P. R. KRISHNA IYER                                     9

None of these affected animals had ever shown worms in the eye and
Filaria oculi are rare in the affected area.

Diseases of the eye due to filariasis are not uncommon in cattle in this
country.

Venkataratnam Chetty [1922] describes a form of ulcerative keratitis
which occurred in an epidemic form among the Corporation Depot Bullocks
and the Buckingham Mill draught cattle in Madras in the years 1917, 1918
and 1919. The outbreak in the year 1919 resulted in loss of sight in over
40 per cent of the affected animals. The pathological changes observed
varied from simple ophthalmia to ulcerative keratitis of one or both the
eyes. Examination revealed a few thread like worms each about an inch
long, wriggling about on the cornea and a bunch of them might be seen under
the eyelid. The worms were identified as Thelazia rhodesi. The author
suggests the possibility of their being carried from the eyes from animal to
animal by flies.

Ramaswamy Iyer [1922] records a similar case of infection of the left
eye of a cow with Th. rhodesi. The animal was lachrymating profusely for
about a month and could not open the eye freely. The eye was washed with
saline solution and five worms were removed. As no more worms could be
found, a boric lotion bandage was applied and the animal was allowed to
go. About three weeks later, the same animal was brought to his dispensary
with lachrymation from both eyes. Now the eyes showed moving worms
over the conjunctiva in both eyes, with slight opacity of the left cornea.
Over a dozen worms were removed from both eyes. The author states that
the parasites cause much irritation, severe conjunctivitis and profuse lachry-
mation leading on to opacity of the cornea and impairment of the vision.

Griffiths [1922] states that members of the genus Thelazia have their
normal habitat in the lachrymal ducts of the eye of various species of mammals
and birds and that some fly acts as an intermediate host and transmits the
parasite to fresh mammalian hosts. The author thinks that it is among the
species of Stomoxys, Musca and allied genera that the transmitting agent
may possibly be found, flies of these species being a constant source of annoy-
ance to all domestic animals by their habits in attacking the orbital region.
He adds that the presence of these parasites in the orbit gives rise to ophthalmia
terminating in loss of sight.

We have not as yet been able to identify the worm responsible for
the causation of this condition, and naturally its life-history is unknown.
According to the Helminthologist of this Institute, " From an examination
of the microfilariae and their ' unsheathed ' character, it appears that the
larvae belong to some Onchocercoid worm. Specific identification is not
possible from the microfilariae seen in the sections ".

From the data given by Steward [1935], Shafi Mohammed [1931], Cleland
[1914] and Heydon, [1927] it would appear that Onchocercoid tumours need
not necessarily be found in cases of Onchocercoid infections. The adult

C