THE HOUSE SPIDEH 201 



wintering individuals, if females, normally live through the 

 coming season as the writer's experiments plainly show. In the 

 ease of the males it is different. ]\Iales even when well fed do 

 not appear to live through the second season, and many of them 

 meet disaster or star\'ation early in the second season. 



A female which hatched from an egg deposited on July 12, 

 1910, reached maturity by November 27 of the same year. She 

 lived until August 20. 1911, when she was removed from her 

 cage on account of the writer lea\nng Ames. Another female 

 reared the same season at Ames, reached maturity before Janu- 

 .aiy 26 of the following year. She lived until August 20, when 

 she was removed from her cage. 



In regard to the longevity of the males but few data were 

 obtained. One male collected with a female on a web in a base- 

 ment on April 12 died May 30. It was not ascertained whether 

 he died a natural death or was killed by the female. A male 

 captured on May 31 and kept by himself was yet alive on August 

 16 when the experiment closed. 



BEHAVIOR. 



No opportunity was afforded for special studies on the be- 

 havior of this specie.s. but some of the observations are here 

 recorded. 



Tropisms. — The most evident response of the species to chem- 

 ical or physical elements of its environment is noticed in the 

 response of the spiderlings to light. They are positively photo- 

 tropic. When the spiderlings were allowed to emerge from 

 their cocoons in glass cages they invariably worked their way 

 to the side next the light. This is not true with mature in- 

 dividuals. In captivity the mature spiders chose places in all 

 parts of the cages irrespective of the light. Out in nature the 

 webs of the mature spider will be frequently found in a dark 

 basement and also in the bright light of the greenhouse. 



Instincts. — That the house spider is guided and ruled in her 

 more purposive responses chiefly by instinct appears evident. 



The little spiderling, when it first reaches the active stage, 

 the second instar, spins its web in the same manner as the adult. 

 It does this regardless of the nature of its surroundings. The 

 small confines of a homeopathic vial are as suitable for this re- 

 sponse, as the more natural environment on the mother's w^eb. 

 If a small insect is caught in this spiderling 's web the latter 

 rushes at it, and upon reaching the insect reverses its position. 



