454 SCIENCE PROGRESS 



spatial configuration of the germ-plasm in three dimensions, parallel to that 

 of the many-celled organism as a whole." 



It seems to me that the consideration of facts such as those which Prof. 

 Harper has set forth in such clear language in the preceding paragraphs leads 

 inevitably to the conclusion that the attempt to find in the divergence of the 

 mutants from type any indication of the elements of which chromatin is 

 built up is a perfectly hopeless one ; that Mr. Huxley's monstrous concep- 

 tion of the chromosome as an edifice of genes, each rigidly determined in 

 location with regard to its neighbour, so that the whole is a vast super- 

 molecule, is a vain chimaera, and that we are, in fact, within measurable 

 distance of a time when the whole conception of qualitative factors will be 

 given up, and replaced by a quantitative one — of precisely that " more or 

 less " type, which Mendel expressly excluded from his view when he began 

 his investigations. 



I now turn to the second point in which my views diverge from those 

 of Mr. Huxley, viz. the question of the possibility of the inheritance of 

 acquired characters. As evidence in support of my belief in the possibility 

 of this kind of inheritance, I adduced the work of Guyer and of Kammerer. 

 Mr. Huxley endeavours to explain away Guyer's results — this attempt I 

 have dealt with in the October number of the journal — and I shall only add 

 now that Guyer's own view is that the transference of the defective lens 

 from one generation to another is effected by the emission of a hormone 

 from the lens itself, which affects the germ-cell, and this, as I have already 

 pointed out, is Lamarckism. 



Mr. Huxley passes over Kammerer's experiments with the remark that 

 the results were obtained by Kammerer alone, in a word that the experiments 

 have not been repeated. Mr. Huxley evidently realises that if Kammerer's 

 results should be confirmed cadit qucestio, as far as Lamarckism is concerned, 

 a conclusion in which all who are acquainted with these results will agree 

 with him. 



I think I can explain to Mr. Huxley the reason why Kammerer's results 

 have not been repeated. Some fifteen years ago I repeated Cuenot's results 

 in crossing wild and albino mice. I easily obtained his results, and I dis- 

 covered that, given certain conditions (which in my case meant the assist- 

 ance of a skilled assistant who had been a rat-catcher), nothing was simpler 

 than to perform Mendelian experiments. It is a great deal easier to breed 

 flies than to breed mice, and, without wishing to detract from the value of the 

 work done by Morgan and his assistants, its " most laborious character " to 

 which Mr. Huxley feelingly alludes, is " a feather's weight, which a child's 

 hand poises, compared to the pig-of-lead-like pressure " of the difficulty of 

 carrying out experiments such as Kammerer describes. Again, I speak from 

 experience. 



It is, therefore, hardly " pla3dng the game " on the part of Mendelians 

 to endeavour to discredit Kammerer's results by criticising his drawings 

 and insinuating doubts as to his bona fides, when they will not go to the labour 

 of repeating his experiments. 



I have pointed out in a previous communication how utterly unlike Mende- 

 lian mutations are the differences between natural species of animals and 

 plants. I shall add only this : when, by the aid of palaeontology, embryology, 

 and comparative anatomy, we are enabled to determine evolutionary series, 

 the great feature of all these is progressive increase or decrease of function, 

 exactly the feature which we should expect to find, if reaction to environ- 

 ment, and the inheritance of its effects, were the driving force behind them ; 

 and it is inheritance of acquired characters, which can alone explain re- 

 capitulation — the reality of which screams at us at every turn when we 

 investigate the life-histories of animals. Recapitulation fits in so badly 

 with the gene-chromosome hypothesis that ardent Mendelians like Morgan 



