HARD WICKE'S SCIENCE-GOSSIP. 



121 



ANOTHER CONTRIBUTION TO THE "RED LEAF" 



CONTROVERSY. 



By G. W. BULMAN, M.A. 



HE question whether 

 the controversy 

 started by my 

 paper on "A Red 

 Leaf" should be 

 continued, or 

 whether, both sides 

 having been heard, 

 the matter should 

 be allowed to rest, 

 has proved a diffi- 

 cult one. On care- 

 fully thinking over 

 Mr. Tansley's last 

 paper on the sub- 

 ject, however, I 

 find an answer 

 seems advisable — 

 at ;least from my 

 point of view. 

 In the first place, I should like to define the position 

 1 have taken up on the "insect-selection theory" a 

 little more clearly, since there seems to be some slight 

 misunderstanding on this point. I should also like 

 to clear up some suggestions of inconsistency, and 

 the charge of fallacy brought against me, both of 

 which seem to have arisen from a misconception of 

 my meaning. 



Following Mr. Tansley's remarks seriatim, I shall 

 endeavour to accomplish these objects, taking ad- 

 vantage of any opportunity to strengthen and make 

 clearer my arguments by fresh facts and reasoning. 

 And since I find that the authority of Hermann 

 Muller is considered conclusive, I shall endeavour to 

 point out that his facts, apart from his conclusions, 

 afford me abundant support. Indeed I venture to 

 assert that if anyone will read Midler's " Fertilization 

 of Flowers," and draw his own conclusions instead 

 of those of the author, he will be cured of the idea 

 that bees show any preference for red and blue 

 No. 343. — June 1893. 



flowers, or that a race of such could be evolved by 

 their selective action. 



As to the red leaf itself there seems little advantage 

 in discussing it further here, although much might be 

 said as to the bright colours often displayed by leaves, 

 and not always as attributes of the period of decay, — ■ 

 since, as I have already pointed out, my arguments 

 from it are admitted. 



With regard to the "fallacy'' which is seen to 

 underlie my remarks, surely the accusation arises 

 from the idea that I have drawn from it some further 

 inference. "Of course," says Mr. Tansley, "the 

 colours of petals may have been developed without 

 insect selection " — and I ask nothing further. " The 

 question is," he continues, " is it likely ? " And this 

 I answer, not from the red leaf, but from observations 

 on the habits of bees. I must pass over also th-e 

 question of function — it is too wide and deep a one to 

 be treated of in this connection. For my own part, I 

 cannot see that difference in functional significance 

 necessarily implies difference of origin, whether we 

 found our arguments on the nature of things, or on 

 the principles of natural selection. I shall, however, 

 accept, for the sake of argument, Mr. Tansley's as- 

 sumptions on the subject. I daresay he is quite right 

 in saying, that having been led to the conclusion that 

 the function of the colours of flowers is to attract 

 insects, the general theory of colour development 

 follows by help of the principles of natural selection. 



But the question arises — and this is the point at 

 issue — are we right in applying those principles in 

 this way ? The case stands thus : Let it be granted, 

 on the one hand, that it follows on the application of 

 the hypothesis of natural selection to certain facts and 

 assumptions that the colour and form of certain flowers 

 have been evolved by the selective action of certain 

 insects. On the other hand, starling from facts and 

 first principles, I arrive at the conclusion that they 

 cannot have been so evolved. 



The obvious inference — if my facts and 'reasoning 



G 



