72 OBSERVATIONS ON PILARIS. 



observation (with view to a post-mortem some day) a dog of French 

 breed, whose blood is so full of the parasites that I often have two em- 

 bryos in the field at the same time. 



" With reference to the Filaria sanguinis Jiominis, I think it must 

 be much less common here than at Amoy. I have not yet found it, 

 and neither has my friend, Dr. Asford, of Fuchow, who has the 

 advantage of a large native hospital, and consequently large oppor- 

 tunities of searching for it. The late lamented Dr. David Manson 

 (brother of Manson, of Amoy) only found one subject (a China- 

 man) of the disease in Fuchow, and there is a curious circumstance 

 connected with tliis case. Dr. Manson had the man to his house to 

 show him to mo. He had " lymph scrotum," and we first punc- 

 tured one of the vesicles, and examined it, then another, but with- 

 out success. We then took blood from different parts of the man's 

 body, and, after working at him for about two hours with a micro- 

 scope each, we had to give up the search without finding a single 

 Filaria. Yet only about a week ago my friend had found numerous 

 embryos ! Can it be that the mature female discharges her ova into 

 the vessels only at certain times, and that the embryos have only a 

 limited period for existence in the blood ? I have not yet been dis- 

 appointed by the dog in this way. Once get a dog who has them, 

 and I have always, hitherto, been able to find when I wanted them. 



" I was amused to notice the other day in the ' Lancet ' (Feb. 

 22, 1879, p. 268) the following, with reference to one of the speci- 

 mens of elephantiasis presented at the meeting of the Pathological 

 Society by Sir Joseph Fayrer : ' It was suggested that the numerous 

 small semi-circular bodies, about the diameter of red blood-capsules, 

 met with in the second case in the lymphatic channels, might be 

 transverse sections oi Filarice. If so, the number of these organisms 

 l^resent must be very large ! ' I should think so ! We do occasion- 

 ally have two embryos in the field at the same time ; but surely to 

 make them anything like so numerous as this is straining the subject 

 to an unjustifiable extent. 



" In the case of the dog, it is extremely difficult to find the em- 

 bryo after the blood has coagulated and movement lias ceased ; 

 after, in short, the death of the Filaria, even when one knows it must 

 be present in the field, and I have never yet succeeded in discovering 

 one next morning after allowing the slide to stand over-night. It is 

 easy enough to observe them for any period within five or six hours 

 after the blood has been taken from the animal. 



