496 BIOLOGY. 



perfection. To the nose are wanting the posterior nasal 

 foramina, to the ears the external auditory meatus, to the 

 eyes the palpebrae and power of motion. 



3081. In the Reptiles the nose opens for the first time 

 into the mouth, and serves for the thorough passage of 

 air. It is thus developed as in Man, while to the ears 

 the external auditory meatus and cochlea are wanting, 

 the eyes being barely endowed with lids and motion. 



3082. In Birds, for the first time, the external auditory 

 meatus, as well as the cochlea, is exhibited in its perfec- 

 tion, while the eyes are scarcely gifted with motion, and 

 have only the inferior lid perfect ; the tongue and nose, 

 with the limbs also, have again become retrograde in 

 character. 



3083. For the first time, in the Mammalia, the eyes 

 are moveable and covered with two perfect lids, without 

 the other organs of sense having suffered degradation 

 through this completion of the eyes. 



3084. Thus in respect to the Senses there are only 

 5 animal divisions of equal value or worth. They 

 should properly be called classes; but, as the lowest 

 division, from comprising within itself the viscera or the 

 vegetative systems, is very rich in contents ; were we to 

 call these divisions classes, many inequalities in rank, and 

 hence also in the number of the orders and families, 

 would originate 



1. Dermatozoa . . Invertebrate. 



2. Glossozoa . . . Pisces. 



3. Rhinozoa . . . Reptilia. 



4. Otozoa . . . Aves. 



5. Oplithalmozoa . Mammalia. 



3085. Now, with the sense of feeling, or the integu- 

 ment, the sexual system is associated or conjoined, and 

 that indeed as the first or lowest development of the 

 tegumentary system. Nevertheless, the sexual system 

 divides into two groups, into the sexual organs, which 

 are impressed with a true sensorial signification, and 

 into their product, or the sexual juices, and the ovum or 

 foetus. With these two divisions the development of the 

 integument proceeds " pari passu." 



