48 THOMAS L. BANCROFT. 



On the METAMORPHOSIS of the YOUNG FORM of 



FILARIA BANCROFT I, COBB, [Filaria sanguinis hominis, 



Lewis; Filaria nocturna, Manson] in the BODY of CULEX 



CILIARIS,IANT$., the "House Mosquito" of Australia. 



By Thos. L. Bancroft, m.b. Edin. 



[Read before the Royal Society of N. S. Wales, June 7, 1899.~] 



Dr. Patrick Manson in a paper read before the Linnean Society of 

 London, March 6th, 1884, 1 remarked : — " Six years ago I described 

 the metamorphosis undergone by the embryo Filaria sanguinis 

 hominis, in the body of the mosquito. 2 I hoped that (considering 

 the practical importance of a correct knowledge of the life-history 

 of this parasite) the statements I then made would, long ere this 

 time, have been thoroughly confuted or confirmed. . . . With 

 the exception of Lewis in India, Myers in Formosa, and Sonsino 

 in Egypt, I do not know that anyone has worked seriously at the 

 subject. And although both Lewis and Sonsino have confirmed 

 my statements as to the entrance of the Filaria into the mosquito, 

 and followed up part of the metamorphosis, neither of them has 

 advanced his observations so far as to be able to confirm my 

 statements as to the later stages of this, or positively to prove 

 that the mosquito is or is not, the intermediary host. Some 

 eminent helminthologists in England accept my statements and 

 endorse the inferences I have drawn — Cobbold for example. But 

 in other quarters, so far from securing acceptance of my theory } 

 the work of Lewis, on account of the hesitation and scientific 

 caution with which he expresses himself, has had the effect of 

 inducing a certain amount of scepticism. Leuckart is sceptical ; 



1 Trans. Linn. Soc. Lond., Vol. n., part x., Zoology, p. 367. 



2 Proc. Linn. Soc, March 7th, 1878. China Customs Medical Reports, 

 Sept. 1877. 



