127 , 



which they have in the fibre. The extension of the fibre 

 supposes that its elements may separate more or less 

 from each other; hut this separation hath its bound, 

 and these bounds are those of the growth. In propor- 

 tion as the fibre grows, it acquires more solidity; for 

 the i] umber of incorporated molecules increase every 

 day, since it only grows by the successive incorporation 

 of molecules of a foreign nature. The more the solidity 

 augments, the more the suppleness diminishes. There 

 are more molecules, more coherence, and more attrac- 

 tion under the same foldage. The fibre then tends to 

 a state of hardness, and tiie last term of its harden- 

 ing is the last term of its growth. When therefore the 

 fibre has acquired its full growth, it is a little organized 

 whole, composed of its elementary molecules, and of ail 

 such as nutrition has incorporated with them during the 

 time of their growth. If then we could separate from 

 the fibre all those molecules which it has assimulated, 

 we should restore it to its primitive state. This may 

 be applied to ail organized bodies. They are, if we cliuse 

 to term them so, net work. A secret force .impels the 

 aliment into the meshes. It increases them in bulk, 

 and supplies Inem by little and little. It likewise insi- 

 nuates itself into the elements of the solid mass itself. The 

 net-work stretches, thickens, and at length becomes hard. 



8. We may easily comprehend, that all the parts of 

 an animal have such strict and indissoluble connexions 

 between them, that they must necessarily have always 

 co-existed together. The arteries imply veins; both of 

 the e imply nerves; the latter the brain; this the heart; 

 and all of them suppose a multitude of other organs. 



In the germ of a chick there is at first perceived a 

 vital pointy vthose constant motion attracts the attention 

 of the observer. The alternate and quick contractions 

 and dilatation of the living point, sufficiently indicate- 

 that iris the heart. Bat this heart seems to be without 

 any covering, and to be placed on the outside of the 

 body. Instead of appearing in. the form of a minute- 

 pyramidical mass, it bears the resemblance of a. serai-- 

 G 3 



