330 BOTANICAL GAZETTE [OCTOBER 
She finds no conclusive evidence for or against the view that the tropic and 
growth stimuli of gravity in this organ are distinct. Her work makes it evi- 
dent that the lack of growth in the older nodes with the stem vertical is due 
both to the lack of the stimulating transverse action of gravity, and to the 
presence of the inhibiting longitudinal action. Thus we see these responses 
to stimuli becoming more and more complex. One wonders whether a study — 
of changes, acid and otherwise, induced in the tissues of the nodes by these 
various exposures might not simplify the matter. Such, I believe, is the 
possibility of real progress in this field.—WILLIAM CROCKER. 
Phylogenetic significance of endosperm. 
endosperm, and also endosperm beginning its development with a free nuclear 
period and later passing into a cellular condition, have been known since the 
days of HorMEIsTeR; and since that time various modifications and peculiari- 
ties have been described, some of them characterizing genera or families or 
even orders; while others seem to be confined to species. Whether the char- 
acter of the endosperm has any phylogenetic significance or not, is a question 
which has often been discussed and often answered, both in the affirmative and 
in the negative. 
The most recent discussion’s is also the most comprehensive. It is a study 
of the literature rather than a laboratory investigation. For all the orders of 
Dicotyledons and Monocotyledons, . literature dealing with the endosperm 
has been assembled and discussed and charts have been made, so that it is 
possible to see at a glance just what ihe endosperm and haustorium conditions 
are in any order. In this bird’s-eye view, the names of the principal investi- 
gators are given and full citations appear in an extensive bibliography. After 
describing the endosperm and haustorium situation in each order, 0 often 
treating the families separately, sometimes the genera, and occasionally the 
species, the author adds a long summary dealing with orders. Both in the 
introduction and in the conclusion it is very plainly stated that the endo- 
sperm character is only one factor among many, but nevertheless endosperm 
and haustoria characters have great phylogenetic significance —CHARLES J. 
CHAMBERLAIN. 
Temperature and photo-perceptions.—In studying the influence of tem- 
perature upon phototropism in the coleoptile of Avena sativa, Miss DeVries 
has determined the influence of temperature upon the rate of photo-perception 
and photo-reaction and the influence of previous heating upon the rate of 
these processes. She finds that van’t Hoff’s law of rate of chemical reaction 
*s JACOBSSON-STIASNY, EMMA, Versuch einer phylogenetischen Verwertung det 
Sitz 
Endosperm- und Haustrsialblidung bei den Angiospermen. ungeb. Kaiserl. 
Akad. Wiss. Wien 123:1-1 si 4 
6DeVries, M. S., r Einfluss der aes ra den Phototropismus. 
Extrait du Rec. Trav. Bot. unis I1:195-201. figs. 7. 
