uteri, lying one anterior, the other posterior; each forms an §-like loop; the anterior ovary is di- rected towards the tail, and, with the posterior, forms an intricate sinuous net-work surrounding the intestine. Eggs elliptical; laid in the morula stage; length, 0.06™™; width, 0.03™™, - Occurrence.—This species inhabits the small intestine of sheep, and attaches itself to the intestinal walls by its stout oral armature—the so-called teeth. It lives upon the blood of its victims. The life history of this species of Dochmius has not been determined, but there is no reason for supposing it different from that of D. trigo- nocephalus, the allied species found in dogs. This life history has been determined by Leuckart (Die Menschlichen Parasiten, Band II, pp. 132- 134), and is essentially this: The eggs pass from the dog to the ground, where, in wet places, they undergo a development of the vegetative organs. If at this stage the young are swallowed by another dog they develop into adults. The development outside the dog may consume from three to six days. The worm may then continue living without further development for an indefinite time, depending on the conditions by which it is surrounded and the favorable opportunities for being eaten by the dog. Its development in the dog occupies about two weeks. The time consumed may be supposed to be that occupied by the development of Dochmius cernuus with approximate certainty. Leuckart states that though he saw some of the embryos enter snails while in their free living state, that this condition was an unnecessary one, and that the worms underwent no development while in the snails. It may be that if these parasites can enter the snails, their opportuni. 156 ties for safely passing the indefinite time prior to finding their way into their final host are increased. In my own experiments in keeping a number of lambs in a cireum- scribed space for five or six months after purchase, and in confining two others raised there with them, allowing them no water save such as was pumped for them, Dochmius cernuus were found of various sizes in the lambs of each set. The two lambs raised on the place must neces- sarily have acquired them there. These parasites either developed to a certain extent in the iron watering trough or in little pools which could have collected and remained in the yard for a day or two after a rain, or the lambs were infected from the dry hill-side of the inclosure. The disease can only be diagnosed by the flock-master from a post- mortem examination. It has been recommended to diagnose these para- sitic diseases from the eggs of the worm found in examining the feces by the aid of a compound microscope. Such a plan is very tedious in its execution, and impractical save to one already skilled in the work. The disease caused by Dochmius cernuus receives little attention in veterinary works. This ‘is due, in all likelihood, to the fact that not more than two or three hundred of the parasites ever seem to be pres- ent in one sheep, and generally there are less than one hundred; then, too, if other parasites are found present the illness would probably be ascribed to them. If, however, we may be allowed to infer the effects which would be caused in sheep from the effects which Dochmius duodenalis, a related species, produces in man,* in whom it has caused epidemics characterized by progressive anemia, and if we may aceu- mulate corroborative evidence from the disease which Dochmius trigo- nocephalus, a third species, produces in dogs, we may fairly infer that the species causes more disease than has been suspected. Nor is its comparative paucity in individuals any contra-evidence, for in human patients affected with this disease the species is represented by usu- ally less than a hundred specimens, although as high as two or three hundred have been found in one patient. In dogs the author has found about the same number. The intestinal lesions are obscure to the unaided eye, except at those points where the parasites have been attached. Here, if the worm has recently loosened its hold, there is a slight blood extravasation. The parasites maintain their hold by the chitinous cup with its projecting oral teeth, and in some way cause a hemorrhage, upon which they feed. The six pharyngeal spinose appendages may aid in wounding the deli- cate epithelial cells. It seems impossible that a dozen or twenty, or even fifty, specimens of Dochmius could, by creating such little injuries in withdrawing blood *Literature: Wilhelm Schulthess, Zeitschrift f. wiss. Zoologie, XX XVII, 1882, pp. 163- 217. J. Ernst, Deutsche med. Wochenschrift, 1888, p. 291. A. Friinkel, ibidem, 1885, p. °443. O. Leichtenstern, ibidem, 1885, pp. 484, 486, 501, 523; 1886, pp. 173, 176, 194, 216; 1837, 565 and five following numbers; 1888, p. 848. ; 157 from its host, cause the severe disease and progressive anemia ascribed to it in man, but such has been determined to be the fact from clinical and post-mortem observations. It may be that there is a reflex, sympa- thetic action stimulated by them of which we can take no account. The further changes observed in patients affected with Dochmius are much the same asin those affected with other parasites, except that anzimia with its attendant effects seems to be the most prominent. The disease is one which begins in early lambhood and progressively continues, the severity depending on the number of parasites entering the intestinal canal. The adult probably lasts through the winter and continually lays eggs which pass to the ground. The character of the season, of. pasturage, and of the water, in being either favorable or unfavorable to the preservation of the young worms while on the ground, will therefore determine the amount of infection and sickness during the following season. The preventive treatment for the intestinal worms is the same as that advised for the lung worms—good care, pure water, plenty of grass, sufficient grain feeding, salt, aud separation of sick from the well. For the reason that the disease has not received the attention its impor- tance demands the medicinal treatment has not been worked out with the thoroughness that some of the other parasitic diseases have re- ceived. Medical treatment.—In man the most effective remedy is extract of male fern, combined with powdered male fern, the remedy to be pre- ceded five or six hours by a dose of castor oil. This combination is also a good one to administer to dogs in the following proportions: Extract male fern, 40 grains; powdered root of male fern, 75 grains. This mass must be made into ten pills with yellow wax, and all given at once. The dose of powder of male-fern root for sheep is from 15 to 3 ounces, and of the extract from 2 to 4 drams. As boluses are not only incon- venient to give to sheep, and do not pass directly into the fourth stomach, the administration should be by drenching. I should advise that the extract be mixed with from 2 to 4 ounces of castor oil. Other remedies advised for the round worms are wormseed, wormwood, and santonine. The latter is an alkaloid obtained from a species of Ar- temisia. As the prairie lambs love to eat sage, of which there are a number of species belonging to the genus artemisia, it is likely that these plants may prove beneficial to them through medicinal qualities. In my examinations of Western prairie sheep I do not now recollect hav- ing met with as many round worms as are found in Eastern sheep. ‘The dose of santonine for sheep is from 1 to 3 grains, given in from 2 to 4 ounces castor oil. The preparations of tansy, Tanacetum vulgare, have long been used as vermicides. The dose of the oil is from 1 to 2 drams, given diluted by adding from 4 to 8 ounces of another oil. The receipt for Spinola’s worm cake sufficient for one hundred sheep is: Take of 158 tansy root, calamus root, and tar, of each 24 pounds, of common salt 1} pounds, make into cakes with meal and water, and dry. The dose of areca-nut powder, which is an effective remedy for round worms as well as tape-worms, is from 1 to 3 drams for lambs. The oil of turpentine has proven of itself a valuable anthelmintic, but should be used with care. For intestinal round worms in sheep from 1 to4 fluid drams may be given, according toage. Theturpentine should be mixed with from 2 to 4 ounces of castor oil. Sweet or linseed oil may be substituted, but their cathartic effects are untrustworthy. More than one dose should not be given until two or three days have elapsed, when, if it is deemed advisable to give a second dose, no untoward re- sults having been noticed from the first, the dose, slightly increased, may be repeated. Do not give more than the maximum dose. Tellor (Dis- eases of Live Stock) gives the following recipe: Linseed oil 2 ounces, oil of turpentine one-half ounce, for a drench. The French veterinari- ans advise, among other remedies, the use of empyreumatic oil, petro- leum, and chimney soot. Empyreumatic oil is animal oil, a by-product of distillation of animal matter for ammonia. Dippel’s ethereal extract is arefined product, and the oil of Chabert consists of animal oil 1 part, turpentine 3 parts. The medicine should be administered as a liquid. The dose of animal oil, or oil of Chabert, is from 1 to 2 drams, to be given in 4 ounces of the chosen vehicle. The oils and alcohol dissolve animal oil, but if the vehicle is a watery mixture it must be well shaken. Bitter vermifuges made up into tea are excellent, as is also a decoction of chimney soot thickened by dextrine or the yellow of eggs. From the certain effect that petroleum has on insects externally we may infer that it should prove a valuable anthelmintic internally,if it may be given in sufficiently large doses. It has been used in man for tenia and round worms. The dose is 30 minims. The dose for sheep may be as large; how much larger future experiments will determine, Until the toxie dose is learned it should be given with caution. It is proba- ble that 2 dram doses may be used. Give with from 2 to 4 ounces of sweet, linseed, or castor oil. Besides these there are many other remedies proposed, as savin, sabadilla, spigelia or pink root, aloes, tartar emetic, asafetida, azeda- rach, kousso, kamala, and pumpkiu seed. The greater part are of doubtful efficacy; others are dear, and can be replaced by remedies equally as good and cheaper. Many of the bitter herbs may be pow- dered and given with grain, but the sheep will not get enough to have the best effects. Often the worst-affected lamb will not eat any, or very little, on account of loss of appetite. This method of administration is, besides, wasteful. The uncertainty of sheep receiving a full dose is the chief argument against such a method. The effect of some of these plants on sheep is also modified by the fact that sheep are plant eaters and become more or less accustomed to the various medicinal principles found in them. Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7. Fig. 8 Fig. 9 Fig. 10. Fig. 11. 160 DOCHMIUS CERNUUS, Creplin. Plate XXII. . Adult male, x 9: la, natural size. . Adult female, x 9: 2a, natural size ; b, vulva. . Cephalic end of male, ventral view: a, head; b, b, esophagus; ¢, c, necis papille ; d, opposite ventral cleft out of which the unicellular gland ducts e,e, empty by a common tube, f; g, unicellular glands; h,h, two ends of the seminal tubes; i,i,i, seminal tube; k, k, intestine. . Head, dorsal view: a,mouth; 6, b, the chitinous oral teeth on the left side ; c,¢,¢, three papille on right side; d,dorsal teeth; e,e,neck glands; f, cesophagus. . Head, right side. Letters as in Fig. 4: g, ventral teeth; h, chitinous capsule. . Pharynx and lower part of capsule of head, ventral view: a, the cut edge of capsule; b, the dorsal tooth; ¢c,c, ventral teeth ; d, pharynx, in which are six club-shaped bodies, which seem to be appendages of the chiti- nous rods of tho wsophagus; e, esophagus; f, enlarged club-shaped body, which is chitinous and covered with rough points. This apparatus seems to be for mastication. Middle portion of female, x30: a, vulva; b, vagina; ¢, c, portions of cephalic uterus; d, d, candal uterus with eggs; e, oviduct ; f,f, cephalic ovary ; 9, 9, caudal ovary; h,h, intestine. . Eggs: a,a, from ovary; 6, in oviduct; the rest from the uterus in various stages of cell division; c, as they are expelled. . Bursa: a, ventral costw; b, ventro-lateral; c, lateral; d, latero-dorsal ; e, dorsal. The two sides are unsymmetrical. Spicula. 3 Portion of spiculum showing fenestrations and openings into the tube: a, tube; b, wing. ae | al ‘ ‘= etaee — 2 ij ‘. Ce PLATE XXII A A.Hoen & Co, Lith. Boliimeore. orm.) DOCHMIUS CERNUUS, (The Bent-head Round W i aaa 161 SCLEROSTOMA HYPOSTOMUM, Dujardin. Plate XXIII. Description.—Male, 16™™; female, 24™™, Body white, cylindrical, andstout. Head, globular, a little ventrally curved and truncate at the mouth; head papille six; neck papillie not observed; ventral cleft about opposite the end of the second fifth of the esophagus, counting from the head. Unicellular glands and lateral lines very conspicuous. Mouth-opening round, obliquely inclined; surrounded by a single circle.of very minute saw-like teeth. The globular chitinous capsule is marked by numerous longitudinal elevations, which are stronger at its bottom. The posterior Opening is circular, unarmed, but roughened. Around the mouth is a circular canal which empties into a dorsal canal. There is apparently no pharyngeal apparatus as in Dochmius. Césophagus slightly swollen caudally. Two lateral ducts opening near the mouth and situated on either side of the head are apparent; they seem to end caudally in the lateral canals. Male about two-thirds the length of the female. Bursa shallow, set on obliquely, campanulate. Ventral cost~ either separate or slightly so; lateral slightly separate if at all; dorsal pair irregular and widely sep- arate; the dorso-lateral and dorsal foruis a single stem with three lateral branches. Spicula 1.5"™ long, linear aculeate, cross-striated, and bordered by narrow margins which roll in towards each other. Two anal papille. Female stout and thick, and ‘usually with a brown crust near the vulva. Vulva very near the tail. Tail full to near the end, but ending in an acute mucronate point. Uteri directed toward the head; one, the caudal, makes a loop at the tail. The ovaries show loops near the tail. Eggs elliptical, 0.1™™ long, 0.06™™ broad, laid in the gastrula stage. Embryo not observed. Occurrence.