462 



NA TURE 



[March 19, 1903 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



Effects of the Gale of February 26. 



This district, and so far as I know a large part of 

 Ireland, was in the early hours of the morning- of February 

 26 swept over by a gale of exceptional violence. The 

 maximum occurred between ih. and 2h. 30m. a.m. 



The destruction of trees has far exceeded that caused by 

 any gale within my memory. Nothing at all like it has 

 occurred here since the celebrated storm of 1839. The 

 damage, I should say, certainly exceeds the total during the 

 intervening interval of sixty-three years. No kind of tree 

 has escaped. 



What has struck me most is the strong evidence of the 

 fact that it is not the absolute pressure of the wind which 

 does the damage, but the unsteadiness of the pressure, 

 giving rise to oscillating motion which, when the periodicity 

 of the gusts happens to be nearly the same as that of the 

 tree, causes it to succumb. 



Owing to the immense number of the prostrate trees on 

 the present occasion, there are exceptional opportunities for 

 testing this. In numerous cases plantations have been 

 practically levelled, but of the few survivors the greater 

 number are usually found on the outside, principally on the 

 weather side. 



Single trees standing alone in fields have usually escaped. 

 Of groups of three or four it is rarely the case that that on 

 the weather side has been the one to suffer. I rather think 

 that where the row lay in the direction of the wind there 

 have been more casualties than where it was at right angles 

 to it, but I have not been able to satisfy myself as to this. 

 There are, however, many cases of trees lying nearly 

 parallel to the fence. 



The trees in nearly every case lie in a north-east direction. 

 A very few are in various degrees of orientation. The gale 

 seems to have been most unequal in its action. Lanes some 

 forty yards wide, which can be traced for several hundred 

 yards, have been swept down, and on each side, perhaps 

 for 200 yards, little or no indication of the tempest is per- 

 ceptible. There seems to be no evidence of any rotation of 

 the blast in these lanes. 



I think that it is clearly proved that in the case of trees, 

 and probably more or less of artificial structures, unsteadi- 

 ness of blast is very largely responsible for damage, and 

 that recorded velocity and mean pressure form very fallacious 

 guides as to force to be resisted. 



It has been remarked to me by several people that trees 

 in exposed situations, even upon the tops of hills, have 

 escaped, while others have been swept away wholesale in 

 hollows where they were entirely shielded from the direct 

 action of the blast. Rossi:. 



Birr Castle, .March 14. 



other in the left, so that if the right hand is used in turning 

 a screw to the right, as screws are all made, a corresponding 

 movement with the left would turn it in the opposite direc- 

 tion. As left-handed screws are not usually made, a left- 

 handed man has to use a different and inferior set of 

 muscles, and works with a disadvantage. In the same way 

 ordinary handwriting cannot be copied by the corresponding 

 muscular and nerve apparatus on the left side ; it is done by 

 a totally different apparatus after much time and trouble. 

 It is much easier to use the corresponding set of muscles, 

 but then this produces backward or mirror writing. The 

 only movements common to the two sides must be near the 

 median line. If the corresponding muscular and nerve 

 apparatus be used in both arms, the result is equally good, 

 but it is not the same, as in writing or turning a screw. 

 If one hand imitates the exact movements of the other, it 

 is done by another apparatus and at a disadvantage, as 

 with a child learning the scale and using different fingers 

 for similar notes. There is, therefore, no such thing as 

 ambidexterity, unless, indeed, it is used in another sense, 

 as in the violin player, where he educates each hand for its 

 own particular object. Samuel Wilks. 



Ambidexterity. 



In the " Notes " of Nature of March 12 you mention an 

 association proposing to teach writing with both hands by 

 the method of upright penmanship. This is quite in- 

 telligible, but when it is said that the child by this means 

 will acquire left-handed skill in all other manipulations, 

 this cannot be correct. Left-handedness means that the left 

 hand can be used equally well with the right ; this is true, 

 but not in the same way. The course of the cricket boll in 

 a left-handed bowler is not the usual one. When a surgeon 

 is left-handed it is not to enable him to do with his left 

 exactly the same thing as with the right, but something 

 different. After making an incision in the eye with his 

 right hand, he takes the knife in his left to complete what 

 he requires, without altering his position or turning the 

 patient round. A left-handed waiter, after removing the 

 limbs of the chicken on one side, changes the knife and 

 fork to the other hands, and does the same on the other side. 

 It only wants a moment's consideration to see that if the 

 arms are turned round one goes in the right direction and the 



Mendel's Principles of Heredity in Mice. 



The experiments respecting heredity in mice conducted 

 by Mr. Darbishire in the Oxford Laboratory at Prof. 

 Weldon's suggestion, and described in Biometrika, ii., parts 

 i. and ii., are of exceptional interest. As the fruitful de- 

 velopment of these and similar experiments depends on a 

 true interpretation of the facts so far reached, I offer a few 

 words in supplement to the conclusions deduced by the 

 author. 



By crossing Japanese waltzing mice having pale fawn 

 and white coats and pink eyes with ordinary white pink- 

 eyed mice, 154 offspring were produced, of which 137 were 

 grey and white, 1 was grey, 7 were yellow and whitish, 

 9 black and white or whitish. The colour-patches showed 

 decided variations in amount and in tint. A fact of extra- 

 ordinary physiological significance (omitted from the pre- 

 liminary account) is that though the eyes of both parent- 

 forms were pink, the cross-breds without exception had dark 

 eyes, a result which, though to some extent paralleled by 

 certain plant cases, is probably as yet ynique among animals, 

 at least in degree. 



The cross-breds bred inter se gave 66 mice, of which 13 

 were pink-eyed albinos, 17 were pink-eyed with more or 

 less colour in the coat, and 36 were dark-eyed, some (pre- 

 sumably all) having colour in their coats. Bred with 

 albinos the cross-breds gave m pink-eyed albinos, and 94 

 with dark eyes and some colour in their coats. The coat- 

 colour phenomena, though exceedingly important, are too 

 complex for consideration in a few lines. The evidence 

 also, as yet, is in some respects insufficient, but did space 

 permit I should be glad to discuss these facts as far as 

 they go. As to eye-colour, the phenomena are simpler, and 

 from them the following conclusion is drawn by the 

 author : — 



" The inheritance of eye-colour is not in accordance with 

 Mendel's results. For since pink eyes occur in parti-coloured 

 mice, the possession of pink eyes must, on Mendel's view, 

 depend on a separate embryonic element from that which 

 determines coat-colour. Pink eyes are, however, not 

 ' dominant,' since the two pink-eyed parents of the first 

 generation always produce dark-eyed young. For the same 

 reason pink eyes are not ' recessive.' Yet although pink 

 eyes disappear in the first generation (the result of cross- 

 ing two pink-eyed parents) they reappear in the second ; 

 but a correlation is then established between coat-colour 

 and eye-colour which is strong in the offspring of hybrids 

 paired together, and at present perfect in the offspring of 

 hybrids and albinos. The behaviour of eye-colour is thus 

 in every respect discordant with Mendel's results." 



The purpose of the allusion to " dominance " escapes me. 

 In what circumstances could pink-eye be dominant, or re- 

 cessive, to pink-eye? The reference to correlation is no less 

 perplexing. The meaning might be clearer if we were told 

 what offspring the writer would have expected if the in- 

 heritance had been " in accordance with Mendel's results." 

 But a negative conclusion, however acceptable, supplies 



NO. 1742, VOL. 67] 



