24 THE POPULAR SCIENCE MONTHLY. 



otlier multitudinous deaths caused by scarcity of food, which, if 

 not wholly, still in large measure, carries off good and bad alike. 

 Among low types, too, enemies are causes of death which so oper- 

 ate that superior as well as inferior are sacrificed. And the like 

 holds with invasions by parasites, often widely fatal. These at- 

 tack, and frequently destroy, the most perfect individuals as read- 

 ily as the least perfect. 



The high rate of multiplication required to balance the immense 

 mortality among low animals, at once shows us that among them 

 long survival is not insured by superiority ; and that thus the sub- 

 human justice, which consists in continued receipt of the results 

 of conduct, holds individually in but few cases. 



And here we come upon a truth of great significance — the truth 

 that sub-human justice becomes more decided as organization be- 

 comes higher. 



Whether this or that fly is taken by a swallow, whether among 

 a brood of caterpillars an ichneumon settles on this or that, whether 

 out of a shoal of herrings this or that is swallowed by a cetacean, 

 is an event quite independent of individual peculiarity : good and 

 bad samples fare alike. With high types of creatures it is other- 

 wise. Keen senses, sagacity, agility, give a particular carnivore 

 special power to secure prey. In a herd of herbivorous creatures, 

 the one with quickest hearing, clearest vision, most sensitive nos- 

 tril, or greatest speed, is the one most likely to save itself. 



Evidently, in proportion as the endowments, mental and bodily, 

 of a species are high, and as, consequently, its ability to deal with 

 the incidents of the environment is great, the continued life of each 

 individual is less dependent on accidents against which it can not 

 guard. And, evidently, in proportion as this result of general 

 superiority becomes marked, the results of special superiorities 

 are felt. Individual differences of faculty play larger parts in 

 determining individual fates. Now deficiency of a power short- 

 ens life, and now a large endowment prolongs it. That is to say, 

 individuals experience more fully the results of their own natures 

 — the justice is more decided. 



• 



With creatures which lead solitary lives, the nature of sub- 

 human justice is thus sufficiently expressed ; but on passing to 

 gregarious creatures, there enters into it a new element. 



Simple association, as of sheep or deer, profits the individual 

 and the species only by that more efficient safeguarding which 

 results from the superiority of a multitude of eyes, ears, and noses 

 over the eyes, ears, and nose of a single individual. Through the 

 alarms niore quickly given, all benefit by the senses of the most 

 acute. Where this, which we may call passive co-operation, rises 



