60 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Arnaud * * * § is identical with the erythrophyll of Bourgarel and the chryso- 
phyll of Harsten ; while the yellow or yellow-red substance extracted 
by Immendorff from green leaves cannot be identified with this pigment ; 
it is a product of transformation of some other colouring substance, pro- 
bably of erythrophyll. The green substance of the chlorophyll-grains is 
constantly accompanied by two yellow cry stalliz able substances, one of 
which, xanthophvllidrine, is soluble, the other, xanthophyll, insoluble in 
water. Besides these yellow substances, leaves constantly contain a 
red substance, erythrophyll, to which authors have given different names, 
and which Arnaud seeks to identify with the carotin of cultivated 
carrots. 
Pigment of the Synchytrium-galls of Anemone nemorosa.f — Herr 
F. Ludwig finds that the attacks of the parasitic Synchytrium Anemones 
on Anemone nemorosa produce in the epidermal cells of the leaves and 
flowers a red pigment very soluble in water, with a very characteristic 
absorption-spectrum, apparently identical with that of anthocyan. It 
apparently serves the purpose of a protection against snails. 
Dulcite in Plants.! — By extracting with alcohol, Prof. J. Borodin 
found dulcite in Melampyrum nemorosum, pratense , sylvaticum, and other 
species of the genus, in all parts except the ripe seeds, especially in 
the secondary shoots, corolla, and unripe pericarp. In other plants 
belonging to the Scrophulariaceas, e. g. Ehinanthus crista-galli and 
Scrophularia nodosa , he was unable to find any trace of it. Dulcite was 
found in all species of Celastracese examined, viz. 11 species of 
Euonymus , 3 of Celastrus , and 1 of Scheefferia, in all parts except 
possibly the root. That dulcite, like the carbohydrates, takes part in 
the vital processes of the plant, is shown by the fact that in Euonymus 
japonicus it entirely disappears from the leaves before their fall. 
Strophanthine. § — Dr. T. B. Fraser publishes an elaborate account 
of Strophanthus hispidus , and its use in Africa as an arrow-poison. The 
poison is obtained exclusively from the fruit, where its active principle 
occurs chiefly in the endocarp, the placenta, and the comose appendages 
of the seeds. It is however found, though to a smaller extent, in the 
root and leaves, as well as in the epicarp and mesocarp. From the bark, 
both of the stem and of the branches, it appears to be entirely absent. 
C3) Structure of Tissues. 
Collenchyme.|| — Herr C. Muller has investigated the nature and 
structure of collenchyme more closely than has hitherto been done. He 
classifies the various forms under the following heads, viz. : — (1) with 
thickening at the angles (typical collenchyme) ; (2) with walls thickened 
on all sides (bast-collenchyme) ; (3) with walls thickened on all sides 
and the inner lamella of each cell strongly differentiated; (4) with 
tangential thickening-plates ; (5) with uniform thickening of the walls 
* Cf. this Journal, 1890, p. 350. 
t Yerhandl. Bot Yer. Brandenburg, xxxi. (1890) pp. vii.-viii. (1 fig.). 
X Rev. Sci. Nat. St. Pe'tersbourg, 1890, pp. 26-31 and 55. See Bot. Centralbl., 
xliii. (1890) p. 175. 
§ Trans. Roy. Soc. Edinb., xxxv. (1890) pp. 955-1028 (7 pis.). 
Ber. Deutsch. Bot. Geselh, viii. (1890) pp. 150-66 (1 pi.). 
