578 ON THE USE OF POLLEN 
A moment’s reflection will show, as a result necessarily 
following from the preceding postulates, that some characters 
are more, some less essential to the performance of a function. 
Another definition, which it is here necessary to supply, 
is the following: The conditions of existence are the mutual 
dependencies which exist between the characters of the 
same organ; or between different organs in the same appa- 
ratus; or between different apparatusses. 
I need, in this instance, no apology for introducing the following;passage 
from the ** Ossemens fossiles" to elucidate the meaning of the “conditions 
of existence." No naturalist can be too familiar with the writings of 
Cuvier;—speaking of himself as contemplating the bones which he had 
procured from the ÉIT of Paris, he says: ‘ I was in the situation of 
* a man who had given to him, péle mele, the mutilated and incomplete 
** fragments of a hundred Se, belonging to twenty sorts of animals, 
* andit was required that each bone should be joined to that which it 
“belonged to. It was a resurrection in miniature; but the immutable 
* laws prescribed to living beings were my directors. At the voice of 
“ comparative anatomy, each bone, each fragment, regained its place. I 
* have no expressions to describe the pleasure experienced in perceiving 
“ that, as I discovered one character, all the consequences, more or less 
“ foreseen, of this character, were scene developed. The feet were 
** conformable to what the teeth had an ced, and the teeth to the feet; 
"7 the bones of the legs and the ‘highs, ger every thing that ought to re- 
** unite these two extreme parts, were conformable to each other. In one 
** word, each of the species sprung up from one of its elements. Those 
* who will have the patience to follow me in these memoirs, may form 
‘ some idea of the sensations which I experienced in thus restoring, by 
-A these ancient monuments of mighty revolutions. This volume 
* will afford much interest to ists, independent of geology, show- 
*' ing them, by multiplied examples, the strictness of the laws of co-ex- 
“ istence, which elevate zoology to the rank of the rational sciences, and 
** which, leading us to abandon the vain and arbitrary combinations that 
“ had been decorated with the name of systems, will conduct us at last to 
“ the only study worthy of our age—to that of the natural and necessary 
* relations, which connect together the different parts of all organised 
** bodies,"—These considerations apply as well to plants as ahimals. 
This leads us to another postulate; let it be granted that 
the conditions of existence require a constant relation be- 
tween characters the most essential, and those less essential 
