T.EXIASIS 177 



segments are broader than long, having the uterus transverse and the 

 genital pores double or irregularly alternate. The segments have long 

 fringes on their posterior borders (Fig. 93). 



Length, six inches or more. 



Its larval form is unknown. 



Occurrence and Symptoms. — All of these worms live in the small 

 intestine. As nothing is yet known of their cystic forms, the mode of 

 infection remains undetermined. Cattle are rarely disturbed in health 

 by the presence of tapeworms. In exceptional cases there may be 

 malnutrition and digestive disturbances accompanied by bloating. 

 Again, it is difficult to with certainty assign these nonspecific condi- 

 tions to the presence of tapeworms. As in all intestinal helminthiases, 

 there is to be borne in mind the possibility of the worms passing to 

 unusual locations, as the bile ducts, and of 

 interference with the movement of the in- 

 testinal contents by massed worms. 



Of the domesticated herbivorous animals, 

 probably sheep most frequently harbor tai^e- 

 worms. A species often found in those of 

 the United States is Thijsanosoma aclinioidcs 

 Avhich, as is true of other species infesting 

 sheep, is most prevalent among the flocks of Fig. 93.— Thysanosoma ac- 

 the Western States. The worms may be tinioides, anterior segments,— 

 found at an}' time of the year, though more ^^ ^'^^^ 

 often during the season of grazing, a fact pointing to the probability 

 that the encysted larvae are taken up with the grass. Thysanosoma 

 actinioides, when brought to certain parts of the Eastern United States, 

 does not multiply. It may be assumed that this is attributable to 

 absence of the proper intermediate host, whatever that may be. In 

 parts of the west it constitutes a form of taeniasis much more severe than 

 that from ]\Ioniezia. This is due mainly to their invasion of the bile 

 duct, a habit which is exceptional with other tapeworms, but with the 

 fringed tapeworm it is the rule rather than the exception. 



Lambs born in the winter and turned upon grass during the rains 

 and moisture of spring are the more likely to suffer from tapeworm 

 invasion. In such cases, or in hea\y infestation, anaemia is indicated 

 by paleness of the \asible mucosae, and this may be accompanied by 

 loss of vivacity and more or less emaciation with arrest in development. 

 Straining and ineffectual efforts at defecation, with prolonged elevation 

 of the tail, are noticed, the feces later becoming unformed or even fluid 

 and containing the segments. 



Death ma}' ensue in advanced emaciation and weakness, or before 

 reaching this stage if the intestine becomes obstiiicted by the worms 

 in mass or there are other resulting complications. Such a course is 



