396 



The Transmission to Man 

 According to Button, who has very minutely 

 described the structure of the proboscis, the 

 worms can only leave the labium at one point, 

 i.e., by perforating an extremely delicate mem- 

 brane, which closes in the extreme end of the 

 labium (see p. 167). If they escape elsewhere, 

 they must penetrate the dense and hard chitinous 

 envelope of the labium — a very improbable 

 occurrence. 



Development of Filaria in the Louse 



In the lymph, e.g., of the subcutaneous tissue, of the swift 

 {Cypselus ajfinis) occur the embryos of F. cypseli. Button has 

 traced the development of these, up to an almost mature stage, 

 in a louse, Leiothina sp., which infests these birds. The mode 

 of escape of the filariae from the louse and infection of a fresh 

 bird is uncertain. 



Filariasis and Eosinophilia 



Wurtz and Clerc found in a case of F. loa (no embryos 

 present in the blood) a marked eosinophilia. A similar increase 

 lias been found by us in a case of ' tropical swellings ' of doubt- 

 ful nature, but resembling somewhat Calabar swellings. The 

 leucocytic counts were :^ 



LITERATURE - 



Railliet, A. Traite de zoologie medicale et agricole. Paris, 

 1895. 2nd edition. 



Annctt, Button, and Elliott. Liverpool School of Tropical 

 Medicine. Memoir IV, Part II. Filayiasis. 