—Sclerostoma hypostomum is found in the large intestine of ruminants. It is present associated with Msophagostoma Colwm- bianum in sheep in this country, but not abundantly. It is closely re- lated to Sclerostoma equinum of horses, a species said to make tumors in the intestines. As S. hypostomum is rare, it has not yet been deter- mined whether it causes intestinal tumors in sheep. Since S. tetracan- thum, whose embryos make tumors in the cecum of the horse, is more nearly related generically to Gisophagostoma than to Sclerostoma, I am inclined to believe, as [ have proven in regard to Gsophagostoma Colum- bianum in sheep, that the species belonging to the genus Gisophagostoma are intestinal—tumor-making parasites rather than those of Scleros- toma. Life history—M. Baillet (Nowveau Dict. de Med. T. VIII, art. Hel- minthes, 1886) is authority for the following: The sclerostoine of ruminants is reproduced in the same way as that of solipeds. Its eggs, of which the vitellus is segmented in the uterus of the female, are laid in the large intestine and carried without by the fecal material. They are hatched after 23038 A pP—-11 te toma tetracanthum. ‘They are cylindroid, subobtuse at the anterior extremity, and a provided with a narrow tail much shorter than those of the young sclerostomes of the — horse. They move, besides, in the same manner as the latter. They can live a long time in the fecal material of ruminants when they are not dried, and in this condition y : they grow. Some young Sclerostomes which, after hatching, were 0.35™™ long to 0.50™™ have been found in the droppingsof sheep. After having been kept damptwo — and a half months these were from 0.66 to 0.78™™ long. Their skin, which is folded on the surface of the body, appears to indicate that, like the Sclerostomes of the horse, ~ they are prepared to indergo a molt. The young Sclerostoma hypostomum can live a long time in water after having reached a definite size in the fecal material of ruami- _ nants. We have not yet observed cysts within the mucous membrane of the large intes- tine of sheep.* But as the Sclerostoma hypostomum are in far less numbers of ruminants than S. equinwm or S. tetracanthum in the horse, we can not yet draw — any conclusion from the negative result of our researches. We will not say then at present whether the Sclerostomes of ruminants pass the second phase of their exist- ence in cysts, or whether they are develeped in the intestinal canal itself in the midst of alimentary material which is found contained there. The eggs of the Scele- rostomes of ruminants taken directly from the uterus of females and preserved in water at a temperature of from 12 to 20° C. (about 55 to 70° Fah.) hateh at the end of four or five days after having undergone all the series of successive modifications which are alike observed in the eggs of Sclerostomes of solipeds. The only possibility of error in Baillet’s experiments is the indentifi- cation of the species with which he was dealing, for he writes: It (Selerostoma hypostomum) is above all very frequent in sheep. There are often found individuals, probably younger, whose mouth, entirely terminal, is less widely _ open, and provided with a single rank of teeth still less numerous. These worms also lack a pharyngeal capsule, and often carry a membranous swelling on the sides of the head. The above describes Gsophagostoma venulosum quite well, and when the learned helminthologist did not experiment with eggs taken directly from the adult worm he may have had to do with the eggs of either. Tiis would account for the similarities found between some of the young embryos experimented with and those of Sclerostoma tetracan- thum. (The author is of the opinion that the last named species should be classed with the Gsophagostoma instead of the Sclerostoma.) The life history of this species is, that the eggs are scattered by the sheep, that they then develop somewhat, and without the need of any secondary host are capable of further development in sheep when taken by them along with the food or drink, and that in the large intestine of the latter they may or they may not make tumors during their embry- onic stages. The prevention and treatment is the same as for other intestinal worms. * This indicates that (sophagostoma Columbianum has not been observed in France.— C. C. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. - Fig. Fig. 10. Bursa spread out: a, ventral costie; b, lateral; c, dorsal; d, the torn edge. #34 SCLEROSTOMA HYPOSTOMUM. PLATE XXIII. 1. Male, x8. Fig. la, natural size. 2, Female, x8. Fig. 2a, natural size. 3. Head, ventral view: a, the consuls b, the dorsal canal; e, lateral duets ; eoeane ; mon duct of the Soacd femiaellnta maid ducts is placed near ae vent cleft; g, the end of the esophagus, showing three dependent lips; h, 3 cut-end of the skin. The drawing shows the longitudinal rauseulan Vee separated into two groups by the lateral canals, i, i, and the three separ tions of the muscular bundles between these canals which appear on tl | surface as lines: k, k, k, cut end of the intestine. ae xiv 5. Head, dorsal view: a, b, c, and das in Fig. 3. ees YT 6. Mouth end of lateral half of chitinous capsule: a, a, a, the venta lateral, a and dorsal head papillie; b, the dorsal canal which continues around the — : head in c, c; d, the mouth, around which is a circle of small thorn-like teeth, about forty in all. aoe 6a. Teeth enlarged. Ss ae 7. Caudal end of capsule: a, the cut wall; b, the dorsal canal; ec, the a lar opening of cesophagus. ie his 8. Section of esophagus: a, a, a, the chitinous support; b, b, b, the walls, & ny the orifice. Sete - 9. Male bursa with spicula. 9a. Portion of spicule: a, the chitinous cylinders ; }, the membranous margins. ee 9b. Diagram of anal papillie. 55) “e y Fig. 11. Caudai end of female: a, anus; 3, ASAE c, ¢, uteri; ‘d, d, loops of the — ovaries; e, ¢, the intestine; /, a dark brown patch usually found on the — vulva; g, an egg. ae = Fig. 12. Cross-section of female: a, intestine; b, ovaries; c, lateral duets ; d, muscu-_ ae lar bundles (Leuckart). | ag Figs. 3, 4, 5, and 6 are somewhat distorted by flattening. ee PLATE XXIII A.Hoen & Co, Lith. Bolrimore. tll anon enn SUNT aA sete N =i ct 17) aml SCLEROSTOMA HYPOSTOMUM THE NODULAR DISEASE OF THE INTESTINES. CESOPHAGOSTOMA COLUMBIANUM, Curtice. Plates XXIV, XXV, XXVI, XXVII. In the Eastern States there exists a hitherto undescribed disease, whichis characterized by tumors present in the upper part of the large intestine. The disease causes heavy losses, for it seriously affects the health of the sheep, and renders the intestine valueless for making sausage casings. Though the latter result would seem trivial at first sight, it is by no means unimportant, for sausage-makers are compelled - to import the greater part of covering material used in their business. The disturbances of health produced are very serious, for there are places in the South where sheep can not be kept with profit, apparently on ac- count of this parasite alone. Dr. D. E. Salmon, Chief of the Bureau of Animal Industry, who at one time lived in the South, performed many post-mortem examinations on diseased sheep, and found nothing but these intestinal tumors to account for the severe symptoms of disease which they exhibited, and has verbally stated tiat he believes this malady is the chief obstacle to successfulsheep husbandry in some portions of the Southern States. Investigation.—The cause of the disease remained until the winter of 1888-89 in obscurity, but owing to a favorable combination of material and methods of investigation it was then ascertained. Some of the larger soft tumors, which are characteristic of this disease, were dis- sected from the intestine, and after being slit open their greenish, cheesy contents escaped in a watch-glass of water. By carefully teas- ing the apparently newer portion of these masses a little worm, the cause of the trouble, was found. Previous to that time Dr. Theobald Smith, of this Bureau, had in the winter of 1886-87 made and examined microscopic sections of these tumors. One of a series of sections (see Plate XXV, Fig. 8) showed what was apparently the fragment of a worm. Numerous other sections made at the same time showed no signs of this parasite, and the investigations were temporarily aban- doned. Although tuberculosis is an uncommon disease in sheep, and although the tumors found in this disease differ in many essential points in both their history of formation and in their histological detail from those caused by tubercle bacilli, there was a superficial resemblance, on ; 165 ——~ 4, account of which Dr. Smith made many tests of the caseous imei for ne the bacilli both by the microscopical methods and by the inoculation of small animals. In the light of subsequent investigations it is needless oh to say that these tests had only negative results. In justice to Dr. — Smithit should be stated that he undertook the experiments more for 2 negative evidence than from any expectation of finding bacilli. The cause of the disease is a nematode or round worm, which, though remarkably similar to some other worms of its group, is nevertheless a — distinct species from any hitherto described. The failure to find this worm in our earliest investigations may be ascribed to two important _ factors. The first is that of the season of observation. We had proba- — E bly overlooked those tumors which were best adapted to show the worms, but mainly on account of the season in which the examination was made. The method of examination was probably the greatest factor in the in- vestigation, for as soon as what may be termed macroscopic superseded — microscopic methods the discovery was easy. The method was not en- tirely macroscopic, for simple lenses of low power were used. The worms found in the largest tumors were never over 5 or 4™™ in length, and presented only an embryonic development, the vegetative ~ organs alone being present. Figs. 1, 2, and 4, in Plate XXV, were made from the largest specimens. As the adult worms of this class may differ materially from the embryos in the character of the mouth parts and in their appearance after the reproductive organs have de- veloped, the difficulty was encountered of connecting the embryonic cystic form with an adult form existing in sheep or elsewhere. Determination of adult.—The most conclusive method of determining the adult would be to directly develop an embryo into an adult, but this proceeding was not attempted on account of its difficulties. A less satisfactory method remained of finding some adult worm whose em- bryo was unknown, and which not only corresponded in structure with the embryo, but whose life history was such that it was possible for it to be the parent of the embryo. It will not be profitable to detail theories advanced to aid in this investigation; suffice it to say that while studying one day a group of worms which came from the large intestines of sheep, I found among them an undescribed species. This species was immediately referred to the Sclerostomine (Raillet, Elements of Zoologie, p. 330), and later to Molin’s genus CMsophagos- toma. There may be an impropriety in accepting this name over others ~ proposed at the same time for species of this genus, but as the same author proposed them, and as the genus is in general use, it is accepted in this classification. For reasons assigned hereafter in a description of the species I have called it a new one—Msophagostoma Columbianum. The specific name is from the fact that the worm was first found in the » District of Columbia. The adult worm is found in the large intestine of sheep in considera- — ble numbers, and in the same animal may also be found the tumors. 167 The parasite is usually found below the narrowing of the large intestine, where the latter changes from a sack-like receptacle to « large tube, and below the mass of the tumors. The tumors may, however, extend eer y.> Wt: the entire length of the intestine. It is evident that the distribution of the eggs of this adult would be favorable for ste becoming again in- fected by them. The oral armature of the embryo from the tumors and the adult Ciso- phagostoma Columbianum differ, that of the embryo appearing to be like a chitinous cup comparable to that found in the young of the Sclerostoma of sheep and the Dochmius of dogs. The young of these species, however, differ as much from their adult form as the embryo in question does from its supposed adult form. The anatomical point that the writer considers of the most moment is . that the embryos of the tumors possessa lapel-like fold on the ventral siae of the worm just anterior to the ventral cleft, the opening of the unicellu- lar gland duct, and that the adult O. Columbianum eer es a similar fold identically situated. (See Plate XIV, Figs.1, 2, and 3, and Plate XXV, Figs. 2 and 3.) The absence of éiite Satan in the omuuen of Sclerostoma and Dochmius that infest sheep at once precludes the possi- bility that we have to deal with these species. That embryos of this character and corresponding adults are found in the same sheep makes the diagnosis more assured. Should we look for a host in some other animal we should expect to find one that had all the opprtunities of _ spreading the eggs that infect the sheep, but amongst our farm animals we find no corresponding parasite, and other wild animals which might be suspected as hosts are at the present time very rare. CHSOPHAGOSTOMA COLUMBIANUM, 0. sp. Description.—Male, 12 to 15™"™; female, 14 to 18™™. Worm similar in appearance to Dochmius cernuus, but having its head bent into the form of a hook. Head ter- minal, very short, somewhat thicker than the neck, and separated from it by a con- striction. Papille six, of which two are dorsal, two ventral, and two lateral. The latter are more obtuse and are the openings of the lateral canals of the body. Mouth terminal, supplied with a chitinous armature, consisting of an annular ring, which supports two systems of twenty-four teeth each; the outer circles are very long and curved, so that near their base they form a truncated cone and at their free extremi- ties an inverted truncated cone. Within the outer is situated the inner and shorter row of bidentate teeth, so arranged that each tooth is opposite one in the outer row. Beneath the armature is the tri-radiate opening of the csophagus. Neck not inflated, but provided with a lapel or fold of skin on the ventral side just in front of the ventral cleft; the fold continues slightly on to the dorsal side. Two lateral, narrow, membranous wings begin at this neck fold and continue for one-fourth the length of the worm. The two lateral opposite papillw are in these wings, at the level of the ‘first third of the esophagus. The pair of unicellular neck glands unite into a com- mon duct and empty at the ventral cleft, situated beneath the nuchal fold. Male about three-fourths the length of the female. Bursa saucer-shaped ; can be spread symmetrically without tearing. Cost or ribs symmetrical; the ventral slightly separated; the ventro-lateral forms with the lateral a group; the lateral also slightly separated ; the dorso-lateral forms with its fellow and the dorsal pair a 1685 xroup; the dorsal rib is composed of two, which are widely separated only towatds oy their free ends. Spicula two; awl-shaped, bordered by a very narrow membrane; the chitinous cylinder is apparently fenestrated. At either side of the genital orifice are two knobbed papille. Female relatively stouter; vulva just in front of anus, Bi « which is midway between it and the acutely pointed tail, usually covered by a hard brown patch; reproductive organs in two symmetrical sets anteriorly directed, ex- cept a small portion of one, which is at first posteriorly directed to form a Joop in a front of the anus. Uteri two, in the caudal end of the body. These may be traced up to the oviduct and ovaries, which continue to the cephalic end of abdomen, where they are reflected to form a loop and thence continue to the caudal end to form still another loop. The ovary of the caudal uterus forms still another loop nearly oppo- site the uteri. ; Eggs laid with gastrula inclosed; length, 0.09"; width, 0.05". Embryos from 0.23™" upwards. The largest found in tumors were 4™™ long; the smallest male found in intestine was7™™ long. The smallest embryos were without digestive ap- paratus. The largest possessed an intestine, unicellular glands, and a well-formed chitinous spherical cup in the head; also six cephalic papillw, and at the neck two -papille and a well-defined fold. Occurrence.