Wasps and Such. 169 



makes the cells for her young. She has no experience 

 with anything but the egg, has never seen a pupa, but she 

 builds each compartment just the right size. I wish you 

 wuuld tell me how she gauges it. By instinct, you say. 

 A very satisfactory explanation. Very. What is the 

 cause of B? \Yliy A, of course. And what is A? That 

 which causes B. Animals are 

 enabled to do sensible things by 

 instinct, and the definition of 

 instinct is that it is that by which 

 animals are enabled to do sensi- 

 ble things. Let me tell you 

 what I think about instinct and 

 a few other such words that 



succinctly answer the riddle of Fig. 3 e. Spider wasp, 



the universe. 1 think they are 

 cheeks drawn by us on a bank where we have no funds. 



The mason wasp catches spiders, paralyzes them with 

 her sting, lays an egg on the under side of the first one, 

 and then packs the cell full of victuals. The mason wasp 

 has three or four cells in each of several tiers, but the 

 carpenter wasp makes a separate hole for each egg laid. 

 She has her own troubles, for there are other membrane- 

 winged creatures too shiftless to build them nests, and 

 while the industrious one is out hunting, the cuckoo wasp 

 slips in and lays her own egg instead. The carpenter 

 wasp has to look out for Chrysis, and what a temper she 

 gets into when she finds one flitting about ! On this 

 account Ammophila is very careful about hiding her nest 

 in the ground when she leaves it to get more provisions. 

 Certain individuals of a species are more particular than 

 others in hiding their nests. They use pebbles to tamp 

 down the soil into them, to fix it so that none may suspect 

 that the earth has been dug up. Others take less pains. 



