544 BOTANICAL GAZETTE [JUNE 
seedling, and that the stem category is rather artificial —CHarLres J. CHAM- 
BERLAIN. 
An arctic-alpine plant association.—Upon the ‘‘snow-flush,” a substratum 
deposited on gentle slopes or flats by streamlets of snow water and composed 
of fine snow-dust material, there develops a characteristic association or suc- 
cession of associations, recently described by SmirH.” He indicates its occur- 
rence on Ben Lawers and cites the work of others, notably that of ScHROTER, 
R@BEL, and BROCKMANN-JEROSCH, concerning its development upon the Alps. 
Pioneer algae are succeeded by a thick mat of the liverwort Anthelia jurats- 
kana, which gives character and name to the association. Polytrichum sp. 
follows and is succeeded by Salix Se boney: Alchemilla, Gnaphalium, and other 
alpine plants, the floristic composition of the later stages varying in different 
localities —Gro. D. FULLER 
ant geography of the heights of Hautie.—ALLoRrGE” has made a floristic 
study of a plateau 15 by 10 kilometers in area, situated northwest of Paris at the 
confluence of the rivers Seine and Oise. e elevation of the plateau is about 
190 meters, and it exhibits a considerable diversity of soil, with comparatively 
natural vegetation. The associations have been segregated according to the 
chemical nature of the soil, and that of the calcifuges is found to be most 
conspicuous and to cover almost the entire top of the plateau. The regional 
affinities of the flora are examined and shown to be chiefly western, although 
the area also seems to be a rather notable meeting ground of certain northern 
and southern forms.—GEo. D. FULLER. 
Nitrite assimilation.—K ossow1cz” has found that molds ( Aspergillus niger, 
Penicillium glaucum, Mucor Bodin, and others) can readily assimilate nitrite 
when it is the only source of nitrogen. It is important that by the most delicate 
test (NESSLER’s method), HN; could not be detected in the cultures except in 
two instances, and in these only after long cultural periods (26 days). The 
nitrite-ion can evidently then be directly assimilated without the intermediate 
production of NH;.—E. M. Harvey 
A cytological life cycle.—In a series of diagrams based upon the life history 
of the fern, GriGcs* presents current notions as to the behavior of chromo- 
somes in the sporophyte and gametophyte, and also during fertilization and 
reduction. While the illustration should not be pressed too far, the diagram 
will be useful for didactic purposes.—CHARLEsS J. CHAMBERLAIN. 
2 Suitu, W. G., Anthelia: an arctic-alpine plant association. Scot. Bot. Rev. 
1:81-89. 1912. 
2t ALLORGE, A.-PIERRE, Essai de eo botanique des hauteurs de |’Hautie 
et de leurs dépendence. Rev. Gén. Beton ie one 417 431, 417-498 1913. 
22 Kossowicz, ALEX., Nitrit pil Zeitschr. — 
physiol. 3: 321-326. 1914. 
23 Griccs, R. F., A cytological life cycle. Ohio Naturalist 13:142-145. pl.6. 1913. 
