December 8, i 898J 



NA TURE 



125 



LETTERS TO THE EDI I OR. 

 '•'J'he Editor does not hold himself fe'p:>iisibk for opinions ex- 

 presset by his correspondents Neither can he undertake 

 to return, or to correspond wi.'h the writers of, rejected 

 manuscripts intended for this or any other part of NATURE. 

 No notice is taken of anonymous communiiations.l 



The Range of the Garefowl (Alca impennis). 

 In 1S56 the late Dr. Gray obtained for the British Museum an 

 example of this extinct species from the collection of the late 

 Prof, van Lidth de Jeude of Utrecht, and for some reason 

 unknown to me had the locality "Labrador" painted on its 

 stand. .\s I had been informed with certainty by the late Prof. 

 T. T. Reinhardt that this specimen was one of those sent to 

 Copenhagen from Iceland, I corrected the error in The Natural 

 ' History Keview of (Jclober 1S65 (vol. v. p. 473, note), and 

 the correction has since been ijenerally accepted. It is therefore 

 with some regret that I find the old error repeated in the 

 recently published volume of the "Catalogue of the Birds in 

 the British Museum" (vol. xxvi. p. 564), and the error is rather 

 a serious one in the absence of evidence of the species having 

 inhabited the coast of Labrador, as well as that of any sUin of 

 proved Transatlantic origin. I niay also mention that on the 

 same page of the " Catalogue," the date of Bullock's Orcadian 

 specimen is wrongly given as 1812 instead of 1813. 



Alfred Newto.n. 

 Magdalene College, Cambridge, December 3. 



Asymmetry and Vitalism. 

 This must be my last word on this subject, and it is only 

 written because Prof. Japp asks me to correct him if I consider 

 liim wrong in his interpretation of my illustration of the separ- 

 ation of tetrahedral atoms. I apologise to him as a chemist if 

 I used the word "compound" where I ought to have used 

 " substance " or " mixture," although it seems to me Messrs. 

 Kipling and Pope use the word compound in a perilously like 

 .sense in the eighth paragraph of their letter. The use of the 

 word has nothing to do with the main argument, the chance 

 production of the optically active " mixture," and then the pro- 

 duction from the "mixture" of the optically active " compound " 

 with only one enantiomorph. By the by, will Prof. Japp 

 guarantee that all vital optically active substances " are 

 "compounds" in this sense, and not largely preponderating 

 "mixtures"? I only put the question, r.ither irresponsibly 

 in passing, owing to something a distinguished biologist let fall 

 in my presence the other day. I am quite prepared to be told 

 that this is as well demonstrated as the law of gravity. Now 

 as to my illustration, I was certainly thinking of a .spin from 

 rest so that the tetrahedra start with an impulse relative to the 

 fluid and further experience its resistance relative to their motion. 

 , Let us take the simplest possible case for an example. Suppose 7.' 

 somewhat larger than v', both considerably larger than x' and 

 H negligible to a first approximation. Then I should expect v' 

 10 set itself nearly in the wake of z', and x' to turn in towards 

 the axis. Thus z', v', x' would be in a plane perpendicular to 

 the axis ; this would bring H above for one type of tetrahedron 

 and below for the other type, or «e have differentiated the 

 positions of right- and left-handed tetrahedra. Hosvever, I do 

 not lay stress on (he illu.stration, for whatever we do now to 

 separate left- and right-h inded tetrahedra, I take will be 

 asymmetrical relative tu the sense of the original spin, and 

 accordingly if I am correct, I am only inventing a clumsy 

 illustration of non-vital asymmetric force, of which i'rof. 

 Fitzgerald has already given a much better illustration in the 

 earth's rotation. Will any physicist having the apparaius at his 

 disposal kindly spin \vith great but irregular speed a couple of 

 tetrahedra in a viscous fluid, the axis of the churn being 

 horizontal ? The balls at the angles of the tetrahedra, being 

 arranged right- and left-handed and of masses somewhat as above, 

 we should be able to settle whether a differentiation of position 

 would or would not take place. I should not be surprised to 

 hear that the two tetrahedra moved to opposite ends of the 

 churn. Kari. Pearson. 



A Shag's Meal. 



