958 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXVIII. 
of the mother it pupates. From what has been said it will be seen 
that the flies included in this group have developed most remarkable 
modifications and adaptations in connection with their parasitic 
habits. It is instructive to trace the stages in which the pupiparous 
habit has been developed. The word pupiparous is inaccurate be- 
cause it is not a pupa which is produced from the mature female, 
but a full grown larva which may pass into the pupal stage on the 
spot where it is deposited by the mother, or ma)'- be capable of moving 
about until it finds a suitable place for pupation. 
The pupiparous habit occurs in three distinct degrees in the 
Diptera. {a) It will be remembered that some Calyptrate Muscoids 
are viviparous. The eggs are retained -within the maternal 
body until after they have developed into larvae. The larvae 
are very small and are born almost as soon as they hatch 
out of the egg. They are laid in a large batch, exactly as the eggs 
of most flies are laid, and undergo little or no development within 
the body of the mother. This habit probably originates from the 
circumstances under which the larval stage is passed. Some Tachinid 
flies, it will be remembered, deposit their young larvae just hatched 
from the eggs, in the bodies of other larvae on which they are parasitic. 
It is therefore of extreme importance, for their welfare and perhaps 
their existence, to reduce the duration of the immature stage so that 
it may be accomplished within a given time. The food supply will 
fail imless the larval stage of the parasite is completed before the host 
pupates. (6) The second degree occurs in certain Muscid species 
which are blood-suckers. There the larva on hatching is retained 
and nourished for part of its life within the body of the mother. But 
it is deposited before attaining matxirity and completes its growth, 
feeding itself in the same fashion as the normal larvse of the Muscidce. 
{c) The third degree is found in the Diptera Pupipara where the larva 
is retained mitil it is ready to pupate. This involves remarkable 
changes in the internal structure of the female fly. The large size 
of the larva during the later stages of its growth renders it necessary 
that the internal organs of the mother should be greatly modified. 
More remarkable still is the development of “ milk glands ” to provide 
nourishment for the growing larva. The similar pupiparous habits 
Avhich are found in the Muscid genus Glossina (the blood-sucking 
African Tse-tse flies) emphasize the close connection between the 
Muscidce and Hippohoscidce. 
Hippoboscida-. This family is probably familiar to Anglo-Indians, 
who are at all observant in matters of entomology, for the flies are 
common parasites of cattle and dogs. They are commonly knowm 
as “ cattle-flies ” or “ dog-flies ” and also as “ skaters ” and Kuku- 
macchi. The native cattle do not seem to be much troubled by their 
presence or blood-sucking propensities, but dogs of British breed 
-are worried to distraction. 
