May ?o. 1M07] 



NATURE 



65 



May II, at the Hotel Cecil, the President occupying the chair. 

 Among those present were the Duke of Teck, Sir Bernhard 

 Samuelson (past President), Sir David Dale (past President), 

 Sir Lowthian Bell, Sir Courtenay Boyle, Sir Andrew 

 Noble, Sir Henry Mance, Prof. Dewar, F. R.S., Prof. 

 Ayrton, F.R.S., Dr. Ludwig Mond, F.R.S., Mr. Norman 

 Lockyer, C.B., F.R.S., and Mr. B. H. Brough (the Sec- 

 retary). After the loyal and patriotic toasts had been duly 

 honoured, Prof. W. C. Roberts- Austen, C.B. , F.R S., proposed 

 " Scientific and Professional Societies," which was acknowledged 

 by Sir John Evans, F.R.S., and by Mr. J. Wolfe Barry, C.B., 

 F. R. S. The toast of the evening, " Prosperity to the Iron and 

 Steel Institute," was proposed by Sir Courtenay Boyle. 



THE CULTURAL EVOLUTION OF 

 " C YCLAMEN LA TIFOLIUMP 1 



ON the occasion of the discussion on " Variation in Plants 

 and Animals," which look place on February 25, 1895, it 

 occurred to me that it might be useful to give an illustration of 

 the amount of change which has been effected in a plant by 

 continuous selection under cultivation in a comparatively short 

 lime. I, therefore, placed upon the table an example of the wild 

 and of the cultivated form of the garden "cineraria" (C cruenta). 



The choice of this species was purely accidental. It was, 

 however, violently impugned. It was contended that the 

 garden cineraria was not the result of the development of a 

 single species, but that it was of multiple origin, and the result 

 of the intercrossing of several. It was further contended that 

 its change from the wild form had not been gradual, but by dis- 

 continuous steps or " sports." Neither contention seemed to 

 me well founded. But I admit that, owing to the lapse of time 

 since the so-called " improvement " of the cineraria commenced, 

 it is impossible to give formal proof that the process has been 

 what I described. Mr. Darwin met with the same difficulty. 

 He remarks : " We know hardly anything about the origin or 

 historyof any of our domestic breeds "(" Origin," 6lh ed., p. 29) 

 As is, however, well known, he regarded them as the result of 

 accumulation by selection of successive slight variations. But 

 he also tells us that "the chance will be infinitely small of any 

 record having been preserved of such slow, varying, and 

 insensible changes." 



It seemed to me important, therefore, to obtain the history of 

 some cultivated species which would not be open to the objections 

 urged in the case of the cineraria. 



After some consideration I selected the plant known in gardens 

 as Cyclamen persicum. Owing to the kindness of the skilful 

 horticulturists who have worked upon it, I am able to place on 

 record a nearly complete history of the changes it has undergone. 



The genus Cyclamen belongs to the small order Primiilacecv, 

 which in its affinities is somewhat isolated. Cyclamen itself is 

 distinguished from the rest of the tribe Lysimachieic, to which it 

 belongs, by the reflexed segments of the corolla. 



Cyclamen persicum, Mill. , is a name given by gardeners to a 

 form slightly modified by cultivation of C. latifolium, Sibth., a 

 species confined to Greece and Syria. There is a good figure of 

 the type in Sibthorp's " Flora Grseca" (t. 185). It has pink 

 flowers, with a ring of darker colour at the throat. The species 

 is said to have been first cultivated in Europe at Lille in 173 1 

 (" La Semaine Horticole," 1897, p. 23), having been introduced 

 from Persia. There must have been some error as to its origin, 

 for Boissier points out that the species is not found in that 

 country ("Flora Orientalis," vol. iv. p. 12). In all probability 

 it was obtained from Syria. The Lille plant ultimately went to 

 Ghent, and it has been asserted that all the cultivated forms in 

 existence are descendants from this one individual. The 

 assertion cannot be proved, but is not improbable. It is known 

 to have been a variety with white flowers. As will be shown, 

 the forms now in cultivation have been derived from a white- 

 flowered one, which in turn might well have been derived from 

 the Lille plant. 



