5'6 



NATURE 



[February 15, 191 2 



can do better than others, let it be tragedy writing or 

 standing on our heads. In children this love of admira- 

 tion or notoriety, instead of being judiciously cloaked, is 

 ingenuously explicitly manifested. So, not impossibly, once 

 discovered, this initial potentiality might have been 



developed. .... . • •/ 



In the elementary school in which the writer himseU 

 graduated, after every show or circus we always tried, as 

 boys will, to emulate the somersaulting, walking on the 

 hands, and the various bodily contortions which won our 

 .Klmiration in our favourite demi-god. Far and away the 

 111. 1-1 successful of us— we numbered eighty or ninety — 

 u.i, invariably a barber's three sons. This barber, 

 though he was then for a score of years hard and fast 

 at his trade, had been in early life for many years a circus 

 rider. We were all then very young, between seven and 

 twelve. We and they were then unaware of this circurn- 

 stance. Even if aware of it they could not have been in 

 anv way impelled by it except as an instinct. 



This case is adduced as supporting the former instance 

 and its deduction. In picking up facts out of books — the 

 sole idea of education in our neighbourhood — the barber's 

 bovs were not quite so good as the average of us, but to 

 double somersaulting they took like ducks to water. 



.As correlative to the saying that it takes three genera- 

 tions to make a gentleman, you will find among trades- 

 folk the statement that it requires an equal number of 

 generations to turn out a first-rate craftsman. I met this 

 opinion first in a pottery district. I came across it since 

 among people of the same class in three countries, and in 

 many distinct districts of one of them. Now if this 

 opinion be sustainable — and personally 1 think so — then 

 increasing potentiality from generation to generation, or, 

 what it amounts to, the inheritance of acquired powers, is 

 a fairly legitimate inference. 



The transmission of like fundamental potentiality, 

 indeed, should scarcely be questioned. The transmission 

 of acquired potentialities, or of capacities enlarged and 

 increased by use, is a further matter ; but countless 

 instances such as those given above could, I am convinced, 

 be adduced in support of it. It would be hard to resist 

 their accumulated force. It is anyway a priori what is 

 to be expected, and the principle is so important that on 

 its truth depends the perfectibility, at least, of man. To 

 explain the transmission of this fresh inheritance remains, 

 I think, the sole problem for men of science. Its solution, 

 so far as I have observed, is hardly yet within sight. 



The Stauhaun, Drogheda. J. M. 



Distaste of Birds for Butterflies 



The Mnemic Theory of Heredity. 



Fifteen years ago Nature allowed me to direct atten- 

 tion to certain variations in the arrangement of hair on 

 the animal body, and this was followed by several other 

 communications elsewhere on the same subject. The con- 

 clusion from these observed facts, which were very 

 numerous, though intrinsically unimportant, was that only 

 by the doctrine that acquired characters can be transmitted 

 were they to be explained. No biologist has ever 

 challenged this conclusion, except by criticising some detail 

 in the observations, or by saying, in effect, " Let us change 

 the subject ! " But this large body of small facts remains 

 on record, and the smaller the individual facts are shown 

 to be the stronger is the evidence that they are removed 

 from the province of Selection. 



If it were not for the statement, made on the high 

 authority of Prof. Dendy, as to the " rapidly accumulating 

 evidence " in favour of the doctrine that acquired 

 characters can be transmitted, I would not have ventured 

 to bring up this vexed question. But the evidence of 

 these facts is entirely in agreement with the mnemic 

 theory of heredity, as it seems to me ; and in view of the 

 attitude of Dr. Beard, and many other biologists, towards 

 the doctrine of the possibility of the transmission of 

 acquired characters, it seems necessary to bring forward 

 facts, and more facts, however small they appear to be. 

 -After all, " things are what they are," and theories very 

 soon after they become orthodox have a way of breaking 

 down. Walter Kidd. 



February 12. 



