INSECTS. 



riods in the perfect state, have been individuals who had not by 

 the sexual conjunction fulfilled one important purpose of their 

 being. Gleditsch asserts, that, by keeping apart the sexes of the 

 grasshopper, their lives were prolonged to eight or nine weeks in 

 place of two or three, the general period of their existence ; and 

 under similar circumstances, Ephemera, which naturally perish 

 in a day. may be kept alive for seven or eight. 



On the habits and instincts of some species of insects volumes 

 have been written without exhausting the subject. The in- 

 stinctive faculty, of which traces are discovered in the other clas- 

 ses of animated beings, is carried among insects to its greatest 

 perfection ; and human reason seems startled at the contempla- 

 tion of the little commonwealths which the individuals of some 

 species form by their aggregation. There is something so strik- 

 ing in their combination of means to one common end ; so won- 

 derful in the geometrical structure of their dwellings, and the 

 exact determination of the material to the space and strength 

 requisite for their purposes : their internal economy ; the wars 

 of rival republics for spoil or for captives, are all so astonish- 

 ing, that one almost feels inclined to doubt, were not the facts 

 established beyond possibility of contradiction, that such things 

 should be related of animals placed at so great a distance in the 

 scale from man. But although the works and habits of insects 

 announce an industry of which the higher classes afford few ex- 

 amples ; yet their intellectual faculties, beyond the instinctive 

 association and united labour of some for the common purposes 

 of individual preservation and the continuance of the species, 

 seem otherwise inferior to many of these. Insects have at birth 

 all the knowledge requisite for these purposes ; and this know- 

 ledge consists of certain ideas, if they may be so termed, relative 

 to their wants and the employment of their organs. The circle 

 of their action is marked out for them by a wisdom which is in- 

 finite ; but so limited in many cases is this instinctive faculty, 

 that it has been ascertained, if the pupa be reversed in its co- 

 coon, with its head placed at the end which has no apparatus 

 necessary for its exit, it will perish in the attempt to force its 

 way through the insuperable obstacle, even though a lateral 

 opening be made for its escape. This natural faculty, which 

 incites them in a determinate and constant manner to seek their 

 proper food and propagate their race, is what is termed instinct. 



