7O BOTANICAL GAZETTE [JANUARY 
India, and England, with the result that they show only minor differences 
facts contrary to the usually accepted view. The paper, which is an 
important one, concludes with a complete bibliography.—E. W. BERRY. 
R. G, LEavirr® has accumulated some interesting data in reference to 
what he calls reversionary stages in Drosera intermedia, stages that he has 
experimentally induced. These data support the general statement “(1) 
that reversions, in either an ascending or a descending direction, are some- 
times occasioned in plants by a deficiency of the food materials supplied to 
developing parts; and (2) that reversions in either direction are sometimes 
occasioned by a superabundant food supply in developing parts.”—J. M. C. 
Bai *™ has recently reinvestigated the influence of strains upon the for- 
mation of mechanical tissue. His results do not agree with those of Hegler 
on the same subject, for by a gradual increase in the pull exerted upon young 
stems Ball was able to produce neither an increase in the ability to resist 
mechanical pulling nor any thickening of the tissues. He substantiates the 
results obtained by Wortmann and by Elfving that when a stem is inhibited 
by force from bending geotropically there arises a marked one-sided devel- 
opment of bast fibers and collenchyma on the upper side; and also when an 
organ is prevented by force from bending phototropically there is a notable 
increase in the tissues on the side toward which it would bend. An 
increased thickening was also obtained on the convex side of stems bent over 
mechanically with gravity neutralized by the clinostat.— W. B. MACCALLUM. 
THE DEHISCENCE of sporangia * of gymnosperms is definitely related 
to their form and position, and favors the distribution of the spores. The 
nearly related Picea and Abies differ in the dehiscence of their sporangia, 
the dehiscence in Picea being longitudinal while in Abies it is transverse. 
The upright staminate strobilus of Picea requires a longitudinal dehiscence 
for a thorough discharge of the pollen, while a transverse dehiscence is more 
effective in discharging pollen from the drooping strobilus of Abies. The 
gymmnosperm which has an endothecium. The Cupressineae are not con- 
sidered, because their small, rather spherical sporangia are not so definitely 
oriented as in the other groups.—C, J. CHAMBERLAIN, 
NOEL BERNARD has added further data in the line of his interesting 
*Leavirr, R. G., Reversionary stages in Drosera intermedia. Rhodora'5: 265- 
272. 1903. 
a BALL, O. M., Der Einfluss von Zug auf die Ausbildung von Festigungsgewebe. 
Jahrb. Wiss, Bot. 9: 395-341. pls. 6-7, 1903. 
OEBEL, K., Morphologische und _ biologische Bemerkungen: 13. Ueber die 
Pollenentleerung bei einigen Gymnospermen, Flora gr: 237-263. figs. 19. 1902. 
*3 BERNARD, NOEL, Conditions physiques de la tubérisation chez. les végétaux. 
Compt. Rend. 135 : 706-708. 1902. 
