214 BOTANICAL GAZETTE [SEPTEMBER 
these has led to the reduction of many of the recently proposed species, par- 
ticularly those of C. Miiller, whose later work was so prolific of “new” 
species. Some of the critical remarks touch American and Antillean species. 
R. B 
Von Derscuavu has studied carefully the process of wall thickening in 
the formation of the teeth of mosses.” He finds that preceding the true 
thickening process, the activity of the cytoplasm consists only of its prelimi- 
nary accumulation on the membrane to be thickened. In this the nucleus 
exerts no clearly recognizable control, but does do so in the thickening process 
itself. This consists of the apposition of materials early produced in the 
cytoplasm, of which cellulose is the primary one, the other substances being 
such as promote hygroscopicity and resistance to decay.—C. R. B 
Dr. GeorG Goetz has restudied the development of the egg in the 
Characee,** which leads him to consider the group as independent of the 
alge and derived from the primitive type of the archegoniates, just as the 
mosses and ferns, The Wendungszellen of Nitella he regards as a reduced 
archegonium wall, and the peculiar separation of a portion of the nuclear 
substance reminds one of the formation of a ventral canal cell.—C. R. B. 
Dr. F. NoLu proposes™ the use of the scape of dandelion for demon 
Strating the mechanics of tendril coiling. By cutting out from the scape # 
long strip not much wider than thick, and, after fastening the two ends Vd 
that they cannot rotate, immersing the preparation in water, the inner tissues 
elongate so greatly that the strip is thrown into a spiral coil with one or more 
points of reversal, thus imitating very closely a huge tendril.—C. R. B. 
ACCORDING to Palladine,*3 though light is not requisite for the regenerate 
of proteids, if cane sugar is supplied to the etiolated leaves of Vicia 
under experimental conditions, the regeneration goes on more €n 
in light than in darkness, and for this the more refrangible light is ¥ 
efficient. Such leaves cultivated on cane sugar solution in light respire more 
than twice as actively as when kept in darkness.—C. R. B. 
. Dr. Oscar Loew brings together a useful summary of the pit 
knowledge of the physiological réle of mineral salts.™ Unfortunately 
Sreater part of the earlier experimentation in this direction has been more 
lees misguided, and one must hold very loosely the conc 
This summary, however, will be useful as a guide to the liter 
subject.—C, R. B, 
ergetically 
s the more 
» Bot. Cent. 82: 161-168, 194-200. 1900. 
*Inaug. Diss. Freiburg. 1899. See Bot. Cent. 81 : 366. 190 
™ Flora 86 : 388. 1899. 73 Revue gén. de Bot. 11:8 
O.: “The physiological réle of neineral nari een 
EW 
Dept. Agric., Division of Veg. Physiol. and Path. 8vo, pp. 60. 
Printing Office, 1899. 
0. 
1-105. 1899: 
