i893. SOME NEW BOOKS. 39i 



another individual. Dr. Romanes calls this a surrender of the perpetual 

 isolation of the germinal substance to a sphere of its own, and 

 evidently holds that it goes towards establishing a reciprocal action 

 between soma and germ-plasma. It is difficult to follow this. Weis- 

 mann has of course always held that germ-plasm is isolated only so 

 far as it does not receive impressions from the body, to be reflected 

 upon the body of the next or after generations. The whole of his 

 theory of the structure of germ-plasm implies that its particles have 

 a determining influence upon the soma, and there is no difference in 

 kind between supposing that determinants can enter and determine 

 embryonic cells, and supposing that they may enter and determine 

 adult cells. It is not always given to a man to know his own father, 

 and there is no reason to suppose that a determinant can nicely 

 distinguish between protoplasm of a developing cell and protoplasm 

 of another cell, even although that other cell belongs to another 

 plant. 



In the theory of evolution Dr. Romanes apparently resents that 

 the recent elaboration of Weismann's views has met many objections 

 to them. This is chiefly in the matter of variation. Dr. Romanes 

 writes : — " Weismann has now expressly surrendered his postulate of 

 the absolute stability of germ-plasm ! We have already seen that, 

 even in the first volume of his Essays, there were some passages 

 which gave an uncertain sound with regard to this matter. But as 

 they seemed attributable to mere carelessness on the part of their 

 author, after quoting a sample of them, I showed it was necessary to 

 ignore such inconsistent utterances — necessary, that is, for the purpose 

 of examining the theory of germ-plasm as even so much as a logically 

 coherent system of ideas." 



How charming ! but with all deference to Dr. Romanes, it is, at 

 least, as fair to suggest that Weismann, by the inclusion of " incon- 

 sistent utterances," was, in the true spirit of science, guarding him- 

 self against " logical coherence " in a shaping theory. It may be 

 given to schoolmen, writing of such matters as the dancing of angels 

 upon a pin-point, to be logically complete — but until, root and branch, 

 we have eaten up the tree of knowledge, any theory of evolution or 

 heredity that is logically coherent and complete will be scientifically 

 incoherent and incomplete. The particular extension in question is 

 the idea that local variations of nutrition, of which all along Weis- 

 mann, as everyone else, has recognised the capacity to produce 

 variations in the individual, may also produce variations in the germ- 

 plasma. As Dr. Romanes rightly points out, this extension removes 

 the great stumbling block of seeing as the cause of variation only the 

 combination produced by amphimixis of original Lamarckian modi- 

 fications of the Protozoa. 



A Dictionary of Birds. By Alfred Newton, assisted by Hans Gadow, with 

 Contributions from R. Lydekker. C. S. Roy, and R. W. Shufeldt. Part ii. 8vo. 

 London: A. & C. Black, 1893. Price 7s. 6d. nett. 



Amongst a certain section of that vast brotherhood ycelpt " Orni- 

 thologists," a work like the present has been a long-felt want ; and, 

 when it was announced that Professor Newton had in hand a 

 " Dictionary of Birds," we are afraid that we allowed our imagina- 

 tion a rather lofty flight. As might be expected in such a case, 

 when the first part actually appeared, we were bound to confess to a 

 certain feeling of disappointment, inasmuch as we had expected a 