TltE following observaiion on the h.rbits of the s\\ag(Phala- 

 crocorax gracuhn), which frequents our coasts, is protjably of 

 interest in itself and not without bearing on the subject-matter of 

 Mr. Lowe's letter (November 24) 



NO. 1519. VOL. 59] 



On August 15 last, when at anchor in Wicklow harbour, in the 

 course of a cruise, we noticed a shag alight upon the water at a 

 short distance from our yacht. Itwasaverycalm,brightday. What 

 follows occurred within a distance of a cable's length or there- 

 abouts of our boat ; and as I observed the proceedings through- 

 out by the help of a powerful " trieder binocle " ( x 9) of Goerz, 

 and my companion. Dr. H. H. Dixon, possesses unusually keen 

 sight and closely followed the events, there is no doubt as to the 

 reality of what is here recorded. 



The shag, after swimming about for a little, dived once or 

 twice — apparently fruitlessly — but finally appeared with a large 

 eel in his beak. The eel was big and strong, and twisted into the 

 form of a figure 8, evidently an awkward morsel. The bird 

 kept snapping and shifting it in his beak, till at length with a 

 few violent gulps it swallowed the eel, the latter evidently going 

 down alive. It was to be inferred, in fact, that the shag was 

 not happy with so large a live eel in his crop, for he swam rest- 

 lessly about, twisting and si retching his neck incessantly. 

 Presently he dived again, was down perhaps twenty .seconds, 

 and came up with an eel as large as the first one. This writhed 

 and twisted like its predecessor, and, after much snapping, 

 finally suffered the .same fate. The same uneasiness was dis- 

 played by the bird, and the bird once more dived. 



Diivon and I were expressing some surprise at the rapidity 

 with which our friend had caught the two eels, and also at his 

 very considerable capacity to hold two such large eels — certainly 

 not less than 15 inches long each — when the bird reappeared 

 bearing a third eel, as big as its predecessors and engaged in 

 the same violent resistance. The .same snapping, same gulp- 

 ing, same uneasiness and down for a dive once again ! This was 

 the third eel. 



While we were taking sympathetic breaths with the insatiable 

 shag, the latter reappeared — yet again with a 15-inch eel. Evi- 

 dently the harbour was so full of 15-inch eels that a shag had 

 only to dive to pick one up. It was also evident that no 

 language could be too strong in which to condemn such un- 

 measured license. Four I5inch eels — all swallowed alive — • 

 within the space of about four minutes I 



But this was only the beginning, as will presently appear. 

 The bird went down again almost immediately after the fourth. 

 We determined to keep careful count and, if possible, get the 

 measure, in eels, of a shag's capacity. Would he bring up 

 another? Ves, there he was again with another i5-inch eel ! 

 A very vigorous eel — just like the others in size and appear- 

 ance, and swallowed in the same manner, after about 30 seconds' 

 resistance. This made five eels. 



The question now arose as to what would be the end of this 

 bird. Was he going to die the death of King Henry I. before 

 our eyes? We called him King Henry to distinguish him from 

 other shags. 



To make a long story short, we counted twelve eels I— all 

 stout 15-inchers, The twelfth seemed, perhaps, rather feebler 

 than the others, but still it nearly got away. For King Henry 

 dropped it in a too vigorous snap, and only recovered it by a 

 prompt plunge forwards. H.R. H. now seemed to reflect that 

 this last misadventure was a warning, swallowed his twelfth, and 

 took flight ; disappe aring in an easterly direction whence he had 

 come. 



There is, of course, only one explanation of all this : the 

 twelve eels were one and the same eel. To suppose the bird 

 caught and devoured twelve eels of this size in as many minutes 

 appears to us incredible. His final appearance as he flew astern 

 of us betrayed no signs of surfeit. He would have had at least 

 two pjunds' weight of eel within had he really eaten twelve 

 such eels. 



The peculiar procedure of ejecting the prey under water 

 appears very remarkable. Perhaps the head-downward attitude 

 of di\ing is requisite to eftect this. 



Has this mode of weakening or playing with his prey been 

 recorded of the shag (or, indeed, of any animal) previously? 



Trinity College, Dublin, November 27. J. JOI.Y. 



Periodic Tides. 



AlTENTiON has lately been called by Mr. II. C. Russell, 

 of Sydney Observatory, to what may be termed a tide of short 

 period, which he has detected in the enclosed hart|OUr of 

 Sydney. 



Mr. Russell traces a connection between this interesting 



