SiBTHORPE — Oti Filaria sanguinis hominis. 
203 
ke its way to the lymphatic system, where both males and females 
Ide and conjugate ; numerous embryos are the result ; and these 
>ear to travel from the lymphatic system, where they are constantly 
nd, into the blood stream, where they are as a rule only seen at 
n|<ht or during rest ; this is known as filaria periodicity." 
An interesting experiment was made, in which a patient whose 
od had been proved to contain embryos discoverable only at night 
[ his habits changed, and was kept awake at night and allowed to 
?p during the day. The movements of the embryos were found to 
e changed with this alteration in the habits of the patient, and they 
-e only remarked in the blood during the daytime, and not at 
ht. These experiments were repeated and confirmed by different 
srvers. 
The most favourable time for finding the embryos is between 6 p.m. 
6 a.m., the maximum number being generally observed about 
night : this Manson first pointed out. Observations in the Madras 
Gjieral Hospital and elsewhere have confirmed the fact. 
Mr. Mortimer Granville has advanced a theory that this periodicity 
lue to the conditions of the circulation and chyle currents that 
)mpany sleep. 
Manson' s idea is that these embryos block up the capillaries or 
sijlller lymphatics, and that this causes obstruction in the stream, 
ch is followed by rupture, leading in some cases to a flow of lymph, 
e:^ sions of lymph, hypertrophy, and occasionally haemorrhages. 
The presence of the embryos has been demonstrated in many of the 
dil ases which have been already enumerated, but in many cases of 
elbhantiasis, especially those met with in India, it is often quite 
ossible to discover a single embryo, so that it is not yet clearly 
^en that all cases of elephantiasis depend upon the presence of this 
isite. 
This short sketch of what has been worked out regarding the con- 
ion of this nematoid worm and certain diseases has been drawn 
uiwith the view of introducing the drawings of portions of the 
aqlt male and female Filaria to the notice of the members of the 
demy. 
These drawings, which were kindly prepared for me by Professor 
Aiior. Bourne, of the Madras Presidency College, from Pilaria, which 
WfB found actively wriggling in lymph, on the cut surface of 
a Lrotal elephantoid tumour, which was removed by me from a 
nJve Christian cook, on March 24th, 1888. He was a fairly 
ncidshed man of intemperate habits, aged forty-seven years, who 
