118 ANIMAL PARASITES. 



with certainty in the muscles of the dog, and in those of 

 the roe, and it is also met with, though more rarely, in bears, 

 rats, apes, and men. Dog-killers, therefore, may infect them- 

 selves with T. solium by means of measly dog's flesh, and other 

 men by eating the measly flesh of the animals mentioned; 

 amongst which, especially with the oriental nomadic people, 

 cattle stand in the first rank ; as from the close, mutual inter- 

 course between the man and his herds, the latter might easily 

 contaminate themselves with the eggs of Tcenia solium. For 

 this reason we see that the immunity of the Jews and Moham- 

 medans is by no means absolute, and, on the contrary, that the 

 occurrence of T. solium, even amongst them, is not impossible. 



Theoretical proof of the identity of T. solium and Cysticercus 

 cellulosse. The latter, like all cystic worms, forms a vesicle 

 of the size of a pea or very small bean, with a little, white head 

 in its interior, from which the true scolex may be evolved by 

 pressure. This scolex bears a head with four, and sometimes 

 six sucking discs, (the latter especially in the human brain), 

 round which the vascular system runs, and afterwards collects 

 into two longitudinal canals 011 each side. The short rostellum 

 bears from twenty-two to twenty-eight hooks placed in a double 

 crown. Besides these, the head exhibits a sparing brownish- 

 yellow, or blackish-brown pigment, 1 and under favorable circum- 

 stances, by pressure, five sacs round the stems of the hooks. 

 The neck is very short, poor in calcareous corpuscles, opaque, 

 and colourless ; the body, which follows, is wrinkled, richly set 

 with calcareous corpuscles, and the head is inverted into it as 

 long as the caudal vesicle is alive and uninjured ; after the death 

 of the worm the head becomes everted. The caudal vesicle 

 consists of contractile tissue, which forms circular, parallel rings 

 when contracted. It is homogeneous, destitute of vessels, and 

 calcareous corpuscles, and consists of an organic substance, which 

 belongs to the class of the so-called mixed protein substances, 



1 Leuckart thinks, because he found the black pigment in Cyst, celluloses and Cyst, 

 tenuicollis of the pig, but never in Cyst, celluloses of the human subject, that the pigment 

 is not produced by the worm itself, but by the animal infested. That Cyst, cellulose 

 hominis bears pigment, is proved by the observations of Virchow, Giinsburg, Moller, and 

 others. It will then probably come to what I formerly stated in opposition to 

 Virchow, when he derived the pigment-crystals solely from the haematosine of man. I 

 supposed, that this property of forming pigment-crystals and molecules belonged not 

 only to human blood, but also at least to that of the pig. 



