INSECTS. 



higher animals. The only exception to this rule occurs in some 

 genera of the order Hymenoptera, where, besides the males and 

 females, a third kind of individuals occur named neuters. These, 

 from what has been observed in the economy of the bees, who, 

 when a new queen is wanted, rear one of the larva of the neuters 

 for this purpose, are conceived to be imperfectly developed fe- 

 males. The males are distinguished from the females by their 

 reproductive organs, by their smaller size, and in general more 

 brilliant colours ; by the form of their antennas, and sometimes 

 by their having wings, while the females are apterous. Repro- 

 duction takes place in the last or perfect state ; and after 

 impregnation, the females, with instinctive sagacity, deposit their 

 ova, of various forms, on objects or places where the young ani- 

 mal when hatched may find its appropriate food. 



Insects are in general oviparous animals ; for though a few, 

 which have been termed ovo-viviparous, bring forth living larvae, 

 as the flesh-fly, or, as the Hippobosca equina, produce their young 

 in the pupa state, yet, generally speaking, the whole class may 

 be considered as oviparous. The ova are of two kinds ; some 

 with a membranous covering like those of the reptiles, and the 

 others crustaceous, like the eggs of birds. The variety, however, 

 in point of form, among these ova is almost incredible, nearly 

 equal, it may be said, to the number of the species. Some are 

 round, elliptical, lenticular, cylindrical, pyramidal, flat, and even 

 square ; some are smooth ; others figured or grooved ; and in 

 point of colour every shade is employed, some shining with the 

 lustre of pearls, and others with the hue of gold. And these 

 ova are all deposited with the most unerring instinct in places 

 where the future animal may find its proper food without the 

 parent's care. 



The number of ova deposited by particular insects is extremely 

 various ; but in general it may be remarked, that the fertility 

 of insects exceeds that of birds, and is only surpassed by the al- 

 most unbounded reproductive powers of fishes. Lewenhoeck 

 found that a single fly could produce in three months 746,496 

 flies similar to itself; the silk-worm moth deposits about 500 ova; 

 the tiger moth 1600. And in insects living in societies, like 

 the wasp and bee, whose manners have been more the subject 

 of observation, the reproductive powers are still greater. The 

 female wasp deposits at least 30,000, and the queen bee from 



