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S 
1904 | CURRENT LITERATURE 157 
WITMER STONE % has published the results of his study of racial varia- 
tion among the violets, and in connection with a general discussion of the 
subject has published a synopsis of the violets of Philadelphia and vicinity. 
eM. © 
L. M. UNDERWoOD* has published synopses of the genera of fertis known 
to exist in the Philippines, and states that the fern flora of these islands as 
known today embraces over 600 species, and that probably exploration will 
yield half as many more.—J. M. C 
TSCHIRCH with the assistance of Herr Gerdts, has examined the anthers 
of a number of Compositae and finds that their union (about which state- 
ments vary from coalescence to mere adhesion) is dependent wholly upon the 
cuticle of adjoining anthers, which is adherent, often freeing itself completely 
B. 
from the epidermis that produced it.5— 
P. GuERIN © has called attention to the strong development of antipodal 
tissue in certain species of Gentiana. This exprésses itself in the increased 
number and size of the cells; and in the extreme case, as in G. campestris, 
the antipodals form a layer of tissue almost completely lining the embryo 
sac. Such tissue is resorbed upon the formation of endosperm.—J. M. C, 
Aso adduces” objections to the view of Kastle and Loevenhart” that 
oxidases are merely “peroxids formed when autoxidizable substances come 
in contact with air, and these peroxids give up a part of their oxygen to other 
less oxidizable substances present in the cell.’ He also has discovered in 
plants traces of nitrites, which seem to be formed by oxidation of ammonium 
salts.—C. R. B 
Mr. and Mrs. WEEVERS find that caffein, which has already as shown 
by Clautfiau and by Suzuki to be probably a decomposition product of pro- 
teids, is not a waste product, but can be utilized in metabolism, as indicated 
by its gradual disappearance from young parts as they develop. From tea 
leaves caffein ee cae only as the leaves become aged and yellowed before 
falling.79 
3S TONE, WITMER, Racial variation in plants and animals, with special reference 
to the violets of ae and vicinity. Proc. Phil. Acad. 1903 : 656-699. 
woop, L. M., mmary of our present knowledge of the ferns of the 
hee ane ‘Por my aa 30: 665-684. 1903. 
15 TSCHIRCH, A., Sind die Antheren der Kompositen verwachsen oder verklebt ? 
Flora 93:51-55. pl. 2. 1904. 
6GUERIN, P., Sur le sac embryonnaire et en particulier sur les antipodes des 
gentianes. Jour. Botanique 17: 101-108. fig. 9. 1903- 
17 Aso, K., On the chemical nature of oxidases. Bull, Agric. Coll. Tokyo Imp. 
Univ. 5: 481-489. 1903. 
18 Amer. ene Journal 26: 539-566. I90l. 
19 WEEVERS, TH., and Mrs. C. J. — DE GRAFF, Investigations of some xanthine 
derivatives in connection with the internal mutation [metabolism] of plants. Proc. 
Konink]. Akad. Wetens. Amsterdam 1903 : 203-208 (meeting of Sept. 26). 
