B. N. SONI                                                 379

V. THE EFFECT OF INFESTATION ON THE CONDITION OF THE HOST

Five heavily " warbled " and two warble-free bulls were kept under
identical conditions of housing and feeding, and their body weights were taken
weekly for nearly three months, from February to April 1937. As will be
seen from Table II, the " warbled " bulls continued to lose weight until about
the middle of March, which is about the time when the majority of the larvae
at Mukteswar escape from their warbles, and from this time onwards they
showed a progressive increase in their body weight. No appreciable loss in
weight was observed in the two control animals. These observations are in
accord with those recorded by MacDougall [1935] in Scotland, who observes
that the " condition [of animals] suffers from the presence of a number of
larvae in the subdermal tissues ".

                                                               TABLE II

                 Tabulated records showing the loss of body weight in "warbled" animals
                 The numbers marked with asterisk represent control (uninfested) bulls.

               VI. SUMMARY AND CONCLUSIONS

Observations carried out at the Imperial Veterinary Research Institute,
Mukteswar, have shown that:—

Over fifty per cent of the hill bulls purchased for experimental purposes
are infested with warble grubs (Hypoderma lineatum) and that it takes nearly
fifty-one days for the larvae to mature after their first appearance in the sub-
cutaneous tissues of the animal's back. The mature larvae have been encoun-
tered as late as the beginning of March, and in this respect the seasonal occur-
rence of H. lineatum at Mukteswar would appear to present a feature somewhat
different from that recorded for the same species in certain other localities in
India. Thus, at Hissar (Punjab), no tumours in the back are noticed after
the middle of January.