1897 ] CURRENT LITERATURE 301 
In germination the diastatic enzyme penetrates from the cell lumen into 
the thickened cell wall, the more copiously the nearer the scutellum. 
seed under investigation was Phenix dactylifera.| Upon the penetration of 
the enzyme there follows a fractional hydrolytic solution by which galactan is 
removed from the cell wall. is produces the hyaline marginal zone. The 
mannin remain ingin this hyaline zone succumbs to alloolysis; that is, the mass 
penetrated by the enzyme passes into various stages of mannin and finally 
into mannose. According to the reactions one can distinguish a leucomannin 
and a cyanomannin.—C. R. B 
PHYSIOLOGISTS will find in the Pharmaceutical Review for September 
two valuable articles touching the chemistry of plants. One is a summary of 
recent literature on oak bark tannins @ frofos of some researches on the 
caffein compound of kola (15: 172) by Knox and Prescott. The other is 
a résumé of progress in the chemistry of the carbohydrates during 1896, by W. 
E. Stone (15: 178).—C. R. B. 
MONTEMARTINI has prosecuted researches upon the physiology of the 
primary and secondary meristem of various plants.” He finds that the activity 
of the growing point shows a grand period dependent upon internal factors. 
There exists a connection between apical and secondary growth; the curve of 
the former is parallel with that of the latter; the maximum of apical activity 
corresponds to the greatest elongation of the growing zone; both are equally 
affected by external agents. The secondary meristem shows a like period- 
icity, independent, however, of that of the apical region. 
he author also discusses the formation of annual rings. He concludes 
(with Jost and Mer) that their production is an immediate consequence of 
Spontaneous and periodic variations in the activity of the cambium, and (with 
Unger) that the periodicity of the cambial activity, though independent of 
that of the primary meristem, is synchronous with it and influenced, like it, 
by external conditions.—C. R. B 
_ ANclentT EGyprian bread taken from the tomb of Mentuhotep and now 
in the Royal Museum at Berlin is found by L. Wittmack * to still give the 
lodine test for starch. Microscopical study shows it to be made from barley, 
and to contain the remains of yeast and bacteria. This indicates that barley 
's probably older as a cultivated grain than wheat, and that yeast, or dough 
om the previous baking, was doubtless used in those ancient times. The bread 
's estimated to be fully 4400 years old.—J.C. A. 
70: 27 
** Bot. Centr. 71: 328. 1897. 
* Atti dell Istit. Bot. della Univ. di Pavia II. 5: —. 1896. Cf. Bot. Centralblatt 
6. 1897, 
