THE HOUSE SPIDER 179 



by herself. By June 14 she was mature. She was dead on July 

 14. No cocoons were left. Again an immature female which 

 had been isolated and had reached maturity before June 16 lived 

 in her cage without cocooning until August 24, when she was 

 released. When we consider that the female will cocoon several 

 times during a season, it appears from these observations that 

 fertilization is necessary before oviposition and cocooning begin. 



Is the female fertilized once for her life time, like the queen 

 bee, or is she fertilized before depositing every egg mass and 

 spinning her cocoon? An experiment performed last summer 

 throws some light upon this subject. On May 4 a male and 

 female found in the college greenhouse on the same snare were 

 confined in a breeding cage. Here they lived together until May 

 21 when the male was found dead. Soon after this, on June 2 

 the female spun her first cocoon which yielded 117 eggs. These 

 eggs were fertilized, for 17 out of 31 which I placed in separate 

 vials hatched. Following the death of the male the female spun 

 a second cocoon on June 22 ; a third, on July 9 ; a fourth, on 

 Sept. 3. The fourth was the last cocoon spun. The eggs from 

 each of these cocoons were isolated, and kept under observation 

 for many days. Not one of them hatched. It appears then 

 that the female is fertilized several times during her life, also 

 that a single fertilization is effective only for the succeeding 

 batch of eggs. 



Nourishment appears to affect the cocooning in a fundamental 

 way. Where female spiders were fed an abundance of their 

 favorite food, house flies, they cocooned more frequently and 

 spun much better cocoons: than when they were more poorly fed. 

 After experience with many individuals it was found that fre- 

 quently a female that had gone for some time without cocooning 

 could be induced to cocoon by feeding her a liberal supply of 

 flies. Improperly nourished females or old females would some- 

 times spin cocoons so thin that the egg masses showed clearly 

 through the walls. 



The House Spider as a Huntsman. — As a huntsman the house 

 spider is both bold and skillful. Victims several times its size 

 are snared and killed with precision. In order to capture the 

 prey snaring is first resorted to. The web spun for this purpose 

 consists of many lines of silk brought back and forth in a per- 

 fectly irregular fashion in some obscure corner or out-of-the-way 



