232 BOTANICAL GAZETTE [SEPTEMBER 
Photosynthesis by carotin.—Kount?3 shows by new experiments that the 
secondary maximum in the curve of photosynthesis, as drawn by ENGELMANN, 
is due to carotin. He eliminates the possible error in this determination (made 
by an improvement of the bacterial method), showing that the bacteria are in no- 
wise affected by the F-rays alone. But when algae are illuminated only by rays 
absorbed by carotin, the movement of the bacteria begins, indicating evolution 
of O.. He also shows that though O, is necessary to the formation of chlorophyll, 
in excess, since they can use the O, set free in photosynthesis. Of etiolin Koxt 
can find no trace, and he holds it certain that neither carotin nor xanthophyll 
(the latter probably a transformation product of the former) can be antecedents 
of chlorophyll. Whatever gives rise to it is probably colorless.—C. R. B. 
less and less toxic as it approaches the flowering period and finally becomes 
entirely harmless. The toxic principle has not yet been determined for these 
species, but is probably delphinine and some other related alkaloids. Other 
poisonous plants mentioned are species of Zygadenus, Cicuta, Lupinus, and 
Hymenoxys. The last plant is not strictly poisonous, but forms after being 
eaten a rubbery mass that may prove injurious. The bulletin contains a use 
bibliography of the literature of plants poisonous to cattle on the range-~™ 
Meap WILCox. 
Ecology in the Philippines.—It is a matter of no small interest to pee 
the first extended ecological study of a region of the Philippines. WHITFORD $ 
account of the vegetation of the Lamao forest reserve introduces us to 4 tropical 
region, where the details of plant ecology are new and fascinating, and . — 
the problems must be peculiarly complex. The Lamao forest reserve 15 7 ef, 
province of Bataan (Luzon), on the east slope of a group of volcanic peaks know® 
as Mount Mariveles. After the introductory statements as to geology and ar 
ography, climate, and soil, the vegetation is discussed at length under six soso 
tions: Strand, Bambusa-Parkia, Anisoptera-Strombosia, Dipterocarpus-Shore® 
Shorea-Plectronia, and Eugenia-Vaccinium. The half-tone plates are numerous 
and present most interesting views of tropical vegetation.—J. M. C 
t. 
23 Kont, F. G., Die assimilatorische Funktion des Karotins. Ber. Deutsch. Bo 
Gesells. 24:222-229. 1906. S 
ta. 
s , 24GLover, G. H., Larkspur and other poisonous plants. Bull. Col. Exp- 
113:1-24. pls. 1-8. 1906. 
5 WuITForD, H. N., The vegetation of the Lamao forest 
2 reserve- Philippiné 
Jour. Sci. 1:373-431, 637-679. map and pls. 1-45. 1906. 
