360 Dr. Wallace on the Oak-feeding 
of a minute portion of air. On its inner surface it is highly 
polished, and of a pink tinge. The gum, whichis thick and strong, 
and when moistened resembles glue in smell, serves not only to 
retain the eggs in situ where deposited, during winter rains and 
storms, but also as a protection against extreme cold, drought or 
heat, &c. It is easily soluble in an alkaline fluid. Some few eggs 
are destitute of gum, aud some possess much more than others. 
This seems to be due to the accident of deposition, the first eggs 
laid being the more thickly coated, the Jast ones more sparingly 
covered. But this variation® in the quantity of the gum is not to be 
taken as an evidence for or against fertility of the eggs,as I have had 
white eggs which have hatched out their Jarvee, and brown eggs that 
have failed to doso. A curious circumstancef connected with the 
egg stage of the insect bas been observed by Mons. Guérin-Méne- 
ville, that the young larva is fully developed a month after depo- 
sition of the egg, and that he lies during the winter perdu within 
the shell, in a dormant condition, until a vernal temperature and 
moisture awake him to the active duties of life. This habit of 
passing the winter within its own shell has not before been ob- 
served in any young larva, and well deserves the close attention 
of Entomologists. In consequence of this peculiar habit, great 
care should be taken, in the transit of eggs through long dis- 
tances in winter, not to expose them to high temperatures, lest a 
premature activity should call the young worm into existence 
before the food is ready. 
In early spring, almost before the oak buds are ready, 
the young larvee begin to emerge, unless retarded by being 
placed in a cool north aspect. ‘This is the case with eggs 
obtained from North France, and, to a greater extent, with 
eggs that have been forwarded from Japan. I should there- 
fore infer from this, as well as from the habits of the Jarvee, which 
will be subsequently mentioned, that, in a state of nature, a cool 
shady locality is selected by the female for the deposition of her 
eggs, which are inserted into the crevices of the bark on the north 
aspect of the tree, in order that the sun’s rays may not awake 
* The same remark is made by Mons. Guérin-Méneville, Revue de Sérici- 
culture, 1863, p. 295. 
+ Vide Revue de Sericiculture, 1863, p.295. This discovery caused great 
anxiety to Mons. Méneville, lest all the eggs might hatch out prematurely, 
and the valuable race be lost to him for that time; but finding that the same 
thing had happened to the possessors of eggs in other countries, he con- 
cluded that it was a natural but curious condition peculiar to the Yamamai. 
It was brought before the Entomological Society of France, but no analogous 
instance was known to the members. 
