118 
DISEASES OF HORSES IN INDIA. 
\ 
that artery was in a state of aneurismal dilatation. I will not 
here allude to the insects produced after the manner of the 
larvae of the CEstrus, which are doubtless generated from ova 
deposited by the parent fly under the skin of deer, as stated in 
Franklin’s account of his journey to the, polar sea. 
Naturalists have described several varieties of worms which 
are found in the viscera, or interstices of the muscles of the 
above mentioned animals. These are, the Ascaris, Taenia, Fila- 
ria, Strongylus, Ligula, Linguatula, and Fasciola. 
I am not aware that such worms as those just alluded to, 
which are found living in the flesh or viscera of animals, have 
ever been observed to exist out of those animal bodies. We 
may except the Fasciola, which is found alive in fresh water, 
in the intestines of the bream and sepia lotigo, and in the liver 
of the sheep. The accounts we have of the Filaria Medinensis 
being found in India, in the morning dew, often twelve feet 
long, and not thicker than a horse hair,” is, I believe, not yet 
sufficiently corroborated. See Good’s Study of Medicine, vol. 
iv. p. 652. Dr. Darwin believed that worms, similar to all the 
kinds discovered in the body, were to be found out of the body, 
but gives no examples. He says, he has twice seen long 
worms like a thick horse hair, in water, in July, in England 
but he does not attempt to identify them with the Filaria Me¬ 
dinensis. The Gordius, or Seta Aquina, is found in stagnant 
water in the low grounds in Lapland ; and Linnseus and Montin 
believed they traced this worm to be the cause of violent 
colics, to which the Laplanders are subject. I have not found 
the observations of others to verify their opinions. See men¬ 
tion of this by Dr. Good, who refers to Linn. Flor. Lapland, de 
Angelica, and to Montin. Amsen. Acad. Splanchnum, ii. 26. 
Several circumstances concur to render it probable that the ova 
of the Filaria Equi are received into the stomach with the food; 
and these ova being taken up by the absorbent vessels, pass by 
means of the circulation to different parts of the body favourable 
to the development of the worm, which having taken place, 
their farther progress may be impeded by their increased size. 
This, however, requires farther elucidation. 
The conclusion I have ventured to express, as to the forma¬ 
tion and progress of those worms which are found in the flesh 
or viscera ol living animals, does not arise from our having been 
yet able to trace the progress of any particular species of worai 
through its different stages of formation, and in various situa¬ 
tions ; but seems to be to a certain degree authorized by the 
combination of several circumstances stated in the above re- 
