DEVELOPMENT OF CYNIPID HYPERPARASITES 457 
The observations of Riley, quoted by Sharp (22), suggest, 
however, that the peduncle may have another function. He 
found that in the ovipositions of Callirhytes clavula 
and Biorhiza nigra only the peduncle is inserted into the 
plant at first, and that the fluids collect at the posterior end 
of the egg. * The fluids are then gradually absorbed from this 
exposed position into the inserted portion of the egg, and by 
the time the leaves have formed . .. the egg-contents are all 
contained within the leaf-tissue.’ 
Pedunculated eggs also occur in certain Chaleids. The egg 
of Leucospis gigas is furnished with a hooked process, 
whose purpose is evidently to suspend it from the cocoon of the 
Chalicodoma bee upon which the larva is parasitic. Imms (17) 
found that the egg of Blastothrix britannica, a parasite 
of Lecanium capreae, has a peduncle which protrudes 
through the body-wall of the host. The tip of the process 
disappears, thus putting the cavity of the chorion into com- 
munication with the outside air like a siphon. ‘Timberlake (26) 
says that the egg of Microterys, parasitic upon Coceus 
hesperidium, is formed by two bodies connected by 
a hollow stalk. The stalk, together with the smaller body, 
projects through the body-wall of the host, and apparently 
serves for the respiration of the egg and of the larva in the 
early stages. The egg of Aphelinus mytilaspidis, 
parasite of Lepidosaphes ulmi (16), has also a process 
which, however, never projects outside the body of the host ; 
and this is also the case with the egg of Comys infelix, 
a parasite of Lecanium hemisphaericum, described 
by Iimbleton (4) as possessing a bifid process. Howard and 
Fiske (15) state that the peduncles of the eggs of Schedius 
kuvanae protrude through the chorion of the eggs of the 
gipsy moth in which they are deposited. It may be remarked 
that four of these cases are parasites of Coccidae, sedentary 
animals whose metabolism and oxygen content must be low 
in comparison with that of other insects. Hggs approaching 
the pedunculated form occur in Eneyrtus aphidivorus, 
Ageniaspis fuscicollis, &c., and here perhaps the 
