AN ESSA Y ON LONGEVITY. 91 



from generation to generation, and passed from man 

 to man by means of speech, which yearly grew more 

 perfect. Meanwhile, he lived in families at first, 

 then in tribes, and still later in societies of various 

 kinds, which have grown, and are daily growing 

 larger, in virtue of which the individual struggle for 

 existence is, almost in the most civilized, and must be 

 eventually entirely, abandoned, Darwin's law of sur- 

 vival of the fittest operating through the emulation of 

 hundreds of varied combinations of men as wholes, 

 instead of through the isolated struggles of the units 

 composing them.i 



The structural differences which have been pro- 

 duced in men by their distribution over the vari- 

 ous parts of the globe, are apparent enough to 

 the eye ; perhaps seeming greater than they really 

 are, as compared with differences amongst other in- 

 dividuals, by reason of our detailed knowledge of 

 the objects compared, when they are men. But 

 these characters of skull-form and hair-form, of com- 

 plexion and hair-colour, and of size, which are what 

 constitute the chief divergencies, other than those 

 of the brain, among men, are not sufficiently con- 

 stant in races to enable naturalists to ascertain the 

 pedigree of the various nations of the earth, and 

 to group their races by descent. Indeed, locality 

 not race is what is marked by these characters. It 



^ Individual men do not struggle for existence— that is assured to 

 them by society — they struggle to ' get on.' 



