ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
449 
deals a heavy blow to the vibration theories of Liebig and Naegeli. 
Their views are only tenable on the theory that most, if not all, of tho 
action takes place in the liquid outside the cells. But if the work be 
done by an enzyme, it must necessarily be intracellular ; for enzymes 
show no tendency to diffuse through such a membrane as the cell-wall. 
It also militates against Pasteur’s theory of intramolecular respiration, 
which demands the idea of the decomposition being brought about by 
chemical action between the protoplasm and the body from which it 
obtains its oxygen. 
Formation of Holes in Emmenthal Cheese * * * § — According to Herr 
0. Jensen, the normal holes in Emmenthal cheese are not formed by 
special agents, by yeasts or by anaerobic bacteria, but by the normal 
agents of cheese ripening, among which must be considered the lactic 
acid ferments. The gases to which the normal holes are due are not 
formed at the expense of the milk-sugar, but at that of the nitrogenous 
substances. The lactic acid ferments of cheese may under certain con- 
ditions form traces of C0 2 from nitrogenous substances ; and these traces 
of C0 9 are the cause of the normal hole formation in Emmenthal cheese. 
B. CBYPTOGAMIA, 
Cryptogamia Vascularia. 
Leaves of Selaginella. f — M. F. Cornaille describes the structure and 
arrangement of the leaves in 24 species of Selaginella , reviewing the 
classification proposed by Harvey Gibson. Starting from an ideal group, 
comprising nearly or quite glabrous species, destitute of fibres, without 
cuticular ornamentations, and with the epidermal cells not palisade-like, 
all the species may be arranged in two parallel series, glabrous and 
hairy. In each of these series secondary groups are established, de- 
pendent on the form of the epidermal cells, the presence or absence of 
palisade tissue, and of epidermal fibres more or less ornamented. 
Selaginella spinulosa.J — According to Herr H. Bruchmann, this 
species differs in several important points from the rest of the genus. 
The primary hypocotyledonary shoot remains for a time in the condition 
of an erect filiform basal member of the plant ; the roots springing from 
its base only, and not, as in other creeping species, from the forks of the 
stem. They owe their origin to a peculiar persistent cushion of meri- 
stem. The primary shoot at first branches dichotomously, but the 
apices of the system soon pass into the condition of fertile spikes ; each 
then produces two lateral shoots, and acquires a sympodial character. 
The stem never has a single apical cell ; the apex consists of a uniform 
meristem not differentiated into layers ; and this is true also of the apex 
of the root. 
Ferns of Multiple Parentage.— Mr. E. J. Lowe § records the results 
of experiments on crossing Asplenium Trichomanes with both A. marinum 
* Centralbl. Bakt. u. Par., 2 te Abt., iv. (1898) pp. 217-22, 205-75, 325-31. 
t CR. Soc. R. Bot. Belgique, xxxvi.(1898) pp. 100-18 (3 pis.). Cf. this Journal, 
1897, p. 223. 
X ‘ Unters. iib. Selaginella spinulosa,’ Gotha, 1897, 61 pp. and 3 pis. See Bot. Ztg., 
lvi. (1898) 2 te Abth., p. 109. 
§ Rep. Brit. Ass. Toronto, 1897 (1898) pp. 866-7. 
