STRUCTURE AND DEVELOPMENT OF ECHINOCOCCUS 



347 



(1271 per cent, to 373 per cent.), whereas in the Hungarian pigs both organs were 

 almost equally infected (1478 per cent, to 12*03 per cent.). 



The data of Lichtenheld, in Leipzig, give the frequency with which various 

 organs were affected, as shown in the following table : 



STRUCTURE AND DEVELOPMENT OF ECHINOCOCCUS (HYDATID). 



An echinococcus is a spherical or roundish bladder full of a 

 watery liquid, which originates by liquefaction of the oncosphere, and 

 in man may attain the size of a child's head, but remains smaller in 



FIG. 251. Echinococcus veterinorum: the fibrous sac enclosing the 

 echinococcus has been opened and laid back in five parts, so that the 

 surface of the bladder worm may be seen, with the brood capsules, visible 

 to the naked eye, showing through it. Natural size. (After Leuckart.) 



cattle (the size of an orange or apple). The thin wall of the bladder 

 is composed of an external laminated cuticle (ectocyst) and an internal 

 germinal or parenchymatous layer (endocyst). The latter again 



