456 MAUD D. HAVILAND 
and if the ovipositor of the hyperparasite were to be thrust 
the smallest degree too far, the egg would be inserted in the 
host’s gut, and be lost at evacuation of the meconium. 
THe Kee. 
The egg (Text-fig. 1) is an oval body, 0-010 mm. x 0-006 mm., 
with a short peduncle continuous with its long axis. ‘The 
oogenesis was not observed, but immediately after oviposi- 
tion a cloud of deeply-stainimg granules was visible at the 
posterior pole. This may represent the germ-cell determinant, 
or, as it has recently been termed by Silvestri, the oosoma. 
An oosoma in the eggs of phytophagous Cynipidae was 
first described by Weismann in Rhodites rosae as 
the ‘ Furchungskern’. Hegner (12) has demonstrated it in 
Diastrophes nebulosus, and Hogben (14) in Synergus. 
The latter says of the last-named species that the oosoma 
appears as ‘a cloud of granules, more and more heavily stain- 
ing, until the determinant: resembles a spherical ball at the 
end of the egg’. On the other hand, an oosoma has so far 
not been seen in other forms, such as Rhodites ignota, 
Neuroterus, Andricus, and Cynips Kollerti. 
The described eggs of Cynipidae are all pedunculated, and 
in certain gall-forming species the peduncle may be five or 
six times the length of the egg-body. Adler (1) first pomted 
out that the peduncle is situated at the anterior pole of the egg, 
which, according to him, differs in this respect from the eggs 
of other Hymenoptera Parasitica. He supposed that the 
function of the peduncle is respiratory, and he was supported 
in this view by Cameron (8), who observed that the species 
which have long peduncles are those which place their eggs 
where they cannot receive much oxygen from the plant, while 
in the spring generations of the same species, which oviposit 
in the leaves, it is usually short. Hegner considers the peduncle 
analogous to the two anterior processes of the egg of Ranatra 
linearis, described by Korshelt, which float out in the water 
from the plant-tissues within which the egg is placed. 
