Sex Ratio of an Arauead 433 



more employed to handle the issuing thread. The rapidity of 

 the applications of the spinnerets was found to be as follows: 



from 6:16 to 6:25, 78 applications per minute, 

 from 6:25 ^^ ^'45' i^° applications per minute, 

 from 6:45 ^'^ 7'-3'-'y ^^5 apphcations per minute, 

 from 7:30 to 8:19, 140 applications per minute. 



At 8:19 she ceased suddenly, perhaps from exhaustion, then spun 

 again at the rate of 108 applications per minute from 8:28 to 8:32. 

 The cocoon was then completed, and the final touches were to 

 anchor it firmly in the web after cementing it to the roof. Now 

 each time the spider applies her spinnerets to the cocoon she draws 

 out a thread having a length of 5 mm. (the length of the fourth 

 tibia); multiplying the distance of such a thread by the number of 

 applications of the spinnerets, the astounding fact is reached that 

 in spinning the cover alone of the cocoon the spider employs a 

 thread having a total length of about eighty meters. The mus- 

 cular energy employed is very great, being a rapidly repeated 

 uplifting of the heavy abdomen. Another spider worked on the 

 cover of a cocoon for one hour and fifty minutes, and two others 

 for five hours each. 



Oviposition usually takes place in the morning before 6:30 

 o'clock, and a little later than that one usually finds the process of 

 cover making. In 143 cases oviposition was between midnight 

 and 7 a.m., in eleven cases between 7 a.m. and noon, in eight 

 cases between noon and 6 p.m., and in only one case between 6 

 p.m. and midnight. 



The young make their own way out of the cocoon, usually 

 through a single circular aperture that they make probably by 

 biting; they emerge in rapid succession, and unlike the adults 

 are positively phototropic. In eight cases the hour of emergence 

 was between midnight and 6 a.m., in twenty-eight cases between 

 6 a.m. and noon, in sixty cases between noon and 6 p.m., and in 

 thirty cases between 6 p.m. and midnight. The afternoon at its 

 hottest hours, between 3 and 5 of the clock, is the most frequent 

 time of hatching. The young do not commence cannabalism 

 until after their first postnatal moult, and the time of this varies 



