304 PHYSIOLOGY. 



generation, nutrition, motion, and sensation; to the other the care of 

 the parent for the offspring, the construction of their habitations, the 

 various localities of various groups, and the thence originating geogra- 

 phical distribution, and lastly, the influence insects exercise during 

 their lives upon nature generally, and especially upon man, and which 

 he, as if nature were created for him alone, distinguishes as the benefits 

 and injuries of the insect world. Each of these main divisions has its 

 several subdivisions. All observations, consequently, which belong to 

 somatic physiology can refer merely to the functions of the organic 

 system, and consequently they follow in the order of these four systems. 

 The subdivision of the second, or psychological physiology, or their 

 psychology, is more difficult, but a portion of their spiritual phenomena 

 may be more or less accurately arranged according to those organic 

 systems, and to which may be appended, lastly, the result of observa- 

 tions upon the influence of insects upon nature generally. This view, 

 presents the following arrangement : 



I. Somatic physiology. 



a. Origin and propagation of insects. 



b. Nutriment and development of insects. 



c. Motions of insects. 



d. Sensual phenomena. 



II. Psychological physiology, or psychology. 



a. Sexual instinct. 



b. Nutrimental instinct. 



c. Dwelling-place degrees of warmth and cold geographical 



distribution. 



d. Benefits and injuries produced to man. 



FIRST SUBSECTION. 



SOMATIC PHYSIOLOGY. 



201. 



THE path pursued by somatic physiology in the development of its 

 contents is the same as that followed by nature in the development of 

 insects. We commence, therefore, with the first appearance of the 



