THE FLY. 67 



little^ tlie first drought would cause eggs and larvae to 

 become desiccated. Having chosen a suitable locality, 

 one neither too wet nor too dry, she protrudes her 

 little ovipositor, and therewith lays her eggs, by the 

 side of, and upon one another, with the same pre- 

 cision as the cleverest hands would arrange larger 

 objects; she then sits perfectly still, without moving 

 a single member of her body excepting her ovipositor ; 

 indeed it would appear as though she were not quite 

 conscious whilst this operation is being performed, 

 for so long as she is not absolutely touched, one may 

 approach her as nearly as one likes, without causiug 

 her to exhibit the least symptom of alarm. During 

 this operation, which lasts half a quarter of an hour 

 (a few minutes more or less), she lays 70, 80, or 90 

 eggs." Generally speaking, the greater number of 

 insdcts die as soon as they have deposited their eggs ; 

 but Keller's observations led him to believe that this 

 is not the case with the Fly, for he retained several 

 alive in a glass for some days after oviposition was 

 completed, and he, as weU as other naturalists, be- 

 lieve that the iasect deposits her eggs three or four 

 times during her life, the duration of which is a few 

 weeks or months. 



Assuming that the Fly deposits 80 ova at a sitting, 

 and that she performs this operation four times during 

 her Ufe, Keller has drawn up the following curious 

 table, from which it would appear that a single female 

 might in one season be the progenitrix of upwards of 

 two million flies : — 



