lOI 



THE SYCAMORE. 



( Acer platanophyllum, St. L ). 



p. Q. KEEGAN LL.D., 

 Patterdale, Westmorland. 



This massy and stately tree is not a native of Lake-land, 

 although Westmorland is . far-famed for its production. In 

 fact, as Wordsworth states, ' it has long been the favourite 

 of the cottagers, and with the Fir, has been chosen to screen 

 their dwelhngs.' It is frequently observed as an apparently- 

 spontaneous outgrowth in sundry wild and sequestered places, 

 as well as in copses, so that we may infer that the rich gravelly 

 soil, the hilly conditions, the open woodland, and the general 

 climatic conditions of the northern districts are well suited to 

 its organic temperament, and respond to the special exigences 

 of its root growth and stem development. Its grand and massive 

 form, the deep tones of its dense foliage, and its easy acces- 

 sibility render it specially interesting to the student of the 

 chemistry of plants, and as an introduction to that study, no 

 better subject can be found. 



Stem. — The wood is moderately hard, and of varying 

 Aveight (specific gravity 0.57 to 0.74), uniformly white, and 

 w^ith no distinction between alburnum and duramen. The 

 medullary rays on tangential section are pointed spindles up 

 to about 0.7 mm. high, and 5 or 6 cells thick in the middle, 

 the number of rays in i mm. of arc is about 12 ; the vessels 

 are numerous and uniformly distributed, of 60 /x width, have 

 spiral thickening, parts of their lateral walls are entirely inlaid 

 with bordered pits, while their slanting transverse walls are 

 pierced by simple pores ; the fibres have very stout walls, 

 beset with a few simple pits ; some parenchyma occurs along- 

 side the vessels. 



In the bark the parenchyma forms tangential bands inter- 

 mixed with sieve-tubes which have a watery ' latex ' ; the fibres 

 are disposed in the inner bast in a few narrow concentric layers 

 extending between the rays, and almost all the parenchyma 

 cells adjacent to these layers contain a single crystal of oxalate 

 of calcium, while the outer bast and inner cortex are thickly 

 sprinkled with groups of stone-cells richly provided with similar 

 crystals ; the pericycle forms a somewhat interrupted ring of 

 fibres separated_at intervals by sclerenchyma ; the periderm 



11,09 March i 



