INSECTS IN GENERAL. 33 



thing but simple developments. It is, therefore, most absurd 

 to think, tliat to have correct notions on a subject like the 

 present, can be matter of indifference to a philosopher. It is 

 the nature of error to propagate itself, as it is of truth to 

 conduct to the discovery of truth ; for one error may be said, 

 without any exaggeration, to be connected with a multitude 

 of others, and the same relation to exist among all important 

 truths. 



As soon as it was recognized that sexual intercourse was 

 necessary to the re-production of insects, the general law of 

 nature, which is applicable to other animals, was, of course, 

 applied to them. However, without a careful and consecu- 

 tive study of the subject, who would have imagined the 

 possibility of their multiplying without the repetition of the 

 fecundating act for a series of generations ? Is it not a new 

 and most interesting phenomenon in animal physiology, to 

 find that the insects to which we have just alluded (the 

 aphides) are viviparous in the fine season, and oviparous at 

 the approach of winter. Nor are these the only insects 

 that should teach us the presumption of limiting nature 

 within the narrow circle of our knowledge or conceptions. 

 From the Mppohoscus we learn, that it is possible for the 

 young of some animals, at the instant of their birth, to be 

 nearly as large as the mother. 



As the appearance of different species of insects, on the 

 return of fine weather, has a direct relation with the tempera- 

 ture of the air, they may be considered, in some sort, as 

 natural thermometers. Some require but a moderate degree 

 of heat for their development, others one much more consi- 

 derable. Some insects may even answer the purpose of 

 barometers. Thus, we may expect storm or rain when we 

 behold the bees returning to their hives with unusual haste ; 

 when the ants conceal their larvae, or their nymps ; or the 

 butterflies do not soar to their usual elevation. Such pheno- 



VOL. XIV. D 



