266 BNTOZOA. 



the cavity of the brood-capsule ; and thus the latter display a 

 bird's-nest-like appearance (Fig. 58). Frequently, however, a con- 

 siderable number of them are seen everted, as is shown in one 

 of the highly-characteristic figures given by Huxley in his memoir. 

 In this way the developmental process is completed. 



Before proceeding further, I may here remark that many modi- 

 fications of this process have been witnessed as regards individual 

 scohces, some of which abort, whilst others, possibly, become new 

 or secondary brood-capsules. All those numerous instances where 

 scolices have been seen free in the cavity of the capsules, or in the 

 great general cavity of the maternal hydatid, or in the cavities of 

 the (subsequently to be described) daughter and grand-daughter 



Fi&. 58.— Series of brood-capsules witli their contained Echinococci ; from the human subject 



(x 76 diam.) — Wilson. 



hydatids, are simply examples of morbid phenomena. They are, 

 in other words, entirely due to post mortem changes. In this 

 condition the scolices are generally quite dead, and therefore, 

 assuredly, do not need a covering of vibratile cilia wherewith to 

 execute their supposed swimming evolutions.^ 



* 



* On one occasion, when engaged in dissecting an antelope {Antilope quadri- 

 cornts) at tlie Zoological Gardens, a fellow-worker seized hold of an enormous soli- 

 tary hydatid cyst with such yigour that the contents burst out with great force. My 

 face, head, and neck were literally covered with myriads of echinococcus heads, and, 

 not being then aware of their death, I felt afraid to si)eak lest I should swallow a few 

 dozen of the scolices adhering to my lips. Though this was a false alarm, some of our 

 breeding-experiments are highly dangerous, and I would particularly warn com- 

 mencing investigators how they handle full-grown tapeworms. — T. S. 0. 



