PERFECT SOCIETIES OF INSECTS. 



131 



only after this period that an uninterrupted laying of male 

 eggs commences. But when it has been retarded, after the 

 same number of hours she begins laying male eggs, and con- 

 tinues to produce these alone during her whole life. From 

 hence it should seem to follow that the former kind of eggs 

 are first in the oviducts, and if impregnation be not effected 

 within a given time, that all the worker embryos perish. Yet 

 how this can take place with respect to those that in a fertile 

 queen should succeed the laying of male eggs, or be produced 

 in the second year of her life, seems difficult to conceive ; — 

 or how the male embryos escape this fate, which destroys all 

 the female, both those that are to precede them and those 

 that are to follow them. Is it impossible that the sex of the 

 embryo may be determined by the period at which the aura 

 seminalis vivifies it, and by the state of the ovary at that 

 time ? In one state of the ovary this principle may cause the 

 embryos to become workers, in another males. And some- 

 thing of this kind perhaps may be the cause of hermaphrodites 

 in other animals. But this I give merely as conjecture 1 : the 

 truth seems enveloped in mystery that we cannot yet pene- 

 trate. Huber is of opinion that a single impregnation 

 fertilises all the eggs that a queen will produce during her 

 whole life, which is sometimes more than two years.' 2 But 

 of this enough. 



I said that forty-six hours after impregnation the queen 

 begins laying worker eggs ; — this is not, however, invariable. 

 When her impregnation takes place late in the year, she 

 does not begin laying till the following spring. Schirach 

 asserts, that in one season a single female will lay from 

 70,000 to 100,000 eggs. 3 Reaumur says, that upon an 

 average she lays about tAVO hundred in a day, a moderate 

 swarm consisting of 12,000, which are laid in two months; 

 and Huber, that she lays above a hundred. All these state- 



1 This conjecture receives strong confirmation from the following observations 

 of Sir E. Home, which I met with since it came into my mind. From the 

 nipples present in man, which sometimes even afford milk, and from the general 

 analogy between the male and female organs of generation, he supposes the 

 germ is originally fitted to become either sex ; and that which it shall be is de- 

 termined at the time of impregnation by some unknown cause. — Philos. Trans., 

 1799,157. 



2 i. 106—. 3 Schirach, 7. 13. 



K 2 



