INSECTA. 817 



existence is generally observed to be in relation to the period of their attaining 

 maturity — that is, that an animal is long or short lived, in proportion as it at- 

 tains puberty in a longer or shorter period. Among insects, this analogy 

 does not hold; for while the larvae of the goat-moth (cossus ligniperda,) is 

 three years, and that of the cabbage butterfly, not three months in attaining 

 maturity, yet the perfect insect in both lives equally long. The Melolon- 

 tha vulgaris, which exists four years in its preparatory stages, lives only 

 eight or ten days as a perfect insect ; some ephemerae, whose larvae have 

 enjoyed two years of preparatory existence, scarcely live beyond an hour ; 

 while the common flesh-fly, whose larva? have attained to maturity in three 

 or four days, exists several weeks. It is worthy of remark, as connected 

 with this subject, that although the general rule seems to be that insects die 

 immediately or soon after the period, when the continuance of the species 

 is provided for by their coupling, and the deposition of the ova, yet if the 

 junction of the sexes be prevented, such individuals seem exempted from 

 the general law. It is probable that some of the instances related of insects 

 having been kept for long periods in the perfect state, have been individuals 

 who had not by the sexual junction 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 imder similar circumstances, 

 Ephemera, which naturally perish in one day, may be kept alive for seven or 

 eight. 



The associations among insects for a common purpose are temporary or 

 continued. The temporary ones owe their origin to a female who has sur- 

 vived the winter, and who lays the foundation of the colony, of all the mem- 

 bers of which she is the common mother. Such are the associations among 

 wasps and hornets. The female queen begins the edifice, and deposits ova 

 in the first formed cells, which are destined to produce assistants, to people 

 and complete the colony. The insects first developed are all neuters, or 

 workers. To these, all the labors of the family are committed. In certain 

 communities of Termes, or white ants, ihe neuters form a body of soldiers 

 ready to defend the commonwealth from enemies, or to make regular war 

 on rival communities, with all the precision and detail of military ope- 

 rations. 



All insects which live in society, with the exception of the Tcrmes, un- 

 deigo a complete metamorphosis. Among the Termcs, the young differ but 

 little from the full-grown insect, except in point of size, the absence or 

 shortness of wings, and other distinctions of slight importance. Among 

 the ants, the neuters are deprived of wings ; but in all the other societies, 

 the three kinds of individuals have wings. The instincts of these societies 

 are modified according to their organic differences. Deprived of wings, 

 the neuters or workers among the ants form their dwelling in clefts of tiees, 

 walls, or under ground. The wasps and bees, on the contrary, whose wings 

 103 69 



