The Nest-building Odynerus 



withdraws a little way into the sheath of 

 the egg; then, reassured, it once more glides 

 forward and resumes the point attacked. 

 At other times a jerk leaves it indifferent. 

 This suspension-stage of the new-born larva 

 continues for about twenty-four hours, after 

 which the grub, now somewhat fortified, lets 

 itself drop and eats in the ordinary manner. 

 The victuals last it for twelve days. Im- 

 mediately afterwards comes the working of 

 the cocoon, in which the insect remains, a 

 yellow larva, until next May. It would be 

 tedious to follow the Odynerus in its career 

 of eating and weaving. The consumption 

 of dishes highly spiced with nitrobenzene and 

 the spinning of the cocoon, of a fine amber- 

 coloured fabric, involve nothing so remark- 

 able as to deserve special mention. 



Before leaving this subject, I will state a 

 problem which the pendulous egg sets to the 

 embryogenist. Every insect's egg, if cyl- 

 indrical in form, has two poles, the front and 

 back, the cephalic and the anal pole. By 

 which of the two does the insect see the 

 light? 



By the hinder pole, the Eumenes and the 

 Odyneri tell us. The end of the egg fas- 

 tened to the wall of the cell was evidently 

 the first to issue from the oviduct, in view 

 203 



