ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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putrefaction, a reduction product which is oxidizable in contact with air, 
and thus reproduces the primitive substance. 
It is probable that this similarity in properties is correlated with a 
similarity of function — in both it is respiratory. 
In a subsequent communication * * * § M. Linossier contests the assertion 
of Phipson f that aspergillin is identical with the palmellin obtained by 
him from Palmella cruenta. 
(3) Structure of Tissues. 
Variations in the Anatomical Structure of the same Species. J — 
Herr P. Schumann has undertaken a long series of experiments on a 
very large number of species, for the purpose of determining to what 
extent anatomical differences occur in different individuals of the same 
species grown in the same situations and under similar conditions, and 
especially whether the larger simply represent a magnified image of the 
smaller examples. The latter question is answered in the negative. 
The difference between a large and a small specimen consists gene- 
rally, in Monocotyledons, in an increase of the fundamental tissue; in 
Dicotyledons in an increase of the pith, the other tissues remaining 
nearly constant in dimensions. In Hyoscyamus niger and Datura Stra- 
monium there is also an increase of the parenchyme between the primary 
vessels ; and in Garum Carui the appearance of medullary bundles. 
Any considerable increase in the cortical system or the vascular-bundle 
system was observed only in a small number of examples. It may then 
be of three kinds : — (1) Increase in size and number of the separate 
bundles; (2) Formation of a continuous secondary ring of tissue; (3) 
Widening of a secondary ring, which occurs also in the smaller examples. 
The increase in the size of the root in larger specimens is almost inva- 
riably due to an increase of the woody cylinder, very rarely to that of 
the cortical tissue. 
Wood of Conifers.§ — Herr P. Schuppan has subjected to a critical 
examination the wood of various Coniferze, especially that of Pinus 
Laricio, P. sylvestris, and Picea excelsa , with reference to the number of 
rows of bordered pits, the width of the annual ring, the distribution of 
the resin-passages, &c. He finds that the diameter of the cylinder of pith 
increases regularly from below upwards in comparison to the diameter 
of the stem. The width of the annual rings in the stem increases from 
below upwards, attains a maximum, and then again decreases. The 
distribution of the resin-passages is the same in the root as in the stem ; 
near the apex of the stem and of the root, the number of resin-passages 
in a unity of surface attains a maximum and then again decreases. 
Abnormal Structure of Annual Rings. || — Herr L. Kny describes 
several instances in which, in contrast to what is usually the case, the 
elements of the autumn wood have distinctly thinner walls than those of 
* Comptes Rendus, cxii. (1891), pp. 807-8. + T. c., p. 666. 
X Bot. Centralbl., xlv. (1891) pp. 357-62, 391-4; xlvi. (1891) pp. 1-6, 65-81, 
145-9, 177-83, 209-15, 242-50, 305-11, 337-43, 369-73, 401-5 (2 pis.). 
§ ‘ Beitr. z. Kenntniss d. Holzkorpersd. Coniferen,’ Halle, 1889, 53 pp. See Bot. 
Centralbl., xlvi. (1891) p. 120. 
|| SB. Gesell. Naturf. Freunde Berlin, 1890. See Bot. Centralbl., xlv. (1891) 
p. 183. 
