WILLIAM BATESON 9 



simplicity sake may be termed positive and negative unit pro- 

 perties possessed by the species : it only establishes the extent 

 of the variation possible within the boundary of the species, 

 and granting the existence of a definite number of allelomorphs, 

 the number of possible strains obtainable within the limits of 

 the species. But here it stops — save that of late workers have 

 recognized the possibilities of fractionation of allelomorphs, and 

 so of increase in the number of permutations and combinations. 

 Accepting Mendelian data (and let me say I accept them whole- 

 heartedly), I fail to see how any amount of interplay between 

 properties already possessed by the species will result in the 

 production of individuals which are outside the species. At 

 most we produce different strains which, by cross-fertilization 

 with other strains, produce individuals reverting to the usual 

 type or types. If you invest in a kaleidoscope at a toy-shop, 

 with the mirrors set at an angle of 60°, no amount of 

 rotation will produce other than a six-sided pattern, or increase 

 the number of colours in the pieces comprising the pattern. 

 Only from without can new elements of other colour be added, 

 thereby producing patterns of a new order : only from without 

 can the angle of the two mirrors be altered so as to produce, 

 say, a four- or a twelve-sided pattern. The interplay of allelo- 

 morphs is not evolution, nor is it capable of throwing light 

 upon the progressive development of new species. When 

 Professor Bateson, from the vantage ground of his studies of 

 the last fifteen years or so, begins to lay down the law regarding 

 evolution, I cannot but help being reminded of Bombus, the 

 bumble-bee — I would not say " in vacuo bombinans," for that 

 was said of a zoological monstrosity, and Professor Bateson is 

 no chimsera, 1 but — blundering out of the fields and hedgerows 

 into a greenhouse, and bumping its head noisily again and again 

 against the glass because of its incapacity to drive into that 

 head the fact that transparency and penetrability are not neces- 

 sarily associated phenomena. 



Nor is he alone. It so happens that some eighteen months 

 ago, at the request of a mutual friend, a Fellow of the Royal 

 College of Physicians, I found myself drawn into a lively dis- 

 cussion with the Nestor of British biologists. I had not sought 



1 Rabelais, Pantagruel, bk. ii. cap. 7. I owe the reference to my friend 

 Mr. Louis Taylor. 



