No. 3. J SEXUAL SELECTION IN SPIDERS. 12'J 



analogue in the human mother bearing her child in her arms 

 or carrying it upon her bosom. Moreover, the excavating and 

 fitting up these subterranean homes is a strong proof of a de- 

 cidedly industi'ious character, and the act requires the exercise 

 of great vigor, which, of course, is exclusively by the female. 



'' As a matter of fact, therefore, I am compelled to think 

 that among all wandering groups, the difference between the 

 activity of male and female is certainly not in favor of the 

 former. Whatever conclusions, therefore, are drawn from the 

 belief that the male is possessed of greater activity and vital 

 force than the female, must, in my judgment, be regarded as 

 erroneous. That he is more erratic in certain species, is true." * 



In "Natural Selection'" Mr. Wallace has brought out 

 certain facts which are inconsistent with his present view. If 

 the frequent superiority in the ornamentation of male birds 

 arises from the fact that they have higher vitality than the 

 females, how is it that in many families (including 1,200 species, 

 or about one-seventh of all known birds f) we find the two 

 sexes alike ornamented with brilliant colors and accessory 

 plumes, which quite equal in beauty those of the male in those 

 species where one sex alone is decorated? These facts while 

 comprehensible under his earlier supposition (tiiat color is 

 normal, and in these species is not kept down by natural 

 selection since they build covered nests), find no explanation in 

 his later theory of the higher vitality of the males. 



And, again, how shall we explain the fact that we often 

 find the males in birds, insects and spiders as plainlj^ colored as 

 their mates, and this, too, when the habits of the two groups, the 

 one plainly and the other brightly colored, are entirelj^ similar ? 



Mr. Pocock allows us to make the following quotation 

 (from a letter of his) which bears on this subject, as showing 

 that there is no relation between the activity of the males and 

 their color : 



"The following case, with regard to whicli I can speak as 

 an expert, seems to me to be rather against Mr. Wallace. 



* American Spiders and their Spiniiiiifi: Work, Yolmne II, pp. 

 tOn Natural Selection, p. i!jl. 