—The adults live in the large intestine of sheep below the cecum; the embryos live in the intestinal walls in tumors, which, though more abundant in the cecum, may be scattered from the duode- num to the anus. The species is distributed in the United States east of the Mississippi River as far north as Maryland, perhaps farther north. On comparing the species with others of the genus it was found that it corresponded more nearly with Gsophagostoma venulosum, a parasite of goats, than any other described in modern works, and that it corre- sponded still more closely with O. acutum, Molin. (Il sottordine degli acrofalli. Memorie dell * * * Istituto Veneto, 1860, Vol. LX, p.. 449.) The latter is apparently a distinct species, although in quoting other authorities he has given an incorrect synonymy. 9. Colwmbia- num differs markedly from O. venulosum in not having an inflated neck, and from the Jatter and 0. acutum by the possession of a lapel of skin upon the ventral side of the neck, just in front of the opening of the uni- cellular neck glands. Molin examined two males and three females of O. acutum from Antilope Rupicapra; one male from Capra Hircus, var. Mamobricus, in association with forty-five Sclerostoma hypostomum; and two males and one female from Capra Ammon. The finding of Seleros- toma hypostomum in association with the Gisophagostoma acutum is the fact which leads me to infer that the latter occurred in the large intes- tine of the above mammals and not in the stomach, as he cites in his synonymy of the species. . Life history — M@sophagostoma Columbianwm seems to have become a parasite of sheep since their introduction into this country. If present in the Old World at all it is sparingly so, and seems to have escaped detection. So little is known about its distribution, that it is impos-_ sible at present to accurately define its limits. From its great abun- dance in the Southeastern States one mightinfer that it had originated as a sheep parasite in that region, and probably from some animal of allied organization and habits. The writer is at preseut inclined to re)! 169 ‘believe that the deer may have been its host at the time European sheep were first introduced. - There are few facts to sustain this hypoth- esis. Though it may yet be too early to form a positive conclusion, - further investigation may determine the section of the world to which this parasite originally belonged and then the former host may be in- dicated with tolerable accuracy. The life history of this parasite seems to be completely known to us during its development from the immature form found in the intestinal tumors to the adult stage; but there is a period from the moment - when the eggs escape from the intestine with the excrement, to the time when it is found again in the intestinal tumors that must remain in obscurity. After the embryo has returned into the alimentary canal it makes its way through the mucous coat of the intestine and becomes - eneysted there. The writer has been unable to learn how it passes through the mucous coat, as even on the youngest specimens no sign of armature is found. The very young forms found in the cysts show little differentiation beyond what they could bave attained in the egg- shell. They are soo. surrounded by a cyst which seems to belong to them and to have been created by them; but whether this cyst is the remains of a molt or not can not be asserted. Later in their history they become surrounded by the products of the inflammation they ex- cite in the surrounding tissues, and eventually break from the cyst and live in the cheesy mass ofthe tumor. In this stage of their growth the worms exhibit the intestine and oral cup and indistinct unicellular glands. They then molt, and show all these features in more distinct outline. Having attained a length of from 3 to 4™", or less than one- sixth of an inch, they break from the tumors to begin their life in the intestine. In the latter they continue their growth and becoming sex- ually perfect and produce eggs which eventually go through the same cycle. In developing, this worm molts at least three times—once in passing out of the stage in which it has no mouth or intestines, once during the development of these parts as we find them in the embryo, awd once while the worm changes from the embryonic form to the adult form. Disease.—The harm that these parasites do the sheep is directly dependent on their numbers and life history. Yearlings may show considerable infection, but it is usually in older sheep that the most -abundant infection occurs. The disease isa seasonal one, in that it can be found in best development in the winter. The lambs begin to be in- feéted in the summer and fall, and from that time the tumors formed increase in size until early in the spring of the next year, when they gradually grow smaller but probably do not entirely disappear. Pathology.—A study of the fresh tumors by compressing the smaller ones between two glasses and by dissecting larger specimens gives the following results: The small tumors, which are scarcely the size of a pinhead, are found in the submucous tissue. They appear like asac filled 170, 2% with fluid and having a little globe floating within. By using a higher i magnifying power the little globe is seen to be a cyst with a worm inclosed (see Plate X XV, Fig. 6). By careful dissection the cystmay be _ separated (Fig. 5), and finally the worm itself may be separated (Fig. 3). At this stage the worm shows little differentiation of parts. In-exam- ining another and oider cyst (Plate XXV, Fig. 7) the same appearance may be observed. There is also a little greenish cheesy substance present. ~ > ed Se as ie: _ Microscopie serial sections made from alcoholic specimens show best the changes which have taken place in the surrounding tissue. On Plate XXVI, Fig. 2, there is figured an enlarged view of one of the ae worms still encysted and surrounded by the tumor of inflammation. From this section it is seen that the irritation setup in the adjoining con- nective tissue causes the cells to proliferate and crowd closer and closer i together. It is also seen that there is a special cyst for the worm and eS a thickened adjoining portion of the tumor which is like a surround- ing membrane. As these two membranes, the so-called cyst and the a outer one, stain so nearly alike, it has occurred to me that they represent __-_- successive efforts of the adjoining tissue to protect itself against the parasite; but in view of the fact that the inner one is so easily enucle- ated, it is for the present considered as belonging tothe worm. At the foot of Plate XXV, Fig. 8, there is given an illustration of a smail tumor in which the worm has escaped from the eyst and in which the surrounding matter has become cheesy, some of it even hard. Around the entire mass the tissue is slightly thickened and forms a capsule. From these two microscopic sections we can learn how these tumors grow. The worm penetrates to the submucous tissue and irritates if. The adjoining cells rapidly increase in number and crowd upon each other. So closely do they crowd and so numerous do they become, that the outer layers cut off the circulation from the inner cells and they die. Their degeneration gives rise to the cheesy mass. Now, if the worm remained in the center of the mass the new growth would event- ually cease, but the worm makes its way to the outside and at that point keeps up this irritation and new growth. This is shown by and - accounts for the dried older parts of the larger tumors and the fresh yellowish-green adjoining parts. As soon as the worm escapes the irri- tation ceases, the tumor shrinks, and absorption of the nass begins. The irritation produced by the worm provides it with food and favorable surroundings for development. Often the worm dies from weakness or other cause, and leaves behind those little hard incompletely-grown tumors which have been mentioned. Since writing the above life history two post-mortem examinations have been performed, which lead me to modify my views regarding the life history of certain other tumor-making parasites. On August 10, 1889, two lambs, one five months old, the other eleven weeks old, died. The older lamb was bred at the experimental farm; the younger was bought with its dam when but a day or two old. These lambs had no water save what was pumped from a well. Among other parasites, each species being found in its proper portion of the intestine, there were numbers of individuals of G/sophagostoma scattered through the length of the large intestine. These individuals were of all sizes, from the smallest stage (7™ long) to those nearly adult. In the younger lamb there were but few very minute tumors in the coats of the large intestine. In the older the tumors were somewhat larger, but none were Pay as oe much larger than a millet seed. The abundance and size of the free parasites indicated that most if not all of them had developed in the interior of the tube. The intestinal tumors indicated that there were others developing in them. , From the above it seems probable that this species develops nor- mally in the intestine, that some‘of the young embryos penetrate into the walls of the intestines, and at times even to the mesenteric lym-— phatic glands and elsewhere ; that those which penetrate into the intes- tinal wall either develop very slowly or eventually die, depending on the tissue penetrated and the favorable conditions the latter offer for the nourishment of the parasite ; that those which develop slowly may in time escape from the tumors and complete their development in the intestinal canal; that this phase of its life history may be one that is favorable for the preservation of the species by preserving a few indi- viduals in tumors throughout the winter which escape in early spring, become adult, and lay their eggs, which are scattered on pastures favor- able tothe preservation of the embryos; that the majority of these embryos, penetrating the intestinal walls, wander into such environ- ments that they are eventually destroyed; that this act of migration is voluntary and only of benefit to the parasite when the latter becomes lodged in the proper place, and that the same power which enables it to arrive at these places also enables it to penetrate farther than is of use to it; that the slow development of the worm in the tumors as compared with the development in the intestine shows it to be a re- tarded development, which may be hastened as soon as the parasite again reaches the proper surroundings. In short, the fact of the intestinal life of these parasites is demon- strated, as well as the fact that some may wander into the intestinal walls and undergo a retarded development before re-entering the in- testine. The diagnosis of this parasitic disease can only be made from a post- mortem examination. In the living sheep there may be signs of general debility—bloodless lips and eyes, thin sides and flanks, dry wool, ete. It may be that nothing else will be noticed, but that, the flock is not in quite good condition ; or in severe cases the diarrhea and emaciation may be excessive. Dr. Salmon believes the disease may bring death to its victims in the severest cases. My own observations have been con- fined to the abattoirs, where salable animals only are brought. As the adult worms are comparatively few as compared with the tumors, it is probable that the adults of this species cause but little trouble; but the embryos, on the contrary, cause a great deal. The disease is an insidi- ous one, for not only is the rate of infection gradual, increasing slowly in amount from week to week, but the rate of development of the ‘tumors is very slow, apparently requiring months. It is only when the disease is well advanced that its cumulative effects can be noticed. The disturbance of digestion caused by this parasite is mainly due to £73 the derangements of the functions of the ewcum. This derangement is not serious until the resulting tumors become exceedingly numerous, _well advanced in growth, and press upon the more essential mucous - membrane, disturbing its functions. _ The most seriously affected sheep found in the abattoirs are notice- ably poorer, and one would be tempted to believe, were he to judge from the “ knotty” viscera, as the butchers call them, that such animals should have died from the disease long before. These sheep usually have diarrhea, a disease which weakens the affected animals. Flock- masters who mistrust that their sheep are not doing well, and who know of no cause for it, should sacrifice one or two of the poorest to make a diagnosis. The meat of such sheep, though not quite as fat as other mutton, is suitable for food, and could not be distinguished in the market from other mutton. _ Prevention.