ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 6G1 
in the ash varies greatly in different organs of the same plant, the pro- 
portion of magnesium being generally much the largest in the seed. 
Both elements are indispensable to the healthy growth of the plant ; 
but if no calcium is present, a very small proportion of magnesium is 
poisonous. Free oxalic acid in the tissues prevents the formation of 
diastase, and hence the conversion of starch into glucose and the trans- 
port of reserve materials ; the principal object of the calcium appears 
to be the removal of this injurious oxalic acid. To fungi, in which 
there is no formation of glucose from starch, oxalic acid is not poisonous. 
Calcium salts hence play an important part in the formation of chloro- 
phyll-bodies and of the nucleus. 
Production of Albumin in Plants.* — Herr A. Mayer maintains that 
the formation of albumin in plants is not due so much to the action of 
phosphorus as to the supply of highly nitrogenous food-material. The 
production of proteids is very rapid, and intermediate products, such as 
amides, do not exist for any length of time. 
B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 
Axis of Vascular Cryptogams.! — According to M. J. Velenovsky. 
the branching of the axis of vascular cryptogams presents a greater 
resemblance to that of cellular cryptogams than to that of phanerogams. 
In the latter, with a few exceptional cases, there is no true dichotomy ; 
the branching is always monopodial. Among vascular cryptogams this 
is the case only in Equisetum ; in all others the axis can develope new 
branches at any spot, and there can be no regular acropetal succession. 
When the two branches into which the axis divides are alike, we have 
a dichotomy ; when they are dissimilar, the appearance of a monopode. 
The axis of vascular cryptogams is not segmented by the leaves like 
that of phanerogams, but is a unit which can divide at any spot without 
reference to the leaves. The Equisetace® may be compared to the 
Charace®, the Lycopodiaceae to the Hepatic®. Cellular cryptogams 
differ from vascular in never producing true leaves ; those of mosses 
are only emergences of the thallus ; the homologue of the true leaf in 
mosses is the sporange. There are no transitional forms known between 
the existing vascular cryptogams and the gymnosperms. 
Calcium oxalate in Vascular Cryptogams.!— M. G. Poirault disputes 
the statement made by several authorities that calcium oxalate is com- 
paratively rare in Vascular Cryptogams. Out of upwards of 500 species 
of Ferns examined, he finds this salt present in by far the larger number 
belonging to a great variety of different genera. It occurs also in the 
Hydropteride®, but has not yet been detected in Equisetum , Selaginella , 
or Psilotum. 
* Landwirthsch. Vers.-Stat., xli. pp. 433-41. See Journ. Chem. Soc., 1893, 
Abstr., p. 224. 
t Kozpravy ceske Acad., ii. (1892) 22 pp. and 2 pis. See Bot. Centralbl., Jiv. 
(1893) p. 299. 
1 Journ. de Bot. (Morot), vii. (1893) pp. 72-5. 
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