THE DOMESTIC SHEEP. 



the smallest pin. Its body is made up of very short but wide 

 joints, increasing in width from the head to the other extremity, 

 at which, as with other tape worms, the mature segments sep- 

 arate and pass out of the intestines. 



These worms have no alimentary canal, but absorb their 

 nutriment through the surface of the segments. The em- 

 bryos exist in the mature segments. They are too small 

 to be apparent to the sight. Each of them is provided 

 with, hooks by which they attach themselves to the coats of the 

 intestines. The worms are found all over the United States, and 

 are at work in every month in the year. In the Spring and Fail, 

 Summer and Winter, they have been found in the intestines of 

 lambs slaughtered at the abattoirs. They are more abundant in 

 some localities than in others, and in the Summer than in the 

 Winter. Overfed and bare pastures are'the most prolific sources 

 of infection, by which it is apparent that the segments ejected 

 from the bowels, and falling on the ground, are in some way 

 picked up by the lambs and become matured in their intestines. 

 There is no intermediate bearer of this parasite. 



The growth of the young worms is very rapid. They have been 

 found two to five yards long in lambs two to four months old, 

 which is equivalent to a foot to two feet of growth in a week. All the 

 knowledge possessed by careful investigators goes to prove be- 

 yond question that this worm does not pass any stage of its exis- 

 tence in the bodies of any other animals of any kind than the 

 sheep, and its life history is thus simple and devoid of the interest 

 in this regard attaching to other tape worms. 



The existence of the worms becomes evident by the appear- 

 ance of the white segments attached to the small balls of dung 

 voided by the sheep, or by these adhering to the wool about the 

 top of the tail. This, however, only happens after the lamb has* 

 been infested some time and the segments of the tape worms 

 have become matured. The worst results to the sheep by the 

 presence of these worms seem to be due to the intestinal irrita- 

 tion set up by them, and the reflex action of this on the nervous 

 system. But the worms obstruct the intestines as well by their 

 large size, irritate it by their movements, produce excessive intes- 

 tinal secretions, non-assimilation of food, and as well abstract 

 nutritious matter from their victims for their own growth. The 

 results are necessarily the wasting of the lambs which become 

 poor, unthrifty, and hidebound, and frequently pot bellied by 

 distension from gas in the bowels, or shrunken and gaunt for 

 want of sufficient support. 



The symptoms in addition to these are pale membranes 

 (paper skin), dry, harsh fleece without yolk or oil, a tottering gait, 

 and the lambs eat and drink more than with their natural appe- 

 tite, but at the same time fail to digest their food or thrive upon 

 it. Finally diarrhea becomes more and more severe and death 

 occurs by actual starvation and exhaustion. 



If, however, the lambs can be safely carried over until the 

 worms are all ejected as segments, and no fresh infection occurs, 

 recovery is rapid and the lambs soon become fat and thrifty. 



