234 JOHN E. GUTBERLET 



Choanotaenia infundibuliformis. Eggs of this species were 

 fed to 88 flies of the species Musca domestica. Besides these some 

 Stomoxys calcitrans were also fed, but these did not live long in 

 captivity. The individuals of Musca domestica used in these ex- 

 periments lived from two to seventeen days. Two flies lived for 

 twelve days and four for seventeen days. The proglottids were 

 broken up and fed to the flies in the same manner as in the other 

 species mentioned. All of these flies were sectioned and examined. 

 One fly preserved at the end of twelve days showed five cysticerci. 

 These cysticerci agree very closely with the structure of the adult 

 of this species, and the hooks are identical. This cysticercus is de- 

 scribed in detail in another paper. 



Grassi and Rovelli (1892: 33) found cysticerci in flies which 

 they compared with this species. They found that there was a close 

 agreement in structure between the cysticerci they discovered and 

 the adult of Choanotaenia infundihidiformis. They therefore in- 

 ferred that the larva they had was the intermediate stage of this 

 species, but did not demonstrate experimentally its connection with 

 the adult tapeworm. 



During the process of my experiments I had hoped to be able 

 to feed some chicks on flies that had been previously fed on tape- 

 worm eggs, but as it was so difficult to keep the flies alive under ex- 

 perimental conditions such an experiment could not be carried out. 

 However, another feeding experiment was tried with the following 

 results : Six chicks were taken from the nest as soon as they were 

 hatched and placed in a cage where they could get no insects and 

 great care was taken during feeding so that no flies could enter. 

 Flies (Musca domestica) were caught around the chicken roosts and 

 fed to three of the chicks. The other three birds were used as a 

 control and were given no flies. Fifty flies were fed to each of 

 the three chicks. Three weeks after feeding, the chicks were killed 

 and examined with the result that two were found to be infested 

 with Choanotaenia infundibidiformis. One bird possessed six 

 worms. These were of the same length, being 35 mm. long, and each 

 one contained 103 proglottids. The other bird had one worm of 

 the same species, but it was a little longer, 43 mm. and having 118 

 proglottids. This bird was fed on the flies three days before the 

 one sheltering the six worms. The three birds which were used as 

 a check on the experiments contained no worms when killed and ex- 

 amined. 



