HYDATID CYSTS 259 



mediary. This parasite produces an intense anaemia similar to pernicious anaemia. 

 It is a frequent parasite in Switzerland, Bavaria, Japan, Scandinavia, and Russia. 

 Recently several cases have been reported from our Northwest, and some of the fish 

 of the waters of that region are said to be infected. The larva is a pleroceroid and 

 is about i inch long. It is said that salting, smoking, or other ordinary methods of 

 preserving fish will not kill it. 



A tape-worm, Diplogonopoms grandis has been reported from Japan. In this 

 there are two complete sets of genital organs to each segment. 



SOMATIC T^ENIASIS. 



While rarely we may have the larval stage of T. solium present in 

 man, and while certain bothriocephalid larvae (Sparganum mansoni 

 and Sparganum proliferum) infect man, yet they are unimportant as 



FIG. 68. Daughter cyst from FIG. 69. A group of daughter 



hydatid cyst, considerably en- cysts from hydatid cysts, 



larged. (Coplin.} (Coplin.} 



compared with the larval stage of the Taenia echinococcus. The 

 adult stage of this parasite is passed in dogs. It is one of the smallest 

 tape-worms known, being only about 1/6 inch long. It has a head with 

 four suckers and a rostellum encircled with hooks. There are only three 

 to four segments. The larval stage, on the contrary, gives one of the 

 largest of larval cestodes. In man it may reach the size of a child's 

 head. The larval stage is also found in hogs and sheep, and it is prob- 

 able that by reason of the dog's eating the echinococcus cyst of such 

 animals at the abattoir we owe the increase in this serious infection. 



Man contracts the infection from association with dogs. The disease is peculiarly 

 prevalent in Iceland. As stated above, the adult stage is passed in the intestine of 

 the dog. Should the egg-bearing segments passed by the dog contaminate the hands 



