458 MAUD D. HAVILAND 
increase of the egeg’s surface, in proportion to its mass, may 
bear some relation to oxygen absorption. 
There is no reason why the peduncle should not in some 
cases be respiratory, as supposed by Adler, and in others for 
attachment, as suggested by Riley. In certain instances it 
possibly serves both functions ; but its reduction in Charips 
probably indicates that it has lost its use, whatever that may 
have been. 
TrExt-Fie. 1. TEXxtT-FIG. 2. 
Fig. 1.—The egg immediately after oviposition. x450. n= 
nucleus ; g.c. = cloud of granules. 
Fig. 2.—Cells of the trophic membrane with degenerating nuclei. 
A from above; Binsection. x 350. 
Tort EmpBryontc MEMBRANE. 
In Charips, as in certain other hymenopterous parasites, 
a trophic membrane or pseudoserosa is formed round the 
developing embryo as a globular sphere of large eosinophil 
cells, with definite nuclei and well-marked walls, polygonal in 
surface view and crescentic in section (‘l'ext-fig. 2). Membranes 
in this stage may be found up to the point of the hatching of the 
larva, after which they soon degenerate and disappear, though 
sometimes degeneration sets in at an earlier stage. A similar 
degeneration can be seen also in the membrane of the 
Aphidius host. 
A membrane, resembling that deseribed above, has been 
observed in certain Chaleids, but it does not appear to arise 
