ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
80 d 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-structure and Protoplasm. 
Pectic Substances in Plants.* — M. L. Mangin has studied the sub- 
stances which come under this head, and which are found in a great 
variety of plants. They may be classed under two series, neutral and 
acid, though the substances pass from one to another by insensible 
gradations, varying in every degree from complete insolubility, through a 
condition in which they absorb water and swell, to complete solubility. 
The series of neutral substances comprises pectose, which is insoluble, 
and is intimately associated with cellulose in non-lignified and non- 
suberized cell-walls, and pectin, which is soluble, and more or less 
easily gelatinizable. The acid series comprises pectic acid, which is 
insoluble, aud usually combined with the bases of the alkaline earths, 
and metapectic acid, which is completely soluble without gelatinizing. 
The chemical and staining properties of these substances are given in 
detail. Those of pectose are but little known, because those reagents 
which separate it from the cellulose with which it is intimately 
associated transform it into pectin. There is a close analogy between 
pectic substances and gums ; the latter are formed by the disorganiza- 
tion of the former as well as of cellulose, and it is in this way that the 
mucilaginous substance which fills up the intercellular spaces is 
formed. 
(2) Other Cell-contents (including- Secretions!. 
Proteids of the Oat.| — Mr. T. B. Osborne gives further details 
respecting the proteids of the oat, which, he states, undergo great change 
by direct treatment with hot sodium chloride solution. It is probable 
that alcohol temporarily suspends a fermentation which is induced by 
water or solutions of neutral salts. The probable composition is given 
of the three primary proteids originally contained in the oat-kernel ; 
one is soluble in alcohol, one, a proteid or globulin, is soluble in 
sodium chloride, and one is soluble in alkali. 
Vegetable Cholesterins.J — According to M. Gerard the cholcsterins 
of the higher and those of the lower plants differ from one another in 
their chemical and physical properties. Those of Phanerogams have 
all the characteristics of Hesse’s phytosterin ; while those of Crypto- 
gams give the reactions of Tauret’s ergosterin. The former were 
obtained from the lupin, Trigonella fcenum-grsecum, the seeds of Datura, 
and olive-oil ; the latter from Penicillium glaucum and JEthalium 
septicum. 
* Journ. de Bot. (Morot), vi. (1892) pp. 206-12, 235-44. Of. this Journal, ante . 
p. 223. 
t Amer. Chem. Journ., xiv. (1892) pp. 212-24. Cf. this Journal, ante , p. 58. 
X Comptes Rendus, cxiv. (1892) pp. 1544-6. 
1892. 3 i 
