60 BOTANICAL GAZETTE [JANUARY 
almost immediately divides, so that there are four or five nuclei in the 
endosperm when the fusion of sex-cells takes place. As the endosperm 
develops the starch disappears. The pollen tube contains starch as it passes 
through the style, but not at the time of fertilization. The author claims 
that the state of the reserves forms a basis for determining the functions of 
the various cells of the embryo sac, and concludes that the antipodals nour- 
ish the sac before fertilization, the synergids give nutrition to the nucleus of 
the pollen tube and the nucleus of the oospore at the time of its formation, 
and the polar nuclei nourish the egg and give rise to the endosperm. 
The ovules of the Mesembrianthemacez and Crassulacee showed the 
same starch reserve. Many other forms were studied, both in monocotyls 
and dicotyls, and the author’s conclusion is that all fleshy plants have starch 
in the embryo sac. Some non-fleshy plants exhibit in a feeble degree this 
character, which is general for fleshy plants. The author thinks that there 
is some connection between the starch reserve and the slowness of the phe- 
nomena which precede fertilization.—C. J. 
Mr. D. T. MacDouGaL* has been investigating the relation of the growth 
of foliage leaves and the chlorophyll function. The main purpose of the 
investigations was to determine the extent to which leaves are dependent 
upon food supplies constructed within their own tissues, and to what extent 
development may proceed at the expense of food stored in neighboring or 
organically connected members. The species used in his work were Arz- 
sema Sampo Calla palustris, Flibiscus Rosa-sinensis, Isopyrum biternatum, 
Justicia sp., Lilium tigrinum, Oxalis floribunda, O vespertilionis, Phenix 
dactylifera, Trillium erectum, T. erythrocarpum, and Zea Mays. In general, 
they were all studied as to the effect of an atmosphere free from CO;, and 
the effect of darkness. It was made evident that the leaves of different 
species exhibit individual reactions to an atmosphere free from CO,. The 
author divides the existence of a leaf into three periods, viz.,(1) from the 
rudimentary condition to the unfolding of the lamina, (2) ie unfolding and 
expansion of the lamina to such an extent as to attain a normal stature, and 
(3) the existence of the organ after maturity has been reached. During the — 
first period the leaves develop without regard to the amount of CO, in the 
air. During the second period the greatest amount of divergence occurs, the 
leaves of some plants perishing quickly in an atmosphere free from COz, 
others developing more or less completely before perishing, others attaining 
a size less than normal and then continuing to lead a healthy life, and others 
developing in a normal way, The behavior of leaves in an atmosphere free 
from CO, and in darkness exhibits the greatest divergences. Thus, leaves — 
of Mimosa and Phaseolus pit attain normal oe te } darkness but quickly 
perish in air Sree from CO2, wh le in Isopy and ¢ ; exactly the reverse 
es 
