DEVELOPEMENT. 
65 
layer, which forms the outer shell. Thus we find an egg 
to consist of the following parts :—a firm calcareous shell, 
perforated with innumerable pores; two membranes; the 
albumen, deposited in three different layers, combined and 
overlying each other, and connected in two places with the 
yolk; the membrane enclosing the yolk; the germ; and, 
lastly, the yolk itself, having a cavity in its centre com¬ 
municating with the former by a tube or duct. 
The apparently insignificant germ-spot is the most 
important of all the individual portions of the whole; in 
it lies the dormant Life, awaiting only the magic warmth 
destined to arouse it. Scarce larger than a grain of 
millet, and yet all the remaining component parts of 
the egg are, so to speak, absorbed in it. All the 
ingredients which chemistry discovers to us in an egg 
are employed by this germ in the construction of the 
body ; there is neither deficiency nor superfluity. Yet in 
it we cannot find the slightest clue which would lead to 
an explanation of the riddle of Life. The fresh-laid egg 
is, to all appearance, dead—though only apparently so— 
for, in reality, it lives. Each component part leads, as it 
were, a passive life, holding, however, constant commu¬ 
nication with the outer world. If action, consisting of 
interchange of matter, is intercepted by the application 
of a coating of wax, oil, or varnish, &c., the faculty of 
life is lost. An egg is possessed of caloric of its own, and 
can preserve it against exterior influences. It takes one 
hour and three-quarters to freeze a living egg at a tem¬ 
perature of 8° B., while one deprived of its vitality only 
requires one hour and a quarter. By further modification 
of material the egg shows loss of weight, the absorp¬ 
tion of matter being less than the amount given off, thus 
a Hen’s egg, while undergoing the process of incubation, 
K 