—For the tumors caused by Gsophagostoma Columbianum there is no remedy except the removal and extermination of the adult worms. These adults are usually buried deeply in the mucous secre- tions and attached to the membrane of the large intestine. They may be found in considerable numbers in older sheep. The medicinal rem- edy must therefore be one which will remove them from these places. It is probable that such a one can eventually be found, but at present none can be recommended. It is probable that some one of the surer remedies advised for other intestinal parasites will do for these. In case medicinal remedies are tried each animal must be dosed. The killing of the adults will of course lessen the number of eggs with which the sheep become infested. As the eggs of this parasite pass to the ground the sheep may get them either while pasturing or drinking. The same care in changing pastures, in providing good drinking water and a plentiful supply of salt, should be observed as for other parasites. Judicious fall and winter marketing of infected sheep will also tend to lessen the chances of infection. If pastures are known to be perma- nently infected, then they should be turned over to other stock for a year or two before being again grazed on by sheep. When it is prac- tical on the smaller farms the sheep lots should be plowed and either planted or left fallow. The object of change of pasture and of plowing is nearly the same; in the one case, to wait until the parasites have died out; in the other, to bury them beneath several inches of soil, from which the sheep-owner may rest assured they will not emerge. Bac: Fig. 2. BS 3s Fig. 4. Fig. 5. Fig. 6. CGSOPHAGOSTOMA COLUMBIANUM, Curtice. PLATE XXIV. Adult male, x9, Fig. la, natural size. Adult female, x9, Fig. 2a, natural size. ) 5 Cephalic end of adult, ventral view: a, head; b, csophagus; c, lateral. emptying ate, the ventral orifice; f, a fold of the skin which forms a balf ring on the ventral side of the neck; the orifice e opens uncer it; g,g, two” pointed neck papille; h, h, narrow membranous wings; é, intestine. Caudal end of adult female lateral view, X45 (about): a, anus; b, vulva;c, vagina; d,d, uteri; e, e, oviducts; J, f, f, loops of the ovaries; 7, intestine. Head: a, mouth; b, b, papille of the two lateral ducts; c, c, two of the four acute, pointed papille opening on the head; d, d, cross-section of cavity of the head; e, e, cross-section of a circular canal, which runs around the base of the head; f, chitinous armature of the head; g, wsophagus; h, its three chitinous supports. ho canals opening on head; d, unicellular glands and ducts uniting and _ * % in ~ rhs Chitinous armature, top view: a, chitinous ring; b, outer teeth; c, inner teeth; d, triradiate pharyngeal orifice ; e, e, e, the ends of the m@sophageal rods. Four of the outer teeth have been removed to better show the inner row. A side view of this apparatus is presented in Fig. 5. . Top view of teeth. . Side view of teeth and basal support. . The bursa spread out: a, ventral rib; b, ventro lateral; ¢, lateral; d, dorso- lateral; e, dorsal; f, the cloacal orifice with two papille behind. . Spicula of male, composed of a chitinous tube surrounded by a membrane with a narrow wing. Portion of spiculum. Eggs: a, a, as they appear when deposited; b, eggs in uterus. Bursa of male, side view: a, a, a, ribs; b, spicula; e, ¢, anal papille. Head, top view: a, mouth; J, b, lateral papillee; c, one of the four acute papille. oe vs rs PLATE XXIV A.Hoen & Co, Lith, Boltimere. jpn Np : rae TTT ore} ROTA : See ee - SOPHAGOSTOMA COLUMBIANUM (The Tumor-Making Round Worm of Sheep.) Fig. 8. (ESOPHAGOSTOMA COLUMBIANUM, Curtice. PLATE XXV. c, intestine ; d, ‘ateetiale Sai e, anus; f, line denotes mritatal Howat Cephalic end: lateral view, X150: a, chitinous cup; b, one of the six cephi which the gland- one d, d, open on che ventral line; e, eT ff intestine. : Worm in first stage when 0.23™™, long. No internal organs were seen this specimen. 3 . Cephalic end, ventral view: a, head; 6b, neck-fold, near, which are_ the neck papillew g, 7; c, esophagus; d, d, eniepllalat MBS which open under the — eg fold b; e, intestine; f, f, glands. ere Worm holueedl 4 in its oget: Oe eae Tumor from which the cyst in Fig. 5 was taken: a, surrounding tissue dis- ee sected from cecum; J, fluid-filled space; ¢c, capsule with inclosed worm. aa Older tumor. This aliiters from tumor of Fig. 6, in having a movable cheesy Bi mass. These tumors are distorted by compression, which makes them too — flat. Figs.6and7, and Fig. 3, Plate XX VI, present three stages in the dis- ease, as seen in fresh tissues under low magnifying powers. a4 Section of an advanced tumor: a, mucous membrane ; b, submucous; ¢, inner muscular layer; d, outer: e, serous membrane; f, the cheesy mass of the — Ne tumor in which is a small section of the worm. This presents a more ad-— a vanced stage of the disease than Fig. 2, Plate XXVI. ‘ rs oe a se nate tinere, A.Hoeu & Co. Lith. Bal GSOPHAGOSTOMA COLUMBIANUM (Young Stages.) 178 (KSOPHAGOSTOMA COLUMBIANUM, Curtice. PLATE XXVI, Fig. — A piece of mucous membrane taken from the cxcum, surface view, natural size. The patch of dots scattered uniformly over the surface represents intestinal glands; the irregularly scattered larger a and elevations are the young worm tumors in their first stages. Fig. 2. A section through a worm tumor in its younger stage: a, a, a, mucous mem- brane; b, submucous connective tissue, in which are ¢ arteries and d veins ; e, the tumor, which is made of connective tissue cells and their nuclei, packed closely together ; near its center is the worm cavity f, with a piece of the worm, which is surrounded by a section of a special capsule; out- side of this is a thick membrane, formed from the surrounding material. Fig. 3. Small tumor dissected from the cecum: a, the outside capsule filled with fluid, in which is b, a hard, cheesy mass: c, the worm in its capsule, which has been pressed out of the cavity in the mass b. This presents a more advanced stage of the disease than fig. 7, Plate xxv. Fig. 3a. The ruptured capsule. Fig. 3b. The worm near the end of its second stage about to moult. PLATE XXVI =e te A.Hoen &Co. Lithocaustic Baltimore. CESOPHAGOSTOMA COLUMBIANUM, 7 (Small Tumors of Ceecum.) ; we a cs coon es ikkad kaa aes “ » i £0 pela a a" Saat Sait don yeas ae porn ee Se eanaea we es fresle ibs Shee BS ora Tee Te NERS: ody Si oa | aut 3 ty, en aeeiisa A op iw at oattae Contgetes . ae Mote ae peek ghia ts SEL Lar j rics ae ksh on 180 (SOPHAGOSTOMA COLUMBIANUM, Curtice. PLATE XXVII. Fig. 1. Piece of cecum exhibiting tumors caused by the embryos of Wsophagostoma Columbianum, natural size. The various stages of growth are represented by the different sized tumois. The smallest are better shown in Plate XXVI, Fig. 1. Fig. 2. Cross-section of Fig. 1, at a a; b, mucous membrane; ¢, submucous; d, muscular and serous layers; ¢ ¢ e, section through the cheesy masses. nen _Lithocaustic Baltimor . (BSOPHAGOSTOMA COLUMBIANUM, eS nae (Large Tumors of Ceecum.) THE CECUM WORM. TRICHOCEPHALUS AFFINIS, Rud. Plate XXVIII. Description.—Male and female about equal, 40 to70™™ long. Body whip-like, pos- sessing a short, stout caudal end, 12 to 18™™ long, and a very thin hair-like cephalic end of twice this length. The latter contains the w@sophagus and intestine; the former the reproductive organs and intestine. The head is very small and thin, without noticeable papille or chitinous armature. It is said to sometimes have two vesicular, transparent, wing-like inflations. Skin of the neck transversely striate, and when highly magnified shows a serration of the sides indicating cuticular layers which overlap each other like shingles on a roof. (Esophagus and cephalic portion of intestine very minute; its posterior end is large and dark, and empties at the caudal end of the body. On one side of the head there appears to be acanal filled with granules, The male is to be distinguished by its tightly-curled caudal end. The testicle, beginning near the caudal end, continues anteriorly as a sinuous tube for about two- thirds the length of the thick portion of the worm; it then becomes plaited to the end of the thick part, where it turns and continues posteriorly as an enlarged seminal duct for about half the length of the thickened body, where it is constricted; the remainder continues to the cloaca as a slightly enlarged tube. The intromittent apparatus consists of two parts, an external membranous tube bristling with spines and an internal long, slim spiculum. It is always found exserted, and usually has one coil in it. The tube shows at its end that the external covering continues around the end into the tube to form a lining membrane, which may be retracted or protruded. There is considerable space between these membranes at the tip, and it assumes various forms, varying between a large sphere, as shown in the figures, and an elongate cylindrical body. The chitinous spiculum is terminated by an acute point. It is from 5 to 6™™ long, with a width of 0.025™™, The tube is about three or four times as wide. The spiny points are turned away from the end. The female has a thick body, only slightly curved. Tail, obtuse; ovary begins at the caudal end, continues as a plaited canal to the cephalic end of the thick part of body, then contracting returns to the caudal end where it enlarges, forms a fold, and becomes the uterus, which empties through the sinuous vagina and the vulva at the cephalic end, where the body begins to enlarge. Eggs characterized by having re- frangent polar bodies at each end. They measure 0,077™™ in length, including these bodres, or 0.056™™ excluding them (Raillet). They are elliptical and dark brown. Occurrence.—This species is found in the cecum of sheep, goats, and cattle. When the fresh intestine is examined the worm may be found with its slim, hair-like head firmly sewed into the mucous membranes. The serrated structure of the skin not only facilitates the progress of the head through the mucosa, but prevents its being pulled backward. The thick large end, which is what one really sees at first, appears to float free in the intestinal contents. 181 182 The life history of this species has been determined by Leuckart, the distinguished helminthologist, who has added so much to this branch of biology. He succeeded in raising young embryos from the eggs to such astage that there was no reasonable doubt that the next stage was passed in sheep. These he fed to a lamb, which he killed after sixteen days. In these he found numerous immature trichocephali about 1”™ in length. He later verified this experiment by another, with like results. (Die menschlichen Parasiten, Band II, 494-499.) These experiments show that the eggs of Trichocephalus affinis, which pass from sheep to the ground, may develop there to some degree, and then, after being consumed with food or drink by a second sheep, con- tinue their development to their adult stages. Disease and treatment.— Unless the parasite should be present in great abundance the species does not seem to be especially harmful. A few may be found in nearly all lambs and young sheep, especially in the all. The means of prevention is just the same as for other round worms. As they are attached so stoutly to the mucous membrane it is doubtful whether medicinal remedies would have the influence on them that they have on those worms situated in the small intestine. ia | 184 TRICHOCEPHALUS AFFINIS, Rudolphi. IPT AME NeNeVeL lL. . Piece of cecum with trichocephali attached, natural size: a,a, females; b, b, males. . Male, X7: a, capillary cephalicend; b, coiled caudal end ; ¢, protruded intro- mittent organ ; d, the convoluted, and e, the straight portion of the seminal - apparatus; f, seminal reservoir; g, intestine. . Female, <7: a, capillary cephalic end; 6, vulva; c, vagina; d, uterus; e, oviduct; f, convoluted ovary; g, intestine. . Caudal end of male enlarged: a, end of the body ; b, spine-covered tube of intromittent organ; c, its inflated end; d, spiculum. . Cross-section of end showing how the outside sheath becomes converted into the inside sheath of the tube: a,a, thesheath; b, the sac formed; c, the hollow spiculum. . End of sheath, much enlarged, to show the relation between sheath and spiculum. . The head. . The vulva and vagina, with an egg in the passage. . Eggs: a, eggs without shells; 6, egg with shell and its characteristic polar bodies; ce, intermediate between a and b. . 10. Enlarged portion of worm from near the head. PLATE XXVIII “nents 1 sd4qdtgdadsd dd cddca ay Say Srey aa ys syn A.Hoen & Co. Gith, Baltimore. TRICHOCEPHALUS AFFINIS (The Hair-headed Round Worm.) 3.3) on 7 te iia 7) ey) qt Wee ; erty Tp LUNG-WORM DISEASES.—PAPER SKIN, HOOSE, HUSK. VERMINOUS PNEUMONIA—VERMINOUS BRONCHITIS. Plates XXIX to XXXVI. The lung worms which cause disease in sheep in the United States be- long to two, perhaps three, different species. They are Strongylusovis- pulmonalis, Diesing, the hair lung worm ; and Strongylus filaria, Rud., the thread lung worm. The third species, which has been reported as infesting sheep in Europe, is the hog lung worm, Strongylus paradoxus, an abundant species occurring in the lungs of swine in this country, and while ithas never been credited as having been found in our sheep it is to be looked for. As its size and the disease it causes is similar to that of Strongylus filaria, it will not be treated separately. The diseases produced by these species of worms are caused by the mechanical injuries the worms inflict on the delicate membranes of the lungs and the clogging up of the air passages by them and the débris which they produce. The twoforms of disease produced depends on the different size and habits of the two species. Strongylus ovis-pulmonalis, being very small, penetrates the air passages to their endings in the bronchioles and infundibuli, and causes disease in them primarily, while Strongylus filaria, which penetrates only into the bronchi, creates a disturbance there which produces a solidification of the lung second- arily. The general diagnosis of each disease is no easy matter. The disease produced by Strongylus ovis-pulmonalis is characterized by the spongy feeling of the lung and the presence of nodules from the size of a mustard seed to that of a pea scattered under the surface of the dor- sum of thelung and at its posterior free edge. These may be counected by agrayish, fleshy, intermediate portion of the lung into patches of con- siderable size. The parasites can scarcely be seen by the unaided eye ; but if small pieces of the affected lung or a tubercle be placed in a shal- low dish of water and teased out with needles under a tripod lens, they cal be readily seen. The disease produced by Stronglyus filaria and S. paradoxus is char- acterized by the posterior portion usually, or some entire section of the affected lung appearing as a solid, usually red, mass which has lost all of its contained air and is in a state of hepatization. A piece cut out generally sinksin water, while pieces from the former disease float. If in the latter disease the trachea is carefully slit open and the branches 185 186 traced down to the affected part the parasites will be found in thread- like bunches, completely filling the tubes. The symptoms of lung-worm disease in sheep can not well be diag- nosed in living animals unless the disease is far advanced, and then only in the severer cases. Sheep affected with either disease generally have pale, bloodless mucous membranes, harsh, dry hair, a dejected look, more or less difficulty in breathing, and often a deep cough. The bloodless condition of the sheep could arise from other parasitic troubles, but the disturbance of respiration should lead one to suspect lung parasites. Consumption or tuberculosis is apparently a rare disease in sheep, and is not liable to be confused with this disease, which can always be diagnosed by finding the parasite. Lung-worm (isease differs from acute bronchitis or pneumonia in being of slow development, and is less severe in its symptoms. Worm diseases consume weeks in develop- ment, while acute diseases are begun and finished in a few days. THE HAIR LUNG WORM—VERMINOUS PNEUMONIA. STRONGYLUS OVIS-PULMONALIS, Diesing. Plates XXIX, XXX, XXXI, XXXII, XXXIII. Description.