342 T. B. KOSSETKR ON CYSTICERCUS QUADllICURVATUS. 



be strong and muscular; that when the hooks are extended a 

 depression will be formed by the pressure of the posterior roots 

 on the crown of the rostrum, but whether the rostrum Avill be 

 seated on an elongated or on a short proboscis it is at this stage 

 impossible to' say. 



There were no markings or indentations on the hooks, such 

 as are invariably found in the neighbourliood of the upper por- 

 tion of the hook, near the anterior root. This, according to 

 Leuckart, shows that the hooks have attained their growth 

 and strength by successive layers of carbonate of lime. Leuck- 

 art's suggestion would account for the small number or 

 absence of the chalk-bodies, which are usually so abundant in 

 the cysts of other Cysticerci, they having been absorbed at this 

 early period in the maturing of the hooks. 



In the majority of cases during the process of simmering with 

 nitric acid the subcuticular membrane collapses and hangs as a 

 bag or covering within the cyst, and is usually evaginated with 

 the embryonic scolex. But in this instance, wdien the cuticle 

 of the cyst was ruptured by the pressure applied to the cover- 

 glass, after the emission of its contents the hard cuticle broke off, 

 leaving the hypodermis perfectly intact, as it does when forming 

 the boundary wall of the fluid cavity or vitelline membrane of 

 the embryonic scolex (Fig. 6). Dr. 0. von Haman supposes 

 that the hypodermis goes to form the neck of the mature worm. 

 Whatever change may take place in this respect on the recep- 

 tion of the Cysticercus into the duodenum of its final host is at 

 the present time a matter of conjecture ; still, truth leans to- 

 wards his suggestion for this reason : " Cysticerci which have 

 been injected twenty-four hours previous to death of their host 

 have been found, when taken from the duodenum, to have 

 evaginated themselves, and the scolex and neck to have been 

 perfectly formed, but no trace of the formation of proglottides 

 at the base of the neck has been seen. This has been my 

 experience gained from post-mortem examination of the viscera 

 of ducks, which I have myself experimented on by injection." 



Neither Dujardin, Davaine, Cobbold, nor Leuckart in their 

 works on Ttenia of Man and Animals, or Krabbe, who in his 

 Monograph and Supplement enumerates 138 species of tape- 

 worms belonging exclusively to birds, make any reference or 

 o-ive any drawings of a Taenia whose rostrum bears hooks 



