156 



ties for safely passing the indefmite time prior to finding their way into 

 their final host are increased. 



In ray own experiments in keeping a number of lambs in a circum- 

 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 i^ools 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 jiarasites ever seem to be pres- 

 ent in one sheep, and generally there are less than one hundred ; then, 

 too, if other parasites are foviud 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 anaemia, and if we may accu- 

 mulate corroborative evidence from the disease which Dochmius trigo- 

 nocephaluSj 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-evideuce, for in human 

 j)atients afi'ected 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 wouuding 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 Schnltliess, Zeitschrift f. tviss. Zoologie, XXXVII, 1882, pp. 1G3- 

 217. J. Ernst, Deutsche med. Wochenschrift, 1888, p. 291. A. Friiukel, ibidem, 1885, p. 

 443. O. Leichteustoiu, ibidem, 1885, pp. 484, 486, 501, 523 ; 188(5, pp. 173, 176, 194, 216 ; 

 1887, 565 aud five following numbers; 1888, p. 848. 



