394 



The following have been shewn by Bancroft 

 not to allow full development to take place. In 

 some species partial development occurs, the 

 larva, however, eventually disappearing : — 



C. notoscriptus (Skuse) 



C. annulirostrts „ 



C. hispidosiis „ 



C. vigilax „ 



C. nigrothorax (Macquart) 



C. procax (Skuse) 



[A.'] musivus ,, 



Grassi and Noe's experiments shew that 

 F. immitis is capable of developing in A. claviger. 

 As regards the re-infection of a healthy dog, the 

 experiments are somewhat inconclusive, for, in 

 the dog used, a single immature worm only was 

 found, about sixteen days after the period of 

 'biting.' They state, however, that of a batch 

 of Anopheliiies dissected before the ' biting,' many of 

 the labia contained filaria, whereas, of a batch 

 dissected after the ' biting,' none contained filaria, 

 the conclusion being that the filaria had escaped 

 through the labia into the blood of the dog 

 during the 'biting.' 



Seven stages of development of the embryo 

 are usually described. The following is a resumd 

 of the changes undergone in Culex . pipiens : — 



First Stage. — One hour after removal of 

 blood by mosquito, the sheath is cast and the 

 embryos exhibit 'active locomotive movements. 

 In twelve to eighteen hours many have bored 

 through the stomach wall, and have reached the. 



