116 



ANATOMY. 



have received the name of ANIMAL ORGANS, and their compass of action 



the ANIMAL SPHERE. 



90. 



The greater development or separation into several distinct organs, 

 and the more complex structure of each, are the phenomena gradually 

 displayed in the progressive ennoblement of the animal kingdom, com- 

 mencing at the most simple conditions of animal existence. Insects 

 maintain in every respect a central situation in this series ; their 

 organs, therefore, will not display to us a very artificial structure, nor 

 will their combination be very complex. But we shall find the above 

 indicated four chief differences, which are dependent upon the vital 

 phenomena of the organism, sufficiently distinctly exhibited in them. 

 Now, as the several organs of each individual system not only aim at 

 one object in their functions, but also display considerable conformity 

 in their structure, it will be suitable to regulate the arrangement of our 

 present investigation by their differences, whence we derive the follow- 

 ing themes : 



I." Investigation of the vegetative system and its organs. These are, 



A. The organs of nutriment, consisting of 



The general integument. As this in insects is a horny case, to 

 which the organs of locomotion are attached, its description 

 must be classed with the consideration of the animal organs, 

 it being but the passive agent of motion. Therefore of 



a. The INTESTINAL CANAL with its appendages, as digestive 



organs ; 



b. The HEART and BLOOD VESSELS, as organs of circulation ; 



c. The AIR VESSELS, as respiratory organs. 



B. The organs of re-production ; consisting of 



a. The FEMALE organs of re-production, and 



b. The MALE organs. 



II. Investigation of the animal system and its organs. 



A. Organs of locomotion : 



a. Passive organs of motion ; here the EXTERIOR INTEGUMENT 



as analogous to the osseous system. 



b. Active organs, the MUSCLES. 



B. Organs of sensation: 



a. The BRAIN; 



b. The NERVOUS SYSTEM in general ; 



