42 Connexion bel-jccen Leaves and Fruit of Vegetables. 



unreasonable to inquire whether the digesting, secreting, ex- 

 creting, and pneimiatic operations of life, are or are not comr 

 patible with each other in the same part, and whether in 

 some examples one of those functions may not singly belong to 

 leaves, and in other cases many of them be associated to- 

 gether *. The greatest number of resemblances between plants 

 and animals are to be found in those of the most simple struc- 

 ture in both kingdoms; and in all such instances the governing 

 influence of j)hysical causes is strikingly obvious ; whereas, un- 

 der a complexity of organic textures, we are apt to put aside the 

 only natural causes which we are permitted to comprehend, and 

 to attribute the phgenomena to an occult cause, known under 

 the ill-defined term, vitality. Assuredly, the leaves of vegeta-^ 

 bles very generally perform the offices of animal stomachs ; as 

 when they convert the raw material of vegetable nutriment into 

 a new and peculiar substance for buikling up the fabric of 

 plants. The extensive variety of new compounds which dif^ 

 terent plants contain, are elaborated from nearly the same kind 

 of raw material ; and doubtless the vast variety of vegetable 

 leaves is in each species adapted to their special secretions. It 

 is probable, that the novelty of these statements may give rise 

 to controversial opinions ; but since I only adduce them as con- 

 nected with general views, and not as universal truths, my ob-. 

 ject will be fully attained if they occasion any new series of 

 accurate and decisive experiments, being m3'self wholly indif- 

 ferent as to tlie side on which tritth is ultiipately to rest, pro-t 

 vided it be clearly elicited. 



My uidlvidual power, or ability, to prosecute these and si-^ 

 milar researches, is forbidden by a hojjeless want of leisure, 

 I therefore gladly concede the tiisk to those who are better cir-, 

 cumstanced, 



* I wish it to be understood, that I consider the green cellular tissue of 

 the bark in young branches to consist of the same material with their leaves, 

 and that it is devoted to the same purposes : this parenchymatous pulp 

 seems to be a reservoir for the next successions of foliage and fructifications, 

 because buds consist chiefly of fibrous material. The branches of the 

 China-rose possess more of this green pulp than the branches of other 

 roses, and which may be the cause of its continued flowering. May not 

 the stock of the China-rose be therefore more efficient for thchcalthy sup. 

 port of buds and grafts, from the yellow and other difficult flowering roses? 



\U. FuftJuT 



