The Mason-bees 



belly from front to back and then returns 

 from back to front on the upper surface, 

 where it ends at almost the same level as its 

 starting-point. Its length is 14 millimetres.^ 

 This fixes the limit of the depth which the 

 probe is able to reach in the Mason-bee's 

 nests. 



One last word on the Leucospis' weapon. 

 In the dying insect, beheaded, stripped of 

 legs and wings, with a pin stuck through its 

 body, the sides of the fissure containing the 

 inoculating-thread quiver violently, as if the 

 belly were going to open, divide in two along 

 the median line and then reunite its two 

 halves.' The thread itself gives convulsive 

 tremblings; it comes out of its scabbard, goes 

 back and slips out again. It is as though the 

 laying-implement could not persuade itself to 

 die before accomplishing its mission. The in- 

 sect's supreme aim is the egg; and, so long as 

 the least spark of life remains. It makes dying 

 efforts to lay. 



Leucospis gigas exploits the nests of the 

 Mason-bee of the Pebbles and the Mason- 

 bee of the Sheds with equal zest. To observe 



1.546 inch. — Translator's Note. 

 288 



