ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
Vdl 
results obtained being with Conifers. The amount of this diastase 
present varies with the species and with the part of the plant; it was 
found in the root, stem, leaves, flower, and fruit, most abundantly in the 
leaves, from which (lucerne, clover) it was obtained in the pure state 
as a white powder, by dissolving in chloroform and precipitating by 
alcohol. 
Hydrocyanic Acid in Pangium edule.* * * § — Dr. M. Treub publishes 
the results of an elaborate investigation on the localisation and transport 
of hydrocyanic acid in this plant, usually classed in the Bixaceae. Its 
special seat is in the leptome, the sieve-tubes, the assimilating tissue of 
the leaf, the basal cells of hairs, and the epidermal cells which contain 
clusters of crystals. Its conduction takes place mainly through the 
cortex of the stem and leaf-stalk. As regards its function, the author 
rejects the explanation that it is protective, seeing that it is not poisonous 
to many animals ; the apices of the stems, where it is especially abun- 
dant, are infested with larvae. He looks upon this substance rather as 
one of the earliest nitrogenous products of assimilation. It is apparently 
formed in the leaves, but only in the presence of inorganic substances 
carried from the soil by the ascending current. 
Mucilage of the Cactacese.f — Dr. B. Longo has made a study of 
the muciferous canals and idioblasts of the Opuntieae. He finds the 
idioblasts distributed through the fundamental parenchyme of all 
the parts of the stem and root. Their contents include plastids and 
starch. In the cladodes and pseudocarps of the Platopuntieae there are 
canals behind the sieve-portion of the vascular bundles, containing 
calcium oxalate in a crystalline condition, gum, drops of oil, starch- 
granules, and protoplasm. 
Deposition of Calcium Oxalate.J — Dr. L. Buscalioni has studied the 
mode of formation of crystals of calcium oxalate, especially in the seeds of 
the Magnoliacese and Papaveraceae, and of the mucilaginous bodies which 
accompany the groups of crystals in a variety of other plants. His 
conclusions are rather in harmony with those of Kohl § than with those 
of Wakker.j| He states that these crystals, whether in the form of 
clusters or of raphides, originate in the cells in w'hich there are special 
accumulations of mucilage of the nature of callose, or possibly of pectoso 
(the “ mucilaginous bodies ”), and that both kinds are developed on the 
periphery of these bodies ; hence they cannot originate in vacuoles. 
These crystals have probably only an indirect connection with the 
thickening of the cell-wall which accompanies their production. The 
reaction used for determining the presence of this mucilaginous sub- 
substance is the precipitate formed by a soluble copper salt (acetate), 
which precipitate is converted into cupric ferrocyanidc by the addition 
of potassium ferrocyanide. The deposition of calcium oxalate appears 
to be entirely w anting in Gramineae, Typhaceae, Naiadem, Selaginellaceae, 
and Equisetaceae, and to be comparatively rare in Muscineae and Algae. 
* Ann. Jartl. Bot. Buitenzorg, xiii. (1895) pp. 1-89 (11 pis.). 
f Ball. Son. Bot. Ital., 1896, pp. 51-2. 
X Malpighia, is. (1895) pp. 469-533; x. (1896) pp. 3-67 (2 pis.). 
§ Cr'. this Journal, 1890, p. 476. || Cf. this Journal, p. 402. 
