232 DENIZENS OF THE DESERT 



envelope is digested, the contained embryo is 

 set free, and immediately starts for its pre- 

 destined resting-place. This microscopic em- 

 bryo is furnished with six booklets by means of 

 which it penetrates the walls of the intestine 

 and embeds itself in the muscular tissue. Here 

 it ceases to move, its booklets fall off, and it 

 slowly develops into a polycephalos [many- 

 headed] vesicle." l 



1 Zoc, vol. I. 



