266 THE PRINCIPLES OF [Part II. 



become efficient seekers, they would have to be endowed 

 with strong passions. The acquirement of such passions 

 would naturally follow from the more eager males leaving 

 a larger number of offspring than the less eager. 



The great eagerness of the male has thus indirectly 

 led to the much more frequent development of secondary 

 sexual characters in the male than in the female. But 

 the development of such characters will have been much 

 aided, if the conclusion at which I arrived, after studying 

 domesticated animals, can be trusted, namely, that the 

 male is more liable to vary than the female. I am aware 

 how difficult it is to verify a conclusion of this kind. 

 Some slight evidence, however, can be gained by compar- 

 ing the two sexes in mankind, as man has been more care- 

 fully observed than any other animal. During the No- 

 vara Expedition 15 a vast number of measurements of va- 

 rious parts of the body in different races were made, and 

 the men were found in almost every case to present a 

 greater range of variation than the women ; but I shall 

 have to recur to this subject in a future chapter. Mr. J. 

 Wood, 16 who has carefully attended to the variation of the 

 muscles in man, puts in italics the conclusion that " the 

 greatest number of abnormalities in each subject is found 

 in the males." He had previously remarked that " alto- 

 gether 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 " 



15 'Reise der Novara : Anthropolog. Theil,' 1867, s. 216-269. The 

 results were calculated by Dr. Weisbach from measurements made by 

 Drs. K. Scherzer and Schwarz. On the greater variability of the males 

 of domesticated animals, see my ' Variation of Animals and Plants under 

 Domestication,' vol. ii. 1868, p. 75. 



16 'Proceedings Royal Soc.' vol. xvi. July, 1868, pp. 519, 524. 

 11 'Proc. Royal Irish Academy,' vol. x. 1868, p. 123. 



