Geology and Natural History. BS 
esting article, relating to the movements of chlorophyl grains in 
the cells of leaves i s 
the whole protoplasmic mass; and Frank (in Bot. Zeit.) finds that 
the result of prolonged unilateral illumination is to accumulate the 
grains In the more strongly illuminated side of the cell,—that, like 
hyl 
a: those of Famintzin, Krauss, Prillenx, Boronetsky (Bot. 
eit., 1871, No. 13), and Pfeffer, go to confirm the now well- 
White light decomposes 100 parts of carbonic acid, 
ed and orange “ 32.1 s 
Ow “ce 
Yell 46.1 : 
Green ee 15.0 re 
Blue, indigo, and 
violet ns 7.6 ~ 
.- Curve of assimilation, nearly parallel to the curve of luminous 
Surmpee culminates between the Fraunhofer lines D and E._ 
henomena which result from the absence of light, Krauss 
4 ond normal dimensions. The blade of a leaf, it appears, 
°mpletes its growth after coming into the light solely from the 
waterials which it assimilates (into starch or its equivalent) ; 
Starch stored up in the older tissues is of no use to it. In dark- 
ms cti a 
otk. » and the ligneous and cortical cells, or passive parts, on the 
wg rom an anatomical point of view the etiolated internodes are 
Tistinguishea by presenting all the characters of very young inter- 
