430 Thos. H . Montgomery, 'Jr. 



only on the webs of females and only from December to February. 

 Here, accordingly, the beginning of the reproductive season is in 

 the early portion of the year. But on the Colorado river about 

 sixty miles northwest of Austin I collected adult males in August. 

 It would seem then that different groups of individuals show dif- 

 ferent mating periods. 



Methods 



It was my object to determine not only the general sex ratio of 

 this species, but also the ratio for each successive cocoon of a given 

 spider. Therefore it was necessary to keep females through a 

 whole reproductive season. That the captivity of the mothers 

 did not produce abnormal results will be shown later. Only by 

 controlling individuals in this way can one obtain accurate notes 

 of the times of making and hatching of each cocoon, and also pre- 

 vent the cocoons from being parasitized. Early in March and 

 April of this year (1907) I collected a number of females and these 

 I have kept until the autumn, up to the close of the time of ovi- 

 position. To each of them was devoted a separate cage of paste- 

 board, most of these cages about three inches high, and most of 

 them triangular with each side about three inches long. A photo- 

 graphic glass plate was used as a cover, and another as a base. All 

 these cages were kept together in a portion of my study where no 

 direct sunlight reached them, and upon the cover of each was laid 

 a paper card that excluded most of the light entering from above; 

 by lifting this card one could look into the web without injuring 

 it or disturbing the inmate. The bodies of their victims, when 

 they have sucked them dry, the spiders drop out of the web; fort- 

 nightly, accordingly, I pulled out the bottom glass plates so as to 

 remove these accumulations. Cocoons were also taken out from 

 below, by removing the same plates. Thus the upper portion of 

 the snare where the spider awaits her prey and where she devours 

 it, was never disturbed, and to spare this web as much as possible, 

 food was admitted through a small hole in one side of the cage, 

 this hole being otherwise closed by a cork. 



Only living food is accepted, and for this I used large house 

 flies caught in the usual wire traps; sometimes the diet was varied 



