194 
OBSERVATIONS ON THE FILARIA OR THREAD 
WORM, 
FOUND IN THE EYES OF HORSES IN INDIA. 
Bij W. Twining, Esq. 
(Continued from page 119 ) 
SINCE the preceding remarks on Filaria Equi were read before 
the Society, I have been favoured with a communication from 
Mr. Gibb, Surgeon to the Honourable Company’s stud at 
Poosah, to whose liberality and kindness I am indebted for an¬ 
swers to some queries, as well as further information in a letter, 
the substance of which I am glad to annex: it is evidently the 
result of careful observation, under circumstances the most fa¬ 
vourable, and in a field for experience, of an extent, I appre¬ 
hend, much beyond what can have fallen to the lot of any other 
person. Mr. Gibb’s communication is made without reference 
to the foregoing paper, which he has not seen. The difference 
which appears as the result of the anatomical researches of Mr. 
Gibb, from those of Dr. Hardtman, induce me to believe that 
there are different species of worms, which infest the bodies of 
horses in different districts in India. The quotation already 
given from Linnmus coincides with Dr. Hardtman’s observa¬ 
tions, as to the worm being found in the cellular tissue. With¬ 
out farther inquiry, it would perhaps be premature to conclude, 
that different kinds of worms are endemic at the stud stations 
of Poosah and Haupper, Filaria prevailing during the cold sea¬ 
son at one station, and Strongylus at the other. Both these 
worms are thread-like, and without the aid of a microscope 
might not be discriminated. One is described by naturalists as 
inhabiting the alimentary canal only; the other as being found 
in the cellular structure and various cavities. 
Mr. Gibb says: I have never found the Filaria Equi, ex¬ 
cept in the stomach and intestines of the horse, and in the eye. 
I have generally found them in great numbers in the stomach 
and intestines, whenever T have had occasion to open horses, 
though more numerous I think in the cold months than during 
the hot weather or rains. 
The fact I allude to in my answer to the Sixth Query, is 
this, that the phenomenon of the worm in the eye is exclusively 
confined to the cold months. I have never, as far as my recol¬ 
lection serves me, seen a case of worm in the eye before the be¬ 
ginning of Octobei;, or later than the end of February or com- 
