*with Hints for their Removal. 53 



examining, to refresh my recollection. The part above where 

 it was budded is more than one third thicker than the part 

 below. Now, the stock must have been of a considerable thick- 

 ness before the bud was inserted ; therefore, if the tree were 

 increased in thickness from the root upwards, or, as I have 

 suggested, horizontally from the bark to the alburnum or stem 

 by the &ap only, each part contiguous must have thickened 

 alike, and the stock must still have been the thickest part, 

 particularly if all the sap ascends from the roots every sprino-. 

 As, however, this is not the case in the instance noticed, and in 

 many similar ones, it would appear that wood is increased 

 from the top downwards; as it is well known that some 

 stocks, when the engrafted scion and stock are nearly alike 

 in their habits, increase regularly in size with the engrafted 

 part, to the very point of union with the roots, the same as 

 trees raised from seeds or cuttings : hence it appears clear, 

 that the branches, twigs, and leaves do increase or assist the 

 growth of the timber. 



I can understand perfectly what Mr. Howden says of 

 " having seen a weeping ash getting on to the size of a 

 pyramid, on a common ash stock with a bole not fit for a 

 ladder." This is an instance of the disproportion which I 

 have been endeavouring to elucidate. Mr. Howden's remarks 

 on another ash tree which he has seen, that was planted at 

 the same time with that named, " with a top that barely 

 makes room for three rooks' nests, yet with a trunk fit for 

 sawing into 1 1-inch planks, I cannot comprehend. As Mr. 

 Howden does not inform us whether it ever had any more 

 branches, or when it was divested of them, nor what length 

 of time it would take to make 22-inch planks, with no more 

 branches than would contain three rooks' nests, it would be 

 well if Mr. Howden would explain that to those whom he 

 advises to " shut their mouths." 



In Mr. Lindley's late lectures on the relation of botany to 

 horticulture, I observe that he appears to have the same opi- 

 nion that I have on these subjects, which I take the liberty 

 to quote : — 



In Lecture 1. (Vol. VIII. p. 382.) he says : — " Leaf-buds 

 (so called to distinguish them from flower-buds) in trees, are, 

 in fact, trees in embryo, and afford the only certain means of 



multiplying varieties Leaves may be called the lungs 



of plants ; as, through them, the sap is exposed to the influ- 

 ence of the atmospheric air. They are furnished with pores 

 (vulgarly, perhaps, called mouths), which can imbibe nou- 

 rishment as well as throw off" superfluous moisture." 



Lecture 5. (Vol. VIII. p. 619.) : — " The sap, having reached 



E 3 



