320 BOTANICAL GAZETTE [APRIL 
nation by birds, its water parasitism, its essentially xerophytic structure, and 
the distortion which it causes in the branches of its host plants. chief 
hosts in the vicinity of Austin, Texas, are the hackberry, elm, mesquite, and 
osage orange. The immunity of certain trees (as the China tree and box 
elder) appears to be due to the character of the external surface and the thick- 
ness of the corky layer.—H. C. Cow Les. 
Statolith theory —NiEMEcC* controverts PEKELHARING’s claim that roots 
respond to the geotropic stimulus after being freed from statolith starch by 
growing in 0.025 per cent potassium alum. Aside from potassium alum, 
NEmEc used aluminum sulphate and chloride and zinc sulphate as destar 
agents. In no case was geotropic response given in absence of statolith starch. 
With such treatments, marked injury always accompanied absence of starch. 
He believes that the statolith ine stands in the face of all suggested evi- 
dence against it—WILLIAM CROCKE 
Cytology of Spongospora.‘*—In the current issue of the Annals of Botany 
two investigators present preliminary accounts of their investigations on 
Spongospora, the organism which causes the powdery or corky scab of the 
potato. Both describe the life history, both note that chromatin at certain 
stages takes the form of chromidia, and both note resemblances to Plasmo- 
diophora, OSBORN suggesting that Spongospora should be placed in the Plas- 
modiophoraceae. —CHARLES J. CHAMBERLAIN. 
Light perception. —HaBERLANDTs answers Wager’s arguments against 
the lens theory of light perception by foliage leaves. In places his —_— 
shows keen retort, though it often lacks any convincing evidence. Such are 
the methods to which one must resort when one defends a questionable though 
favorite hypothesis—WILLIAM CROCKER. 
43NEmec, B., Der — entstarkter Wurzeln. Ber. Deutsch. Bot. 
Gesell. 28: State 1gI 
“ OsBorn, T. G. B., A preliminary note on ve on eee and cytology of Spon 
set ces agiinaneg Wallroth. Annals of Botan wie 
1 iepsccatd note on S rein saad “Brunch. Annals 
bias 4 bes ee II. 
‘s HABERLANDT, G., H. WAGER’s Einwiinde gegen meine Theorie der Lichtper- 
zeption in den Laubblatter. Jahrb. Wiss. Bot. 48:337-390. 19109. 
