192 IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



to approach the female and all the while the two keep up their 

 sig'naliii.t;. If the female is pleased with tiie male she frequently 

 meets him half way, if not she will suddenly assault him, where- 

 upon he flees hurriedly. 



Following this initial rebuff the male may, after a few minutes, 

 return to the bottom of the snare, and wait until the female is 

 in a more receptive mood (fignre 38), or he may renew his ad- 

 vances. If this is done it is usually at the peril of his life, for 

 the female is dangerous to her mate even when she is to all 



Fig. 38. — A house .spider home in a lidless cigar box. Male and female in 

 their usual positions. Pour-fifths natural size. 



appearances desirous of him, but many times more so when she 

 is not in a receptive mood toward him. 



Copulation in the case of the house spider takes place on the 

 snare. The male after the usual preliminaries of courtship 

 rushes toward the female as she hangs with lier back do'\\'iiward 

 and applies one of his sperm-filled palpi to the vulva (figure 39). 

 This the male does while he is in a reverse position from that 

 which he usually has in the web, i. e., his back is upward. After 

 one of the palpi is applied to the vulva the other may be ap- 

 plied. However, the males do not alternate regularly in applying 