Such a modified form was, in fact, that described by Miller, 

 in 1768, in the eighth edition of his "Gardener's Dictionary," 

 under the name of Cyclamen persicum. He describes the flowers 

 as " pure white with a bright purple bottom." It was figured 

 in the Botanical Magazine in 1787 (t. 44), and it has come down 

 little altered to our own day. In 1875 Boissier describes it as 



1 " The Cultural Eivolution of Cyclamen latifolmtn (Sibth.)." By W. T. 

 Thiselton Dyer, C.M.G., CLE., F.R.S. Received and read at the Roy.il 

 Society, March i8. 



" forma hortensis a me nunquam spontanea visa." It still exists 

 in cultivation, and is the (old) "crimson and white " of Messrs. 

 Sutton. It seems always to have been popular in cultivation on 

 account of its agreeable fragrance. This confirms the Syrian 

 origin of the original stock, for a white-flowered form "is found 

 in Palestine which is very fragrant" {Roy. Hort. Soc.Journ., 

 N. S., vol. xiii. p. 163). 



Early in the century some colour variations were in cultivation. 

 Several as well as the typical C. persicum were figured in the 

 " Flore des Serres" in 1877 (t. 2345). These record the amount 

 of change from the wild type which had been accomplished in 

 a century and a half. One striking seminal sport (C persicum, 

 var. laciniatum) is figured in the Botanical Register in 1827 (t. 

 1095). It is remarkable for spreading corolla- segments broader 

 than usual, and cut at the edges. It does not appear to have 

 been perpetuated, but in some degree it anticipated some of the 

 remarkable modern developments. 



I am informed by Mr. James Martin, the accomplished pro- 

 pagator of Messrs. Sutton, that the recent remarkable develop- 

 ment of the cyclamen began about i860, and, at any rate in 

 their hands, started with the old "crimson and white." It will 

 be seen from the accompanying figures how little this differs 

 from the wild type. Fig. i represents a flower of the latter 

 from a plant imported by Messrs. Sutton from Syria after six 

 years of cultivation. It is not appreciably altered. Fig. 2 

 represents a flower of their "crimson and white"; it only 

 differs from the wild type in having shorter, broader, and less 

 twisted corolla segments. 



In considering the progress which has been made since i860 

 under the skilful hands of Mr. Martin and others, it is important 



NO. 1438, VOL. 56] 



to bear in mind that there is no question of hybridity. Cyclamen 

 latifolium has resisted every attempt to cross it with any other 

 species. We are dealing then with the evolution under artificial 

 conditions of a single species. Further, in the following state- 

 ment, I have confined myself to the result of continued self- 

 fertilisation, and have not thought it necessary to investigate the 

 results of crossing races which have assumed characters more or 

 less distinct. 



Size. 



Mr. Martin strongly insists on the principle laid down by Mr. 

 Darwin from De Vilmorin, that " the first step is to get the plant 

 to vary in any manner whatever" ("Animals and Plants under 

 Domestication," vol. ii. p. 262). As Mr. Martin puts it, " the 

 breeder must work with nature." It is his practice to seize the 

 smallest deviation, even so small an indication as the slightest 

 difference in a cotyledon of a germinating seed. The first direc- 

 tion of work would, however, for commercial purposes, be to 

 develop the size of the corolla. Figs. 3 and 4 show two stages 

 which have been reached by progressive selection from " crimson 

 and white." Messrs. Sutton have sent me photographs of the 

 largest flowers hitherto produced by them. Fig. 5 is copied 

 from one of these. The vertical depth is 3 inches. This is more 

 than double that of the form with which they started ; the in- 

 crease in breadth of the segments is at least six times. This 

 represents the continuous work of forty years. As the work was 

 not done for a scientific purpose, the whole of the progressive 

 steps have not been preserved or recorded. Only saleable 

 st^es have survived. But Mr. Martin emphatically denies that 

 they have been attained by other than progressive selection, or 



