24 PECKHAM. [Vol. 1. 



tions, and only for a few days, at the mating time, is to be seen 

 in the web. 



Class III. When the adult male resembles the adult 

 female the young of both sexes resemble the adults. 



The greater number of species in this class have dull col- 

 ors, which seem to be protective, as in the Lycosidse, many of the 

 Drassidas, Epeiridm, Thomisidse and others. The same problems 

 are presented here that are so ably discussed by Darwin in the 

 case of birds belonging to this class. It seems likely that in 

 the orb-weavers a large part of the courtship is conducted by 

 vibrating the web lines, and that the males depend upon their 

 skill in this direction, and not upon color alone, in attracting 

 the female. The modifications of the first pair of legs, so com- 

 mon in the male spiders of the group, might be explained as 

 useful in producing variations in these vibrations. We have 

 some little evidence on this point, but defer consideration of it 

 until treating of mating habits. In the Attidse, when the male 

 is not strikingly colored, it is more than probable that the 

 choice of the female is determined by his antics and grace of 

 movement. Saiiis pulex is a good example. While in the 

 greater number of instances in this class the colors are dull, we 

 have many species which are brilliant. Thus, in the genus 

 Homalattus, many of the species have metallic greens or lovely 

 iridescent blues or violets, while others are soft brown, 

 mottled with white. We have not enough data to throw any 

 light on the very intricate problems here presented, and can 

 only refer the reader to Darwin's work,^ where the whole sub- 

 ject is admirably discussed. If, therein, he will substitute 

 spider for bird, whenever the latter word appears, he will see 

 how full of difficulty is the whole subject. 



We have other cases that come under several classes, but 

 as the instances are few, we will simply describe them indi- 

 vidually. Ill Hasarius hoyi the adult male is more conspicuous 

 than the adult female, which, indeed, was first described as a 

 separate species under the name pinus. The young, very early, 



iLor. cit.. j>. -IRl. 



