K.— BOTANY. 199 



the material at our command — since isolated specimens, detached from 

 their environment, do not allow the Taxonomist to judge to what extent 

 a species may be plastic. 



It may well be that the single specimen is not truly typical, for it may 

 be of the nature of a habitat form, which Cockayne terms an ' Epharmone ' 

 — the ' phenotype ' of Turesson — or, on the other hand, it may be a ' geno- 

 type,' that is, a ' Jordanon ' according to Cockayne, and represent one of 

 a group of such units which can be linked together in a ' compound 

 species ' ; or, again, it may be one of a ' hybrid swarm ' or a segregate 

 resulting from hybridisation. 



That we are appreciating now the problems surrounding every species 

 which we are able to examine critically, through studying it in the field and if 

 need be under cultivation, is a healthy sign ; for it is, I think, clear that the 

 Taxonomist, in undertaking experimental and field studies, will be able to 

 throw much light on the ' origin of species,' and on the meaning and import- 

 ance of the so-called ' variations ' which such experimental study reveals. 



This seeking after truth by means of experiment is not exactly a new 

 development, though it may be claimed that the conception and planning, 

 during the past few years, of new lines of inquiry has raised the status of 

 these experiments to the definite plane of research. 



It will be recalled that isolated experiments to test the persistence of 

 individual forms, varieties or species have been made from time to time 

 since Linnseus' day, but it is only in recent years that they have been 

 carried out under careful control. 



The classical experiments of Gaston Bonnier are well known. I may 

 remind you that Bonnier cloned herbaceous perennial plants ; half of an 

 individual was grown in a lowland garden, while the other half was planted 

 in a high mountain garden in the Western Alps or in the Pyrenees.* 



His results were striking and full of interest. Fifty-eight of the species 

 with which he experimented were able to maintain themselves at the 

 higher altitudes, and underwent changes which caused them closely to 

 resemble indigenous Alpine plants. Remarkable as his results un- 

 doubtedly were, it is unfortunate that they appear to have been conducted 

 without sufficient control, and also that he did not work with a much 

 larger number of individuals of the same species. We also lack the full 

 details of his experiments, nor are there any herbarium specimens as 

 evidence of the changes described, which would serve as records of these 

 interesting experiments. It is therefore much to be hoped that his work 

 may be repeated in France or Switzerland in the light of modern require- 

 ments, since in England it is hardly possible to carry out experiments of 

 this character with regard to effects of altitude. Daniel,* working on 

 Asphodelus luteus, transplanted portions of plants growing at Rennes to 

 a seaside garden at Erquy. Such striking changes were brought about 

 by this transplant experiment that he described the derived forms as a 

 distinct species, A. luteioides. 



F. Krasan* has also published papers recording the direct influence of 

 the environment on plant characters. 



* See Rev. Gen. Bot. (1920), XXXII. 305. 



= Rev. Oen. Bot. (1921), XXXIII. 225, 316, 357, 420. 



6 Flora, XCVIII. 389 (1908). 



