1917] CURRENT LITERATURE 351 
general prevalence of the trilacunar trace in the seedlings, and the almost 
universal occurrence of a single ring of bundles connected at a very early age 
by cambium. This interfascicular cambium is usually absent in the adult 
stems of the ee anunculaceae, but it is invariably present at some 
stage in the seedling. The evidence of the origin of herbs from woody plants 
is increasing.—J. M. C 
Germination of ascospores.—BRIERLY® has experimented with the ger- 
mination of the ascospores of Onygena equina, a fungus occurring on decom- 
posing horns and hoofs of cattle, sheep, etc. The results showed that “ripe” 
ascospores will germinate directly after a prolonged resting period, and that 
this period may be curtailed or eliminated by treating the spores with arti- 
ficial gastric juice, but not by subjection to low temperatures. “The full- 
grown unripe ascospores and the chlamydospores will germinate immediately 
in the absence of digestive treatment.” —J. M. C 
Respiration.—APPLEMAN® has investigated quantitatively the relation of 
oxidases and catalase to the process of respiration in potatoes. He found that 
there was no correlation between intensity of respiration and oxidase activity, 
but that catalase activity of the extracted juice of the potato shows a close 
correlation with the respiratory activity of the tuber. He considers, therefore, 
that the oxidases are not the controlling factor in respiratory intensity, at 
least in potato tubers, whatever réle they may have in connection with biologi- 
cal oxidations.—Cuaries A. SHULL. 
History of forest ecology.—In a rather extensive review of the literature 
of botany and of forestry investigations, BOERKER* has attempted to trace the 
influence of both upon the development of the new phase of science known as 
forest ecology or silvics. Perhaps the most important part of the paper is-that 
in which he traces the ecological principles which were stated by some of the 
earlier leaders in forestry, but which have received little attention from their 
fellow foresters. Of almost equal importance is the rather extensive bib- 
liography.—Gero. D. FULLER. 
Wandering tapetal nuclei—Prckerr® has described in detail the differ- 
entiation of the tapetum and its subsequent behavior in Arisaema triphyllum 
# Brrerty, Witi1am B., Spore germination in Omygena equina Willd. Ann. 
Botany 31: ja ea 1917. 
® AppLEMAN, CHARLES O., Relation of oxidases and catalase to respiration in 
plants. Amer. Jour. Botany 3:223-233. 1916. 
* Borrxer, R. H., A historical study of forest ecology; its development in the 
fields of botany and forestry. Forestry Quarterly 14:380-432. 1916. 
8 Pickett, F. L., The wandering tapetal nuclei of Arisaema. Amer. Jour. Bot. 
3:461-469. pl. 20. figs. 8. 1916. 
