Volume /.] August, 1900. \_No. 5. 



BIOLOGICAL BULLETIN. 



ABNORMALITIES IN THE CESTODE MONIEZIA 



EXPANSA. I. 



IMPERFECT AND PARTIAL PROGLOTTIDS. 

 C. M. CHILD. 



IN November, 1 899, a large number of specimens of Moniezia 

 expansa, a common parasite of the sheep, was obtained from the 

 Union Stockyards in Chicago. Nearly every specimen exhibited 

 one or more abnormalities in the form of the proglottids, but 

 one specimen, some two feet in length, was found, which pos- 

 sessed over a hundred abnormal proglottids. This was incom- 

 plete, for in the oldest proglottids present the uterus had not 

 yet appeared. The abnormalities in this individual are not 

 different in kind from those found in others, but are much more 

 abundant. Most of the cases described were selected from this 

 specimen. 



This paper, the first of a series, is devoted to a description of 

 some of the simpler forms of abnormal proglottids. In the 

 second paper a number of spiral anomalies will be described, 

 and the third will include a general summary of the facts, to- 

 gether with some suggestions as to causes and significance. 



The figures are all drawn with the aid of the camera from 

 stained and mounted preparations. Pigs. 2-6 are magnified 

 about fifty diameters ; all others about twenty. All except 

 Figs. 7, 14, 15, 19, and 23 are taken from the single specimen 

 mentioned above. These five figures are selected from different 



individuals. 



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