31o PHYSIOLOGY. 



remark, that the preponderating sex takes the right side, and that 

 associated to it the left. This appears to harmonise with the prepon- 

 derating plastic nature and energy of the right side in general, and to 

 proceed from the same fundamental law. 



Another question is do such hermaphrodites suffice to themselves ? 

 The observation of Scopoli speaks in favour of it, but all other, and 

 even regular hermaphrodite organisms speak against it. The her- 

 maphrodite Mollusca never impregnate themselves, but mutually ; con- 

 sequently, how should imperfect hermaphrodites be able to impregnate 

 themselves ? Even this self-impregnation appears to be mechanically 

 impossible, as the penis and the vulva are enclosed by valve-shaped 

 organs, and by this means separated from each other. If, therefore, 

 Scopoli's pine Bo-mbyx really laid eggs, it did so like all the female 

 Bombi/ces, namely, in the anguish of death ; and if caterpillars were 

 developed from these eggs, this development must have occurred as 

 independently as the abovementioned instances of spontaneous deve- 

 lopment, an assertion which is rendered the more probable, as here, by 

 the presence of the male organs to a certain extent, a subjective female 

 sexuality already existed. 



206. 



As we have now shown that the several kinds of generation, except- 

 ing the sexual by means of separate sexes, are irregular, and having 

 proved that the observed instances are mere exceptions, it remains for 

 us to notice this last mode of propagation, as that which is regular and 

 general. We may therefore adopt that all insects are of separate 

 sexes, and that they require the intermixture of both sexes to be 

 fruitful. .Experience confirms this doctrine. Indeed, in some families, 

 as in the bees and ants, there are sexless individuals, which can operate 

 neither masculinely nor femininely, and therefore never copulate ; but 

 observation proves that such individuals are merely abortive females, 

 and that in these families the female functions are divided between 

 two different beings, the one of which copulates and lays eggs, and the 

 other attends to the nurture of the offspring. If we therefore more 

 closely investigate sexual generation by means of separated sexes, as 

 found among insects, our first object of inquiry will be the differences 

 of both sexes ; which is succeeded by their union for propagation or 

 copulation, the consequence of which is impregnation, and thence fol- 

 lows the formation of the egg and the development of the embryo. A 



