194 ON BRASSrCA rOLYMOUPIIA. 



describes two forms; one, aimuol, with a sleutler root and rapid produo- 

 tiou of seeds, lending itself to the purposes of the oil-expresser ; the 

 other, biennial, with a root which is enlarged and escident. Probably, a 

 succulent-rooted variety of almost any plant with anything- like a biennial 

 habit, might be obtained by patient cidtivation and selection. Turnip- 

 rooted forms of Chervil {Authriscus CerefoUum, Hotfm.) and Parsley 

 (Pefroseliiiitm sativum, Hofim.) may be bought in the shops ; even the 

 wild Radish {RaplumusRaplianldrum, L.) has been made in France, as a 

 matter of experiment, to yield an esculent root. Generally speaking, a 

 generous supply of food tends to develope the leafy or nutritive organs of 

 such plants, and checks the evolution of the reproductive organs — or, what 

 is in biennials practically the same thing, the growth of the ascending- 

 axis. Hence these plants when stinted in their food, as when growing 

 amongst standing crops, rapidly run up and attain maturity ; or, in 

 other words, are apt to become annuals. 



B. campc'stris, De Cand. (I.e. 588J, includes two very important agri- 

 cultural plants — the Swedish Turnip and the Rape or Colza. As far as 

 my experience of these plants goes, they certainly are forms of the same 

 species, only differing in the presence or absence of an enlarged root. If 

 the mature radical leaves of either form of this plant be examined both 

 will seem almost glabrous, and it is only by a careful scrutiny of the ribs 

 on the uuder surface that a few scattered cartilaginous hairs can be 

 detected ; the young leaves are, however, quite obviously hispid. It is 

 worth while remarking that externally there is a wade difference between 

 the root of the Swede and the ordinary Turnip, which is well known to 

 agriculturists. The Turnip, whether globe or tankard {depres&d or obJoucja) 

 has the crown of leaves sessile without any elongation of the iuternodes. 

 The Swede, which, without being oblong is straight-sided in its middle, 

 has its upper portion prolonged into a "neck" marked by the scars, 

 separated by partially developed iuternodes of the decayed lower leaves of 

 the crown. Of the history of the Swedish Turnip (var. Napo-Brasslca, 

 De Cand.) almost nothing seems to be known. De Candolle remarks, 

 that possibly it may be a hybrid between B. campedrh (Rape) and B. 

 Rapa ; and Mr. Buckman states " that the seeding of Rape and common 

 Turnips in mixed rows has resulted in the production of malformed 

 Swedes ; which, however, improved very much by careful cultivation " 

 ('Treasury of Botany,' p. 165). Lamarck, struck probably with the 

 character of the iieek, observes that the Swede is a variety in the same 

 race as the Chou-rave {B. oleracea, var. cnnlo-rapa, De Cand.), the Kohl- 

 rabi of English seedsmen ; and this would be pretty nearly the opinion of 

 LinuEeus, if, as it seems probable, De Candolle is right in quoting, as a 

 synonym of the Swede, B. oleracea, var. Napo-Brassica, L. (Sp. 932), 

 identified with J3. Napus, var. y. escidenla by Kocli, who seems to include 

 the hispid Rape as well as the Swede under Napus. One variety of the 

 Swede has large entire cabbage-like leaves (Wilson, ' Farm Crops,' i. 275). 

 Mr. Watson, in his second paper, remarks that " Turnip and Swede are 

 species about as distinct from each other as Swede and Cabbage " 

 (viii. 370). He is certainly correct in contrasting the larger and pale 

 orange-coloured flowers of the Swede with the bright buttercup yellow of 

 the Turnip. Hybrids permanent in their characters have been obtained 

 between the Swede and the White Turnip, and are quoted in seedsmen's 

 lists. It cannot be doubted that both Swede and Rape must often occur 



