60 THE DESCENT OF MAN. 



of the varying organism, tlian to the nature of the conditions to 

 which it has been subjected. 



Conclusion. — In this chapter we have seen that as man at the 

 present day is liable, like every other animal, to multiform in- 

 dividual differences or slight variations, so no doubt were the 

 early progenitors of man; the variations being formerly induced 

 by the same general causes, and governed by the same general and 

 complex laws as at present. As all animals tend to multiply be- 

 yond their means of subsistence, so it must have been with the 

 progenitors of man; and this would inevitably lead to a struggle 

 for existence and to natural selection. The latter process would 

 be greatly aided by the inherited effects of the increased use of 

 parts, and these two processes would incessantly react on eacti 

 other. It appears, also, as we shall hereafter see, that various 

 unimportant characters have been acquired by man through sex- 

 ual selection. An unexplained residuum of change must be left to 

 the assumed uniform action of those unknown agencies, which 

 occasionally Induce strongly marked and abrupt deviations of 

 structure in our domestic productions. 



Judging from the habits of savages and of the greater number 

 of the Quadrumana, primeval men, and even their ape-like pro- 

 genitors, probably lived in society. With strictly social animals, 

 natural selection sometimes acts on the individual, through the 

 preservation of variations which are beneficial to the community. 

 A community which includes a large number of well-endowed in- 

 dividuals increases in number, and is victorious over other less 

 favored ones; even although each separate member gains no ad- 

 vantage over the others of the same community. Associated in- 

 sects have thus acquired many remarkable structures, which are 

 of little or no service to the individual, such as the pollen-collect- 

 ing apparatus, or the sting of the worker-bee, or the great jaws of 

 soldier-ants. With the higher social animals, I am not aware that 

 any structure has been modified solely for the good of the com- 

 munity, though some are of secondary service to it. For Instance, 

 the horns of ruminants and the great canine teeth of baboons ap- 

 pear to have been acquired by the males as weapons for sexual 

 strife, but they are used in defense of the herd or troop. In regard 

 to certain mental powers the case, as we shall see in the fifth 

 chapter, is wholly different; for these faculties have been chiefly, 

 or even' exclusively, gained for the benefit of the community, and 

 the individuals thereof, have at the same time gained an ad- 

 vantage indirectly. 



It has often been objected to such views as the foregoing, that 

 man is one of the most helpless and defenseless creatures in the 

 world; and that during his early and less well-developed con- 

 dition he would have been still more helpless. The Duke of 



