158 GRAMMAR OF ENTOMOLOGY. 



regularly, with a distinct pulse, in every part of 

 the body. 



598. The organs of respiration are tubes per- 

 meating the whole body, and communicating 

 with the air by means of lateral spiracles or 

 openings in the side of the insect. 



599. The organs of generation in insects are 

 situated in the last segment almost invariably. 

 Insects are of two distinct sexes, male and 

 female ; those called neuters are abortive females. 



600. Insects are long in proportion to their 

 breadth : they are transversely divided into thir- 

 teen segments ; each segment seems to possess 

 in itself a distinct vitality. 



601. Insects are excessively tenacious of life, 

 even to so great a degree, that heads separated 

 from the body have eaten voraciously for hours, 

 the food passing completely through them ; and 

 bodies without heads have occasionally fled, and 

 have repeatedly walked about for days. 



602. Insects appear to possess no mental 

 power ; to be incapable of memory ; to assume 

 the winged state in the plenitude of perfection ; 

 to perform the acts their parents performed with- 

 out the possibility of tuition or observation. 



603. The author is aware that several repe- 

 titions occur in the course of this book, but they 

 appeared to him essential to make the subject per- 

 fectly clear ; he hopes that those who do not see the 

 necessity of these repetitions will yet pardon them. 



