1878.] T. R. Lewis — Hsematozoa in Stomach of CmIqx Mosquito. 89 



2. Hemarhs regarding the Hsematozoaybim^ in the Stomach of Culex 

 Mosquito. — Bi/ T. E. Lewis, M. B. 



The paragraphs which have latterly appeared in Indian newspapers to 

 the effect that it had been definitely ascertained that the cause of ' Ele- 

 phantiasis' is communicated to man by means of the Mosquito have been 

 very generally commented upon, and it has been suggested to me that a few 

 words as to what is definitely known of the circumstances upon which the 

 statement is based might prove of interest to the Society. Indirectly I am 

 perhaps to some extent responsible for there having been grounds for such 

 a view being advanced at all, as some five years ago, I drew attention to the 

 circumstance that the blood of persons suffering from certain classes of 

 disease in this country was infected by numerous minute nematoid parasites, 

 each about one-hundredth of an inch in length and about the width of a 

 red blood-corpuscle ; and that all that was necessary for the demonstration 

 of their existence in the circulation of persons so affected was to prick any 

 part of the body with a needle, and to transfer the drop of blood thus ob- 

 tained to the stage of a microscope. 



One of the diseases with which these hsematozoa were found to be 

 associated was a form of Elephantiasis, not, howev.er, necessarily associated 

 with what is known as ' elephant leg', though both forms were frequently 

 combined in the same person — a circumstance which has given rise to some 

 confusion in pathological discussions.* 



These parasites, or at least a very closely allied species, have now been 

 detected in the blood of persons in various parts of the world — notably by 

 Dr. Sonsino in Egypt, by Dr. Bancroft in Australia, and by Dr. Patrick 

 Manson in China. Dr. Manson has, moreover, made the extremely inter- 

 esting discovery that embryo-hsematozoa may be detected in the stomachs 

 of mosqaitoes which have been caught preying on the bodies of persons in 

 whose circulation these parasites exist. I had repeatedly examined, in a 

 cursory fashion, these and other suctorial insects, but had not observed any 

 parasites suggestive of these embryo-hsematozoa, hence, when, on receipt 

 of a communication from Dr. Manson a couple of months ago, a renewed 

 search was made, I was surprised to find that four out of eight mosquitoes, 

 captured at random in one of the servants' houses, harboured specimens of 

 hsematozoa to all appearances identical with those found in man in this 

 country. After this, however, several days elapsed before any mosqui- 

 toes could be obtained which contained these embryo-nematoids, and the 



* As this is purely a matter of professional interest it need not be specially referred 

 to here : the disease in question has been carefully described by Dr. Vandyke Carter, 

 Sir Joseph FajTer, Dr. Kenneth McLeod and other writers, and has received various 

 designations, e. g., Elephantiasis lymphangiectodes, Nsevoid elephantiasis ; Lymph- 

 scrotum ; Varix lymphaticus, &c. 



