474 BOTANICAL GAZETTE , [JUNE 
is two-layered (overlaid by the epidermis), the inner layer differentiating as the 
tapetum; the stalk cell is represented only by a nucleus; the two male cells are 
equal, and occasionally three or four male cells derived from a single body cell were 
observed; four to ten archegonia are included in the single complex; the fusion 
nucleus becomes invested by the starch-filled cytoplasm of the male cell; at the 
first segmentation the male and female chromatin groups are still distinct — 
jl.Meé 
Respiration.—CzAPEK%° gives an excellent summary of all work done on 
respiration of plants up to the present time. It is marked by conciseness and by 
emphasis on important points. One is surprised that the subject can be treated 
so thoroughly within the limits of twenty-five pages. The following topics are 
considered: definition and history, the amount and distribution of aerobic respira- 
tion in plants, physical and chemical factors capable of influencing respiration, 
postmortem carbon dioxid production and oxygen absorption, chemical materials 
of aerobic respiration, and the mechanism of vital oxidation (statement of our 
knowledge of respiratory enzymes). The literature considered involves 126 
citations. 
In discussing the materials used (oxidized) in aerobic respiration, CZAPEK 
mentions sugars and fats as the principal ones; but emphasizes the fact that in 
many bacteria (hydrogen, sulfur, nitrifying, etc.) the simplest inorganic substances 
as a source of energy for carrying on life processes, while in many 
other cases the most complex proteins are split and finally oxidized for the same 
purpose. It is evident that this gives aerobic respiration a broad meaning. 
CzaPEK seems very much inclined to distinguish vital oxidations (vitalen Verbren- 
nungsprozess) from other oxidations. Vital seems to mean more to him than 
merely a term to express the unknown.—WILLIAM CROCKER. 
The fertile spike of Ophioglossaceae.—The nature of the so-called fertile 
spike of the Ophioglossaceae has been a prolific cause of discussion, culminating 
. in the divergent views of Bower and CAMPBELL. CHRYSLERS' has now w attacked 
the problem from the standpoint of vascular anatomy, examining all the genera, 
and has reached some important and apparently convincing conclusions. 
The fertile spike is regarded as representing two fused leaflets or pinnae 
(basal pair) of a fern leaf. The proof is most obvious in Botrychium virginianum, 
in which each one of the pair of vascular bundles that supply the fertile spike 
leaves a gap in the trough-shaped leaf trace. This is sometimes less distinct in 
B. ternatum and B. obliquum, and certain other species show no trace of the gap; 
all of which are taken as indications of reduction. Abnormal specimens also 
confirm the view. The condition in Ophioglossum is considered to be derived 
30 CzaPEK, Fr., Die Atmung der Pflanzen. Ergebnisse der Physiologie 9:587- 
613. Igto. 
3t CuRrysLER, M. A., The nature of ~ — spike in the Ophioglossacea€- 
Annals of Botany act pls. I, 2. figs. 16. 
