106 
HALF HOURS WITH INSECTS. 
[Packard. 
Regarding this estimate of what one Aphis can do to pop¬ 
ulate the world, Prof. Huxley makes the following state¬ 
ment : “I will assume that an Aphis weighs one-thousandth 
of a grain, which is under the mark; a quintillion will on 
this estimate weigh a quadrillion of grains. lie is a very 
stout man who weighs two million grains ; consequently the 
tenth brood alone, if all its members survive the perils to 
which they are exposed, contains more substance than five 
hundred million stout men, to say the least more than the 
whole population of China.” That the individual with the 
potential ability to produce such a mass of young only suc¬ 
ceeds in leaving perhaps two eggs to represent its species at 
the beginning-of winter, all its offspring dying off, is a sig¬ 
nificant fact, illustrating forcibly the terrible struggle for ex¬ 
istence going on in the animal world. 
I scarcety know how to present in a popular way the mode 
of growth of the embryo Aphis. It has been well described 
by Huxley, and in a more exhaustive manner by the Russian 
naturalist Metznikoff. This study of the earliest phases in 
the life of an insect, or in fact any animal, leads us up to 
the very threshold of the mysterious portals of life. The 
problem g\ven is, a sac full of protoplasm, a drop of jelly 
like the jelly in the cell of a plant, to our eyes the same, so 
far as our finite analysis at present extends, and yet poten¬ 
tially an animal, even representing the initial point of man 
himself. How is this result attained? This drop of oily 
jelly contains another sac filled with albumen, called the 
nucleus. Now when that mysterious act, the mingling of 
the contents of a sperm cell with the ovarian cell, or as in 
the virgin Aphis, the act of budding—the simplest genera¬ 
tive process known—has occurred, let us with the practised 
eye of our Russian guide watch the behavior of the two ele¬ 
ments, the general oily contents of the egg, or yolk, and the 
albuminous nucleus. The original protoplasmic mass has, 
prior to the union with a sperm cell, increased in size and 
10 
