134 PHYSIOLOGY OF INSECTS. 



Matter, chiefly in its solid form, is the element of which the 

 systems of organs are composed ; and organs are the in- 

 struments by which functions are performed : in all animals 

 there are seven systems of organs to perform seven series 

 of fimctions. The seven systems of organs and their 

 respective functions are these : — hones, ior support ; mus- 

 cles, for motion ; air-tubes, for respiration ; blood-vessels, 

 for circulation ; alimentary canal for digestion ; nerves, 

 for sensation ; and the organs of the sexes, for reproduc- 

 tion. The fluids in insects are blood and various secre- 

 tions : the blood is supplied by nutriment transmitted from 

 the alimentary canal : the solid parts are renevred by secre- 

 tions from the blood. 



Motion, in the animal frame, is of two kinds ; dominant 

 motion, which acknowledges not the authority of the mind ; 

 for instance, circulation of the blood : and subservient 

 motion, which operates only in accordance with the behests 

 of mind. 



Sensation is the ultimate power of matter so perfected 

 as to take cognizance of facts beyond the limits of the body : 

 sensation is of two kinds ; that derived from external ob- 

 jects, which appears the aim of animal life, and conduces 

 to its maintenance, and that which conveys information from 

 matter to mind, and behest from mind to matter. 



Mind is the commanding element ; the other elements 

 in acting obey it, but in existence and characters are inde- 

 pendent of it : no powers of mind can prevent the exist- 

 ence, or change the characters of matter, motion, or sensa- 

 tion: mind argues, then commands; it takes cognizance 

 of causes, and provides for consequent effects, before the 

 other elements can obey its behests. The great powers of 

 mind are speculation and retention: speculation is the 

 power w^hich supposes an event that has not yet occurred ; 



