HA RD WICKE'S SCIENCE- G OSS I P. 



263 



lirain, which was certainly smaller than that of a 

 frog. — A. E. Pcake. 



The White Flower Question. — In view of 

 , the undoubted importance of variation as an aid to 

 the study of the developmental history of plants, it is 

 gratifying to see so much attention being directed to 

 the subject. Henslow, in his "Origin of Floral 

 Structures " says : "To attempt any theoretical 

 •exposition of the evolutionary history of flowers 

 considerable caution is required, for the causes^ of 

 variation are generally so obsaiire, the chances of seeing 

 them in activity so small, and experimental methods 

 of verification well-nigh impossible, that speculations 

 on the subject cannot altogether escape the bounds 

 of hypothesis so as to become demonstrable facts." 

 Notwithstanding this, we find him at a later stage 

 declaring that "variation in the number of parts of 

 the floral whorls is largely due to an excess or a 

 deficiency of nutriment," and that "colours are a 

 result of nutrition:" He further says, "The paler 

 ■tints, or even a total absence of colour may seemingly 

 occur as a variety of any plant ; it is often a concomi- 

 tant of habitual self-fertilisation in cases where the 

 variety of species is a degradation from some con- 

 spicuous and brightly-coloured insect-visited form. 

 "White-flowered individuals often appear as 'sports' 

 among seedlings, the immediate cause of which it 

 would be difficult to assign, beyond the general one 

 of the absence of those nutritive conditions which are 

 requisite for colours." Here, then, we have a theory 

 of colour, whether or not it will stand the test of 

 experiment is a different matter, but if temperature 

 nnd the character of the soil affect the forms of 

 flowers, why may they not also affect their colours? 

 Grant Allen glances at the subject in his " Origin of 

 the Colours of Flowers," but he has no better explana- 

 tion to offer of reversion in a red or a blue flower 

 to white than the tendency to reversion that exists in 

 all forms of plant-life, especially such as have been 

 recently evolved. Thus, writing of reversion in the 

 wild hyacinth, he says : "The frequent recurrence of 

 white varieties in our wild hyacinth proves that it is 

 ■still far from having completely adapted itself to its 

 present level of development, as thoroughly well- 

 established and ancient species do not throw back so 

 easily or so often to less advanced ancestral forms," 

 a view of reversion which accords with that expressed 

 by Darwin in his "Origin of Species" (6th edition, 

 p. 121). These statements suggest one or two 

 points to which, as it seems to us, attention may 

 profitably be directed, (i.) Is it the case that when 

 flowers change from one colour to another it is in an 

 unvarying order, from yellbw to white, from white to 

 red, and finally to blue? — reversions, of course, in 

 inverse order. (2.) If this is so, why is it that blue 

 flowers — the wild hyacinth, for instance — revert 

 directly to white instead of to red, the colour from 

 which they have more recently been evolved ? (3.) Is 

 it the case that lessened vegetative vigour tends to 

 check the development of colour, and if so, to what 

 extent does the check operate? If I am not greatly 

 mistaken, there are numbers who would warmly 

 welcome authoritative answers to these questions. 

 This season I have carefully noted the occurrence 

 of white varieties, and as the list may be of interest 

 to others, I append it for comparison. The district 

 embraced in my observations is the north-west 

 portion of the border county of Dumfriesshire, which 

 has a varying elevation of from 250 to 1600 feet. 



Viola pahistris, Viola tricolor, Polygala vulgaj-is, 

 Epilohium montana. Scabious succisa, Campanula 

 rotundifolia, Erica cinerea, Calluna vulgaris, Gcntiana 

 campesti'isy Veronica scutellata, Euphrasia officinalis, 



Pcdicularis sylvatica, Ajuga rcptans. Prunella vulgaris, 

 Symphytum officinale. Orchis mascula, Hyacinthus 

 nonscriptus. — yohn Corrie, 



The White Flower Question. — In connection 

 with the correspondence on this subject, it maybe 

 interesting to mention that a few weeks ago at 

 Malvern Wells, I found a quantity of Bartsia 

 odontites growing by the roadside leading up from 

 the Midland station. A large proportion of the 

 plants had pure white flowers, while of the remainder 

 a great many had flowers of a pale pink colour, a 

 great deal lighter than usual. This was not a case 

 of an isolated albino, as the white flowers predomi- 

 nated. Near Cambridge on the Hills road, Geranium 

 pyrenaicuin grows abundantly in one spot, but the 

 flowers are invariably white. I have never seen lilac 

 specimens in Cambridgeshire The same remark 

 applies to the comfrey, Symphytum officinale, which is 

 always white-flowered about Cambridge. I have 

 found albinos of Ononis arvensis (rest-harrow) year 

 after year in the same spot by the road leading from 

 Cambridge to Newton. Also solitary white speci- 

 mens of Cichorium intybus, and Centaurea scabiosa. 

 Two years ago I found white Gentiana campestris at 

 Fort Augustus, while at some height above the Lake 

 of Como, in 1878, I found Gcntiana acaulis with 

 some flowers of a pure white and others of a pale 

 "Cambridge blue," forming a striking contrast to 

 the usual dark " Oxford blue" hue of tlie flowers. — 

 G. H. Bryan. 



The White Flower Question.— Now that Mr, 

 P. Q. Keegan has evinced an interest in this subject, 

 I begin to hope for some workable information. To 

 his queries in last month's number, I subjoin the 

 following :— The heather is in full bloom in this 

 neighbourhood, from the early part of August to the 

 close of September, white varieties included. _ The 

 atmosphere of this county, undoubtedly contains a 

 deal of moisture ; and it is certainly as indisputable 

 that with certain winds, the atmosphere is also highly 

 charged with saline substances. Perhaps it will be 

 only fair to add, while this question is being discussed, 

 that the flowers of the white heather which I have 

 pressed this summer, have turned to a delicate pink in 

 the drying process. The colour, I noticed, asserted its 

 presence in about forty-eight hours after the plants 

 were placed in the press. Of course it is not near so 

 pronounced as the normal tints of the heather. — 

 Fred. H. Davey, Ponsanooth, Porati-ar-tuorthal. 



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