114 



PERFECT SOCIETIES OF INSECTS. 



by a particular diet in childhood; a warmer or a colder, a 

 looser or a tighter dress, or the like. Thus, for instance, the 

 Egyptians, who went bare-headed, had their skulls remark- 

 ably thick ; while the Persians, who covered the head with 

 a turban or mitre, were distinguished by the tenuity of theirs. 

 Again, the inhabitants of certain districts are often remark- 

 able for peculiarities of form, which are evidently produced 

 by local circumstances. 



The following reasoning may not be inapplicable to the de- 

 velopment or non-development, according to their food and 

 habitation, of the ovaries of these insects. An infant tightly 

 swathed, as was formerly the custom, in swaddling bands, 

 without being allowed the free play of its little limbs, fed 

 with unwholesome food, or uncherished by genial warmth, 

 may from these circumstances have so imperfect a develop- 

 ment of its organs as to be in consequence devoted to sterility. 

 When a cow brings forth two calves, and one of them is a 

 female, it is always barren, and partakes in part of the cha- 

 racters of the other sex. 1 In this instance, the space and 

 food that in ordinary cases are appropriated to one are divided 

 between two; so that a more contracted dwelling and a 

 smaller share of nutriment seem to prevent the development 

 of the ovaries. 



The following observations, mostly taken from an essay of 

 the celebrated anatomist John Hunter, in the Philosophical 

 Transactions, since they are intimately connected with the 

 subject that we are now considering, will not be here mis- 

 placed. In animals just born, or very young, there are no 

 peculiarities of shape, exclusive of the primary distinctions, 

 by which one sex may be known from the other. Thus se- 

 condary distinctive characters, such as the beard in men, and 

 the breasts in women, are produced at a certain period of 

 life ; and these secondary characters, in some instances, are 

 changed for those of the other sex ; which does not arise from 

 any action at the first formation, but takes place when the 

 great command, " Increase and multiply," ceases to operate. 

 Thus women in advanced life are sometimes distinguished by 



i See J. Hunter's Treatise on certain Parts of the Animal (Economy. 



