BURROWING HABITS OF SPIDERS. 29 



mandibles, the palps in the meantime girdling them at the side and 

 beneath, and so were carried away from the burrow to the dumping 

 ground. (Fig. 11.) 



I never observed any scratching and scraping the dirt backward, in the 

 fashion of a dog digging in a rabbit burrow, which is also the action of 

 bees and wasps when excavating the earth. Always the pellets were de- 

 liberately loosened as I have indicated, squeezed together into a ball and 

 carried off. During the act of digging, and indeed quite habitually during 

 all actions such as eating, etc., tarantula kept her spinnerets curved above 

 the posterior end of the abdomen, while a diverging ray of threads issued 

 therefrom to the surface beneath. 



VIII. 



Miss Estelle Thomson, a correspondent of a weekly journal, 1 gives an 



interesting account of the nesting and burrowing habits of the California 



Trapdoor spider (Cteniza calif ornica), which contains some ob- 



California serva t j ons worthy of a more permanent place and wider circula- 



rap < ir ^. Qn amon g araneologists. The spider's location of her nest is 



carefully planned. It is never made in a hollow, but invariably 



upon high, dry, sloping knolls so placed that moisture from the winter 



rains drains off in every direction. This accords with other observations 



of nesting site communicated to me. 



A young man in the neighborhood of San Diego made a number of 

 experiments to determine if the occupants of the trapdoor nests would re- 

 place the doors of their burrows. He removed as many as sixty 

 epairi g^ ^ e course o f a we ek, unhinging them at night, marking the 

 site, and going to the nests in the morning to note results. With- 

 out exception the spider completed and hung a new door in the interval. 

 There was, however, a limit to this industry, and a remarkable series of 

 progressive deterioriation in the quality of the successive doors. The sec- 

 ond door was always of coarser fibre than the first, its proportion of silk 

 being smaller. The third was in about equal proportion of silk and earth ; 

 the fourth largely of mud ; the fifth of mud, with barely sufficient webbing 

 to coat and hinge it. The sixth was a poor attempt at forming a mud 

 closure without any webbing, and no instance was observed when a single 

 spider completed more than five new doors, with perhaps half of the sixth. 

 One may attribute this behavior either to the natural exhaustion of the 

 spinning material required for replacing such continuous losses, or to the 

 physical exhaustion of the spider, with a strong element of intellectual dis- 

 gust and discouragement over such an unusual series of accidents. Did the 

 spider's mind at last reach the conclusion that it had come across an ex- 

 perience quite separated from the realm of accidents ; and dimly apprehend 



1 The Christian Union, New York, May 20th, 1893. 



