170 EEPOET OF THE BUEEATJ OF ANIMAL IKDUSTEY. 



the land connection of North and South America would permit of 

 the infection of deer of both continents with the same species of par- 

 asites. 



Tc&nia fimbriata is lanceolate when contracted, linear when re- 

 laxed. It is quite thick, the fimbrise on the contracted specimens 

 presenting the appearance of plush. The segments can only be dis- 

 tinguished on the more relaxed specimens. Adult specimens are 

 from 15 to 30 cm in length, and about 8 mm in width. Immature speci- 

 mens range from less than 5 mm upwards. The greatest width is 

 about 2 cm from the free end, from which point the segments become 

 narrower. There are at the free end of adult specimens from three 

 to four or more segments which are of nearly equal width, which 

 have lost their contractility and are in the process of being shed. 

 The shedding of segments begins in youngest specimens and contin- 

 ues throughout the life of the parasite. 



The head or organ of attachment is depressed and tetragonal, and 

 quite large, sitting on the neck like a pin head; it is from l mm to 

 1.5 mm wide, hookless, and has four very large suckers. The sub- 

 stance of these cups forms the greater part of the head. 



The neck or the part where segmentation begins is very short in 

 contracted specimens, but can be seen in the relaxed condition. The 

 segments are very short and flat near the head, but concave or cup- 

 like toward the free end, each one lapping the succeeding, and all 

 appearing linear on the surface of the tsenia. The terminal relaxed 

 segments are cuneate. The borders of segments nearest the head 

 are slightly wavy or crenate. They soon become nmbriate even in 

 youngest tsenia; so that the smallest specimen found demonstrated 

 the fringed character of the species. The fimbrise may either be 

 contracted, when they are stout and short, or relaxed when they are 

 flaccid and proportionately longer. They are obtusely pointed. The 

 segmentation in contracted specimens is made out with dimculty. 

 It is indicated by transverse striae. In relaxed specimens it is plainer. 



The sexual organs are symmetrically placed, two sets in each seg- 

 ment, each opening in a lateral pore. Each set of organs is com- 

 posed of a male and female portion, or is hermaphroditic. They be- 

 gin to develop at some distance from the head and attain maturity 

 towards the middle of the tsenia. 



Besides being remarkable in the fimbriate character of its seg- 

 ments this species is also peculiar in the form of its reproductive ap- 

 paratus. The male portion develops first and occupies the whole 

 width of the young segments. It consists of sacs connected by tu- 

 bules with a large tube which finally becomes the much convoluted 

 efferent tube. 



The ovaries develop later, and are situated at each side of the seg- 

 ment. They are not shown in the plate. 



The uteri develop last. Each is made of a series of bags arranged 

 side by side in a fringe which extends along- the top of the segment 

 from side to side. These bags open into a larger tube from which 

 they receive the developing embryo. The tube connects with the 

 ovaries. The embryos develop in the uteri, and probably remain 

 there until the segments go to pieces on the ground, and thus permit 

 them to be scattered. They are six-hooked and not essentially dif- 

 ferent from those of other tsenia. 



This tsenia is found in the duodenum and gall ducts of sheep. The 

 former is sometimes found containing from thirty to one hundred 

 specimens. More often, however, there are from two to thirty. The 



