ORDER ACCIPITRES. 1^«> 



acting on the organs in a propelling direction to the external 

 surface, in proportion as reparation takes place. This ^nutation, 

 or evolution of living beings, is the source of the changes 

 which their external surfaces undergo in the different periods 

 of their existence. These changes are of great importance to 

 study, inasmuch as an ignorance of them has often caused the 

 multiplication of species and confusion of sexes, and distinc- 

 tions in many instances where there was no real difference. 



The first rudiments of the plant are already organized in the 

 grain or seed, and the first rudiments of the animal in the 

 egg. Nutrition, through the interior, augments all the dimen- 

 sions of the living body, and increases it to a determined 

 point of size. Each individual part of the organised being has 

 its peculiar nutrition, emanating from the general nutrition of 

 the body, because each has its pecidiar force originating in 

 the vital principle, common to the whole machine. Thus the 

 body has not only a general evolution, but each of its organs 

 has a particular one, which may take place even independ- 

 ently of the other parts, and augment at their expense. 



If each organ has its own peculiar life, it has also, without 

 doubt, its age and duration, independently of what it receives 

 from the whole body. In fact, certain organs grow old and 

 die before the general death ; as, for instance, the organs of 

 generation. These are not developed until long after the 

 birth of the living body, and they die before it. Their parti- 

 cular vitality has, therefore, much less duration than the 

 general vitality. It is the same with many other parts, the 

 vital duration of which is very short in comparison to that of 

 the individual. This is particularly the case with several 

 external organs, such as horns, teeth, hair, feathers, shells, &c. 



Since each part of the animated body is thus endowed with 

 its peculiar life, it has its period of youth, perfection, decrease, 

 and particular death. This is matter of daily observation in 

 organised productions; for when an organ is completely dead 

 in a being endowed with life, it separates and falls, because a 



Vol. VI. L 



