1899] CHEMISTRY OF OUR FOREST TREES 59 
of beautiful anhydrides, which never reach the humus-like, dull, dirty 
browns yielded by other tannins. The most striking constituent is the 
highly fluorescent aesculin described by Martius and St. George in 1818 ; 
it is related to the fraxin of the Ash, and this latter is also contained in 
the tree under review. In the bark a fluid oil, phlobaphene, and very 
small quantities of aesculetin and its hydrate, are also found. The 
leaves are eminent for their richness in carotin in early June, their 
abundance of queraescitrin (glucoside of quercetin), fat, wax, phloba- 
phene, and resin, and much tannin in autumn. The seed contains 
about 4 per cent fatty oil and 14 per cent starch, also fruit sugar, and 
a series of curious glucosides and bitter principles representative of 
proteid disorganisation. It is rather a remarkable feature that this tree 
and its allies exhibit very slight indications of the presence or decom- 
position products of gum, mucilage, etc.; they are all starch-producing 
trees, but apparently there is no superfluity, waste, or prodigality of 
this substance, and at the same time, and especially in some of the 
maples, there is an abundant deposition of waxy matters, and of silice- 
ous incrustations. It is quite possible that some of the foreign species 
of Sapindaceae unknown to me may be practically fat-trees. On the 
whole, this order is extremely interesting ; and coming away fresh from 
its analysis, we are impressed with the struggle, as it were, between 
the starch and the fat—the sugar rising into a supremacy, culminating 
in A. saccharinum, and with the lavish abundance and superb beauty 
of the products of de-assimilation. 
One more tree remains to be noticed, viz. the Linden (Tilia euro- 
paea), which possesses morphological and chemical characters of extra- 
ordinary interest. It is the most pronounced fat-producing member of 
our woods. Its seeds contain no starch, and very little carbohydrate, 
but store up 58 per cent of a bright yellow non-drying oil. The wood 
seems to have some difficulty in parting with its reserves of fat, which 
remain, especially in the older rings, up till June or later, and the 
starch that creeps into its place begins to dissolve early in the autumn, 
none whatever remaining in the pith, wood, or bark during the winter. 
A special peculiarity of the tissues is the inconvenient abundance of 
mucilage both in the intercellular spaces of the parenchyma of the 
primary cortex and in the epidermis of the leaves. The large and very 
conspicuous sieve-tubes of the inner bast contain very thick, mucilagin- 
ous masses of albuminoid matters, but no starch. The amount of 
mineral matters in the leaves is very great, and in autumn they are 
incrusted with silica. On the whole this tree exhibits, except as regards 
starch, a very considerable energy of assimilation ; and if some of its 
outcome tends towards decomposition or degradation, the proportion of 
the higher products of de-assimilation is decidedly not relatively high ; 
in fact, those which depend on the destructive metabolism of starch 
are, under ordinary conditions, markedly absent. 
PATTERDALE, WESTMORLAND. 
