314 BOTANICAL GAZETTE [ark 
of evergreen trees of Japan in winter. He found that the broad-leaved trees 
used in his experiments transpired per day 16.58"™ per 1008 of fresh weight, 
and conifers 8.18%. The time of minimum transpiration agrees with that of 
minimum temperature, —5.9° C., and occurs at the end of January. These 
experiments, taken with those of Miyake," who has shown that photosynthe- 
sis takes place without intermission in winter, seem to indicate that the 
abundance of evergreén trees in Japan is chiefly due to the favorable climate. 
The Puget sound region has a climate much like that of Japan, which may 
account for its great coniferous forests also.— H. N. WHITFORD. : 
STARCH FORMATION in Hydrodictyon is described by T 
There is no sharply differentiated chromatophore in this alga, the pers" 
being distributed seta through the protoplasm between the plasma mem- 
brane and vacuolar membrane. The numerous pyrenoids are the centers of - 
starch formation. , Piindaas of the pyrenoids are cut off and changed directly : 
into starch grains which lié in the surrounding protoplasm, arranged in such 
a manner as to show clearly their relation to the mother pyrenoid. List 
pyrenoid is then an active body contributing its substance to the starch 
grain. Kleb’s distinction between pyrenoid and stroma starch in acl 
tyon is not justified, for the latter are only older grains pushed away from f : 
__ pyrenoids by the formation of younger starch. This study su 5 
si B ~— 
_ing comparisons of other algal types with and without pyrenoids—B. 
Davis 
. AN ACCOUNT OF FERTILIZATION in another species of Pythium has 
appeared since the recent paper of Trow (Annals of Botany, Je 
Miyake has investigated Pythium Debaryanum, and his results are 
- the Same as those of Trow for Pythium ultimum. There is a mitosis 1? ™ 
_ Oogonium and antheridium, the spindle being intranuclear as in ae 
Ss The contents of the oogonium becomes differentiated nto 2 
the ooplasm from the periphery and becomes the functional female - 
_ those in the periplasm finally degenerating. There is n° coenoce he are 
single male nucleus is discharged into the oogonium together with 
_ part of the contents of the antheridium. Fusion of the sexual | nuclei 
_ Shortly. The investigation gives no data on the number of chrot 
; : the various phases of the life-history.— B. M. Davis. 2 
Nor tone ago reference was made to the rather striking ex] 
- 
-™ Bot. Centralb. 80: 172. . 
: 5 TIMBERLAKE, H. G., Starch formation in aoe " : : oe 
Somes 15: ee ge 1901. | “Annas of B 
oe K., The fertilization of os Debaryanum oe 
£5655 607 i ae o 