NO. 2207, VOL. 88] 



In WW of the recent discussions in .Nail.... .■^,..iding 

 the distaste of birds for butterflies (December 21, 191 1), it 

 will doubtless be of interest to know of the results of an 

 investigation into the relation of birds to an outbreak of 

 butterflies {Eugonia californica) in northern California 

 during the summer of 1911. 



The fact that in the examination of some 4o,<x>o 

 stomachs by the U.S. Biological Survey there have been 

 but few instances where birds have been found to feed on 

 butterflies makes the results of the investigation carri'-d 

 on by the California Fish and Game Commission with 

 respect to the recent outbreak of still greater interest. 



During the early part of the summer the snow brush 

 (Ceanothus sp.) was entirely defoliated by the work of the 

 larva; of Eugonia californica in many places in the moun- 

 tain districts of the northern part of California. During 

 the latter part of July and the first weeks of August th*- 

 great army of caterpillars had transformed into bulterf 

 These insects were so numerous that the ground was oi 

 blackened by them, and great swarms of them filled the 1 

 air from morning until evening. I 



Field observation showed the Brewer black' '■-'■' 

 (Euphagus cyanocephalus) to be the most efficient desti 

 of the butterflies, certain individuals being observed tc 

 an average of five butterflies a minute. Two other h. 

 the western kingbird (Tyrannus verticalis) and the we>i' 

 meadowlark (Sturnella neglecta), were seen to feed on the j 

 insects. _ ! 



Stomach examination revealed the fact that two n' 

 birds, the blue-fronted jay {Cyanocitta stelleri front 

 and the Say phcebe {Sayomis sayus), fed on the bu 

 flies to sonie extent. Sixty-one stomachs in all were 

 amined, representing twenty-one different species. F> : . 

 five species of birds were noted in the locality where ilwj 

 investigation was carried on. ' 



The most important fact brought out by the work 

 that birds will turn to food which is abundant and re: 

 accessible, even though it be a little-relished type of fot^.. 



H. C. Bryant. 



East Hall, University of California, Berkeley, 

 Cal., January 27. 



Thomas Young and Giittingcn. 



Thomas Young, more particularly famous as the founder 

 of the wave theory of light, and whom Helmholtz descr 

 as one of the most clear-seeing men who had ever h 

 matriculated at Gottingen University on October 29, i7"5, 

 and took the doctor degree there in medicine on April 30, j 

 1796. , . j 



This fact is little known, even among Young's admirers. 

 Indeed, it had escaped the knowledge of the Gottingen j 

 authorities. With the view of perpetuating Young's i 

 memory at Gottingen, the present writer brought the 

 matter before the notice of Dr. E. Riecke (professor of 

 e.xperimental physics at Gottingen University). Prof. 

 Riecke placed the matter in the hands of the Pro-Rektor, , 

 Geh. Rat. Prof. Dr. W. Voight, who instituted inquiries; 

 as to the place of Young's abode. 



It transpired that Young had lived in the building which 

 later became the Physikalisches Institut, and is now the 

 Institut fiir Angewandte Mechanik und Mathematik. I 

 a pleasing coincidence that in this same building i< 

 and Weber did their work on the first electromagi- w^ 

 telegraph. 



Shortly before Christmas, as a result of Prof. Yoigt's 

 representations to the Magistrat of the town, a neat little 

 tablet to the memory of Thomas Young was affixed. This 

 tablet is in appropriate proximity to that in memory of 

 Gauss and Weber. 



To Prof. Voigt grateful acknowledgment is due for the 

 enthusiastic and warm-hearted manner in which he has 

 superintended the erection of this little memorial to one of 

 the greatest of all physicists. H. S. Rowell. 



Glazed Frost. 



Referring to the letters of Mr. Charles Harding and 

 Prof. Meldola on the phenomenon of freezing rain, I re- 

 member the occasion referred to; it was on January 11, 

 1868, when trees were covered with ice by rain which 