—Male, 16™™; female, 25™™; width, male, 0.5™™; female, 0.17™™. Cap- illary integument of worm very transparent, the cavity of the body appearing as a dark line. Head not winged; four papillie ; mouth naked. Male, bursa pointed, compressed, terminal; cost (apparently) seven; one posterior ; twice-notched ; two pair lateral, one pair anterior; spicula s oeecal spatulate, curved; 0.15™™ Tone divided into two nearly equal parts; the anterior consisting of a oniindiaasan chitinous skeleton with a membraneous expansion, the posterior of a transversely ribbed skele- ton, margined by a thin broad curved membrane, the twospicula forming a partially closed tube. Female oviparous, with two uteri and ovaries. The formerempty into a vagina at 0.8™™ from vulva. Vulva 0.1™™ from anus. Anus 0,08™™ from tip of tail. Tail ends ina blunt point. Eggs in uteri 0.1™™ long, 0.04™™ wide. The eggs segment after being laid. Embryo provided with a very sharp-pointed tail. Life history.—The young of the hair-lung worms escape from the lungs of infected sheep and become scattered over the pastures, yards, and other places frequented by these animals. They are then taken with the food or drink and in some way arrive in the lungs of the sheep. Arriving at the extreme ends of the bronchial tubes, they break down some of the tissues and become encysted. In the cyst they grow to adult size and take on sexual characteristics. Escaping from the cysts they make their way into the small air-tubes (bronchioles and bronchi), where the sexes mate and reproduce. The eggs are then laid in sur- rounding cavities and hatched into young worms, which make their way into the neighboring air-chambers (infundibula). Afterwards some of these worms may be coughed out of the lungs onto the pastures and in- fect other sheep. In their life history there are but one or two points about which there can be any question. Many learned helminthologists believe that the 187 _ young worm must escape from the sheep in order to spend a portion of its life on the ground or in some of the minute forms of animals before they are capable of further development in the sheep. Most authors are agreed that the worm passes into the lungs by the trachea either during feeding or rumination. The length of time which it takes the worm to complete its cycle of life is yet unknown. As the most pro- nounced cases among slaughtered animals are in the older sheep, it would; seem as though this parasite was of very slow growth, requiring years instead of months for successive generations to produce a disease fatal to the infested sheep. It may be, however, that many lambs and young sheep are so seriously affected with the parasite that they either die or become so inferior in quality that they are never taken to the abattoir. In this case the cycle of life would prove to be rapid. Disease.—The diagnosis of verminous pneumonia in living animals is a difficult matter. Not until the disease is so far advanced that its cure is hopeless are any well-pronounced symptoms developed. The worst affected sheep may have a deep cough, be out of condition, and be generally anemic, as showr by the pallor of the visible mucous mem- brane and the dry, harsh coat. They are likely to lose flesh, but some, if not seriously affected, fatten tolerably well. The post mortem diagnosis is as certain and definite as the diagnosis in life is unsatisfactory. So pronounced are the lesious caused by the worms inthe lung tissue that any one having once seen a diseased lung would easily recognize it again. The little tubercles, filled with greenish material and surrounded by more or less of the thickened lung tissue which when cut exudes a frothy liquid, are diagnostic. — The presence of the worm in these tubercles is decisive. The prognosis of this disease can not be definitely given. From many examinations of affected lungs it seems to me that the disease is a pro- gressive one, producing its worst effects as the sheep growold. Where the sheep are marketed young the loss from this parasite is compara- tively small; but where the disease is wide-spread and affects whole flocks, though but a few cents may be lost per head, the aggregate loss to the sheep industry must be considerable. To this must be added the loss from the disease in its more severe stages. When the disease is once in a flock and the farm or range is infected with it there will bea steady loss resulting until the disease is in some way exterminated. Pathology.—The disease created is dependent upon the life history of the parasite as to character and upon the numbers of the invading hosts for its intensity. The changes produced in the lungs are but the agere- gate of all the changes which result from the different invading individ- uals, and the history of the changes wrought by a single parasite illus- trates the changes produced by all. The minute worm, when entering, penetrates the air passages to their extremities. In the ultimate alveoli it breaks down some portion of the membranous partition and becomes surrounded by the products of the inflammation which it excites and 188 formsavery minute tubercle. When this tubercle has reached from oneto two and one-half millimeters (one twenty-fifth to one-tenth of an ineh) in size, it is composed of a distinct central part, filled with a soft, greenish, central portion, which is surrounded by a thicker membranous capsular portion, composed of cells of new growth, the inner part of which degen- erates later and enters into the formation of the cheesy central mass. Within this tubercle is the young parasite. Inlater stages this tubercle enlarges until it becomes 3"™ in diameter. In this stage the soft interior mass will be firmer. The parasite is always found between the interior mass and the capsule, and is surrounded by the soft, freshly-formed greenish material, which it seems to produce by the irritation of the adjacent capsule. When the parasite attains its adult size it evidently breaks from the tubercle and thereafter lives in the adjacent bronchioles. There is quite a difference in the external appearance of the little tuber- cles during the different stages of growth. In the earlier stages they appear as little blood-red spots just beneath the pleural coat of the lung; later they look like little brownish fluid-filled tumors, surrounded by a red zone; still later a yellowish, green, cheesy material appears in their center, and the tumors present a greenish-gray appearance. The gray is due to the thickened capsule and a thickening of the pleural coat of the lung over the little tubercle. There is usually a slight ele- vation of the surface of the lung over these nodules, but this feature is dependent on the depth at which the nodule is situated. They may occur at any depth in the lung substance, but are usually near the sur- face. When the parasite escapes from the nodule a new phase of the disease begins. It wanders through the bronchi until it meets one of the opposite sex, when they mate. Soon after the female begins to lay eggs in the bronchioles and alveoli, which she infests, and these eggs in turn hatch into young worms. These young worms are very lively, and help to increase the disturbance of vital functions of the lung sur- rounding them. That part of the lung then becomes as if sodden, the air tubes fill with eggs, worms, cast-off epithelial cells, mucus, wan- dering cells, and air globules; the tissues of the walls of the alveoli become thickened and encroach upon the contents, and the function of the part.is entirely suspended. The effect of the worm and its brood at this stage is to produce a pneumonia, hence the disease has been termed verminous pneumonia. This pneumonia is limited to the neigh- borhood of the parasite and does not extend beyond. The patches are from 1 to 2.5°" in width, but in those recently formed they rarely ex- tend more than 2 or 3™" deep. The injury seems to be mainly a me- chanical effect, due to the irritation set up by the parasites. When one of these patches is cut into a frothy liquid exudes, bearing quanti- ties of eggs and embryos in all stages of development. They may be seen with a glass magnifying six diameters. In later stages of the disease the tubercles become little hard masses. These have been said to be calcareous, but they are not soluble in acid, 189 and seem rather to be the contracted, hardened remains of the cheesy mass. There are sometimes found in certain lungs raised patches of a rather dry, emphysematous tissue, which seems to be due to the deeper lying parasites. in other lungs the patches which once showed the pneumonia have becomed thickened, firmer, denser, and a cut across them shows the thickening to extend to a considerable depth. The abundance of the nodules and patches of pneumonia is very vari- able. There may be a dozen nodules of different sizes and twoor three patches, or the nodules may be diffusely scattered over the whole pos- terior surfaces of the lung, or there may be associated with them numbers of patches due in part to the close proximity of the nodules and in part to the extension of the disease. In other cases there may be a few of the nodules with a series of patches ranged along the dorsum of the lung. Each lung seems to present a slightly different phase, dependent on the degree and the time of infection and possible reinfection. Source of infection.—That verminous pneumonia is caused by a worm (Strongylus ovis-pulmonalis) and that sheep become infested while feed- ing or drinking has already been enlarged upon. It is obvious, there- fore, that the best way to keep the sheep well is in some way to pre- vent them from becoming infected with the parasite while feeding. Preventive treatment.—In giving rules for prevention the value of knowing the complete life history is fully illustrated. The unexplained gaps in this history are two, viz: there has been no complete demonstra- tion of the manner and place in which the parasite spends its life be- tween the time of its escape from the lung of one animal and its recep. tion into that of another, nor has it been demonstrated that the worm must escape from the luug before it may complete its development. This latter item is an important one, for if the worms can continue multiplying indefinitely in the lung then there is little hope of freeing a Sheep after it is once infected. On the other hand, if an infected sheep is to be regarded as incapable of continuing the infection within itself then the case is more hopeful. If the parasite must become para- sitic on a second host while external to the sheep, as some claim, this is au important factor in its life history, for its continuance then depends on the presence, abundance, and seasonal appearance of this second host, and influences adverse to the life of the second host would be un- favorable to the parasite. As the parasites are present in the lungs of sheep throughout the year in all stages, this theory does not seem to hold good. The infec- tion of lambs is proof enough that the parasites are continually passing from one sheep to another, and whatever be the mode of living there are certain precautions which may be taken to keep the sheep less in- fected if not to entirely exclude the worms. The older sheep, which seem to be more infected and which are the source of infection for young ones, Should be marketed. Lambs should be weaned as early as they safely can be, separated from the older sheep, pastured in fields where 190 there have been no sheep since the previous winter at least, and never allowed to pasture, water, or yard after infected animals. ; Sheep should be supplied with water from running streams or troughs, and should not be allowed to contaminate the waterin any way. Filthy drinking water is one of the most prolific sources of the parasite. There are two kinds of seasons which especially favor the production of parasitic diseases. The one is a very wet, warm season, during which the parasites seem to be able to live on the damp ground. The other is a very dry season, when the pools of water become diminished and stagnant, and whatever parasitic eggs or embryos there are in them are gathered into so small a volume of liquid that sheep drinking of the water become more readily infected. Wet, damp pastures, and pastures with puddles in them are alike favorable to the worm diseases. Sheep should be excluded from such places as much as possible. A constant watch of the condition of the lungs in dead and slaugh- tered sheep will enable the flockmaster to judge of the progress that — his care in preventing the disease has made. Medicinal treatment.—There is no medicinal treatment that can be profitably followed. Salting, grain-feeding, and healthful surroundings are required not only to keep up the health of the animal for the pro- duction of wool but to fit it for the market, which is the best plage for seriously affected sheep. 192 STRONGYLUS OVIS-PULMONALIS, Diesing. PLATE XXIX. . Cephalic end: a, esophagus; b, intestine. . Head with papillex. 3. Caudal end of female: a, anus; b, vulva; ec, vagina; d, d, uteri; e, e, ovi- ducts; f, f, ova; g, g, intestine. . Middle of female with tail of male coiled around her. . Spiculum: a, cylindrical part of the skeleton; 6, D SPAtHAtS ribbed part; c, wing of tube: d, membranous tip. . Spicula as they fit together. . Adult male and female, x6. . Caudal end of male: a, spicula. . Male bursa with appressed cost. - Male bursa with separated cost and spicula in situ, . Caudal end of female, lettered as in Fig. 3 PLATE XXIX A.Hoen & Co. Lith, Baltiinore. PULMONALIS- ‘The Hair Lung Worm.) STRONGYLUS OVIS- air aEhG Sm yolks gaps x 2 “ mah es is 137 ie 194 STRONGYLUS OVIS-PULMONALIS, Diesing. PLATE XXX. Portion of left lung slightly affected by the strongyli. The purplish spots are those more recently invaded. The small gray spots are older. The large gray spots are caused by the worms and their young, which have produced an appearance of local pneumonia. ; PLATE XXX Haines, del. . A Hoen & Co. Lithocaustic, Baltimore SURFACE OF LUNG RECENTLY INVADED BY STRONGYLUS OVIS-PULMONALIS. 