345 



i 



3, that the plant figured by Eh ret, not being one of 



ted Yams, ought not to be designated 4 sativa ' : " 



vat _^_ „ 



7J. sativa : Lamarck made no attempt to identity any one of 

 these incongruous elements but he did particularly advert to the 

 circumstance that the species with broad capsules figured by 

 Plunder, which is D. sativa, Linn. [4], cannot possibly be con- 

 specific with the plant figured by Ehret, which is I), sativa, 

 Linn. [1] ; 



the culti- 



w this n;i me 



Lamarck consequently rejected altogether, substituting for it 

 the name D. Cliff ortiana, Lamk (Encyc. Mrth. I.e.). 



Even as regards the identity of the plant which he thus named 

 D. Cliff ortiana, Lamarck was doubtful, though it appeared to him 

 possible that it might be the plant, then represented only by 



male examples, which throve in the open in the Royal Garden 

 at Paris and was known there in 1789 as D. sativa. This plant, 

 Lamarck states, had all the characters of the Dioscorea from 

 Florida figured by Plukenet {Aim. p. 46. t. 375. fig. 5), which 

 was cited by Linnaeus in 1753 under D. villosa, Linn. (Sp. PI. 

 ed. 1. n. 7). "We know now, what Lamarck probably did not 



f know, that Miller may have held the same view, since one speci- 



men written up by Miller as D. sativa, Linn., is D. villosa, Linn. 

 We also know, what Lamarck certainly did not know, that 

 Linnaeus himself was in like case, since the only specimen which 

 he has written up as D. sativa — and he received that plant from 

 Kalm prior to 1753 — is his own D. villosa. It is more convenient 

 to digress for the moment from the chronological sequence of our 

 references and explain the fate which befel Lamarck's conclusions. 

 Lamarck thought it desirable to prepare a plate to illustrate the 



| genus Dioscorea, thus repeating a step which Plunder had already 



I taken in 1703 (Gen. t. 26). The date of issue of Lamarck's plate 



is not quite clear, but is believed to have been about 1798. The 

 plate itself shows (Lamk. 111. t. 818) that he preferred to employ 



f for the purpose figures already familiar to botanists rather than 



to provide drawings made from specimens of species less generally 

 known. As illustrating a male Dioscorea he therefore employed 



j an adaptation of one branch from Rheede's figure of Mn-kelengu 



(Hart. Malah. vol. vii. t. 51); as illustrating a female Dioscorea 



\ he was satisfied with a repetition of the version by Gaertner 



(Fruct. vol. i. t. 17. fig. 4) of the species chosen by Phimiei' {Gen. 

 t. 26). Both of the species selected had been included by 

 Linnaeus under D. sativa in 1753; they constitute D. sativa, 

 Linn. [3] and D. sativa, Linn. [4], respectively Both of them 

 had, however, been explicitly excluded from D. sativa, Linn., in 

 1789, by Lamarck himself. In conformity with the decision at 

 which he bad then arrived we find that Lamarck refrained from 

 suggesting on his plate a specific name for either of the species 

 figured. In any case he was under no necessity to make such a 

 suggestion; his immediate purpose was to illustrate the genus as 

 a whole. The text deemed necessary to elucidate Lamarck's plate 

 was not published until 182-3. For this text Poiret, who con- 

 tinued Lamarck's studies, was responsible. In this text (TahL 

 encyc. Mctli. vol. iii. p. 429) Poiret states that Lamarck's plate 

 (III. t. 818) represents D. sativa, Linn. This statement is in one 

 sense correct, since of the two species there figured one is D. 



