598 
Nycteribiidae 
the larva beconaes whitish. Then the insect leaves its host and runs 
rapidly about on the wooden perches to which the bats cling, and on 
the walls of the cage. From time to time it stops and raises its abdomen, 
which it brushes with its hind legs. Having at length discovered a 
suitable place in which to deposit its larva, the female stops, and, 
keeping the thorax still, moves the abdomen several times from left to 
right: at the same time it rapidly expels the larva, which by con¬ 
striction and stretching passes through the narrow genital orifice and 
then almost instantaneously resumes its normal shape. 
The larva does not move about after birth, but immediately adheres 
to the substratum on which it is laid. The female also immediately 
moves backwards, places itself over its progeny, and by alternately 
raising and lowering itself presses the ventral surface of its thorax 
closely against the larva. By this means the latter is, as it were, 
gummed to the substratum, from which it can only with difficulty be 
detached undamaged. The female repeats this pressing movement 
three or four times, then stays a moment uplifted on its legs, after which 
it runs quickly back to its host. 
Puparia were never found on the bodies or in the excrement of the 
hosts: the numerous examples were all laid close to the bats, in most 
cases on the lower surface of the wooden perches from which the latter 
hung, sometimes on the wire-gauze or glass walls of the cages. Smooth 
and dry surfaces seem to be preferred for the deposition of the larvae. 
In a natural state the bats sleep suspended from branches, particularly 
those of Dracaena, on the smooth branches and trunks (perhaps also 
leaves) of which the larvae are probably laid. 
[At this point it is important to compare the observations of Muir 
(1912, pp. 357-8), which show that at any rate some forms of 
Nycteribiidae fasten their larvae to their hosts. His observations are 
concerned with the kind described below as Eremoctenia progressa, 
referred to by him as Penicillidia progressa, and may be cited as follows: 
“ The full-grown larva, when passing out of the uterus, becomes greatly 
flattened, especially on the ventral surface, and is held by its anterior 
end for a short time between the external flaps of the vagina, its ventral 
surface being pressed against the skin of its host; generally near the 
junction of the wing-membrane with the body or limb. The chitinous 
exudation...first appears along the edges of the flattened ventral surface 
and fastens it to its host...”] Kolenati attributed to a Nycteribiid 
certain puparia which he found attached to the hairs of a- Vespertilio, 
but proof is required that these were not puparia of a Streblid. As 
