164 



NA TURE 



{July 2, 1874 



Names of number among Malayan and Polynesian tribes 

 may be referred to as a proof of degeneracy. Tlie sound 

 " man " is 10,000 among the natives of Samoa and Tonga, 

 as it is in Chinese, but it is 4,000 in the Sandwich island--, 

 and 1,000 in New Zealand. Islanders avoid high numbers, 

 and allow the significance of a name of high numbers to 

 sink. This is proof of degradation. The reason why the arith- 

 metical faculty among the New Zealanders has become weaker 

 than elsewhere is because of their enormous distance fiom the 

 continent of Asia. Samoa and Tonga are much nearer, and ac- 

 cordingly in those islands the religious traditions, e.g. circum- 

 cision, resemble those of Asia very closely. The Polynesians 

 formerly had a decimal arithmetic, now it has sunk in Australia 

 to quaternary or quinary arithmetic. In Ponape, one of the 

 Caroline group, and comparatively near to the continent, aftild 

 is too of men, trees, or yams, but 1,000 of egg.-, cocoanuts, or 

 stones. In Chinese pak is 100. After centuries of use high num- 

 bers fluctuate in value, because the intellect of islanders dechnes 

 in power as the effect of long- continued isolation. The ideas, 

 names, and usages of civilisation are gradually lost, and with 

 them the human intellect becomes dwarfed. 



Prof. F. Miiller, after showing that the Polynesians could 

 originally count to 100, adds, "Dies ist gowiss ein Zeugniss fiir 

 die nicht geringe geistige Bcgabung und Iriihzeitige EntA-icklung 

 dieser Volker." * The Polynesians, then, have sunk in power, 

 and were, when viaited by Capt. Cook, in a state of progressive 

 degradation. 



The question raised by Mr. Tylor was only — "Did Dr. Mar- 

 lins change his opinion about the degeneracy of Brazilian tribes?" 

 Dr. PtsJiel thinks he did, but has not yet given sufficient proof. 

 While I venture to think that the question — " I:; savage man a 

 degenerated being?" cm be solved in the affirmative by the 

 careful comparison of facts, without our needing to know that 

 each scientific traveller holds this view, it would be most inter- 

 esting to be assured that all such men are agreed upon it. 



Joseph Edkins 



Disuse as a Reducing Cause in Species 



In a letter of mine (Naturk, vol. ix. p. 361), entitled "Natural 

 Selection and Dysteleology," there occurs a footnote upon the 

 above srbject. As this footnote was rather carelessly written, I 

 v\ ish to txpliin my meaning more clearly. 



In the first place, it is evident that the fact of disuse causing 

 atrophy in individuals is no proof that it likewise causes atrophy 

 in specits ; for if it does so, the laws under which it operates in 

 ihe two ca^es must be quite different — the one set toeing as 

 exclusively related to Inheritance, as the other set are inde- 

 pendent of this principle. The primary question therefore is : 

 Does inheritance here reproduce the character of immediate 

 ancestors, as in congenital atrophy, &c. ; or of distant ancestors, 

 as in mutilations, &iz. ? I think there can be no reasonable 

 question that it does the former, and so have no doubt that 

 disuse is a cause of atrophy in species. The question as to 

 dfgree, however, remains. 



One sentence in the footnote I am explaining may be taken to 

 imply that the effects of disuse are exhausted in a few generations. 

 Nothing can be further from my meaning. If disuse acts at all 

 in species, its modus operandi, as just stated, must be that of 

 causing variations which are capable of being inherited ; conse- 

 quently, if disuse acts thus at all, it is impossible to assign limits 

 to its operation in time. The question, however, is. In what 

 proportion are the effects of disuse in the parents reproduced in 

 the offspring? Variations caused by disuse certainly differ from 

 congenital variations, in that they are not fully inherited ; and it 

 is the degree in which they are inherited that must determine the 

 rate at which disuse here operates. This degree, however, is 

 unknown : we only know that it is something very small. Now 

 as disuse is in competition whh other reducing causes, the 

 rapidity of its action is an important factor in the estimation of 

 its proliable effects. 



By the omission of the word " proportional " near the end of 

 the footnote, I appear to institute an absolute comparison 

 between the effects of disuse in wild and in tame species. This, 

 of course, would be absurd. What I mean is, that supposing 

 disuse to be the chief cause of atrophy in wild speaies, it has not 

 produced so much effect in tame species as we should ante- 

 cedently expect ; for, although the facts are very scanty, so far 

 as they go tliey tend to prove, that when an organ is disused for 

 several generations only, the rate of its reduction is much 

 greater than it ought to be, supposing disuse to be the main 

 * "Reise (Icr Novara.'' Linguisticher Thcil, 1867, p. 2S7. 



cause of atrophy in our domestic animals, and supposing the 

 action of this cause to be uniform. 



