704 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXVlll, 
ternally by mechanical means. It pierces the skin of sleeping per- 
sons with its small sharp jaws and imbibes their blood. The habit 
is without parallel among Diptera. The larva is a footless maggot 
with very minute jaws and cannot attach itself to the skin of the 
host except by the mouth-parts. It cannot cling whilst piercing by 
any structure except the mouth-hooklets. Such a habit could hardly 
have arisen but for the fact that the African natives sleep on mats 
on the earthen floors of their huts. The larvae, which probably 
originally fed on foul liquids, are common beneath children’s mats 
which become stained with urine. The adult flies are attracted by 
the smell and lay their eggs under the mats. 
It has been stated previously that the parasitic habit of the (Es- 
tridae is apparently the most ancient. The Glossina habit comes 
next. The habit of blood-sucking of the Congo floor-maggot is evi- 
dently a comparatively recent development. The stages of parasi- 
tism can thus be placed in order. In the Hippoboscidae, which are 
imaginal parasites and which will be described in the section on Pu- 
pipara, the peculiar mode of reproduction of Glossina is carried a 
stage further. In Glossina the larva when extruded has sufficient 
power of movement to find a suitable place for pupating ; thereupon 
its integument becomes chitinized to form the pupal envelope. The 
Hippoboscid larva upon extrusion at once undergoes this change ; 
the Hipposboscid female therefore deposits the larva in a situation 
suitable for it to remain during the pupal period. 
The Hippohoscidce are probably an offshoot from the old muscid 
stock. The (Estridce are possibly an earlier off-shoot in an oppo- 
site direction from several stems of the same stock. Townsend 
regards the (Estridce as a polyphyletic group showing affinities with 
various sub-families and tribes of Muscoidea. Its preponderating 
characters are due to similar parasitic modes of life in the larvae with 
corresponding similarity in the adults. These suggestions are en- 
lightening when one tries to discover the origin of the different forms 
of parasitism among flies. 
J. Pantel in his “ Eecherches sur les Dipteres a larves entomo- 
bies ” has suggested ten groups of Muscoid flies fomided on re- 
productive and parasitic habits. * These may be compared with the 
five Tachinid groups of Townsend referred to further on and based 
also on reproductive habits. ToMmsend considers that Pantel’s 
• Two parts of this great and interesting contribution have appeared: I .Cara- 
teres parasitiques aux points de vue biologique, ethologique et histologique. La 
Cellule (1910) Vol 26 pp. 2 /-216. II. Les enveloppesde I’oeuf avec les formations 
qui en dependent; les degats indirects du parasitisme (1913) Vol 29 pp. 1-289. 
Each part contains a bibliography of the literature on parasitism in the Diptera. 
The earlier part of Pantel’s two papers has been reviewed and criticised in Eng- 
lish by C. H. T. Townsend : “ Review of work by Pantel and Poitchimski on Je- 
productive and early stage characters of Muscoid flies.” (1911) Proc. Ent. Soc. Wa- 
shington., Vol 13, p. 151. 
