MR. H. D. GELDART ON FILARIA SANGUINIS HOMINIS (NOCTURNA). 547 
I. 
NOTES ON FILARIA SANGUINIS HOMINIS 
(NOCTURNA). 
By Herbert D. Geldart, Vice-President. 
Read 30th May , 1893. 
For the objects which I exhibit to-night, I am indebted to the 
kindness of Mr. Charles Williams, F.R.C.S., who sent me one 
night in March last, at about eleven o’clock, twelve slides of 
freshly drawn blood taken from a patient who resided many years 
in India. In these twelve slides I counted over one hundred and 
fifty Filarite , no doubt missing some, as when the blood lies 
unevenly on the slide it is rather difficult to distinguish them. 
In one slide alone I counted thirty-live, and assuming that the 
whole of the blood was infested equally with the portion received, 
and estimating that portion as certainly not exceeding the ,,' (7 of an 
ounce, and taking the weight of the patient at 10 stone 10 lbs., or 
150 lbs., using the usual formula of t '.- of the weight of the body 
as the blood-weight, there would be just about half a million of 
these parasites moving in the patient’s blood that night. 
Filarim in the state in which you have seen them this evening 
are asexual and apparently internally organless embryos of a 
Nematode worm known as Filaria hancrofti, named after Dr. 
Bancroft who first discovered the mature form at Brisbane — the 
mature female is a thread-like worm about three and a half inches 
long, the mature male being somewhat smaller — the embryos are 
from yTj to , y \ T of an inch in length, and are said to be of an 
inch in breadth, their slimness enabling them to travel into the 
capillary blood vessels. As I show the embryo in slide No. 1, 
which contains (or rather contained, for some of the blood has 
been cleaned off) twenty Filarite , it is still invested with the egg- 
covering (called its sheath) in which it was born, and in this state 
