420 TROPICAL WILD LIFE IN BRITISH GUIANA 



straight to her nest. The dauber returned to the general 

 locahty without much difficulty, but actually to reach the 

 cells she must feel about with curled antennae, and depend 

 upon smell rather than a mere sense of direction. 



To build a cell including its foundation requires between 

 seventy and eighty loads of mortar. The freshly made nin*s- 

 ery weighs about seven and two-thirds grams, but by the 

 time it is ready to receive provisions, evaporation has reduced 

 it to three. From these figures I conclude that to build a 

 nest containing ten cells requires some seven hundred pellets 

 of mud. In accomplishing her task the tireless, energetic 

 mason carries 1,000 times her own weight in mortar and fash- 

 ions it grain by grain into the abode for her progen3\ 



In storing her cells, the dauber shows a varied taste. 

 I have before me, two open cells. One contains two large 

 fat spiders that easily fill the store-room, the other is stored 

 with a variety of victims, nine in all, including many grades 

 of size and color. In these two cells I have at least three 

 genera and five different species of paralyzed spiders. 



Upon the side of the abdomen of the largest one in each 

 cell, the wasp deposits a pale yellowish white egg, then she 

 seals the nursery entrance with a few pellets of mortar and 

 abandons the nest for good. 



In seventy-two hours the egg hatches, or I should say, 

 comes to life. Here is a strange process. Watching the 

 erstwhile egg through the lense, a spasm suddenly takes 

 place within its fihn-like shell, which is nearly transparent 

 and allows a fairly clear view of what takes place within. 

 This spasm is a sort of pumping wave, similar to the move- 

 ment in a big fire hose under pressure from the engine. It 

 starts at the anterior end of the egg and transverses its en- 

 tire length, fading out as it reaches the opposite end from 

 which it started. Thus does the new-born take its first 

 mouthful of liquid food from the spider. There is no actual 

 hatching and crawling forth from tlie egg, no empty shell 

 behind the larva. Instead, its mouth appears first to eat a 



