182 



KEPOKT OF THE BUREAU OF ANIMAL INDUSTRY, 



of these was adult; many small T. fimbriata, varying from l cm to 7 cm long; also six 

 cysticerci, somewhat larger than the earlier found. 



April 20. Killed No. 106. It contained many T. fimbriata, over twenty-five in 

 all, which were over 7 cm in length; none were smaller. The duodenum and gall 

 ducts were packed. None Were adult. 



May 7. Killed No. 110. It contained one adult western tsenia and several cysti- 

 cerci. 



March 14, 1887. Killed No. 103. It contained from fifty to sixty tsenise from 

 l cm to 10 cm in length; four of these were in the gall ducts and were among the largest 

 in size. Taenise immature to adult. 



March 29. Killed No. 101. Found teeni^e in duodenum, gall ducts, and pancre- 

 atic ducts. The gall ducts were engorged; the liver smaller than normal. The 

 tseniae ranged in size from 7 cm to the adults' length; three were adult. There were 

 three cysticerci. 



April 28. Killed 104. Found five taenise from 2 cm to 4 cm in length, but no cysti- 

 cerci. 



April 28. Killed 102. Found fifteen tasniae. The largest were not over 7 cm in 

 length, and immature. There were two cysticerci. 



Table C is made up from data obtained from the six lambs, Nos. 

 105 to 110, inclusive, transported from the prairies to Washington. 

 It shows the comparatively slow growth of the parasite; also the 

 abundant infection of some of the animals so long as they were ex- 

 posed to infection. It also presents either the possibility of infec- 

 tion after they were taken from the prairie or the retention of the 

 embryo in the rumen through a considerable time. 



C. 



October 15, the date on which the lambs were taken from the prairie and corraled. 

 December 1, the date on which the lambs were received in Washington. 

 December 31, the date on which the adults, Nos. 101 to 104, were removed. 



Lambs K and I, Table B, show that the tsenia was developed to a 

 length of 2 cm in less than ten or twelve .weeks, for the number of 

 taenise found shows a slight infection, and some time may have elapsed 

 after the birth of the lamb before its infection. 



Lambs A to I, Table B, show that in from twenty-three to twenty- 

 eight weeks the tsenia may develop to 8 cm or 10 cm in length, and that 

 the infection is proportional to the time exposed. The infection is, 

 however, a variable quantity, and no definite statements can be de- 

 duced. 



As the lambs do not begin to nibble grass and drink wator until 

 some few days after their birth, the development of tsenia in K and 

 L probably required not over two months. Lamb A, examined Oc- 

 tober 21, about twenty-three weeks after birth, gives, when compared 

 with K and L, an approximate rate of growth of the tsenia of 2 cm a 

 month, more or less. The rate of growth must so vary at different 

 times that no definite rate can be determined at present. 



The tsenise of No. 105, one of the same lot of lambs as the foregoing, 

 were no larger after thirty-two weeks than those of K and L after 

 ten weeks. This points to a recent infection of No. 105, i. e. , within 

 ten weeks, or about the time the lambs were taken off the prairie 



