320 THE DOMESTIC SHEEP. 



Pacific. It has been found in deer killed in many parts of these 

 Western localities, and the author has identified it in several 

 specimens sent to him mostly from Arizona and New Mexico, 

 from both deer and sheep. 



FIG. 5. Adult, Natural Size. 



Segments 

 near Head. 



The illustrations, fig. 5, show the special character of this 

 tape worm, with the fringed edges, of the segments. Its form is 

 lanceolate in its contracted state, but linear when extended. 

 When contracted, the fringes being drawn closely together appeal- 

 like plush. The shedding of the fertile segments begins early in 

 life and continues until death. The head is provided with four 

 cup-like suckers. 



These worms are found in sheep during the whole year, but 

 none in lambs under ten months old. It seems that the breeding 

 locality is the duodenum, as worms less than one-tenth of an inch 

 in length have been found in it, when the gall ducts were en- 

 tirely filled. The manner of reproduction is by the separation of 

 the final segments as in other tape worms. At two months age 

 the worms are about half an inch in length, in four months the 

 worm has grown to five inches in length, at which time they be- 

 gin, to affect the condition of the infected sheep. This effect is to 

 stop, or dwarf, the growth; reduce fat lambs to skeletons, thin, 

 hidebound, and dwarfed, with little wool, and that weak and ten- 

 der in the fiber. 



The lambs show the first indications of the disease by their 

 gradual loss of condition. A desire to eat coarse, indigestible food, 

 a depraved appetite in fact, is one of the first evidences of in- 

 fection. Thus the sheep have been found to eat large quantities 

 of the so-called loco or crazy weeds of the plains, but more cor- 

 rectly the two plants known by this name, but correctly as As 

 traloagus mollismus, and a closely related other plant, a species 

 of Oxytropis. These are well known to the stockmen of the 

 Western plains, as being injurious to horses and cattle and as wel.l 

 to sheep. 



