ANIMAL GRAFTS AND REGENERATIONS. 251 
of it. The fact is, that species heretofore have been sub- 
jected only to the action of Nature’s spontaneous influences, 
and of the arts of zootechny ; but that which forces of this 
kind were powerless to effect yesterday might very well be 
accomplished to-morrow by the powers which the physiolo- 
gist now has at his disposal. By directing action to the 
eggs, as Claude Bernard suggests, that is, to the living 
germs, we gain a far more powerful and solid grasp on the 
remote plans of life. The embryo, that faint and indefinite 
sketch of the future being, that microcosm in which the 
silent forces of vitality slowly possess themselves of a soft 
pulp, sensitive to the slightest disturbances, is not forced 
to unfold itself in accordance with any unbending law: 
Robin has demonstrated this.’ It might then be possible 
to occasion, in the embryo of an animal, modifications com- 
patible with life, to maintain these in the animal once formed, 
to repeat and multiply them gradually upon the products 
of following generations, so as to fix them definitely by 
means of heredity. Some experiments made in this direc- 
tion, among others those of Dareste, Brown -Séquard, 
Trécul, etc., are highly promising; but the subject, we 
easily see, requires the diligent codperative labor of many 
lives of men. It isin this way that the philosopher will be 
able to disturb the mechanism of things, and invert the 
course of natural transmutations. He will impose his own 
will on the forces of the universe. Whenever he is shat- 
tered by them, they know nothing of it; when he subdues 
them, it is with absolute knowledge of what he is doing. 
These corpuscles themselves, these ultimate monads in 
which life dwells, may we not regard them in their turn as 
being susceptible to the action of inward modifications, and 
capable of displaying new properties? It is very interest- 
ing to remark that the same anatomical element shows 
1 See his remarkable work on the “‘ Appropriation of Organic Parts,” 
1869. 
