Beard, Heredity and the cause of Variation. 3G9 



an „amphimixis" or mingling of characters, and to set iip laws of 

 inheritance by average contribution. With a coiistant environment 

 or with what is assumcd to be such, man first rejects (individiials 

 of) certain varieties, and in this way favours (individuals of) some 

 particular variety. By closely intercrossing these he accentuates 

 particnlar points, becausc, of conrse, even in the characters of germ- 

 cells suited to a particuler environment there niay be degrees. In this 

 man takes a com-se the reverse of that adopted by Nature. Her 

 method may be slower, but it is sure. When she causes Variation, 

 she initiates it by altering the environment. Wliile some one or 

 more varieties of a species may be able to adapt themselves to 

 the nevv conditions, others will fail in this, and these will be 

 eliminated either as individuals, or even if fertile with the favourable 

 variety or varieties then by germinal elimination. Germinal election 

 and elimination appear to offer adequate and simple explanations 

 of all the phenomena, at any rate the author has encountered no 

 real difficulties. They throw light upon the Mendelian cases of inter- 

 crossing peas, etc., on mimicry, protective coloration, bud-variation, 

 and the loss of organs, such as the bind limb of the Greenland 

 whale, for which latter cases Weismann found it necessary to 

 call in a new principle, that of „panmixie" or the cessation of 

 natural selection. They expiain why the giraffe, for example, has a 

 long neck; this is not because as the Lamarckians assert, it was 

 in the habit of stretching its neck, the effects of this being handed 

 on by the inheritance of acquired characters; and again, not be- 

 cause, as the Darwinians maintain, by natural selection Nature 

 picked out those individuals whose necks tended to be long, and 

 destroyed those with shorter necks; but simply because Nature 

 eliminated in the germ-cells those characters, which tended to 

 the production of a short neck, while she fostered and pre- 

 served those other characters of the other parental line, which 

 tended to the formation of a longer neck, and she increased the 

 value of these characters from generation to generation. The 

 principle resulting in the self-regulating mechanism offers a simple 

 construction of all the phenomena of genetic Variation, an ultimate 

 and a far more natural one than „natural selection" orthe „germinal 

 selection" of Weis mann. Indeed, under it there is no necessity 

 to invoke these: by germinal election and elimination their positions 

 are completely and decisively outflanked, and rendered untenable! 

 As like other zoologists Weis mann has not recognised the exi- 

 stence of a germinal elimination, the real Import of the environment 

 under bis views is the weeding-out of certain individuals and the 

 selection of others owing to the struggle for existence and the 

 survival of the littest. Darwin and Wallace attached little Im- 

 port to the influence of the environment as a factor, but for 

 Buffon and Lamarck, as in recent years for Semper, Thi- 

 selton-Dyer, and E war t it was one of immense gravity, and for the 

 followers of Lamarck it has been the only factor in inducing Variation. 

 The reality of a struggle for existence is not denied, but it is not 



XXIV. 24 



