ZOOLOGY AND BOTANY, MICROSGOPY, ETC. 
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Dionsea muscipula, &c. The amount of ammonia required to produce 
this result is inconceivably small ; in Spirogyra it is brought about by a 
solution of 1 in 10,000. Other alkaline reagents produce similar results ; 
caffeine is especially to be recommended. All the phenomena appear to 
depend on a transition of the albumen of the living cell, which is in a 
turgescent condition, into a denser condition caused by traces of alkaline 
substances. 
Composition of the Cell-wall.* — According to Herren Schulze, 
Steiger, and Maxwell, many other carbohydrates besides cellulose enter 
into the composition of the cell-wall. They propose to limit the term 
cellulose to that constituent which is only slightly attacked by very 
dilute mineral acids, is soluble in ammonium- copper oxide, is coloured 
blue by chlor-zinc iodide or iodized sulphuric acid, and which yields 
dextrose on saccharosis by strong sulphuric acid. The other carbo- 
hydrates differ considerably in their properties from cellulose. They 
appear to be insoluble in ammonium-copper oxide, and some of them 
yield a cherry-red fluid on warming with phloroglucin and hydrochloric 
acid, they are rapidly saccharized by dilute mineral acids which scarcely 
affect cellulose, yielding galactose, mannose, and pentaglycoses. 
The authors propose for these the designation “ paragalactan-like 
substances ” ; paragalactan (or paragalactin) itself, the result of heating 
galactose with sulphuric acid, has been obtained by them from the seeds 
of Lupinus luteus. These substances appear to enter much more readily 
into the soluble condition than cellulose, as, for example, in the process 
of germination ; paragalactan is a reserve-substance in the seeds of the 
lupin, and it is doubtful whether true cellulose ever serves this purpose. 
History of Cell-theories.f^ — Herr E. Altmann gives a brief resume of 
the various theories propounded as to the constitution of the cell. He 
considers the animal to be far more favourable than the vegetable cell 
for the solution of problems as to its true nature. His general con- 
clusions are that there is no uniform sarcode, but only a polymerous 
protoplasm, and that the cell is not an elementary structure, but a colony 
of such structures. 
C2) Other Cell-contents (including Secretions!. 
Deposition of Starch in Woody Plants.^ — According to M. E. 
Wotczal, the resorption of starch in tissues when the active period of 
vegetation commences, begins at two opposite spots — in the youngest 
branches, and in the youngest roots, and proceeds from these towards 
the older parts in two opposite waves. But between these, in the oldest 
parts between stem and root, a considerable portion of reserve-starch 
remains un consumed. The deposition of newly-formed starch also takes 
place in two opposite waves, in the reverse direction to its absorption. 
* Zeitschr. f. Physiol. Chemie, xiv. (1889) pp, 227-73. See Bot. Centralbl., xli. 
(1890) p. 181. 
t ‘Zur Geschichte d. Zelltheorieen,’ Leipzig,* 1889, 8vo, 20 pp. See Bot. 
Centralbl., xli. (1890) p. 183. 
X Arb. Naturf.-Yer. Kasan, 1888, 6 pp. (Russian). See Bot. Centralbl., xli. 
(1890) p. 99. 
