ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
825 
the terminal bud is removed. The same is the case with the tendrils of 
the vine. In both these cases, as well as in the flower-bud of Papaver , 
we have examples of anisotropy, one portion of an organ growing in 
exactly the opposite direction to the remainder of the same organ. 
Electrical Currents in Plants.* — Herr 0. Haacke has made a series 
of observations on plants belonging to different sections of flowering and 
flowerless plants, with the view of determining the causes of the 
electrical currents which so commonly exist between one part of the 
plant and another. His conclusion is that these currents depend mainly 
on the various processes of metastasis, and especially on the assimila- 
tion of carbon dioxide and elimination of oxygen. The movements of 
water may take some part, but only a subordinate one, in causing these 
currents. 
0 
(4) Chemical Changes (including Respiration and Fermentation). 
Chemical Researches on Germination.^ — M. E. Belzung has studied, 
in certain plants ( Lupinus albus and luteus, Cicer arietinum, Cucurbita 
Pepo, &e.), the nature of the essential products resulting from the ger- 
mination of the seed, keeping in view more particularly the intracellular 
crystallization of the principles normally contained in solution in the 
sap of the living cell. All the crystallizations were effected by the 
simple method of enclosing the living tissues in pure glycerin ; this 
reagent, giving rise to a more rapid exosmose of water than of the 
dissolved crystalline substance, brings the sap more or less rapidly to 
the point of saturation, and thus brings about the intracellular precipi- 
tation. 
An account is given of the most abundant crystallizable substances 
contained in young plants of the various species examined. Only one, 
asparagin, was found in all, its proportion in the different species being 
in an inverse ratio to that of starch. The other nitrogenous organic 
principles found, amides, alkaloids, &c., are, like asparagin, the result of 
the metamorphosis of reserve albuminoid substances, each species having 
generally its own special substance. But the metamorphosis of these 
substances gives rise also to purely mineral compounds, such as nitrates 
and sulphates, the nitrogen and sulphur returning to their original 
mineral form. The author believes that the sulphates of germination 
are the result of a process going on within the plant which may be 
called sulphuric fermentation, just as the nitrates are the result of a 
nitric fermentation, and that the action of the atmospheric air is indis- 
pensable for the process. 
B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 
Prothallium and Embryo of Marsilea.f — Prof. D. H. Campbell 
describes in detail the structure of the fruit, of the microspore and 
* Flora, lxxv. (1892) pp. 455-87 (4 figs.). 
f Ann. Sci. Nat. (Bot.), xv. (1892) pp. 203-62 (2 pis.); and Journ. de Bot. 
(Morot), vi. (1892) pp. 49-53 (2 figs.). 
t Pr°c. California Acad. Sci., iii. (1892) pp. 183-205 (2 pis.). Cf. this Journal, 
ante, p. 642, and 1890, p. 637. 
1892. 3 k 
