438 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
‘ Handbuch der Pflanzenphysiologie,’ and sums up the evidence in 
favour of the view, advanced by Bokorny and himself, of the distinction 
between passive and active albumen. Active albumen coagulates in all 
those conditions in which protoplasm dies. 
(2) Other Cell-Contents (including- Secretions). 
Chlorophyll and its Derivatives.* * * § — Herr F. G. Kohl communicates 
a number of fresh observations on the absorption-spectra of the various 
constituents of chlorophyll. Among other points he considers it as 
established that phylloxanthin cannot be a derivative of chlorophyll. 
Calcium Malate and Malophosphate in Plants.f — M. M. Mirande 
states that although malic acid occurs most commonly in plants in the 
free state, C 4 H 6 0 5 , it is also met with in combination with calcium as 
neutral calcium malate (C 4 H 5 0 5 ) 2 Ca, or as calcium malophosphate. It 
was studied especially in Nolana yaradoxa , from which it can be pre- 
cipitated by the action of alcohol in the form of sphero-crystals of 
neutral calcium malate, of the orthorhombic type ; and as two forms of 
calcium malophosphate, the one consisting of sphero-crystals of needles, 
with excess of phosphoric acid, the other in the form of orthorhombic 
prisms, in which malic acid predominates. The quantity of malophos- 
phate generally exceeds that of malate. 
Gum of Canna.J — According to M. L. Lutz, the gum of Canna is 
formed in a lysigenous, and not in a schizogenous manner, as might be 
supposed from a cursory examination. It forms in a thick layer in the 
interior of the cell, and, gradually condensing, forces the cytoplasm and 
its contents into the centre. The protoplasm and the thickened mem- 
brane surrounding it finally blend into a mucilaginous mass. 
Gum in Elm-galls.§ — Sig. N. Passerini finds, in galls on TJlmus cam- 
jpestris, produced by the attacks of an aphis, Schizoneura ulmi , a gum 
differing in its properties from other gums — arabin, cerasin, &c. — and 
from mucilage, dextrin, and other carbohydrates found in vegetable 
tissues. The solid portion consists chiefly of a gummy substance pre- 
cipitated by alcohol, the precipitate being amorphous, yellowish, tasteless, 
very soluble in water, presenting the appearance of gum arabic, but 
differing from that substance in several properties. It is strongly 
dextrogyrous, and has an energetic reducing effect on cupric salts. 
(3) Structure of Tissues. 
Central Cylinder of Vascular Plants.|| — According to Mr. E. C. 
Jeffrey, there are three main types of fibro- vascular arrangement in plant 
axes, viz. (1) a single so-called concentric aggregation ; (2) several such 
aggregations, commonly but not always grouped in a circle ; (3) a ring 
of so-called collateral or bicollateral bundles. The author points out 
the primitive development of the tubular arrangement, which occurs in 
many Pteridophyta and Equisetaceee. In the latter family the primitive 
* Bot. Centralbl., lxxiii. (1898) pp. 417-26 (1 fig.). 
t Journ. de Bot. (Morot), xii. (1898) pp. 6-12, 32-42, 58-60 (6 figs.). 
% Bot. Gazette, xxv. (1898) pp. 280-1. 
§ Bull. Soc. Bot. Ital., 189S, pp. 70-1. 
|| Rep. Brit. Ass. Toronto, 1897 (1898) pp. 869-70. 
