ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
217 
(2) Other Cell-contents (including Secretions). 
Structure of Starch-grains.* * * § — As the result of very careful observa- 
tions Dr. O. Biitschli concludes that the lamination of starch-grains is 
connected with a honeycomb-like structure. The regular formation of 
the layers is especially well seen in slightly swollen grains of arrow- 
root starch. Each layer has a distinct radial striation, and the striation 
of any one layer does not correspond in direction with that of the layers 
on each side of it. The honeycomb structure was even more distinctly 
seen in artificial starch-grains. The phenomena above described appear 
to agree rather with the theory of growth by apposition than with that 
of intussusception. 
Composition of Vegetable Albuminoids. t — M. E. Fleurent has ana- 
lysed some of the more important albuminoids found in plants — gluten, 
gluten-caseine, gluten-fibrine, legumine, and albumine — and finds that 
they have a somewhat different constitution from that determined for 
animal albuminoids by Schiitzenberger. The crude fixed residue of 
gluten and caseine contain carbon and hydrogen nearly in the proportion 
C„H 2n . In the former the percentages are C 49*70, H 8*87; in the 
latter C 48*55, H 8*20. 
Accumulation of Carbohydrates in Leaves.^ — Experiments made 
by Herr W. Saposchnikoff on vine-leaves show that where the atmo- 
sphere contains a more than normal amount of carbon dioxide, the limit 
of the accumulation of carbohydrates is more quickly reached. 
Inulin and its Allies.§ — According to M. C. Tanret, the inulin 
extracted from Inula Helenium and Helianthus tuberosus is not pure 
inulin, but is accompanied by two other allied substances, which he 
calls “ pseudo-inulin ” and “ inulenin.” The mode of separating these 
substances is described. Pure inulin is very soluble in warm, but only 
very slightly soluble in cold water ; moderately soluble in dilute alcohol. 
Both pseudo-inulin and inulenin are much more soluble than inulin in 
cold water. 
Distribution of Oxalic Acid in Plants. |j — Herr R. Giessler finds (in 
Hume x, Oxalis, and Begonia') that the oxalic acid is chiefly localized in 
the epiderm, or at least in the superficial tissues, where it is of the 
greatest use in protecting the plant against the attacks of animals. 
There is no oxalic acid, or but very little, in the underground organs. 
By far the largest quantity is found in the epidermal tissues of the 
leaves ; in the stem it occurs chiefly in the cortical parenchyme. The 
function of oxalic acid is the same as that of tannins, and there is a close 
correspondence also in its local distribution. The amount of calcium 
oxalate in a plant generally increases with its age. 
* Verhandl. Natur.-Hist. Ver. Heidelberg, v. (1893) pp. 89-102. See Bot. Cen- 
tralbl., lvi. (1893) p. 150. 
t Comptes Rendus, cxvii. (1893) pp. 790-3. 
X Ber. Deutsch. Bot. Gesell., xi. (1893) pp. 391-3. Cf. this Journal, 1891, p. 370. 
§ Comptes Rendus, cxvi. (1893) pp. 514-7. 
|| Jeuaisch. Zeitschr. f. Naturwiss., xxvii. (1893) pp. 344-78. See Bot. Centralbl., 
lvi. (1893) p. 35. 
1894 
Q 
