536 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
also in the epiderm of the young stem. In the leaf : — in all the paren- 
chymatous cells, in the liber, and in the epiderm. 
Gelsemine in Gelsemium sempervirens. In the root and stem : — in 
the liber and cortical parenchyme ; also in the pith of the stem. In the 
leaf and leaf-stalk : — as in the stem. 
Berberine in Berberis vulgaris. In the root : — in the interior of the 
cells of the cortical parenchyme, liber, cambium, and medullary rays ; 
in the interior and in the walls of the vessels of the xylem ; in the walls 
of the ligneous fibres. In the stem : — in the interior of the cells of the 
cortical parenchyme, liber, and cambium. In the seed : — in all the cells 
of the embryo and endosperm. 
Taxine in the yew. This principle occurs in the root, stem, leaf, 
and leaf-stalk, and in all the cells of the embryo and endosperm. 
Crystalloids of Phytolacca.* — In the conical mucro which forms the 
apex of the leaves of Phytolacca abyssinica, Sig. 0. Kruch finds, both in 
the epidermal cells and in those which constitute the special tissue of 
the mucro, proteinaceous crystalloids of a regular polyhedral form. 
They aro insoluble in water and in absolute alcohol, and are frequently 
aggregated together in the cells. 
Winter-Starch.j — Herr 0. Rosenberg finds that, in the perennial 
parts of many herbaceous plants (Spirsea Ulmaria, Scrophularia nodosa ) 
an increase of starch takes place in the winter — as has already been 
shown to be the case in woody plants J — which cannot be due to assimi- 
lation ; since the leaves are entirely wanting and the buds inactive. 
The amount of starch in the various parts of the rhizome varies from 
month to month ; and in other cases ( Plantago major , Potentilla argentea , 
Hepatica triloba) the amount of starch in the underground organs de- 
creases, or it entirely disappears, between November and April. 
Red Pigments of Plants.§ — According to Herr L. Weigert, there 
are only two well-marked classes of red pigments in the vegetable 
kingdom — the wine-red ( Ampelopsis , Bhus typhina , Cornus sanguinea , &c.), 
and the carrot-red (Beta, Amarantlius , fruit of Phytolacca , &c.). The 
mallow-violets ( Coleus , &c.) form another group. In black grapes and 
in whortleberries there are two pigments, one of which is a glucoside ; 
the colouring matter of yellow vine-leaves is a glucoside ; as is also the 
pigment of the mallow. The pigments of the grape and whortleberry 
appear to belong to a class of tannins. 
Distribution of Tannin in Wood.|| — M. E. Henry has investigated 
the distribution of tannins in the wood of various trees, and finds that, 
as a rule, the proportion diminishes, both in the bark and in the wood, 
from the base to the summit of the tree. The richness in tannin is 
generally in proportion to the vigour of growth. In the bark and in the 
alburnum the tannin is dissolved in the cell-sap, while in the duramen 
it impregnates the cell-walls. The maximum proportion is attained in 
the outermost layers of duramen. In trees which have no proper duramen 
the proportion of tannin increases to the centre of the trunk. 
* Atti It. Accad. Lincei, v. (1896) pp. 364-6. 
t Bot. Centralbl., lxvi. (1896) pp. 337-40. J Cf. this Journal, 1891, p. 485. 
§ JB. K. K. OEnol. Lehranst. Klosternenburg, 1895. See Bot. Centralbl., lxvi. 
(1896) p. 353. || Bull. Soc. Bot. France, xliii. (1896) pp. 124-8. 