196 STRONGYLUS OVIS-PULMONALIS, Diesing. PLATE XXXI. Left Inng diseased by Strongylus ovis-pulmonalis, the hair lung-worm. Natural size. Each dot is caused by the irritation set up by a young worm, and its size cor- responds to the age of the worm. The larger patches consist at first of separate dots; as these enlarge they run together and finally become so fused that their identity is lost. The patches show the stage at which the worms become adult and produce their young, which wander into the adjacent air cavities. PLATE XXXI 4 Hoen & Co, Lithocaustic Baltimore SURFACE OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS. ; ; sib ra a oF aR aa 7 \ io “ oe haere eae ol Ghent keh re ot He area A neh bhes ita pia er tec One eck eS re bes ad iG sh ok epi wih lM tap a FY ne 9 she shih: hat, iat spsies reig male ray nhihie eas base aK " 198 STRONGYLUS OVIS-PULMONALIS, Diesing. PLATE XXXII. Portion of right lung, exhibiting an advanced stage of the hair lung-worm disease. The small dark spots show the youngest stages, the large patches show the disease well advanced, while the large light spots are the oldest. A section cut across one of these shows the depth at which the lung is affected. PLATE XXXII — ee’ OCeO*. eS Oe ee ee eee Haines, del. A.Hoen &Co, Lithacaustic, Baltimore SURFACE OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS. ve Nee. “PASS Fig. Fig. Fig. Fig. £ Fig. 200 STRONGYLUS OVIS-PULMONALIS, Diesing. PLATE Xoo lms . Section of lung tissue through two small tumors caused by the worms X20: a, caseous degeneration of tissue in the center of the tumor; b, the same in the pathway of the moving, growing worm; c, cut fragments of the worm (the pathway of the worm is interrupted between a and b, because the plane of the section did not include it); d, a bronchus into which the parasite has almost found its way; e, portion of a second tumor made by another worm; f, nearly normal tissue. 2. Section through an older tumor at the stage which has been likened to pneu- monia, X20: a, tumor with fragments of worms; b, fragments of an adult worm; c, eggs in segmentation stage ; d, embryos somewhat developed; e, young embryos; f, bronchi; g, nearly normal tissue. . An enlargement of b, Fig. 2, showing fragments of adult worm in the bron- chi and alveole. . Anenlargement of e, Fig. 2, showing young worms in the alveolz. . An enlargement of c, showing segmenting eggs in alveoli. . An enlargement of d, showingd eveloping embryos in alveoli. In Figs. 5 and 6 the outlines of the egg-shells are not shown. Figs. 3-6, X90. (These illustrations were made from specimens selected from a number of serial sections which were stained with alum-carmine; the dots represent the nuclei of the cells. All sections show the great multiplication of cells about the points of irritation, whether excited by the adults or embryos.) Fig. 7. a, embryo of Strongylus filaria, and b embryo of S, ovis-pulmonalis, each equally enlarged to show comparative differences in size and outline. PLATE XXXII Haines, del. A.Hoen & Co. Lith. Bo SECTIONS OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS. THE THREAD LUNG-WORM—VERMINOUS BRONCHITIS— HUSK OR HOOSE—PAPER SKIN. STRONGYLUS FILARIA, Rud. Plates XXXIV, XXXV, XXXVI. The thread lung worm, or Strongylus filaria, is the best known of the sheep lung worms, for the reason that at times it causes extensive epi- zootics in the flocks, and that the worm is large enough to see when the bronchial tubes are slit and spread open. From personal observation it appears to be much rarer than Strongylus ovis-pulmonalis, and the disease it causes much less extensively distributed as to number ot animals infected than that produced by the latter. In most of the American literature on this subject the disease caused by the hair lung. worm seems to be ascribed to the thread lung worm, and no mention is made of the former. | Description.—Male, 33 to 54™™; female, 55 to 80™™. Worm filiform, white, with a dark hair line showing throughout its length; head obtuse, withuut notice- able papillz or wings; mouth circular, naked; unicellular neck glands quite large ; cuticle longitudinally striate. Male: Bursa shallow, campanulate, opening later- ally ; five sets of costz; the dorsal are trifid, the lateral bifid, and the ventral sepa- rated. Spicula arcuate cylindrical; 3.35™™ long by 0.075™™ wide; short, very thick, dark brown; chitinous portion a curved fenestrated conical tube; fleshy por- tion amembrane, which formsa bulb-like expansion toward their free end. Female: Vulva three-sevenths of her length from the head; uteri symmetrically directed anteriorly and posteriorly ; posterior oviduct becoming continuous with the uterus near its flexure at the tail; ovo-viviparous; eggs ellipsoid, 0.075 to 0.120™™ long ; 0.045 to 0.052™™ wide. Embryo 0.25 to 3™™, The life history of Strongylus filaria is in general that of other para- sites. In some way the young worms arrive in the bronchi, grow, de- velop, become adult, mate, and lay their eggs in the surrounding mucus. The eggs laid are not true eggs, for each egg-shell contains a young worm within, a feature which is described by calling the female ovo- viviparous. The inclosed young escape from the shell, and many of them are expelled from the lungs in the coughing fits along with other discharges. These young, which are scattered about watering-places, pastures, sheep-yards, or corrals serve as infecting and reinfecting ma- terial for a considerable length of time. Professor Leuckart (Hntwickel ung d. Nematoden, Arch. d. w. Heilkunde, 1865, p. 299), kept the young of this species alive for several weeks on damp earth, and observed them pass through a stage in which they molted or threw off their skins, 201 202 after which many died. Baillet (Colin, G., Bull deVAcad. de Méa., t. XXXI, 1866, p. 874) preserved them alive in water for several months. Ercolani (Newmann, Traité des Maladies parasitaires, p. 515) is author- ity for the statement that they can be resuscitated after being dried a year by putting them in water. The writer has kept them in stagnant water for weeks. Ercolani’s statement is by far the most remarkable, and accounts for results obtained in an experiment in which the writer kept sheep for five months on a narrow dry pasture, supplying them with water from a pump only. When these sheep were examined they were found affected with Strongylus contortus, 8. filicollis, 8. ventricosus, Dochmius cernuus, and Tenia expansa in very youngand old stages. The eggs of these were introduced on the pasture from two or three older sheep which were with the younger ones, or possibly by the young sheep themselves, some of which were between three and four months old at the time. Two of the lot were born and raised under experi- ° mental supervision, and these were also infected. Strongylus filaria was not present, but it was not discovered in any of the sheep from the same lot killed at the time of selection of the experimental animals, nor has any trace of this parasite been discovered in any of the older ones kept at the Experimental Station. Professor Raillet details experiments (Recueil de Méd. Vétérinaire An- nexe, 7 Serie, Tome VI, No. 8, April 30, 1889, p. 173) in which he dried embryos of Strongylus filaria under different conditions, and found, after a few failures, that some could be revivitied as late as sixty-three hours afterward by placing them in water. His success depended on the condition of the embryo at the time of drying. It may be accepted, therefore, that the young parasite may retain vi- tality indefinitely, depending on telluric and atmospheric conditions. From Leuckart’s experiment it is to be inferred that though moist earth and damp places are favorable for the life of the young parasites, yet they are liable to molt and then may die from the loss of the olderand tougher external skin. From Ercolani’s and Raillet’s experiments we may infer that the drying of the young parasite suspends its functions, which revive again when the surroundings are suitable, and that the parasite is in this state the most dangerous to sheep. Preventive treatment.—The foregoing indicates that after a farm is once infected the prevention is not an easy matter, for dry embryos may be scattered everywhere. Although the parasite is more abundant at some seasons than at others, yet it may be found in limited numbers at all seasons, and animals affected will distribute the eggs throughout the year, thus increasing the difficulties of prevention. All animals which show the least appearance of being affected should be separated from the sound ones. The water supplied to the sheep should be pure, i.¢., either taken from wells or led into troughs from sources which can not be contaminated. If the sheep are allowed to drink from running water, then all of the brook should be fenced out except where the 203 sheep drink. Dry pastures without bog-holes or sloughs are best for the animals. As the germs live for some time ina dried condition the old pastures should not be used for young sheep at least, nor shouid the latter be allowed to graze after older sheep which have had the dis- ease during the previous year, nor should the pasture be overstocked so that the grass is eaten to its roots. Disease.—Verminous bronchitis attacks young animals, those under two years being the more susceptible. Animals poorly nourished and those already weak from other parasitic diseases are also more liable to become a prey to this worn. Damp, warm seasons are most favorable for the preservation of the parasite and the disease it produces. The disease is most prevalent in summer and autumn, becomes less in winter, and disappears in spring-time. The symptoms of this disease, as in verminous pneumonia, are im- perceptible in the first stages. Itis probable that, beyond the slight but deep cough produced in some of the worst cases, but little else can be noticed. The sheep may have difficulty in breathing when driven or be short-winded. ‘They may be anemic, as shown by the harsh, dry skin, dry wool, and pale mucous membranes. In later. stages the symptoms will be aggravated; difficulty in breathing, coughing, and general debility, associated with an anemic condition, will be the most prominent symptoms. Occasionally shreddy masses will be coughed up, which, on close examination, will prove to be worms. This is a decisive test of the nature of the disease. The sheep has a fair appetite, but will gradually lose flesh. In the last stages the bronchial cartarrh is severe, the respiration very feeble aud jerky, the cough deep, convulsive, and evidently painful, coming by fits and followed by suffocation, which leaves the patient still more exhausted. The nasal discharge becomes more copious, and contains quantities of embryo and worm fragments. Owing to the diminished respiration productive of anzemia, the skin becomes dry and harsh, and resembles parchment; hence the popular name * paper-skin.” The wool _is also affected and is easily pulled off, exposing the white, bloodless skin underneath. Duration. —Death occurs in three or four months either by exhaus- tion of vital forces or by suffocation. As the first stages pass unnoticed the total time from infection to death is probably nearer five or six months, The duration of the disease depends on the amount of infec- tion, the previous health of the patient, the care it receives, and its vi- tality. Where the symptoms are very decided the patients rarely sur- vive. The disease is most intense in autumn, and if the sheep do not die, it becomes less intense in winter to more or less completely disap- pear in spring. When the season has favored the development of the disease and the lambs show severe symptoms, the outlook for their re- covery is very unfavorable. A large percentage of those attacked die. 204 Others fall away in flesh to a serious extent and the growth of the fleece is retarded. Occurrence.—It is ausual thing to find lungs affected with Strongylus ovis pulmonalis, and more rare to find them affected with 8S. filaria. When the latter occurs it is ordinarily associated with the former, owing toits abundance, but it is easy to separate the two diseases. In the beginning of the S. filaria disease the very posterior tip of the lung is affected, turns dark red or grayish, and has a solid feeling and ap- pearance. From this the disease spreads anteriorly, lobe after lobe of the lung becoming involved as the bronchi choke up. These termi- nal patches are very sharply separated from the adjacent portion of the lung, which appears normal, except that it may be infected with S. ovis- pulmonalis, as indeed may be the part infected by S. filaria. The cause of this solidification or hepatization (so called because it becomes solid like liver) is the stoppage of the air tubes by the worms and the débris they produce. When they exclude the air from the part the air cells fill with débris and the part becomes solid. Portions of lobes elsewhere may become involved, but more rarely. The anterior lobes often ap- pear red and solid, but it will generally be noticed that in these the red part is thin and not as spongy and resistant as the lobes in the poste- rior end. This state is due to the air being driven out of the lobes and the walls coming together, producing a state of collapse (carnification or atelectasis). The solid lung produced by S. filariais often covered by a thickened whitish membrane, the inflamed serous membrane, which often grows fast to the chest or thoracic walls. After the worms disappear, either having been killed by remedies or from some unknown reason, the heal- ing process begins, and the lamb recovers if not too much weakened. Treatment of this disease is far more hopeful than that of the pneu- monia due to Strongylus ovis-pulmonalis. It may be dietetic, preventive, and medicinal. In an essay on this disease Mr. Stephen Powers (The American Merino, O. Judd Co., 1887, p. 283) says: To sustain the strength and vitality of a sheep already affected is exceedingly diffi- cult, because the appetite is feeble and capricious. The lamb can seldom be induced to eat enough even of the most nutritious food, to make any considerable impression on it in the way of betterment; and the danger in giving it by force stimulating gruels, etc., is that, owing to its bloodless condition, the process of digestion will be so illy performed that the food will do it more harm than good by causing scours. High feeding is of transcendent importance as a preventive measure; but when the lamb has reached such a pass that vermifuges have to be employed, it is necessary to proceed with great caution in giving rich food. These remarks commend