J8 Rev. P. Keith on the Pith of Plants. 



Laid do stress upon it, but proceeded in pursuit of a pith to 



examine the rents as well as stems, not of aged trees, but of 

 young Beedlings. 



A-Ccordinglvj on the 24th of June 1836, I took up a seed- 

 ling of the sycamore^ Acer Pseudoplatamts. The stem mea- 

 sured about three inches in height. It was still furnished with 

 it-- seed leaves, which were elevated about two inches above 

 the level of the soil, with a pair of terminal stem leaves two 

 inches in length by one and a half in breadth, and with a se- 

 cond and immature pair protruding from their axils. On a 

 horizontal section it exhibited a circular layer of bark and a cir- 

 cular layer of woody fibre, enclosing a central pith conformable 

 to the terms of the definition as it regards the ascending axis, 

 or stem, which on being partly cut and partly broken asunder, 

 exhibited also spirals both above and below the seed leaves. 

 On the same day I took up a seedling of the beech tree, Fayus 

 syhaticus. The seed leaves were still attached to it and were 

 fully expanded ; and the stem on the horizontal section was 

 divisible into bark and bundles of woody fibre, together with 

 a central pith and spirals. 



All this is what was to be expected ; and the next thing 

 remaining to be done was the inspection of the roots of the 

 siid seedlings which was now undertaken. In the above spe- 

 cimens this root measured from two to three inches in length, 

 with a good many lateral fibres, and on a horizontal section 

 exhibited, like the stem, a bark, a circular layer of woody fibre, 

 but without spirals, and a central or axial mass, which mass 

 differed in nothing visible from the central mass of the stem, 

 whether as relative to its colour or to its spongy and cellular 

 texture. On this account I have no hesitation in pronouncing 

 it to be a true and legitimate pith, though lodged in the de- 

 scending axis. If it be said, that owing to the elevation of the 

 seed leaves in the above cases, the place of the collum must 

 have been rendered doubtful, and that of the commencement 

 of the real root uncertain, then I will present a case from 

 which doubt is altogether excluded. 



On the 15th of July, 1836, I stumbled on a seedling of Co- 

 rylus Avellana. I took it up with much care and found that 

 the seed lobes and half of the investing shell were still attached 



