THE NJEMATOID H^MATOZOA OF MAN. 249 



as to represent the helminth as magnified 300 diameters instead 

 of 1000 as in the original. This will facilitate comparison with 

 Dr. Cobbold^s figure representing his nematoid ova parasites^ 

 (fig. 2). Notwithstanding the discrepancy in size, Dr. Cobbold 

 considers that the helminths are referable to one and the same 

 species. They are both manifestly the off'spring of some 

 oviparous nematode; further than that it is, I think, hardly safe 

 to carry the comparison. 



The figures will also serve to elucidate another matter, as Dr. 

 Cobbold has since asserted that his parasite is not only identical 

 with Dr. Salisbury's, but also identical with the Filaria sanguinis 

 Jiominis^ a figure of which under a somewhat like magnifying 

 power will be found in PI. XII (figs. 3 and 5). Dr. Douglas 

 Cunningham several years ago pohited out that such a view was 

 untenable -^ moreover, the mature Filaria sanguinis Jioininis is 

 not oviparous but viviparous. 



Changes undeegone by the Embryos of Nematoid H^ma- 

 tozoa when ingested by the mosquito. 



It would occupy too much space to attempt an epitome of all 

 that has been written regarding the Filaria sanguinis-hominis 

 and the somewhat numerous diseases which have been ascribed to 

 its influence, so that for the present the foregoing must suffice. 

 It remains to be considered how it is that the embryos get into 

 the circulation and what becomes of them afterwards. A most 

 important step towards the solution of these queries has recently 

 been made by Dr. Patrick Manson of Amoy.^ He has shown 

 that, immediately after a mosquito has fed itself on the body of 

 a filaria-affected individual, the insect^s stomach will contain living 

 examples of the hsematozoon ; and that the latter will attain con- 

 siderable progress towards maturity therein, in the course of a few 

 days. It is believed that it then escapes from the mosquito when 

 th& latter dies in the water to which it betakes itself, and the 

 filarise thus find their way into the human body. Dr. Hansen's 

 highly interesting paper gives a full account of the various 

 developmental stages, together with figures of the object as they 

 appear from time to time. 



I have repeated many of Dr. Manson's experiments and have 

 been able to satisfy myself, from personal observation, that his 

 statements as to what occurs in China may, in most particulars, 

 be made applicable to India also. I had on many occasions ex- 



1 ' British Medical Journal,' July 27, 1872. page 92. 

 ' ' London Medical Record/ No. i, vol. i, 1873 ; the ' Lancet,' July 13, 

 1878. p. 64. 



3 The ' Lancet,' June 14, 1873, page 835. 

 * • China Customs Report,' No. xiv, 1878. 



