C 338 3 



thinks this is proved by the ftate of luxuriant 

 plants in general, and by the efFedls of depriving 

 them of this fuperfluity : on which head he 

 quotes the experiments of Mr. Fitzgerald^ re- 

 corded in the Philof, UranfaEl, vol. lii. p. 71, 

 as confirming the truth of the theory here ad- 

 vanced. 



After having eftabliihed the cortical part as the 

 organ and depofit of nutriment, he proceeds to 

 Ihew, that heat alone excites to adlion and vigour, 

 the life or protrufive and expanfive force of the 

 medullary part 5 which is ever fpent in propagat- 

 ing the plant, by forming hudsy hulbs^ or feed^ as 

 its final and moft perfedl ifiue : and that this in- 

 tention of nature fucceeds in a proportion equal to 

 the degree of nutriment afforded by the cortical, 

 to that of the heat adminiftered to the medullary 

 part refpe6tively. 



In the fecond chapter, M. Ferher treats on the 

 origin and evolution of buds; in which he accedes 

 to the dodlrine of the progreffive perfedion of them^ 

 mentioned in the difTertation juil reviewed. 



The lafl chapter is appropriated to the Involu- 

 tion of Plants in the Seed, Buds, and Bulbs in 

 which he afTerts, that in the feeds of the Nymph^a 

 Nelumboy the very leaves of the future plant are 

 vifible. In bulbs the rudiment of the next year's 

 plant is alfo confpicuous : in like manner buds 

 contain the perfedl plant, although the evolutioa 

 in thefe requires a longer procefs. 



Thofe who would attain a complete idea of the 

 theory of vegetation, advanced in the works of 

 our authors are referred more particularly to the 



following 