themselves to all who have had experience with afflicted sheep. Keep the lambs up to the highest point of ex- cellence and health by feeding and they will the better withstand the ravages of the parasites. Corn and oats, bran, chops, and oil-cake are all good fatteners, and should be given in proper proportions. Salt should be placed where the sheep have free access, not only as a diet- 205 ary article, but for its medicinal influence. In addition they should have pure, fresh water once or twice a day. When the animals have become sick good diet should be supplied. Asintimated by Mr. Powers, those animals which seem most in need of food take the least, and if they do eat it may even be of harm tothem. However desirable it may be to feed animals well as a hygienic measure, still no amount of feed- ing will keep them from being infected when a season favorable to the parasite appears. There must therefore be a continual diligence exercised in keeping the pastures in good condition and the young sheep especially from becoming infected. As the parasites seem to thrive best in water, it follows that dry pastures should be preferred. The danger of infection from pastures should be diminished by limiting the number of sheep, so that they will not have to eat the grass close to the roots, and by a judicious distribution of the young sheep on practi- cally virgin pastures. Should a pasture have become permanently in- fected from long use it should be plowed up and either cultivated a year or two or allowed to stand idle or surrendered to other stock. The effect of the cold upon the embryos of these parasites is not yet known, and it may be that the alternate freezing and thawing which they sustain is in the Northern States the cause of the destruction of large numbers of them. Leuckart’s experiment of keeping the worms in moist earth, during which time many molted and died, indicate that a pasture would be much safer when thoroughly dried after a pro- longed rain than before, and also that such a wet time would be more dangerous for the sheep. A judicious selection of pasturage through- out the year, together with a shifting of the sheep from pasture to past- ure as the season and ages of the sheep seem to require, is the best that can be counseled at present. Medicinal treatment may be productive of much good, but is usually resorted to so late that its best effects are lost. Medicines have been administered with the food -by drenching, by fumigations, and by tracheal injections. Salt and copperas in proportions of from 1 of cop- peras to 25 of salt, and of 1 of copperas to 4 of salt, the last mixture being given in wet weather, has been advised (The American Me- rino, by Powers, 1887, p. 285). The weaker mixtures may be kept con- stantly before the lambs for eighteen months. The stronger should be alternated every two or three weeks with clear salt. Powers kept it constantly before the lambs until after the second summer. I would deprecate the use of copperas for any continued length of time, for it rot only harms the teeth, but if persisted in loses its force as a tonic remedy. In administering dry medicines in food much of their force is lost, for they are very apt to accumulate in the paunch or first stomach. Medicines given by drenching are more expensive in the dosing but more effective, for small quantities of fluids pass directly into the mani- folds or third stomach, and thence into the fourth stomach, especially if the sheep be thirsty. But few of the many remedies advised are in 206 the least effective except they be general tonics and stimulants. Many advise the use of anthelmintics, but these are of value only in driving off the intestinal parasites. Turpentine seems to be an exception to this rule, as some of it is eliminated by the lungs and so reaches the worms. Powers (op. cit., p/283) advises turpentine and linseed oil mixed in equal parts, a tablespoonful at a dose. Mr. W. G. Berry saturates lumps of salt with turpentine, then crushes the salt, mixes with bran, and feeds as a preventive. Neumann (Maladies Parasitaires, p. 517) states that the following have been recommended: Picrate of potash, from 3 to 6 grains per dose, dissolved in oatmeal, water, or mucilage; a mixture of equal parts of turpentine and spirits of camphor, a teaspoonful daily in mucilaginous drink; a mixture of creosote 120 parts, alcohol 500 parts, water 700 parts, dose a teaspoonful; creosote 60 parts, benzine 300 parts, water 2,000 parts, dose a teaspoonful for each patient daily for eight days. Hall ( Veterinarian, 1868) says that he employed with success 10 drops prussic acid (to be diluted in water) for a dose morning and evening. Neumann adds, however, that experience shows there is little reliance on these methods of treatment, and the administration is, besides, more or less difficult. The same author states that success is less uncertain with fumiga- tions which penetrate directly to the worms, benumbs them, and pro- vokes a cough by which they are brought up and ejected. The sheep to be treated should be driven into as nearly an air.tightshed or stable as is practicable. Then rags, horns, feathers, hair, old leather, tar, asafetida, etc., should be placed on a red-hot shovel or in an iron pot filled with burning coals or in a tinnev’s fire-pot. The intensity, dura- tion, and number of fumigations should be graduated according to the tolerance of the sheep. Hither some person should subject themselves to the same fumigations, or a very close watch should be maintained in order to prevent the lambs suffocating. Tracheal injections.—The method of treatment by tracheal iajenbtne promises much better results, but should only be practiced by a relia- ble veterinarian, who can oversee the results and take all necessary pre- cautions. The method has been detailed in the Second Annual Report of the Bureau of Animal Industry, 1885, page 284. It consists of intro- ducing remedies directly into the trachea by means of a hypodermic syringe which cause the death of the parasites. The medicines thus introduced have an opportunity of acting upon the parasites directly, before they are all absorbed by the mucous membrane ot the air pas- sages. There is no reason to doubt that they may have even a second- ary effect after their absorption if they are naturally thrown off by the mucous membrane of the air-passages and the epithelium of the ave which is the case with most volatile substances. The method of tracheal injections was first tried by Gohier in the early part of the present century, after learning experimentally that considerable quantities of liquid can be introduced into the trachea without producing suffocation. Delafond some 207 years after conducted some experiments to determine the absorptive powerof the air passages. He found that mucilaginous decoctions and solutions of sugar or honey are speedily absorbed when injected into the trachea, inducing slight symptoms of suffocation for one or two hours. He also found that solutions of narcotic agents and stimulants manifest their physiological effects very soon afterinjection, and that oils and oily medicines produce a congestion of the lungs which is but slowly dis- sipated, and that even very dilute solutions of mineral and vegetable acids produce inflammation, with copious secretion of mucus, giving rise to symptoms of asphyxia and even leading to death. Dr. Levi, of the University of Pisa, has recently applied this method in the treat- ment of a number of diseases (Manuel pratique des injections trachéales dans le cheval, 1883). His experiments also tended to show that the mucous membrane absorbs very rapidly, and is therefore less apt to suffer from the injection of irritating substances than if the absorption were less rapid. He also determined that the injection of small quantities of oily substances is not dangerous, the oil probably being emulsified and absorbed. Finally, there is always a slight reduction in the number of respirations, amounting to about three or four per minute, after the introduction of liquids, even when distilled water only is injected. Without entering into interesting questions concerning the administration of med_ icines in this manner in other diseases, which are discussed at length in the work mentioned, we find that the author has experimented on but one case of lung worms to test the efficacy of the method. Others, however, have reported cases in which their success justifies a detailed account of the method for future application. The instrument to be used is a simple hypodermic syringe holding from 1 to 2 fluid drams. The needle of the syringe must be provided with a removable solid rod or trocar, so as not to become plugged when it is pushed through the skin and walls of the trachea. As the needles are apt to break, a number of them should be kept on hand. After the operation the syringe should be carefully washed in pure water, the piston supplied with a drop of olive oil, and the trocar replaced in the needle. It is best to disinfect by filling the syringe and needle with a 5 per cent. solution of carbolic acid, or a 0.1 per cenv. solution of mercuric chloride* before washing in pure water. The disinfection, however, is not absolutely necessary in this operation if the syringe and needle be kept thoroughly clean. To administer the medicine first fill the syringe and place at the side. Hold the sheep for drenching, and extend the head of the animal so as to fix and make promi- nent the trachea, which will be felt as a tense elastic tube along the middle line of the neck. The most convenient point for the introduction of the needle is at about the middle of the length of the neck. It must be remembered that some care is to be observed, as the trachea is near some important structures on either side—the jugular vein, the carotid artery, and the pneumogastric nerve. Having fixed the trachea with the left hand, the needle with the trocar is inserted beneath the skin, and then an interannular space is sought so as not to pierce a cartilaginous ring. Or the needle may be pushed directly into the trachea without necessarily avoiding a . cartilaginous ring. The unimpeded movement of the free end of the needle as if in an empty space is asuresign that the needle is in its proper place. The trocar is now removed, the syringe screwed upon the needle, and the contents very slowly forced into the trachea. Before the needle is finally withdrawn Dr. Levi thinks best to wash it out with some pure water so as to remove the injecting fluid. In withdraw- ing the needle this might accidentally be discharged in the wound made by the needle and set up inflammation if the substances introduced be irritating. How this wash- ing out is to be done he does not state. It seems that a small pipette or medicine- *The former is prepared by adding 5 parts by weight of pure carbolic acid to 100 parts by weight of pure water previously heated ; the latter by adding 1 part of the corrosive sublimate (a violent poison) to 1,000 parts of water, 208 dropper filled with water and inserted into the end of the needle would suffice to wash it out, or drawing back the piston of the syringe would leave the needle compara- tively empty. The needle might also be washed out by removing the syringe, wash- ing it out, filling with water, and forcing a few drops into the trachea through this needle. This, however, would cause unnecessary delay before the animal is released, and is therefore not to be recommended. The simplest method, then, to empty the needle would be to draw back the piston, for the discharge of anything but the purest water into the wound may produce more irritation than the medicinal substances themselves. The animal should be watched for some time, especially after the first operation, to observe how the injection has been borne, and whether any symptoms arise which indicate difficulty of breathing. If, as has been suggested, a slight incision be made in the skin before iinedatoee the needle, and if a cartilaginous ring be avoided in piercing the trachea, the ordi- nary needle with beveled extremity will be sufficient, and the trocar may be dis- pensed with. When the needle has entered the trachea, a slight hissizg noise, due to the entrance and exit of air with each inspiration and expiration, indicates that the needle has reached its destination and is not plugged. The substances to be injected should have distinctly vermicide properties, with- out being at the same time too irritating or poisonous in their effects on the animal. Levi gives two formule which he used with success upon asheep. The werms were discharged in three days and the catarrh cured: Iodine, 2 parts; iodide of potash, 10 parts; distilled water, 100 parts, by weight. Begin with half a dram of this solution, add half a dram of water, and increase by half a dram of the above solution each day up to5drams. Anotherremed» is the following: Mix equal parts of turpentine and olive oil, and inject from 1 to 4 drams. In this case the writer probably intended to state that the dose should be invreased from 1to 4 drams on successive days. Eloire (Recueil de Med. Vet., 1883, p. 683) gives the following formula: Orv inary oil of poppy and oil of turpentine, each 100 parts; carbolic acid and purified oil of cade, each 2 parts. The oil of poppy, being a bland oil, does not possess any medicinal properties and may be replaced by olive oil. Each sheep to receive about 2 dramsa day for three days. é; Six animals treated in this way showed immediate improvement and were finally cured. Penhale (Veterinarian, 1835, p. 106) reports immediate relief and ultimate cure in two calves by injecting the following mixture: Oil of turpentine, 2 drams; carbolic acid, 20 drops; chloroform, 4} dram. One-half of this amount may be given to a sheep and the dose subsequently in creased if necessary. Hutton (loc. cit., p. 62) reports favorable results in six out of eight cases by inject- ing the above liquid, in which 1 dram of the tincture of opium was used in place of chloroform. This completes the list of remedies thus far suggested and tried. The favorable testimony, though not abundant, is very encouraging. There are many substances, no doubt, the use of which might be more beneficial than those mentioned, but poste can be said of them until they have been tested. The dose for young sheep should be proportioned to the age and size of the animal. The preparations with turpentine seem to have given the best results. During treatment the patients should receive the best of care. The prevention of this disease is very desirable, though it may never 209 be completely attained. Ifa farm is completely free from it in the first place, then prevention simply lies in not allowing infected sheep to be brought on the premises. All purchases of sheep should be from flocks which have shown no signs of the disease in preceding years. Brooks which run from pasture to pasture offer a chance of infection where the neighbors’ flocks upstream are infected. Strange sheep should not be pastured unless they are known to be free from parasites. Feeding and care to keep up the general health are essential. Careful separa- tion of affected animals should be practiced, and the worst diseased ones may beslaughtered. Treatment should not be neglected. During treatment it is best to keep the sheep up, and after the course of treat- ment is concluded they should be turned into new pastures. 