64> Transactions of the Horticultural Society. 



ture, and adopted it with some variation in the Encyclopaedia of 

 Plants. The most original part of his communication is what 

 respects those varieties which are cultivated for their seeds, to 

 be crushed for oil, from which it appears that, in Britain, we are 

 not possessed of the most valuable variety for this purpose. 

 This variety is the colsat or colsa, of the Flemish, and the 

 brassica campestris oleifera., of Decandolle. " It would be 

 desirable for agriculture," Mr. Decandolle observes, " that 

 in all countries cultivators would examine whether the plant 

 they rear is the brassica campestris oleifera, or the brassica 

 napus oleifera, which can easily be ascertained by observ- 

 ing whether the young plant is rough or smooth ; if his- 

 pid, it is the brassica campestris ; if glabrous, the brassica 

 napus. Experiments made by M. Gaujac, show the produce 

 of the first compared to that of the second, to be as 955 to 

 700." The true colza or B. c. oleifera, is in Belgium gene- 

 rally sown about the middle of June in a piece of well ma- 

 nured garden ground, from whence it is transplanted after har- 

 vest into fields in good heart, which have been once ploughed 

 after the corn has been removed. It is kept clean and top- 

 dressed, or watered with liquid manure in November, after 

 which it stands the winter, blossoms in the spring, and soon af- 

 ter runs to seed." Decandolle. Radcliff's Flanders. 



We hope soon to hear of the seed of the Colsa being on 

 sale at the shops of our agricultural seedsmen, and of trials 

 being made with it against the common rape, which is the bras- 

 sica napus oleifera of Decandolle ; the B. napus of Linnaeus, 

 and of Eng. Bot. 2146. 



In comparing the oil-bearing cruciferous plants together, 

 Mr. Decandolle has the following observations : 



" Most of them, and perhaps the whole number, are susceptible 

 of two different variations, the one having a thin, slender, slightly 

 fleshy root, the other a thick and fleshy root : in general, those 

 of the first kind bear a considerable quantity of seeds, and are cul- 

 tivated throughout Europe as oleiferous vegetables ; the others, 

 on the contrary, bring few seeds to perfection, and are cultivated 

 in general for their roots, as excellent for field or garden vege- 

 tables. So in the brassica oleracea, the varieties that have a thin 

 stalk are cultivated for their seeds; and those that have swelled 

 radicles are reserved for food. Among the varieties of the bras- 

 sica campestris, which, by reason of its large seeds, appear to be 

 eminently oleiferous, the colsa is the most productive, and has the 

 thinnest root ; for the produce of the oil, the ruta-baga and common 

 napa brassica are much less useful. In the brassica rapa, the na- 

 vette with a thin root is cultivated for its oily seeds, whilst the 

 turnip, or brassica rapa depressa is used for food. In the brassica 

 napus, the navette with a. thin root is cultivated for its oil, and the 



