3 i6 THE POPULAR SCIENCE MONTHLY. 



individual lives to the life of the race, adds better and more enduring 

 life, life more likely to maintain and sustain the qualities of the par- 

 ents, giving therefore to these qualities in the race at once more sta- 

 bility and wider influence. In other words, the qualities best suited 

 for the propagation of the race, and best suited for the race, will on 

 the average be developed, while qualities having opposite tendencies 

 will either be eliminated, or though they may remain will occupy a 

 lower place and have diminished influence on the fortunes of the race 

 a circumstance tending of itself still further to their eventual elimi- 

 nation. 



But, within a race and in the relations of the race to other races, 

 there are causes which influence the evolution of conduct. Members 

 of a race fight out the contest for existence not alone but more or 

 less in the presence of their fellows and in the presence of members of 

 other races. Each individual in providing for his own wants or for 

 his own defense affects more or less others, either of his own race or 

 of other races, in their efforts to defend or sustain their lives. Very 

 often, as Mr. Herbert Spencer quaintly puts it, "a successful adjust- 

 ment by one creature involves an unsuccessful adjustment made by 

 another creature, either of the same kind or of a different kind." The 

 lion and the lamb, for instance, already anticipate the millennium ; 

 but the lion adjusts matters so much more successfully than the lamb 

 as to take the outside place ; the lamb lies down with the lion, but 

 inside. Among all races, herbivorous as well as carnivorous, similar 

 relations exist. The more vigorous get the better food, food which 

 the weaker contend for in vain or have to resign, when obtained, to 

 superior strength. Within one and the same race there is still the same 

 law. The stronger monopolize, if they can, the feeding-grounds of 

 the race. The weaker, whether originally so, or become so through 

 age or disease, succumb in greater numbers than the stronger in the 

 struggle for existence. Only, while the death of those weak through 

 age does not affect the evolution of the race, the greater mortality 

 among those originally weaker than the rest modifies the race-quali- 

 ties. 



In these contests conduct plays an important part. Unnecessary 

 contests involve unnecessary risks. That conduct must prevail best 

 in the long run, and therefore that conduct must eventually be evolved 

 and developed, by which adjustments for the advantage of one creat- 

 ure do not needlessly interfere with adjustments for the advantage of 

 other creatures. If we imagine a carnivorous animal carefully limit- 

 ing his search for animal food to his requirements, not killing where 

 there was no occasion, and keeping carefully all food he had once 

 obtained, we see that his chances in the life-struggle would be better 

 than those of a carnivore of the same race who killed whenever he 

 got the chance. It would be more the interest of other creatures (as 

 for instance those who wanted the same sort of food) to eliminate 



