992 THE OVARIAN EGG. 
the organs are there, though, as we have seen in 
the Turtle’s egg, they were not there at the be- 
ginning. How, then, are they formed? We 
may answer, that the first function of every or- 
gan is to make itself. The building material is, 
as it were, provided by the process which divides 
the yolk into innumerable cells, and by the grad- 
ual assimilation and modification of this material 
the organs arise. Before the lungs breathe, they 
make themselves; before the stomach digests, it 
makes itself; before the organs of the senses act, 
they make themselves ; before the brain thinks, 
it makes itself. - In a word, before the whole 
system works, it makes itself out of the elements 
given by the formation of independent eggs: its 
first office is self-structure. | 
At the period described above, however, when 
the new generations of cells are just set free and 
have taken their place in the region where the 
new being is: to develop, nothing is to be seen of 
the animal whose life is beginning there, except 
the filmy disk lying on the surface of the yolk. 
Next come the layers of white or albumen around 
the egg, and last the shell which is formed from 
the lime in the albumen. There is always more 
or less of lime in albumen, and the hardening of 
the last layer of white into shell is owing only te 
the greater proportion of lime in its substance — 
{n the layer next to the shell there is enough of 
~~ 
