320 ' BOTANICAL GAZETTE [ocTOBER 
ently does not belong to that genus at all, since it is without the very striking 
internal transfusion sheath of the lower cretaceous genus, has a double 
instead of a single foliar bundle (a point of great importance, as will be recog- 
nized by those versed in the anatomy of Pinus in its living species), and no 
centripetal xylem. The authors make light of the absence of the last feature, 
but in this they are apparently not well advised.—E. C. JEFFREY. 
Conduction of stimulus.—RoTHERT has shown that the conduction of 
stimulus of unilateral illumination from the tip of the Avena seedling to the 
darkened basal portion occurs when the vascular strands are cut; and that a 
horizontal incision on one side, whether toward, away, or on the flank in ref- 
erence to the one-sided illumination, still permits conduction. Frrrmnc showed 
that when the incision was away from the light and a mica plate inserted, no 
conduction occurred. The insertion of a slice of rattan in the same position did 
not prevent conduction; the latter of course allows the continuity of water and 
solution. When the mica plate was inserted in an incision on the lighted side, 
conduction was not hindered. JENSEN" finds that with the incision away from 
the light, no conduction occurs in dry air or in water. He assumes that 
under favorable conditions the stimulus can be conducted across the wound 
while under unfavorable conditions it cannot. In saturated air the stimulus 
was also conducted from the tip to the darkened base, even after the tip (1 cm. 
long) had been entirely cut off and set back and fastened by gelatin and cocoa 
butter.—WILLIAM CROCKER. ; 
Embryo sac of Pandanus.—In 1909 CAMPBELL published an account of - 
the embryo sac of Pandanus, which was reviewed in this journal (47:485, 
1909). In this Javanese material the fertilization stage was not secured, 50 
that it was not certain that the interesting situation described is the one at 
fertilization. Now there has come to hand additional material (P. coronatus) 
which has supplied the missing stage.*5 An ordinary egg apparatus is organ- 
ized, but there occurs “‘a large discoidal mass of cells” at the antipodal end 
of the sac, and fusions of “polar” nuclei (up to six) were observed. Then 
ber of cells in the sac at the fertilization stage would thus seem to be greater 
than that recorded for any other angiosperm. The amount of antipodal tissue 
suggests the situation in Sparganium, the difference being that in the latter 
genus this tissue develops after fertilization.—J. M. C 
» 
kumpflanzen. r. Bot. Gesell. 28:118-120. 
1s CAMPBELL, Doucias H., The embryo sac of Pandanus coronatus. Bull. Torr. 
Bot. Club 24: 293-295. figs. 6. 1910. 
14 JENSEN, P. Boysen, Ueber die Leitung des phototropischen Reizes in Avena- — 
Be gto. 
