May 22, 1896.] 



SCIENCE. 



781 



vidual adapts to an environment (' social liered- 

 Ity ') because of what he is congenitally. In the 

 language of evolutionists this is survival of the 

 fittest or natural selection, though Prof. Bald- 

 win seems to think he has introduced a new 

 factor-in his ' social heredity. ' The name is new 

 and to my mind objectionable, as there is no 

 real heredity ; the idea is not. 



Ordinary people express themselves by say- 

 ing that we become what we are because of 

 'education,'' circumstances,' etc. We say, 

 ' ' The man is the product of his age. ' ' 



People tend to believe too much in the power 

 of education, circumstances, etc., and too little 

 in heredity ; hence all sorts of cures for deep- 

 rooted evils are ever welcome. But we find 

 that the changes wrought by ' social heredity ' 

 are very much on the surface, and in conse- 

 quence there may be but little outcome from 

 these efifects, possibly none in some cases, in 

 heredity, as ordinarily understood, which does 

 not, however, contravene the Lamarckian or 

 any other well recognized principle of hered- 

 ity or evolution. To return to the con- 

 crete : A and B have offspring, differing slightly 

 from themselves. The ' social heredity ' has 

 had little effect, therefore, on the race ; in the 

 case of the lower animals, much less than in 

 the case of man, possibly, and if the offspring 

 C and D be placed in widely different environ- 

 ments the slight extent to which they have 

 varied (congenitally) will be all the more evi- 

 dent. 



A Lamarckian explains these variations, such 

 as they may be, by the influence of the use and 

 disuse of parts, and evolutionists of other schools 

 in other ways. Prof. Baldwin misapprehends, 

 I take it, the sense in which I employed the term 

 'use' in the phrase which he quotes from my 

 last letter. The Lamarckian sense was that in- 

 tended. 



I must repeat that, after reading a good deal 

 of what Prof. Baldwin has written on this as- 

 pect of evolution, it still seems to me that while 

 he has with new terminology set forth old views 

 in a new dress that there is really no new prin- 

 ciple or factor involved. I do not, of coui-se, 

 consider such writing without special value, 

 though it may sometimes be provokingly diffi- 

 cult to understand fi-om the new technicalities 



employed, for the relative parts played by 

 heredity and environment in the make-up of 

 each individual is an interesting and practically 

 very important problem. 



If I have failed to understand Prof. Baldwin 

 fully and so to appreciate his views at their full 

 value on the score of originality, I regret it. 

 However, it is likely that others are in the 

 same case, and I venture to suggest that the 

 remedy for our denseness, if such it be, is to be 

 found in a specific and concrete treatment of 

 the subject. Wesley Mills. 



MCGILL TJNIVEESITY, MfoNTEEAL. 



NOTES ON PERCEPTION OF DISTANCE. 



It appears to me that the best data for de- 

 termining the psychological elements in the 

 perception of distance, as I suggested some time 

 since in Science apropos of mountain climbers, 

 is to be derived from those men of mature and 

 reflective mind who, finding themselves in very 

 strange surroundings, are compelled to learn a 

 new language of distance. From them we can 

 obtain direct evidence of what passed in their 

 consciousness, an evidence thus far superior in 

 value to the indirect judging from the action of 

 infants or young animals, or even the meager 

 and few reports of the blind who have suddenly 

 received sight. Even supposing a blind genius 

 for psychological analysis to be suddenly given 

 sight, the fact that an absolutely novel and 

 complex experience was produced which in- 

 cluded much else than mere perception of dis- 

 tance, as light, color, form, would tend to 

 make his evidence to some extent unsatisfactory. 

 For the best results in the study of perception 

 of distance we must then find it in course of 

 formation with individuals sufficiently educated 

 and reflective to give some account of their ex- 

 perience. Even then the forming perception 

 may be so instinctive a process that the ele- 

 ments may not be clearly discernible. For in- 

 stance, Mr. Casper Whitney in the strange 

 surroundings of the Barren Grounds had to 

 learn a new form of distance which he thus 

 describes in Harper's Magazine for April, 1896, 

 (p. 724 ) : "I began my first lessons in Barren 

 Ground distance-gauging by guessing the yards 

 to a stone and then pacing them off. I was 

 not only astonished at the discrepancy between 



