26 



HARDWICKE'S SCIENCE-GOSSIP. 



wholly different explanation, were originated by this 

 means. 



Here I may conveniently deal with some remarks 

 of Mr. Bulman's in his recent papers, bearing on this 

 point. He says, for instance, that his conclusion that 

 a brilliant red may be developed in a plant without 

 the selective action of insects, "does not prove the 

 selection theory impossible, but it does show that it is 

 not necessary." Again, in referring to the cases of the 

 appearance of red in the stigmas of Poterium and 

 Corylus, he remarks that if these cases can be effected 

 without insect agency, " it is simple dogmatism to say 

 that petals might not be so also." Lastly, " It is doubt- 

 less unwise to argue from the existence in flowers of 

 certain colours which cannot have been influenced in 

 their development by insect selection, that the colours 

 of flowers in general cannot have been so developed ; 

 it is, however, a legitimate and necessary conclusion, 

 that they may have been developed without the 

 selective action." Are not all these remarks per- 

 meated by the same fallacy ? Of course the colours 

 of petals may have been developed without insect 

 selection ; the question is, is it likely, considering the 

 circumstances under which they appear, and the 

 varied nature of the colours themselves ? And does 

 the fact of the appearance, a brilliant red in leaves, 

 render the selection theory unnecessary ? Surely not, 

 unless there is a reasonable theory to explain the de- 

 velopment of the colours of flowers through chemical 

 causes connected with some process going on in the 

 plant, such as we have in the leaf, and adequate in 

 each case to produce the particular distribution of 

 colour in each species. Has this been done, or is it 

 likely to be done ? 



The case of the stigmas of Corylus, quoted from 

 Hermann Miiller, simply enforce this view. Miiller 

 considers " that the red colour of the stigmas is solely 

 an effect of chemical processes connected with the 

 development of the female flowers to maturity." Has 

 such an explanation been attempted of the colours of 

 cntomophilous perianths ? To put tlie case in other 

 words, in each female hazel plant the red colour in 

 the stigmas is brought about by something which 

 must happen in the economy of the plant, whereas in 

 cntomophilous corollas we suppose the colour to have 

 been brought about by the laws of heredity, themselves 

 brought into play by the selective action of insects. 

 It is therefore apparent that my objection that the 

 red of the leaf is not fixed, — in the sense of hereditary 

 in the species — can be urged [against this example, 

 and that the red colour in the stigmas of Corylus and 

 Poterium is brought about every year by chemical 

 causes connected with vital processes, and is not 

 "stereotyped and perpetuated," i.e. made permanent 

 in the species from a functional reason. 



Mr. Bulman says that the connection in which I 

 use the word "development" " seems to imply that 

 the colouration of the flower was as completely 

 effected as that of the leaf before insect selection came 



into play to stereotype and peq^etuate it." Now I 

 did not mean to imply anything of the kind ; I used 

 the word " development " here to mean simply the 

 appearance of the colouring pigment, that is to say, 

 chemical development. I am sorry that Mr. Bulman 

 has misunderstood me, but I cannot say that I think 

 the passage is ambiguous. " The development of 

 the coloured pigments in both leaves and flowers is 

 due to the same primary chemical set of causes." Is 

 there anything in this sentence which "seems to 

 imply that the colouration of the flower was as com- 

 pletely effected as that of the leaf before insect selec- 

 tion came into play to stereotype and perpetuate 

 it ? " Surely it is clear that my statement has nothing 

 whatever to do with intensity of colouration. 



Again, Mr. Bulman frequently alludes to a sup- 

 posed "stereotyping" theory of mine; in one place, 

 indeed, after instancing the development of colour in 

 the monkshood, quoted from Mr. Grant Allen, as a 

 case of the sort of process he (Mr. Bulman) under- 

 stands when he speaks of the colour development 

 through insect selection, he expresses the opinion, that 

 this is "more in accordance with Darwinism " than 

 my " theory." 



Now, in the first place, I have no independent 

 theory to account for the colours of flowers ; and, 

 secondly, the word " stereotype " is a word which I 

 find I have unconsciously borrowed from Mr. Graiat 

 Allen, and which I used in the same sense that he 

 does, simply to mean the making permanent in a 

 species a useful variation, by means of natural selection. 

 In this case the process would doubtless result in 

 intensification of the colour, but the point which the 

 word in question is intended to emphasise, is its be- 

 coming hereditary. My " stereotyping theory " then, 

 at least as far as the " stereotyping " goes, is identical 

 in all respects with M r. Grant Allen's, and therefore 

 can hardly be less in accordance with "Darwinism ! " 

 How Mr. Bulman, from my sentence quoted above, 

 and aTiother remark that the colours of flowers were 

 stereotyped and perpetuated in the species by insect 

 selection, while those of leaves were not, came to the 

 conclusion, that I considered that the colours were 

 '■^ only stereotyped and perpetuated" by the insect 

 selection, I cannot understand. 



Mr. Bulman next informs us that my statement, 

 that ' * the contention of the upholders of the theory is 

 that they (bees) have learned to consider blue or red 

 as an index of high specialisation," and that this is 

 the reason of their preferring these colours, deals a 

 death-blow to the theory I am defending. He goes 

 on to enforce this idea, by considering the time when 

 flowers according to the theory had not become blue. 

 " The bees' taste for blue being simply the result of 

 experience, does not exist. So the few flowers with a 

 chance shade of blue ... are not specially selected by 

 the bees visiting the blooms for honey, and do not 

 obtain any advantage : the chance variations towards 

 blueness, not conferring any benefit, are not seized 



