70 BOTANICAL GAZETTE [ JANUARY 
than the rain is to be regarded as the realcause. ‘The rain of itself produces 
injury, not mechanical but of a secondary nature; the fall of leaves several 
hours after a rain may be regarded as due to the fact that the organic 
separation of the leaf from the tree is hastened by the increased turgescence 
caused by the rain.-—H. C. C. 
A RECENT PAPER by Kny“ confirms the earlier work of Boussingault and 
Jodin, in affirming a close dependence of the chlorophyll function upon the 
living plastid and the cytoplasm. The author used as test fluids various blue 
solutions which had been decolorized with sodium hydrosulfite. Any free 
oxygen which might be present was driven off by heating, and the liquid 
again decolorized. This precaution had apparently been neglected by 
Regnard, who had employed similar methods. Engelmann’s bacteria test 
was also used, this being a very delicate indicator of the presence of oxygel. 
In studying chlorophyll separated from its living matrix, its solution in 
olive oil, or dried into absorbent paper, was used, also portions of plants 
killed by scalding or drying. All the tests agreed in finding no oxygen 
liberated during isolation. The results of experiments upon living chloro- 
plastids removed from cytoplasm do not agree with those obtained by 
Engelmann, Haberlandt, and Pfeffer. Plastids from plants liberated oxyg@ 
in no case except where cytoplasm was adhering to them. i 
Certain external influences were next applied in order to note their com 
parative effects upon the cytoplasm and chlorophyll function. Plasmolysis did 
phore before the chlorophyll function was checked. The same thing: 
observed when weak solutions of ammonia and of nitric acid were appll® 
The general conclusion from these experiments is that the injury tol 
chlorophyll function does not proceed parallel to that of the cytoplasm ® 
nucleus.-W. D. M 
“Die Abhingigkeit der Chlorophylfunction von dem Chromatophoren und v0 
Cytoplasma. Ber. d. deutsch. bot. Gesells. 15 : 388-403. 1897. 
