46 
BEITISH APHIDES. 
have clearly seen a continuation into the soft parts of 
the body of the inner tube or duct, which undoubt- 
edly traverses the cornicles. 
By far the larger portion of the cavity of the body 
in Aphis is taken up with the ovaria and the forty or 
fifty embryos in a more or less advanced stage of 
development; but surrounding these and the other 
organs, there is a mass of transparent fluid, charged 
with numerpus globules of an oily nature, and which 
often are of beautiful pink, green, yellow, or violet 
shades. Towards the autumn these globules increase 
largely in quantity, and are found most plentifully 
stored around the bases of the nectaries or cornicles. 
. There would seem to be reason for believing that the 
I cornicles are in immediate connection with these 
apparently unconfined fluids ; at any rate, the oily 
globules freely pass to the exterior through the cor- 
nicular channels, and would thus appear to relieve the 
insect of that which would cause its death if allowed 
.1 unduly to accumulate. Death actually happens, if 
‘ these oily spherules crystallize in the nectaries and 
choke them. In such cases the whole body seems to 
pass into a semi-crystalline condition, — partly fatty, 
and partly saccharine. 
Occasionally this adipose matter exudes from the 
summits of the cornicles in large drops, which crystal- 
lize into botryoidal masses, having a radiated structure 
similar to cystine, or else to margaric, or some such 
homologous fatty acid. 
Leon Dufour* thinks that the adipose matter, so 
abundantly stored in some insects towards autumn, 
may possibly play some part towards their mainten- 
ance in winter, just as we find in hybernating animals. 
If we search in July the distorted and curled leaves 
of the elm, inhabited by Schizoneura ulmi, we shall 
probably notice a number of shining, colourless, and 
* ‘ Reclierclies anatomiques et pliysiologiques sur les Hemipteres,’ 
p. 143. 
