But the mode in which they multiply is as
follows: The first change noticed in a cell, when warmed into vital
activity, is the appearance of a second nucleus within it, while the
cell gradually becomes oval in form, and then is drawn inward at the
middle, like an hour-glass, till the two sides meet. The two portions
then divide, and two cells appear, each containing its own germinal
nucleus. These both divide again in the same manner, proceeding in the
ratio of 2, 4, 8, 16, and so on, until most of the yelk becomes a mass
of cells.
The central point of this mass, where the animal itself commences to
appear, shows, first, a round-shaped figure, which soon assumes form
like a pear, and then like a violin. Gradually the busy little cells
arrange themselves to build up heart, lungs, brain, stomach, and limbs,
for which the yelk and white furnish nutriment. There is a small bag
of air fastened to one end inside of the shell; and when the animal
is complete, this air is taken into its lungs, life begins, and out
walks little chick, all its powers prepared, and ready to run, eat,
and enjoy existence. Then, as soon as the animal uses its brain to
think and feel, and its muscles to move, the cells which have been
made up into these parts begin to decay, while new cells are formed
from the blood to take their place.
Pages:
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147