458 BIOLOGY. 



Mammalia. Respiration is originally but an act of deglu- 

 tition, which has gradually become perfected, by the 

 animal trunk being associated with it to a greater 

 extent. 



2779. The pumping in of air has therefore become in 

 the highest degree a process of suction, and in this re- 

 sembles the digestive function when it has become 

 animal. 



2780. Then also the air passes no longer through the 

 mouth, but through the nose, as being the peculiar 

 opening of the thoracic cavity in the head. Even the 

 Fishes have as yet no nostrils opening into the mouth. 



2781. The thoracic motion is a limb-motion, and 

 would become locomotion, were the ribs not conjoined. 

 In many of the lower animals the branchiae are at once 

 organs of motion, such as fins or rudders. 



2782. Every inspiration is a self-manning towards 

 the animal ; every expiration a retro- depression unto the 

 plant ; the abdomen in this case regains the upper hand 

 from the diaphragm reverting to its usual position, and 

 the thoracic cavity narrowing. Respiration is a becoming 

 animal. 



2783. The motions in themselves, without reference 

 to the trunk, are the motions of the limbs, as standing, 

 walking, &c. The movements of the arms and feet are 

 sympathetic, because their muscles are of equal sig- 

 nification. 



B. FUNCTIONS OF THE NERVE-ORGANS. 



2784. These functions have relation only to the nerv- 

 ous system itself, because all nerve-organs are elevated 

 above the trunk, and live in themselves. They are 

 simply the functions of the sensorial organs. 



a. Functions of the Vegetable Sensorial Organs. 



2785. These must be regarded as those that still en- 

 croach upon the inferior organs. They are not, however, 

 the inferior processes themselves, but their ascensive 

 formations into the nervous system. This therefore 



