53 



pated the left cleido-mastoid muscle of the calf; and, 

 while performing the operation, he had the satisfac- 

 tion of seeing the cysticercus vesicles lodged within 

 the muscles. They were larger and more opalescent 

 than those of the Cysticercus Tsenise cellulosse, but 

 nevertheless permitted the recognition of the young 

 worms through their semi-transparent coverings. 

 The heads of the contained Cysticerci exhibited all 

 the distinctive peculiarities presented by the head of 

 the adult strobila, the T. mediocanellata." 



From these experiments there can be no doubt as to 

 the fact, that the T. mediocanellata is not an old T. 

 solium, nor as to whence it is derived. Besides the 

 appearance of the head and neck, the distinctive 

 mark between the scolices of this Tsenia and those 

 of the T. solium consists in the larger size of the 

 vesicles. 



3. Cysticercus tenuicollis. This scolex is consid- 

 ered as the embryo of the T. marginata, found in the 

 intestines of dogs, and probably of wolves. As, in 

 the adult state, it is doubtful if it exists in the intes- 

 tine of man, I have omitted the description of the 

 Tsenia. 



The head resembles somewhat that of T. solium, 

 except in the form, number, and size of the hooks, 

 which are more slender, less strongly curved, and 

 remarkable for the extraordinary length of the stem. 

 They are arranged in two series, from 32 to 42 in 

 number, and, according to Leuckart, measure 0*178 

 and 0-114 mil. in length, while Kuchenmeister gives 

 0-175 to -215 and 0-117 to -126 mil. The caudal 



