812 



THE NATIONAL GEOGRAPHIC MAGAZINE 



WITH CLAWS AND BACK THE WASP JIMMIES UP THE LID OR 

 ELSE GNAWS A HOLE RIGHT THROUGH IT 



Guided by instinct to the spider's subterranean dwelling, the sleek criminal 

 in "The Case of the Curious Cocoon" raises the trapdoor with her strong 

 claws and supports it on her back (upper picture) as she slips through to 

 attack her victim (opposite page). If unable to lift the tightly sealed 

 portal, she tears a hole in it with her powerful mandibles (lower picture) . 

 Because the parasitic hunting wasp belongs to the Family Psammocharidae, 

 she was nicknamed "Psammy" (page 815). 



Study of the spiders themselves. There were 

 still a number of unanswered questions 

 concerning their lives, but the ground had 

 already been well covered and beautifully 

 photographed by Passmore and Beck.* 



On the other hand, very little was known 

 about the wasp, and nothing at all about 

 the other mysterious enemy. So both of 



* See "California Trapdoor Spider Performs 

 Engineering Marvels," by Lee Passmore, Na- 

 TiuNAL Geographic Magazine, August, 1933. 



them offered new 

 trails to explore. 



From the very first 

 it was apparent that 

 my role would be sim- 

 ilar to that of a de- 

 tective or a G-man, 

 starting with a few 

 slight clues and fol- 

 lowing the two trails 

 patiently and persist- 

 ently until I "got my 

 man." And I saw 

 that here there would 

 be advantages over 

 similar investigations 

 among ordinary web- 

 spinning spiders and 

 their enemies. Here in 

 the locked, silk-lined 

 rooms of the trapdoor 

 spiders, every clue, 

 every bit of incrimi- 

 nating evidence, would 

 be preserved for my 

 examination many 

 months after the kill- 

 ers had come and 



Every time I 

 opened and examined 

 a trapdoor nest there 

 would be a chance of 

 finding new evidence 

 against one racketeer 

 or the other. The 

 more nests I dug up, 

 the more evidence I 

 would find, and so it 

 would be up to me to 

 dig and dig and dig. 



THE CASE or THE 

 CURIOUS COCOON 



At the same time I 

 must search the offi- 

 cial scientific records 

 for information about 

 the habits of all known insect racketeers, 

 and check that evidence carefully against 

 the new facts I was unearthing. 



My examination of the first day's collec- 

 tion of nests showed considerable similarity 

 between the crimes. In all cases I found 

 the remains of partially devoured spiders 

 in the bottom of the tubes. In about half 

 of these cases there was also a curious two- 

 story cocoon hanging in the tube (p. 818). 

 I had seen a photograph of such a cocoon, 



