By Anthony Carlisle, Esq. 



m 



aniinals, upon a few slender analogies ; but the additional 

 offices known to be performed by leaves, shew them to be 

 also allied to the digestive and assimilating organs. Nor is 

 it at all unreasonable to enquire whether the digesting, 

 secreting, excreting, and pneumatic operations of life, are, 

 or are not compatible 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 together.* The greatest number of resemblances 

 between plants and animals are to be found in those of the 

 most simple structure, in both kingdoms : and in all such in- 

 stances, the governing influence of physical causes is strikingly 

 obvious ; whereas under 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 phenomena 

 to an occult cause, known under the ill-defined term, vita- 

 lity. Assuredly, the leaves of vegetables very generally 

 perform the offices of animal stomachs ; as when they con- 

 vert the raw material of vegetable nutriment into a new and 

 peculiar substance for building up the fabric of plants. 

 The extensive variety of new compounds which different 

 plants contain, are elaborated from nearly the same kind of 



* 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 con- 

 sist 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 the healthy support of buds and grafts, from the yellow, and 

 other difficult flowering Roses ? 