It will be asked. If we thus in part reject this cause, what 

 other have we to substitute ? This, of course, is a collateral 

 issue ; but as it is an important one, it may here be discussed. 

 I would suggest the cessation of selection (see N.VTURE, vol. ix. 

 p. 440) as a co-operating cause, for it seems to me that this must 

 have acted here to some extent, and if no other causes have been 

 at work, this extent must be the complement of the effects due 

 to disuse. For the sake of definition, therefore, we shall assume 

 disuse to be in abeyance. Now, on this assumption, we should 

 expect to find that atrophy proceeds more rapidly during the 

 initial stages of reduction than subsequently. But without 

 dwelling upon this point, what may we infer from the existing 

 degree of atrophy in the affected organs of our domestic animals ? 

 Supposing the cessation of selection to be the only cause at 

 work, what degree of atrophy should we here expect to find ? 

 Before I turned to the valuable measurements given in the 

 "Variation," I concluded (Cf. N.-wure, vol. ix. p. 441) that 

 from 20 to 25 per cent, is the maximum of reduction we should 

 expect this unassisted principle to accomplish, in the case of 

 natural as distinguished from artificially-bred organs. Now on 

 calculating the average afforded by each of Mr. Darwin's tables, 

 andtlien reducingthe averages topartsof too, I find that the highest 

 average decrease is 16 per cent., and the lowest 5 ; the average 

 of the averages being rather less than 12. Only four individual 

 cases fall below 25 per cent., and of these two should be omitted 

 (Cf. " Variations," p. 272). Thus, out of eighty-three examples, 

 only two fall belo w the lowest average expected. Moreover, we 

 should scarcely expect disuse alone to affect in so similar a de- 

 gree such widely dilTerent tissues as are brain and muscle. The 

 deformity of the sternum in fowls also points to the cessation of 

 selection rather than to disuse. Further, the fact that several of 

 our domestic animals have not varied at all is inexplicable upon 

 the one supposition, while it affords no difficulty to the other. 

 We have seen that disuse can only act by causing variations ; 

 and so we can see no reason why, if it acts upon a duck, it 

 should not also act upon a goose. But the cessation of selection 

 depends upon variations being supplied to it ; and so, if from 

 any reason a specil"ic type does not vary, this principle cannot 

 act. Why one type should vary, and another not, is a distinct 

 question, the difficulty of which is embodied by the one suppo- 

 sition, and excluded by the other. For, to say that disuse has 

 not acted upon type A, because of its inflexible constitution, 

 while it has acted on a closely allied tyiie B, because of its 

 flexible constitution, is merely to insinurte that disuse having 

 proved itself inadequate to cruse reduction in the one case, it 

 may not have been the efficient cause of reduction in the other. 

 But the counter-supposition altogether excludes the idea of a 

 casual connection, and so rests upon the more ultimate fact of 

 differential variability, as not requiring to be explained. Lastly, 

 it is remarkable that those animals which have not suffered re- 

 duction in any part of their bodies are likewise the animals 

 which have not varied in any other way, and conversely ; for as 

 there is no observable connection between these two peculiari- 

 ties, the fact of the intimate connection between them tends to 

 show that special reduction depends upon general variabiUty, 

 rather than that special variability depends upon special reducing 

 causes. 



Dropping, however, our argumentative assumption, it will be 

 remembered that I deem it in the last degree improbable that 

 disuse should not have assisted in reducing the unused organs of 

 our domestic animals ; and the effect of this remark is to show 

 that the cessation of seleciion is not able to accomplish so much 

 reduction as I antecedently expected. On the other hand, it 

 seems to me no less improbable that the cessation of selection 

 should not have here operated to some extent ; but in what de- 

 gree the observable effects are to be attributed to this cause, and 

 in what degree to disuse, I shall not pretend to suggest. 



No doubt the above considerations are of a very vague de- 

 scription ; but this only foUows from the scarcity of the data at 

 our disposal, and it is to this very scarcity that I am principally 

 desirous of calling attention ; for although it is with reluctant 

 diffidence that I venture thus, even in part, to dispute the doc- 

 trine of one whom most of living men I venerate, yet, for the 

 reason ju^t given, I cannot help feeling that the time has not yet 

 arrived for a final quantitative decision upon this subject. How- 

 ever, as before remarked, "the question thus raised is of no 

 practical importance ; since whether or not disuse is the principal 

 causi of atrophy in species, there is no doubt that atrophy ac- 

 (otnpanits 6.\sxis,s." Gkorge J. Rojianes 



