350 



THEORY OF VEGETATION. 



VII. 



A concise View of the Theory respecting Vegetation, lately 

 advanced in the Philosophical Transactions, illustrated 

 in the Culture of the Melon. By T. A. Knight, Esq. 

 F.R.S., Sfc* 



Theory of ve- 

 gera*ion exern 

 j>I>fied in the 

 melon. 



The seed. 



The plumule. 



Caudex. 



1 HE Council of the Horticultural Society having desired 

 that I would send them a general view of my theory on 

 vegetable physiology, which has been published by the 

 Royal Society, I have great pleasure in obeying their wishes ; 

 and conceiving, that I shall be able to render it more clear 

 amd useful, by making it illustrative of the proper culture 

 of some particular plant, and by referring the reader to the 

 papers in the Philosophical Transactions for evidence in sup- 

 port of the circumstances stated, I have for this purpose 

 chosen the melon. 



A seed, exclusive of its seed-coats, consists of one or more 

 cotyledons, a plumule or bud, and the caudex or stem of the 

 future plant, which has generally, though erroneously, been 

 called its radicle +. In these organs, but principally in the 

 cotyledons, is deposited as much of the concrete sap of the 

 parent plant, as is sufficient to feed its offspring, till that has 

 attached itself to the soil, and become capable of absorbing 

 and assimilating new matter. 



The plumule differs from the buds of the parent plant in 

 possessing a new and independent life, and thence in assum- 

 ing, in its subsequent growth, different habits from those of 

 the parent plant. The organizable matter, which is given 

 by the parent to the offspring in this case, probably exists 

 in the cotyledons of the seed, in the same state as it exists 

 in the alburnum of trees; and like that, it apparently un- 

 dergoes considerable changes before it becomes the true cir- 

 culating fluid of the plant: in some it becomes saccharine, 

 in others acrid and bitter, during germination +. In this 

 process the vital fluid is drawn from the cotyledons into the 

 caudex of the plumule or bud, through vessels which cor- 



* Hort Trans, vol. I, p. 21" 

 journ. vol. XXV, p. 118, 



t Phil. Trans. 1809, p. 169: 

 t Phil. Trans. 1805. 



respond 