23038 A P——14 . Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. -~ 5. 6. 08 8. 210 STRONGYLUS FILARIA, Rud. IPTEATEOXEXERT Vie . Adult female, x3: a, head; 6b, vulva. . Adult male, X3: a, head; b, bursa and spicula. The dark line in Figs. 1 and 2 is the intestine. . Cephalic end: a, mouth; 6, esophagus; c, intestine; d, unicellular glands, . Middle portion of female: a, vulva; b, vagina; c, c, uteri with developing eggs. Piece of skin showing striz. Spicula: a, the fenestrated chitinous cylinders; 6, the bulb like enlargement of the surrounding membrane. Caudal end of female: a, anus; b, b, intestine; c, loop of the caudal uterus, d, ovary. Caudal end of male, ventral view: a, intestines; 6, seminal reservoir; c, the torn edges of the spread bursa; d, ventral cost; e, ventro-lateral; f, lateral; g, dorso-lateral; h, dorsal; i, spicula. Fig. 9. The same lateral view. Fig. 10. a, female, natural size; 6, male, natural size. Fig. 11. Eggs showing various stages of development of embryo in the following order: a, b, c, d; e, embryo escaped from shell. LX: 10 A.Hoen & Co. Lith. Baliiniore PLATE XXx STRONGYLUS FILARIA, (The Thread Lung Worm.) STRONGYLUS FILARIA, Rud. ss ae Puate XXXV. pas Portion of right lung of lamb, dorsal view. The affected region is ee ored posterior end. It is clearly marked off from the healthy portion. ; spot about the middle of the figure is also caused by the worms, but: is | E to find these lobes affected in atl stages. . PLATE XXXV A Hoen & Co, Lithacaustic Baltimore. Haines, del. STRONGYLUS FILARIA. LAMB’S LUNG AFFECTED BY THREADWORMS LA CuAL PE AY Y ocx) Se ta ; roe Sa ee a foes hit, thab Dedasl hi ty thine ee * eke i ’ Fos i Veit qaeitetew ; fe oe ee Bates UNE LPN) 195, 209 AE Ta fe 214 STRONGYLUS FILARIA, Rud. PLATE XXXVI. Portion of right lung of lamb, ventral view. This is the same lung figured in Plate XXXV. The affected portion is in the posterior end. The lung tissue has been dissected to show the tracheal branches and the bronchi. The bronchi leading to the dark-colored affected region are filled with the life-sized figures of the Stron- gylus filaria, PLATE XXXVI Haines, del. A.Hoen & Co. Lithocaustic, Baltimore. LAMB’S LUNG INVADED BY STRONGYLUS FILARIA, = — < — ae 4 INDEX. : Page. Abdomen, parasites in (see Linguatula tenoides and Tenia marginata). Mbundanee Of parasites. ..... 2.22. cccncs cacmncnccees nnne nencenennnns cnen 9 PM Me Reece rec cnc cs sees secces eee stn stcsenleascerinccs sccjecntsseers 5a LA OTMISE Ce BS SEE CECB EEE ICE EEO eee ES Ron pea a eee eine poe eeeeinaers 53 PRT ee RTA SS So Coe cos ade aa neces Nacacss sp oeeisse tes ncemocssleenaseae 22 SMAPS TE CORLOUMYS 0a '- oom svn sees 24s esos no eseelnnt ec asendee™ -casmc 16, 138 meme eOAt LOHEGL 2. = = 2-5 2202 ones 2a- 0 cnoced nance sade taeees eesecsien===s 50 Antelope as a bearer of sheep parasites..-....--.-..----- ---200 conn ee nnn e ee 15 Arrangement, plan followed in bulletin...-....---. ..--2. 00-2 cece e--een---e 22 Ie PP sine oe. 2s dan doers cba casc Soates saeeaceasees cum ceawenmens 18 PARES PTECOLLCS aos 2, ccc one ae bah oe 5 cocoa ee ee sae eae ecoee ane ecesae 16, 145, 151 GesCMIPMONuaheede cea} caste Cates eseeee cow awsacenieaos 151. PURO « utnas Camas we estecen eet ses ee nce ae casaaeseny 154 DUT errata ee a2 ch. csecasa staceee ses Seatenwegetecere sacece 151 Mine MRL IEEE es oie cas ea oc vw lahce ee Sace Koos ccleeee coeme otoaeeee s 152 ME MCTIRO GUN ce scence a 2 one ce tact case ces see less closets c ese caelnewiass 18 RAPINOIAWIOLINE Meat os ose ok aa secede dis as cede cases tees s cone ewbeee 72 Brain, parasites in (see Cenurus cerebralis). Reape ee VBLMNDOUS > caste ss Adonai ce sen ques 7s ceed neaeca rt caas Saae eae 185, 201 Se HUME MOnWVOLMei Nee ees o 225 acco ces nemesis = coe secitee, coe oa ce ncteliomees 181 Inne NACA Sans poten cee wo ocunwisnceoneeea saccade ee nesaa sneseeenmmastee 25 MONTESCONUMUNIS VAT NOUS) osn\- sme acene aoa s sisal ael aaiae oe saianin sitar 53, 65 PAUL EIE ESA cM se ols coced ccss scecas os ceen seec ssiccs Saeco eae ameomeans ss 18,117 CORTUPUSICETEUT AUS scrcmc oscccc acua aac « 2b ohne Ree ren ee ie eeeciee 30, 72, 83 Common scab (see Psoroptes communis var. ovis). RG OCCNMW.OLINS RID a= coo sais cick ose ane eet oearoscn sticis\ce cateuse ce mace weasel 14 OT RACELCUOROUIS Bam ahaa walwue lad ssaielkalseeswcemes see en escent eecoeealasiere seeen we sene 131 216 Page. Distoma hepaticum, disease period of anwemia.......2.. 22. eee cece ene ee ence 129 CMIPTRLION sacwccves ce acees eee eee 130 IMMNIPTREION .a/1. os «<<. 000 see 129 lose Of Mlesh.232~ <2 cds vance meeeeeee 3 130 PTOGNOBIS . Joao powerpc cena seee te cease ee 131 symptoms........- S amaeineie Seen eer Eee "isa treatment... ce scee onion sebwss sca eeele a= eee 133 Pi PUTOS. 2 nea; cas ascls o Ae micalsinteccisiecic) wae etenae snicioe bic cn/cemmeerace ciate e 14, 16, 69 Gescriphionssoss ascot sce ckecies ceiearaciaionn foe sors cpeteeiee 69 @Iseuse: Ga Nsedgb Vj cesar ajscnces Sms vsns ss Palo tooereLiters 69 DUINON ws ae oc ieiwice cic sees ce ae eee etn J oosee eee 140 lifechishonyn. acejcscicecee eles ceces ete tone eae dees 69 PTE LMOTP R IE iat tae tae ee a wiv iw ioe Sim eise nia oe ciate Cale cape wine Aelapmetciorae 69 MA ieoMmaparasiieseGGSCRINOG ss mas. Jo. onc lecicale ce ccwieces case casscnioonaeeataes 16 ExsuorMna lM PANABIOOSE aes ees cock cs oc aw cick e wes Ek Cee be zics. ne ete eniemep aan 18 _ Liver, parasites in....-. ---. - 20-222 eee ee eee ene ne eee ee ee te eee eee 127 reuse eee roe tetany torn cmos vcdalbec cee oee bse cows cesses 127 immer. uke (see. Distoma hepatioum)......---. cecesseentes cnccse woos waccee ss 127 KSEBPDistominmlanceolatwi)ccwccneeta cote ttacce sees Saeeeceeseee 137 Lombriz (see Strongylus contortus). _ Louse fly (see Melophagus ovinus). SP NIMEMI REPO iets so ciicl so vn, acacoeccccme sandesl occurs lesa cneces 185, 186, 201 CUIAON OSI Ses seen ote waa cs sce ate selene wea Seema th ame ttalererciats mere 186 SVECIOS ROLE ye seem ee eet d= Seek eine Ik oN aes Rea oe yee we 185 parasies.oL the Oldie World 1223... -se cco sesccs tae see ances aes eaiewic einen Lz Lye water and whitewashing in scab......-...--------.--- ae cave acetate 12 ol AL DIUGI TT! Sc SORE AR SEIS Se GEE AOE CIDE OEEOD SERCO ac B cn cignriscpsc 45 eenaranites .Gi,.common to dog. :s\...s..0.54 ots. sbede easel ocuee seeker 14 SHOP: ses iie ccsatecoeuecwessees neon aeeecee 16 PPA MENVO NMOS UMN 2S ts chaos alana a ciate coo kletheortoe See eatione te ciot Ase Sern mie lett 14 andyineheepiseets se Scns. ccc 2 oot erie eee ate eee 87 Maines destrucuon or 6mbryos il. 2c 2-25 c.- ck cawwecceeeance me cesee- 13 aconomicwnanarOment Olas. qjseic cee s cece eiae eee lioee release ere 12 MES TUEGIOL es WOH eh 2s2 oe 2s os seas ees seee ances cee eee eee amas 13 BRONCO Ol Maraslwe IDTOCHON: . 52 .s24s5 sel ssaee dance hess cacebs Seee 13 Measles, in mutton (see Tenia tenella). MPAMIUO MUS mete) See ots Soa 4 acle caciowes ca sas cas ccenee sbclemalos melee ae . 23 Semen POARINGDT.- toes cac cds as wictes cas abe en we Weine owns Soe hanieen mseasenne 15 MMEEINOEGET ODM 2.258) Gann Se os eee wen cise m cee De sete’ ott V ebieane se nasi an 16, 39 disease caused by....-....- 22 toe one cone ne wn ee ene nae 41 PEGAGILG Ite ae Stee See ee eles Sere else ale sioieteatatalaete 41 CPE MIMON Gs Wilby. sass sees Sees te cnicsl- seen lesen (= dan'smaae 41 MepmPeneeers = ee Son U2 os Sete ocak cee aoe beemes oar aeenees 44 HADMG OLS Been oY ee ee Joe coeicslesise ce nceint 40 inte Nishonyeeeee Vee eee oe eae Se. ceed cece baw see tee 40 MUMMETOTIE GAO Femeet ne: anatase aos oncbes vecces -sebieeme Al ROURC OM ates Soe a See aa eel net cee ole dates saan seers Al PMR nr NATSSLEN MRS) eee Joao oop ant pdainstee denise welse ea selss vinsees 87 Wodular disease of intestines <. .. 2... 2... oe on on cae ciccne coon coc eon case coeses 165 ME GLUR COR lise ano teae tees aawa cesaias/ swan guncccna coca aces je cccowncs 25 218 Page. CBaophagostoma Gcutur ..-5 voc ne -ces pvesneweumec Gude eeee ¢oecenedeeaaneaeen 168 Gsophagostoma columbianum....--..--...--..-2--- 16, 17, 20, 21, 22, 118, 145, 161, 162 ; description 2350-502 pens eee oo co See 167 determination: of ‘adult... 20... 00 cc co8. eee 166 disease cansedThy222 sooo brace See 169 diagrnosis ss. Sete ce, oes ee ees eee 172 pathology. 525 32200 J neiee Lee oun 169 prevention (222282 da ae Lees ee 173 distribution: :..Y2-2.'..< .5t veseee reese oe oe 165 figures... 22.010 255. acpteccs povemens Mees lap 70a arn investigation concerning - .......-------- eseses 165 life history | 3. 52's s ooo eee eee ee eee 168 OCCUTTENCE. aca coe cw nas quereeieeees ateee eee 168 (Estrus ovis. ..+. 2. a nenne wisioslsaeees cine cece ce ane eee e Cee Eee 16, 17, 19, 20, 25, 85 description. - 2-226 22 2 Seo e ce oe dee Roa ee ee 25 Of larvie is... 220 50. 2G ss Sane Senelde eeeree eee eee 26 effects of sheep <2. 255.0. 6 5) sce ee oe 27 HM PULCR eae oe vey sabeetubbs decks Soe OCCULTONCE WS 252 ne nk Soc ee Eh Seine eee ee 30 pathology, --\. .. 2.co2- sau J2ess eS eee aoe eee eee 28 treatment 2 2... Sole sce ccd atin. Re ogace no ene eee ee 31 BUrPICal 2522 sees occ tuceas eeee en cceee eee Seams 33 (Paperiskin =o. Soo2es = oc co etc ooo w ook cle eek ene ee 185, 201 Parasites, abundance ,--=2< 2.2 0scc oo oo occa coe ee ee 9 ANIM Bless see se eee eee See eee siptedasreweste scence ily common to sheep and dog soc i. seu srancevctese peewee eee eaeeee . 14 external, definition Of2sc....2cebcconaceeeelte ocean cece Eneeee 18 destructiveness >. sc. shoe AO. oe sae eee scuzeeseeteceee 22 how sheep become infested. 2.:..2....c- sce ceeseccecee eee eee eee 19 length of time of development... -....ce0 sco ence nnoe coe cedsene 20 locatION,. 3.3 e ssi ca ca see See Ee eee Eke se 18 of the'skin« 2. 202 Sars ee i eee 39 seasonal appearance sic. cosc.cl deen coe ee cee slascte sates 21 vegetable... ts32 23 eke cocdc ot nese ee eee 17 Parasitic diseases the chief source of losses...--. .--- ----20 e--cee cee ene cnnee 9 Pastures, as'a source of infection’... -ses:s=---5 Laos osc eee eee eee 13 CALO (OF 2255 Socata ee oo 5 5 de aSesa See ee See ee ee 13 Pentastoma denticulathun s. 23s. v= ovddu wade waacae vote dav eeocdueeed eee 69 Pentastomea tenioides <2. oo ee ae eee ee #o eles cei abe 69 PHGHIPISSI8 2s 2 sees Sek. woes ne wn ccc ree Hee Bea ee 39, 45 Pneumonia, Verminous 2.22... .:22 ccc cascode sce ea nase ease eee eee eee 185, 186 Paoroptes conmunis, Vars Ovis 2 oo nocakn'a- on veann's Saceseen neon eee ee 16, 17, 53, 56 Giseasé Caused by .. cscs --65 eccebece-0 scab tase eee 56 diagnosis . 205. ccc hod ee wet ence ee eee eee 57 differential 22s jacd cee sesececsceme nse 59 pathology <<. 32d Sa 5nd ee eee 57 prognosis..222--\.c-eesebeeeees baleos pee 58, 59 source Of contagion .cccc..ca5 cess cesues cane seer = 58 symptoms Of .225...s--esnece~o eo eeeee eee == ee 56 treatment, medicinal: .-.2-- seg-eeresse--cneseee 60 PFOventiVe .csccsesenes sees eeeaeeeee 56 firures.o6 3-5 soo coaon coe ceases cee oe Rete 66, 68 legislation concerning ....-..-----+-------- aL Receseee 64 Purchasing sheep, examinations in ......:22020 ocdees suecevectecweeseemees 15 219 Page. Rabbits, not infested by parasites of sheep ........-.--.----. ee eeee one none 14 Ranges as a source of infection........... Bene neetteeeal tact ocicnusae sacateons 13 ee ee ed ile ln Gm ein ae ae cae waninwescadeniaseneb sseecsia-' 13 BS Rae elas ee a clan ecco widead Coven s caceincus cnccsubcue eececs secs 53 ee EEN TOH OM dawn n'= os o's a senate eae cae eeeealce one a= 54 acess 53 ee eee tee fe steer cee ses hae ae sae ewe eame oS ea sae SnonQese 53 PRISON ea ainc mc sa Sa ce acocamen woarecte ese ren ceeene Geek sacs noes 53 white-washing and lye water -............ aida ce CBOnde Bae eeE a6 12 DEEN CNAN OU oo oa. oo o~ na oacudece weeans sclesommuas sosacaqs~sase 53, 54, 56 MMBEPNPAION v5 2250 26 oo Saem casa cease asa len eb eee Sea 54 SARPUBE CAUSED, Diy) Wo scen oF oe acisaat Somes Seceee wcunca tess gens 54 MiAPNOBIS.2 a5 .cos eye mee ece ao cle coey seeay nade Seoe 56 PLOONOSISS ee Footie oe Seer eae ecb ae cose eee ees 56 SUNICE Ul- COHLEMION. Jc). 5 Seacce ence ecaosscaceees 55 TERUMONU sc wacsys sient som ee lente Seclecd cee os 2inamo(s sam ca on nls seisaais a ousjecedacea Roeciscicocee el Oly los Sheep grub (see Gstrus ovis). (STIRS ApS) SE ee A el ee er en err ee en 9 Sheep louse (see Trichodectes spherocephalus). MeRIy IME oe Sat end So oaecaidiask pu doe= Sete s we'd Tans oe ee 45 MIRE ren iit fie Nie Me no ofa on anno siden anne oc oracasn/-oeeuee ee 39, 45, 49 PEMnCes Oh niconmabion, LECOONTION! Of sac sainbim aie -n no < sSsmesieenleece secs. cece 23 SrEeere a RunG an win WM bed. SLES Sond. ce st nico as fo sete panineocadunbecee aces 16 American and European compared ....-. ..-.-. e--- .2een- ene nne new cee 16 MOESCTIDOO) see c-\aiauein siete ccs! hnwiocicieia's aneieniticsa soe saa oe eee eee ae 17 COSiTHEhEY Oven volcan puiscs Secale sone sont oe eee e oes oer eee te eae 17 Ni MOU MILE OUALOSR sock ans acacmcemecnaatts cae cial e Sear oe eee eee 16 QHEXLELR A) PATASULES) <<. 2-+ os Sano al caee cs Voices daceeumasenernleemeee 16 PARG pin UMibed Stables a sose 2s -apcescnc se cmclenoee a Septem eer eae 16 Staggers (see Tenia cenurus). Stomach round worms (see Sirongylus contortus). PROG ULUS: CONTOTUUS: <2 3252 to mace scan atecepcnclieeece 16, 17, 20, 22, 117, 118, 141, 146, 202 descriptions. <2. ok ss te tee eee none eo mae aon tome 141 disease caused: by’ << 222/s-7 sSeeecescstec ne eaeeeercees 142 hreabMentes 22. - o2 sees sce coe stemeeleseinoaee 142 DGRTAR Ls Sue ee one on aoe oh eee aa eee Moa eee 144 Lite PASGOPY . cS cntan Coe ets ae auntie Got teen 141 the Lombriz disease ssc. set ae ee cael ne aoe eee aes 141 TI EI LOING ooo a we) a nnin nyicinbs. ale ta mcnlsais ce '= = 4d caer ea eae 16, 17, 20, 21, 185 Peeemption 5. 6... 5 oe eeeaee ee cn oseeeus cen eee eens 201 - GISOANE, CANSDUL D's 2 «a= =n v= ses 46 Trichodectes spherocephalus ..2 22. --20 ccna ence conece cece ceecce wane cans 16, 20, 45, 49, 51 description ...-.. BER e on cee nob Cote caer ceosboOSeC 46 diseane Caused Dyiks=-ce~ sn oeee eee eee eee 46 figures. .<-. --- -cceccons ocncscunes esses ssn sep sme 48 life (higtOLy \s <2 5-