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♦ KNOWLEDGE ♦ 



[Aug. 17, 1883. 



at first actions were random and aimless. The Amoiha 

 wanders from place to place, not by the action of limbs but 

 by a process which may be called diffluence. In so doing 

 it may come into the neighbourhood of objects fit to 

 form its food ; these it enwraps, and absorbing what 

 is digestible rejects the rest. Or its wanderings may 

 lead it into the way of some creature by which it is 

 itself absorbed and digested. There may be some 

 higher law than chance guiding the movements of such 

 creatures ; but so far as can be judged this is not the 

 case. In other words there is but the suspicion of some- 

 thing like conduct in the actions of the Amceba. Among 

 other creatures belonging to the same kingdom, but 

 higher in type, we find actions so much better adjusted, 

 that though even yet we cannot recognise such evidence of 

 purpose as enables us to describe their actions as conduct, 

 we yet see in their adjustment to certain ends the develop- 

 ment of something akin to conduct. The actions seem 

 guided by what mimics purpose if it is not purpose itself. 



Now we note that with the improved adjustment of 

 actions comes an increase in the average duration of life, 

 or rather in the proportion of this average to the length 

 of life possible among these several creatures. 



So when we pass to higher and higher orders of 

 animals, we find in every case among the lower types 

 irregular and seemingly purposeless actions, while among 

 the higher we find actions better adjusted to the sur- 

 roundings. And again we note that where the combination 

 of actions, or what we may now call the conduct, is not 

 adjusted to the environment, the creatures' chances of life 

 are small, great numbers dying for each whose life 

 approaches the average duration. An improved adjustment 

 of conduct to environment increases the chances of sur- 

 vival, many attaining and some passing the average of 

 longevity in their particular type or order. 



Now structural development is guided by the fitness or 

 unfitness of particular proportions in such and such struc- 

 tures for the great life struggle in which all animal life is 

 constantly engaged ; and functional development is guided 

 by the corresponding fitness or unfitness of such and such 

 functional activities. Just as certainly the development 

 of conduct in all orders of living creatures is guided by the 

 fitness or unfitness of such and such combinations of 

 external actions for the constant life-contest. 



We might find illustrations of this in every kingdom, 

 sub-kingdom, order, and type, of animal life. Let us, how- 

 ever, content ourselves by noting it in man. 



In the lower races of man as at present existing, and 

 in still greater degree among the lower races when the 

 human race as a whole was lower, we see that the adjust- 

 ments of external actions to obtain food, to provide shelter 

 against animate and inanimate enemies, and otherwise to 

 support or to defend life, are imperfect and irregular. The 

 savage of the lowest type is constantly exposed to the risk 

 of losing his life either through hunger or cold, or through 

 storm, or from attacks against which he has not made ade- 

 quate provision. He neither foresees nor remembers, and 

 his conduct is correspondingly aimless and irregular. The 

 least provident or rather the most improvident perish in 

 greatest numbers. Hence there is an evolution of conduct 

 from irregularity and aimlessness by slow degrees towards 

 the regularity and adaptation of aims to ends, seen in 

 advancing civilisation. The ill-adjusted conduct which 

 diminishes the chances of life dies out in the struggle 

 for life, to make way for the better-adjusted conduct by 

 which the chances of life are increased. The process is as 

 certain in its action as the process of structural evolution. 

 In either process we see multitudinous individual excep- 

 tions. Luck plays its part in individual cases ; but 



inexorable law claims its customary rule over averages. In 

 the long run conduct best adapted and adjusted to environ- 

 ment is developed at the expense of conduct less suitable to 

 the surroundings. 



With man, as with all orders of animals, conduct which 

 tends to incresise the duration of life prevails over conduct 

 having an opposite tendency. Wherefore, remembering 

 the ever-varying conditions under which life is passed, the 

 evolution of conduct means not only the development of 

 well-adjusted actions, but the elaboration of conduct to 

 correspond with those diverse and multitudinous con- 

 ditions. 



To these considerations we may add that the evolution 

 of conduct not only tends necessarily to increased length 

 of life (necessarily, because shortening of life means the 

 diminution of such conduct as tends to shorten life), but it 

 results in increased breadth of life, and (in the highest 

 animal) in increased depth of life also. It is manifest that 

 in the elaboration of activities by which length of life is 

 increased, breadth of life is increased pari passu. For 

 these activities may be said to constitute Vireadth of life. 

 Passing over the numerous illustrations which might be 

 drawn from the lower orders of animal life, we recognise 

 in man a vast increase in the breadth of life as we pass 

 from the limited orders of activity constituting the life of 

 the savage to the multiplied and complex activities involved 

 in civilised life. Increased depth of life we recognise only 

 (but we recognise it clearly) in the most advanced races of 

 that animal which not only thinks and reasons but reflects. 



We find then that the evolution of conduct is not only 

 accompanied by increased fulness of life, but is to be 

 estimated by such increase. We do not say that that con- 

 duct is good in relation to the individual which increases 

 and that conduct bad which diminishes the fulness of 

 individual life in the individual. We assert, for the pre- 

 sent, only what observation shows, — that conduct of the 

 former kind is favoured (other things equal), and therefore 

 developed, in the life struggle, while conduct of the latter 

 sort tends to disappear as evolution proceeds. 



Thus far we have only considered conduct in relation to 

 individual life. We have still to consider the evolution of 

 conduct as related to the life of the species. 



(To be continued.) 



LAWS OF BRIGHTNESS. 



Tin. 

 By Richard A. Proctor. 



I HAVE hitherto said nothing about the absorption of 

 light, although it obviously affects the brightness of 

 objects. The fact is that in considering the celestial 

 objects we are more directly concerned with the absolute 

 intrinsic lustre of their surfaces, whether that lustre be 

 inherent or imparted. The absorption exercised by our 

 own atmosphere of course afiects their apparent brightness; 

 but as a rule we compare their lustre under similar circum- 

 stances, selecting also those epochs when, owing to their 

 considerable elevation, the absorptive effects of our atmo- 

 sphere are as small as possible. And as respects absorptive 

 efiects exerted by the atmospheres of the planets them- 

 selves we need not specially concern ourselves, because it 

 is, in point of fact, to a certain extent self-compensatory. 

 If a planet possesses an atmosphere so rare and pure that 

 nearly all the light falling upon it passes into and through 

 it to the planet's surface, then, although a greater pro- 

 portion of the received light is thus exposed to the 



