1908] CURRENT LITERATURE 389 
MINOR NOTICES 
Botany and Pharmacognosy.—A third edition of KRAEMER’s Textbook? has 
appeared with great promptness after the publication of the second.s The 
changes made have to do chiefly with the illustrations, fifty unsatisfactory half- 
tones being replaced by line drawings, and several new illustrations being intro- 
duced, especially of solanaceous drugs and plants.—J. M. C. 
NOTES FOR STUDENTS 
Chlorophyll and assimilation.—LupimENKO, who has been devoting his 
attention to the influence of light upon various processes, has endeavored to 
solve these questions: Is the intensity most favorable for the decomposition of 
HCO, likewise the most favorable for the production of dry matter? What 
is the optimum illumination which will produce the most dry matter in different 
gteen plants? How is this optimum related to the various quantity of chlorophyll 
quantitative variations in chlorophyll due to illumination and temperature are 
Smaller than in the latter, which also for the production of a maximum quantity 
Tequire a more feeble light than the former. In general the maximum of Pig 
ment corresponds to a light sensibly weaker than that required for a maximal 
Production of dry matter. From which it would appear that light, as inferred 
for other reasons, has a special action in the formation of chlorophyll. : 
The production of dry matter increases with the light absorbed, up to a maxi- 
Mum, then diminishes. This optimal light is constant with the same species at 
‘onstant temperature, but diminishes as the latter increases. [This indicates 
that the energy optimum is a constant.] The optimal intensity for the produc- 
“on of dry matter varies according to the quantity of chlorophyll, in petaaserns 
as the pigment diminishes, and vice versa. In nature the maximal production 
Plants poor in chlorophyll corresponds to the normal daylight, but in those 
Ear err 
* KRarMER, Henry, A textbook of botany and pharmacognosy. Third edition. 
Pp. Vili+ 850, figs. 328. Philadelphia and London: J. B. Lippincott Co, 1908. 
$ Reviewed in Bor. Gazette 46:231. 1908. : j 
*LusmwenKo, W., Production de la substance séche et de la chlorophylle 
is végétaux supérieures aux différents intensités lumineuses. Ann. Sci. N . 
73321415. 1908, 
