28o 



NATURE 



l[OCTOBER 28, 1920 



Dare one suggest that perhaps these " orchids " rather 

 like going to shows? 



It is, of course, very easy to criticise and very 

 diflicult to construct. It would be presumption on my 

 part to suggest how the Association should proceed to 

 preach the good tidings to all the world, but no one 

 can doubt that the thousand or so of scientific men 

 who attend the meetings year by year could do a great 

 thing for humanity if they chose, and could very soon 

 discover the best means of doing it also. But the 

 methods of the days when, as one of your correspon- 

 dents recalls,* crowds used to appear wherever Huxley 

 was e.xpccted to speak are certainly incfTective to-day. 

 To begin with, I am not aware that we have any 

 Hu.xleys nowadays, and if we had I doubt if they 

 would have that sort of hold on the common or British 

 Association public of to-day. Scientific men should be 

 the last to try to put new wine into the old bottles ; 

 it should be an easy matter for them to devise newer 

 and better bottles. 



An old member of the .Association said to me during 

 the Cardiff meeting: "Well, you may say what you 

 like about it now, but it's a kinema compared with 

 what it was when I first knew it ! " I was reminded 

 of this bv a chance paragraph in the newspaper the 

 other day describing " the most remarkable film which 

 has ever been made in France," called " Les Mystires 

 du Ciel," and there is no doubt that it made an impres. 

 sion on the Parisian correspondent of the Observer, 

 who belongs to a profession which takes a lot of 

 impressing. He lays stress on the fact that some of 

 " the best-known experts have been glad to assist in 

 the making of this remarkable and ingenious film, 

 which has a real educative value." I suppose this 

 will horrify some of our revered seniors, but really 

 the British .Association micht do worse than kinema- 

 tise itself a bit further. After all, rightly or wrongly, 

 the kinema does attract and instruct the people more 

 than the .Association does, and it certainly collects 

 their money. R. V. Stanford. 



Radvr, October 23. 



Testing Einstein's Shift of Spectral Lines. 



I AM not aware that anyone has applied centripetal 

 acceleration to the outstanding Einstein prediction, 

 instead of depending on solar gravitation. It is 

 feasible to whirl a steel disc, i metre in diameter, at 

 3000 revolutions a minute ; and this gives a peripheral 

 acceleration five thousand times earth-gravity, whereas 

 solar-gravity is only 25^. 



A few vacuum tubes braced to such a disc would 

 fjive the effect of continuous illumination ; and some- 

 one with refined spectroscopic appliances may be 

 willing to try the experiment — unless there is a 

 fallacy in the suggestion. Oliver Lodge. 



GuUane, October 20. 



Recapitulation and Descent. 



In Nature of October 14 my friend and colleague, 

 Mr. L. T. Hogben, contributes a thoughtful letter 

 on "Recapitulation and Descent," on which you will, 

 perhaps, allow me to make one or two comments. 

 Mr. Hogben traverses the position taken up bv Dr. 

 Bather in his address to the Geological Section of 

 the British .Association that "recapitulation" in the 

 development of animals is a proof of evolution. His 

 objection is that "experimental breeding" does not 

 justify the inference that a mutant recapitulates the 

 characters of its ancestral type, and that "factorial 

 omission " rather than "the perennial desire of youth 

 to attain a semblance of maturity " is the key to "the 

 omission of some steps in the orderly process." 



>fow I fully agree with Mr. Hogben that if by 

 NO. 2661, VOL. 106] 



"experimental breeding" and "genetic investigation" 

 we mean the endless and wearisome repetition of the 

 crossing of " Mendelian mutants " wiin one another 

 and with the parent species, we shall wait until 

 doomsday before we obtain any light on recapitula- 

 tion, or, indeed, on any of the other broader aspects 

 of the evolution theory. 



When the upholders of a theory confess, as docs 

 the leading British Mendelian, that it is totally un- 

 able to throw any light on the origin of adaptation 

 — which is, after all, the very heart of evolution — the 

 biologist must indeed regard it as bankrupt, at any 

 rate if it claims to be a full exposition of heredity. 

 Not all "genetic investigation," however, is of the 

 -Mendelian type, and quite recently some patient re- 

 searchers claim to have accomplished something 

 like evolution on a small scale experimentally, and to 

 have found traces of recapitulation. I am aware that 

 these results have been regarded by Mendelians with 

 scepticism, as I think quite unfairly; but until the 

 Mendelians have repeated the experiments and dis- 

 proved the results, these results must stand as the 

 relevant facts. They are beginning to come in from 

 widely divergent sources, and the easy method of 

 getting rid of them by doubting the bona fides of the 

 researcher is no longer available. 



The great evidence in favour of the reality of re- 

 capitulation is that in our survey of the animal 

 kingdom we encounter facts which literally compel 

 every naturalist who encounters them to interpret them 

 in this way and no other. When, for instance, we 

 find a tortoise with a soft, flexible skin devoid of the 

 bony plates which support the carapace of all his 

 brethren, and it transpires that this tortoise enters on 

 his career as an ordinary tortoise with a regulation 

 carapace, what other explanation than recapitulation 

 can be possibly entertained? When, further, we find 

 that Coeloplana, which looks like a flat-worm, and 

 Tjalfjella, which resembles a Sponge or an .Ascidian, 

 both begin their free life as exquisite little Cydippid 

 Ctenophores, does anyone consider it possible to doubt 

 recapitulation, and therefore evolution? This may not 

 be logical, but it is convincing, and as Huxley long 

 ago said : " If a man chooses to maintain that a fossil 

 oyster-shell is a concretion, and not the remains of 

 an organism, it is impossible to drive him from his 

 position by logic." 



I differ totally from Mr. Hogben in believing that 

 the "omission of factors" has anything to do with 

 the shortening of the developmental process. Rather 

 I am convinced that this shortenintj is akin to the 

 greater quickness with which an habitual act is per- 

 formed after countless repetitions. If, for instance, 

 we compare the degenerate eyes met with in the 

 pathological cripples known as Mendelian recessives 

 with the degeneracy due to loss of function owing to 

 changed habits, we meet \vith a totally different pic- 

 ture in the two cases, as anyone consulting the 

 literature can see. 



Nor can I agree with Mr. Hogben that much of 

 the reasoning of the past originated in an emotional 

 recoil excited by popular prejudice. The reasoning 

 of the past reflected the burning impression created 

 bv the irnoact of myriads of new and unsuspected 

 facts, and we owe Dr. Bather a debt for pointing out 

 in his brilliant address that the old methods are per- 

 fectly sound if jtroperly applied. .At first they were 

 applied in a wild and careless manner, and hence the 

 reaction against the doctrine of recapitulation w-hich 

 set in, and of which .Adam Sedgwick in his later years 

 was a victim. But this reaction was no more justified 

 than would be a react'ion apfainst Egyptology because 

 some of the earlier Egyptologists drew rash con- 

 clusions from insufficient facts and sketched out 



