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     5. Various improvements in laboratory technique have been introduced
such as culturing hookworm larvae under much more natural conditions
than was done before, and a much better method of isolating ascaris
eggs from soil was worked out. Both these procedures will be of value
to anyone working on the epidemiology of these infections.

     6. A considerable amount was formerly done on the distribution and
pathology of filariasis and some contributions made to our knowledge of
the subject. Filariasis research is being still carried on, the principal
objective being the discovery of a curative drug. Many drugs including
most of the new heavy metal preparations have been tried without
success, but some advance has been made in the treatment of the
secondary infections common in elephantiasis, by vaccines and some of
the new complex benzene derivatives. During the course of surveys two
new species of microfilariae have been found, one of these Mf. actoni is
new to science and the other Mf. malayi originally reported from the
Dutch East Indies has been found in several parts of India. The adults
of these larvae have not yet been seen.

     7. Guinea worm surveys have indicated that the distribution of infec-
tion does not depend on the presence or absence of certain species of
cyclops but rather on the limitation of water supply. The condition is
prevalent where there are relatively few tanks in and around villages, and
it is not seen where there are numerous tanks. It has also been found
that if tank water reaches pH 8 or over, as it often does, cyclops will not
live in it.

     8. Work on the control of guinea worm has been successfully carried
out in some villages in Mysore by the introduction of certain species of
fish, which eat cyclops, into village tanks. Experimental work with
guinea worm infection on dogs has also resulted in the finding of several
adult male worms. This has never been done before and the worms will
be described shortly.

     9. In the course of the same research it has been found that a small
proportion of the larvae differ from the majority by having a ventral
spike-like process or second tail. The significance of these different
larvae is not yet understood but it has been suggested the variations are
sexual in character.

     10. Human infection by migrating Gnathostoma spinigerum larvae
or adults which is a fairly common condition in Siam and has been seen
once or twice in China, Japan and Malaya, has been recently found four
times in India. These are the first records of this worm as a human
parasite in this country and as they have all been found in Bengal and
all the specimens identified at one place, the Calcutta School, it is
thought that the condition may be commoner than is realised. It is of
some importance because the swelling caused by the worms in their
migration through the tissues may involve vital organs and thus endanger
life, though up to now no deaths have been reported.