194 IOWA ACADEMY OF SCIENCE Vol. XXV, 191S 



appeal's to l)e a tendency toward normal mono^ain}^ Many of 

 the males doubtless mate with a single female, then are either 

 killed by her or die of starvation. Before this mating takes 

 place the male may be found for several days on the snare of 

 the female, hence one might infer that the species was strictly 

 monogamous, but careful observations show it to be otherwise. 



Food Habits. — Young males spin their snares like the young 

 and adult females. They appear to be as proficient in the art as 

 the female spiderlings. But this is not true of the adult male. 

 He spins very little. What prey he snares is caught generally 

 on a web built by the female. Frequently males will inhabit 

 temporarily deserted snares, making use of them to the best of 

 their advantage. 



Wlien. inhabiting the web of the female the male Anil fre- 

 quently snare victims by himself. If he does, however, he never 

 shares directly in the spoils, for no sooner will he catch his prey 

 than the female will drive him away and appropriate it for her- 

 self. Upon the web of the female the male sulisists almost en- 

 tirely from the discarded morsels of his mate. He literally lives 

 upon the crumbs that faU from her table, being for the time 

 being economically dependent on her. 



LIFE HISTORY. 



]n the araneids very little has been done in working out the 

 details of the life history for any of the species, and nothing upon 

 T. tepidariorum. In the writer's work with tlie house spider no 

 less than forty-seven individual life history experiments were 

 carried on so that the number of individuals that were followed 

 through any stage was sufficiently great to give good averages 

 except for possibly the last two stages. 



The Egg. — The egg is almost pure white, but appears some- 

 what traiLslucent. The shell is smooth, slightly shiny, but re- 

 flecting little light. When freshly laid the egg is almost a per- 

 fect sphere, but as the emliryo develops it becomes somewhat 

 molded to suit the sluipe of the latter. The interior of the egg 

 is minutely grannlar. The egg shell is membraneous and not 

 more than one-twentieth the total thickness of the egg. 



The incubation period was determined for 14 eggs. None of 

 the eggs hatched in "less than 7 days, and all were hatched in 

 8 days.^ The average obtained lor the length of the incubation 

 period was 7.8 days. 



