314 NATURAL SCIENCE [November 



therefore haphazard, variations of the organism ; and the Almighty 

 Natural Selection now steps in, weeds out the unfittest, and so 

 induces the endless variety of form and function in the Organic 

 Eealm. This has been irreverently termed the 'toss-up' or 'dice-box' 

 theory of variation. It is hard to see how variations in feeding or 

 starving hypothetical determinants can have ever ended in the 

 development of a vertebrate eye, or in the exquisitely co-operating 

 organs that render possible the parasitism of the offspring on the 

 viviparous mother : it would be difficult if we had limitless aeons of 

 biological time at our disposal, instead of the paltry million of 

 centuries conceded as an outside limit by Lord Kelvin, even when 

 multiplied by 4000, as Perry and Poulton suggest. We have all 

 heard of the German astronomer who was reading Lucretius, and 

 said to himself as noontide approached, " So if the atoms had been 

 flying about for all time, cold potato, oil, vinegar, garlic, and salt 

 might have combined to form a salad." " Yes, dear," said his wife, 

 who had come in unperceived to call him to dinner, " but not as 

 good as you shall have with your beef." 



It must be admitted that marvellous ingenuity is shown in giving 

 explanations on this theory to cases where they are not needed ; we 

 may cite the limitations of propagation by small fragments of 

 Animals or Plants, and the variations in the power of leaf propaga- 

 tion in the latter, which are so readily explicable without the germ- 

 plasm hypothesis. On this hypothesis, however, we are asked to 

 overlook the plain and obvious questions of nutrition, cork-formation, 

 and bud-formation, and to concentrate our ideas on the presence of 

 more or less dormant germ-plasm in the tissue-cells. We may well 

 note here that among " Inductive Fallacies " Bain cites the error of 

 assigning more causes than a phenomenon needs. " It is involved 

 in the very idea of cause that the effect is in exact accordance with 

 the cause ; hence the proof that more causes were operative than the 

 effect needs defeats itself." l 



But the cardinal defect in the theory is its objective base- 

 lessness. It professes to be founded on the microscopic study 

 of the changes in the nucleus in cell-division ; but there we 

 find nothing to justify the assumption of two modes of nuclear 

 division in the embryo, the one dividing the determinants, and 

 the other only distributing them between the daughter-cells. To 

 justify such a theory there should at least be some such basis in 

 fact, as indeed there is for the author's ' id ' theory of the relations 

 of ' amphigonic ' inheritance (from two parents),' 2 which does not 



1 "Logic," by Alexander Bain. Part II., Induction, ed. 2, 1873, y>. 395. 



2 To avoid complication and the undue lengthening of this essay we have been 

 obliged to omit the consideration of the effect of double parentage in the higher 

 organisms that reproduce sexually. lint it is obvious that of itself it must tend to efface 

 and not to accentuate the variations from the average standard of the race. 



