ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
415 
per cent.). Experiments with soil showed the presence of denitrifying 
organisms, and that by adding starch a considerable amount of the 
nitrates present in the soil could he destroyed, while the addition of 
straw had very little effect. 
The amount of nitrogen utilised by the reducing organisms is very 
slight, nearly the whole of the nitric nitrogen being liberated as gas, 
chiefly free nitrogen. Reduction takes place more readily in closed 
vessels than in the open air, and is retarded by passing air through 
solutions containing starch and potassium nitrate. There is no danger 
of loss of nitrogen by the application of the usual amounts of manure. 
Reduction of nitrates would only take place when the manure amounted 
to 400,000-800,000 kilos, per hectare. Hence it is quite unnecessary 
to treat stable manure with sulphuric acid before using it. 
Nitrates in Seedlings.* — Herr E. Schulze finds potassium nitrate 
in very small quantities in etiolated seedlings of gourd and lupin grown 
in soil which does not contain nitrates. This may be the result of the 
oxidation in the soil of nitrogenous substances excreted by the root, the 
resulting nitrates being then again absorbed ; or it may be the result of 
the air of the laboratory containing small quantities of nitrates resulting 
from the oxidation of atmospheric impurities. 
B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 
Anatomy of Lycopodium.t — According to MM. E. David and 
L. Weber, the ultimate ramifications of the vascular bundle consist (in 
Lycopodium clavatum) of a xylem-bundle and two halves of a bast-bundle. 
The central cylinder is surrounded by a pericambium composed of three 
or four layers. The outer and inner layers of the cortical tissue have 
sclerotised cell-walls. The phloem completely surrounds the xylem in 
each bundle. The sporange consists of a cup, from the hypodermal 
layer of which are developed the spore-mother-cells. The outer wall 
is composed at first of a single layer, which subsequently splits into 
three ; the innermost of these three is the nutrient layer of the spores. 
Oophyte of Botrychium.f — Mr. E. C. Jeffrey has studied th& 
structure and development of the gametophyte (oophyte) generation of 
Botrychium virginiamm. The middle of the upper surface of the pro- 
thallium is occupied by a well-defined ridge, upon which the antherids 
are situated. The archegones are found on the declivities which slope 
away from the antheridial ridge. The cells of the tissue which composes 
the lower surface of the prothallium are filled with a yellow oil, and 
contain an endophytic fungus. The antherids project but little above 
the ridge ; the antherozoids are large, and resemble those of typical 
ferns ; only the neck of the archegone projects above the surface. The 
first division of the oospore (oosperm) is at right angles to the long 
* Zeitschr. f. Phys. Chemie, xxii. (1896) pp. 83-9. See Bot. Centralbl., lxxii. 
(1897) p. 361. 
f Bull. No. 15 Soc. syn. d. Pharmaciena de la Cote d’Or, 1897. See Bot. Cen- 
tralbl., lxx. (1897) p. 359. 
X Proc. Canadian Inst,, i. (1897) pp. 8-10. Ann. Bot., xi. (1897) pp. 481-6. 
897 2 g 
