ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
221 
purpose of respiration. The most satisfactory test for the presence of 
nitrites was found to be the reaction with chloride of naphthylamin in 
the presence of hydrochloric and sulphanilic acids. 
Influence of Anaesthetics on Respiration.* * * § — Sig. A. Mori has 
investigated the effects of anaesthetics on the respiration of green plants 
in light and darkness. Light and the anaesthetic favoured, darkness 
and the anaesthetic hindered, the emission of carbon dioxide. He 
inclines to believe that the anaesthetic, acting in sunlight, suspends the 
synthetic function with which the chlorophyll is associated, and thus 
increases the amount of carbon dioxide liberated. In darkness the 
anaesthetic certainly hindered the general respiration, for the amount of 
carbon dioxide liberated was less than the normal. 
Presence of a Diastatic Enzyme in Plants.f — Herr J. Wortmann 
is unable to accept the statement of Mayer and others, that a diastatic 
ferment is universally present in all parts of plants, and that this 
substance is as widely distributed as starch itself, and indispensable to 
its absorption. He maintains that not only can starch be absorbed 
without the assistance of diastase, but that diastase may occur where it 
can have no physiological function in connection with the absorption of 
starch. 
For the demonstration of the presence of diastase, the author recom- 
mends that the part of the plant in question be extracted, after being 
thoroughly crushed, with an equal volume of water, and that, except 
where large quantities of starch, mucilage, or albuminoids are present, 
the extraction should not last over more than from two to three hours 
in the cold. The presence of diastase is then shown by its action on 
starch. 
As the result of a very large number of experiments, Wortmann finds 
that in reserve-receptacles where great quantities of starch are stored 
up, such as seeds, tubers, and rhizomes, diastase is also present in con- 
siderable quantities; while, on the other hand, it is not present in 
assimilating leaves, the disappearance of starch from these organs not 
being in any way dependent on the action of diastase. In opposition to 
Krabbe,J he states that protoplasm can disintegrate starch-grains in 
precisely the same way as diastase, by the formation of pore-canals. 
Oil-decomposing Ferment in Plants.§ — From experiments made by 
Herr W. Sigmund, chiefly on the seeds of Brassica and Bicinus , he con- 
cludes that there exists in plants a ferment capable of decomposing the 
fatty oils, the fatty acid resulting from the decomposition being princi- 
pally oleic acid. The operation of the ferment is very much slower and 
less energetic than that of the pancreatic secretion of animals. 
Fermentation of Bread. || — According to experiments made by Miss 
Katherine E. Golden with German yeast, both yeast and bacteria can 
separately raise bread, the yeast sometimes better than the bacteria; 
while in the ordinary making of bread they act together. 
* Atti e Rend. Accad. Med. Chirurg. Perugia, ii. (1890) pp. 135-41. 
t Bot. Ztg., xlviii. (1890) pp. 581-94, 597-607, 617-27, 633-51, 657-69. 
x Cf. this Journal, 1890, p. 749. 
§ SB. K. Akad. Wiss. Wien, xcix. (1890) pp. 407-11. 
|| Bot. Gazette, xv. (1890) pp. 204-9. 
