476 BOTANICAL GAZETTE [DECEMBER 
have the spiral arrangement. The leaf traces arise in the cortex, between the 
cotyledonary bundles, and there are three for each leaf. Girdling is acquired 
early. There is no clearly differentiated root structure in the embryo. 
The manner of germinating is the same as that described for other cycads. 
The tardily appearing root is tuberized by the activity of a zone of cambium which 
appears immediately within the endodermis, and proliferates to such an extent 
that the components of the root cylinder are displaced and the cortex is exfoliated. 
The root cylinder may be diarch, triarch, or tetrarch, and reduces toward the tip. 
In its lower part all the tissues are well differentiated, even the endodermis and 
pericycle. The stems of young seedlings have no secondary wood, the cylinder 
being composed entirely of endarch leaf traces, which become mesarch farther 
out in the leaf. The pith of this siphonostelic stem sometimes contains a few 
isolated vessels. Contrary to the usual custom of looking upon these vessels 
as remnants of the embryonal protostele, the author prefers to regard them as 
vestiges of ancestral structure. 
Marre corroborates the discoveries made by Lanp and the reviewer that the 
cotyledonary node of Zamia is of the usual cycad type, that there is a tendency 
to lobing at the tips of some of the cotyledons, and that there is an irregularly 
arranged cortical cambium, though he describes the last as vaguely cambiform, 
and does not attribute to it any phylogenetic significance. 
The microphotographs are a retrogression from the clear and beautiful draw- 
ings of the earlier papers—HeLEn A. DorETY. 
Temporary anaerobiosis.—NaBoxIcu has published from time to time in the 
past ten years short papers upon the behavior of plants under anaerobic conditions; 
now he gives us a monograph on the temporary anaerobiosis of higher plants.>* 
There is an elaborate consideration (45 pp.) of the previous work, practically all 
of which is decidedly adverse to his views. Then follows the experimental part, 
showing how anaerobic growth is recognizable and presenting the results of an 
analysis of its physiological characteristics, its periodicity, dependence on temper 
ature, réle of sugar and alcohol, energetics, and cell division. 
NABOKICH reports two categories of physiological facts which are not clearly 
consonant. On the one hand, anaerobic growth seems to be identical with 
aerobic as to the grand period, geotropic response, and cell division (including 
karyokinesis). On the other hand, there are peculiarities of anaerobic growth, 
such as the course of its curve at different periods (though: this can be paralleled 
in aerobic growth under proper conditions), its specific dependence upon tempera 
ture and sugar solutions, and the invariable death of the cells. Though NABo- 
kiIcH holds that his experiments have fully established his fundamental assump- 
tion of the capacity of higher plants for anaerobic growth, he confesses that he has 
not succeeded in obtaining an amount of growth beyond the limits of possible for- 
3 Nasoxicu, A. J., Temporare Anaerobiose héherer Pflanzen. Landw. Jahrb. 
38:51-194. pls. I, 2. figs. 2. 1909. 
