APHANIPTERA. — PULICID. 491 
The thorax is composed of three short segments, the second of 
which, or the mesothorax, has a small scale (fig. 123.1) affixed 
at its hind margin, on each side, behind the coxa of the middle legs, 
and resting upon the coxa of the hind legs, whilst the metathorax 
has a much larger pair of these scales (fig. 123. 1x x), which nearly 
cover the sides of the first and part of the second abdominal segment. 
These scales, evidently representing the four wings of the Ptilota, 
were first clearly defined by Duges, although Hooke had first repre- 
sented them; Mr. Kirby, also (Znérod. vol. iv. p. 383.), says that 
something like elytra and a scutellum appear, and MacLeay (Hore 
Eint. p. 357.), that vestiges of wings are visible. 
The legs are long, the posterior formed for leaping; the coxe are 
very large; the fore legs are singularly placed, appearing to arise 
from the front of the head, the coxz defending the sides of the ros- 
trulum. This peculiarity is caused by the prothoracic epimera being 
detached from the body, and extended obliquely beneath the head. 
The large coxe articulate in the four hind legs with the epimerz * by 
means of a minute joint, which, according to M. Duges, does not 
exist in the fore pair; the coxa is succeeded by a minute trochanter, 
considered as a supplemental joint by Duges; the femora are short, 
but strong, the tibiz very setose, and the tarsi 5-jointed, terminated 
by a pair of strong claws (fig. 123. 11.). 
The history of these insects in the perfect state is well known; 
their eagerness for blood, and their powerful muscular activity, enabling 
them to leap to an amazing distance, and which has been turned to 
account by ingenious mechanics, for the purpose of making them per- 
form various feats, such as drawing miniature carriages, &c., needs no 
lengthened account. The transformations of the insects are, however, 
especially interesting. 
On opening the body of a female flea, ten or a dozen oblong eggs, 
of a rounded form and white colour, are discovered, which are depo- 
sited by the female in obscure places, such as cracks in the floor, or 
amongst the hairs of rugs, where dogs are accustomed to lie. From 
these eggs are hatched long worm-like grubs (fig. 123. 18, 14. ditto 
magnified), destitute of feet, with thirteen distinct (pilose, according 
to De Geer) segments; the last furnished with two hooks ; the first, 
or the head, not variable in form, somewhat corneous, subovate, fur- 
* M. Duges, erroneously regarding the epimere as the cox, the coxe as femora, 
and the femora as tibia, has described the real tibia as the basal joint of the 6- 
jointed tarsi. He has corrected this error in his memoir on P. penetrans. 
