ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
481 
(4) Chemical Changes (including Respiration and Fermentation). 
Analogies between Fermentation and Solar Combustion.* — Prof. 
E. Duclaux points out that certain analogies exist between tlie processes 
of fermentation and of solar combustion. Thus, for example, if glucose 
and lactose in alkaline solution be put in the sun, they are gradually 
burnt up, the products of their combustion being formic acid, alcohol, and 
carbonic acid ; this is just what happens in alcoholic fermentation, though 
the quantity of alcohol produced is but small, barely 3 or 4 per cent, 
of the weight of sugar. In the earlier experiments the liquids were 
alkalinized with baryta or lime ; but when these are replaced by potash 
or soda, lactic acid is formed instead of alcohol, and this may amount to 
50 per cent, of the weight of sugar. Moreover, the acid formed is not 
the same, sometimes being laevolactic, sometimes dextrolactic, and some- 
times inactive lactic acid. 
In solar combustion this appears to depend on the particular rotatory 
property of the sugar used. It is also noted that saccharose, so long as 
it is not inverted, resists solar combustion just as it does the action of 
ferments. 
7. General. 
Archenema, Protonema, and Metanema4 — Prof. C. Macmillan pro- 
poses to limit the term “ gametophyte ” to any structure derived directly 
or indirectly from a sporopliytic spore or its analogue, and itself capable 
of producing, directly or indirectly, a gamete or gametes. Examples are 
afforded by CEdogonium , Coleochsete, leafy moss-plants, fern-prothallia, 
the endosperm of Araucaria, the pollen-tube of Burmannia , and the 
embryo-sac nuclei of Narcissus. The gametophyte of any species of 
Hepaticae or of Mosses consists of two distinct developmental stages which 
may be termed respectively protonema and metanema. For gameto- 
phytic structures lower than the Hepaticae, which do not show any dif- 
ferentiation into protonema and metanema, the author proposes the term 
arcJienema. 
B. CBYPTOGAMIA. 
Cryptogamia Vascularia. 
Classification of Ferns.t — The late Prof. K. Prantl proposed a new 
classification of the Pteridophyta — viz. a primary division of the Filicinae 
into the two sections of Pteridales and Osmundales, depending on the mode 
of formation of the sporange. In the former division are included the 
Hymenophyllaceae, Cyatheaceae, and Polypodiaceae ; and the author con- 
siders that the Salviniaceae and Marsileaceae are also more nearly allied 
to them than are the Osmundales. In the latter family are included the 
Schizasaceae, Gleicheniaceae, Osmundaceae, Ophioglossaceae, and Marat- 
tiaceae. The Polypodiaceae are further divided into the Aspidieae, 
Asplenieae, Pterideae, and Polypodieae. 
Development of Marattia.§ — Prof. D. H. Campbell has followed out 
the early stages in the development of Marattia Douglasii . The spores 
* Ann. Inst. Pasteur, vii. (1893) pp. 751-4. 
t Bot. Gazette, xix. (1894) pp. 19-24 
X Arb. K. Bot. Garten Breslau, i. pp. 1-38. See Bot. Centralbl., lvii. (18C4) 
p. 384. § Ann. Bot., viii. (1894) pp. 1-20 (2 pis.). 
