SEXUAL SELECTION' 295 



•'the greatest number of abnormal+ties in each subject is 

 found in the males." He had previously remarked that 

 "altogether in 102 subjects the varieties of redundancy were 

 found to be half as many again as in females, contrasting 

 widely with the greater frequency of deficiency in females 

 before described." Prof. Macalister likewise remarks" that 

 variations in the muscles "are probably more common in 

 males than females. ' ' Certain muscles which are not nor- 

 mally present in mankind are. also more frequently devel- 

 oped in the male than in the female sex, although exceptions 

 to this rule are said to occur. Dr. Burt Wilder" has tabu- 

 lated the cases of 152 individuals with supernumerary digits, 

 of which 86 were males, and 39, or less than half, females, 

 the remaining 27 being of unknown sex. It should not, 

 however, be overlooked that women would more frequently 

 endeavor to conceal a deformity of this kind than men. 

 Again, Dr. L. Meyer asserts that the ears of man are more 

 variable in form than those of woman."' Lastly, the tem- 

 perature is more variable in man than in woman. " 



The cause of the greater general variability in the male 

 sex than in the female is unknown, except in so far as 

 secondary sexual characters are extraordinarily variable, 

 and are usually confined to the males; and, as we shall 

 presently see, this fact is, to a certain extent, intelligible. 

 Through the action of sexual and natural selection male 

 animals have been rendered in very many instances widely 

 different from their females; but independently of selection 

 the two sexes, from differing constitutionally, tend to vary 

 in a somewhat different manner. The female has to expend 

 much organic matter in the formation of her ova, whereas 

 the male expends much force in fierce cfentests with his 

 rivals, in wandering about in search of the female, in exert- 



" "Proc. Eoyal Irish Academy," vol. x., 1868, p. 123. 



" "Massachusetts Medical Soc," vol. ii. No. 3, 1868, p. 9. 



" "Archiv fur Path. Anat. und Phys.," 18T1, p. 488. 



«8 The conclusions recently arrived at by Dr. J. Stockton-Hough, on the 

 temperature of man, are given in the "Pop. Science Review," Jan. 1, ISTAj 

 p. 91. 



