13 



mosquito which acts as a favorahle intermediate host in many 

 parts of th(^ world, is one of the commonest species of mosquito 

 found in ^lanila. However, it should be remembered that, 

 notwithstanding the existence of some very strong presumptive 

 evidence, the exact manner in which filariasis is transmitted is 

 still an open question. The brilliant ol^servations of Manson 

 and Bancroft showing the metamorphosis of F'daria nocturna in 

 the bodies of certain mosquitoes, and the further confirmation and 

 extension of their views by the more recent work of Loav (8) and 

 James, (9) all tend to convince one that the disease is transmitted 

 by the bite of certain mosquitoes.^ But the facts that a number 

 of persons can live for years with a filariated patient, when 

 apparently a favorable intermediate host is present throughout 

 the year, without their acquiring the disease, as in our case, and 

 the similar cases cited by Maitland, (10) and the "relative 

 immunity ' ' of Europeans and others who are careful with regard 

 to their food and drink, raise the old question wliether ]Manson 

 may not have been correct in his original assumption that the 

 filaria escape from the mosquito to some watery medium and then 

 gain entrance to their definitive host. 



REFERENCES CITED IN THE TEXT. 



(1) Herrick, Jas. B. Repeated Small Hemorrhages as a Cause of Severe 



Aniemia. Jour. Ainer. Med. Assoc, Sejit. 27, 1902. 



(2) Strong, R. P. Circulars on Tropical Diseases, No 1, 1901, Chief 



Surgeon's Office, Manila, P. I. Report of Snrgeon-Geuercd, U. S. Armij. 

 Washington, 1901, p. 212. 



(3) Calvert,, W. J. Eosinophilia in Filariasis. Jolms Ilojikius Hosjutal 



Bulletin, 1902, 13, 133. 



' In the older literature on the transmission of filariasis, C'nlex cilkirh L. was 

 named as the intermediate host, but in recent years our knowledge of the 

 ('nlicklx has heen greatly extended, and it has been shown by Theobald (11) 

 that (\ rilliiri.t L. is identical with ('. jnpieas, and further, that in all probability 

 Manson's original work in China and Bancroft's later work in Australia was 

 not done on ('. ])ii>iem L. but on ('. fatlt/aihs Wied. (12). This widespread 

 species is a voracious night feeder and occurs in large numbers in Manila. 

 According to Low, ( 13) "it is the chief si)reader of filarial disease in the West 

 Indie.^, acting as an intermediate host for /•'. itoctnrud. * * * It is inefii- 

 cient for F. demnrquaii.'' That the intermediate host is not restricted to one 

 genus or species of mosquito is shown l)y the feeding experiuients of James, 

 (9) in which Anopheles romi Giles and possibly a species of Culex — CiUe.x 

 inirro(ainiilfitii.t Theob. and Stet/oniiiia scntellaris Walk. — were shown to be 

 suited for the metam(»ri)hosis of Filarki vorturnn. 



