Trap-Door Spiders. 95 



velopments. The spider will move quite large stones that 

 fasten the door, but if it is pinned back so she cannot lift it, 

 she will build a new door. I have tested them many times in 

 this way in the spider towns of the foothills. Not long after 

 one successful experiment of the kind, I heard of a very rare 

 specimen of a "Tarantula's" nest in one of the stores, for 

 which the dealer would not take any price, because it was 

 such an uncommon thing for spiders to have double doors to 

 their homes! 



I removed the door from one of my spider's houses and she 

 built seven doors in succession in a short time ; but some are 

 content when the door is torn off to spin a web over the open- 

 ing. Sometimes the screw seed-vessel of Alfilaria worms its 

 way into the top of the door and makes a convenient handle 

 for us to open the portal, or a bit of grass roots there and 

 hides the dwelling; but I have never noticed any attempt on 

 the part of the spider to cover the trap with vegetation as a 

 protection. 



The nests are well hidden by burr clover and crane's-bill in 

 the green season, and in the dry season, when most they need 

 concealment, the earth is so baked and cracked that it takes a 

 keen and experienced eye to pick out the trap doors from the 

 multitudinous mud cracks which surround them. 



After the young leave the mother they can easily conceal 

 themselves in the cracks and fissures of the dry soil, and their 

 first tiny nests are so small as to escape detection. The small- 

 est I have seen have been in diameter about the width of a 

 pea. ■ They are said to enlarge their tubes from time to time, 

 as they increase in size. The young must leave the nest very 

 early, for I have never found any with the mother except the 

 swarms that are there in April and May, and the little ones 

 then are about the size of a medium pin head. They proba- 

 bly make their tubes in summer, for the floods of the rainy 

 season would sweep them out of temporary resting places and 

 out of existence. It is reported that the mother shuts herself 

 up in the nest and offers herself an unresisting victim to the 

 insatiable appetite for her swarming offspring, and that after 

 the repast they go forth in the world refreshed and ready for 

 the duties of life. I trusted to this cannibalism in an attempt 

 to raise some young. There were hundreds of them — little 

 reddish mites creeping over the mother — and, believing in the 

 survival of the fittest, I left them to devour her and each 

 other, and thus help along my studies. When I examined the 

 nest months afterwards, the mother was alive and had spun a 



