THE OVARIAN EGG. 291 
are, in fact, the component parts of the little Turtle 
that is to be. They will undergo certain medi- 
fications, to become flesh-cells, blood-cells, brain- 
cells, and so on, adapting themselves to the dif- 
ferent organs they are to build up; but they have 
as much their definite and appointed share in the 
formation of the body now as at any later stage 
of its existence. 
_We are so accustomed to see life maintained 
through a variety of complicated organs, that we 
are apt to think this the only way in which it can 
be manifested ; and, considering how entirely the 
life of an adult animal is dependent upon the 
organs through which it is sustained, it is natu- 
ral that we should be deeply impressed by their 
connection. But embryological investigations 
have taught us that during the incipient growth 
of the higher animals none of these organs exist. 
and yet the principle of life is active, and even 
after the organs are formed, they cannot act at 
once, most of them being enclosed in the whole 
structure, in a way which interferes with their 
later functions. In the little Chicken, for in- 
stance, before it is hatched, the lungs cannot 
breathe, for they are surrounded by a fluid; the 
senses are inactive, for they receive no imprcés- 
sions from without, and all thnse functions estab- 
lishing its relations with the external world lie 
dormant, for as yet they are not needed. But 
