520 BOTANICAL GAZETTE [june 



Statolith starch. — Miss Zollikofer'* finds that the statolith starch of 

 seedhng organs is relatively readily removed by periods of illumination fol- 

 lowed by periods of darkness. The persistence of the statolith starch is a 

 function of the degree of etiolation. This the writer considers a biological 

 adaptation. By growing seedlings of Tagetes erecla and seedlings of other 

 Compositae in light 1-4 days, followed by 3-4 days of darkness, hypocotyls 

 were obtained that bore no statolith starch. These hypocotyls were still 

 growing and capable of phototropic movement, but incapable of geotropic 

 movement. Light rendered them geo-sensitive only after it had produced 

 statolith starch. Working by similar methods the author shows a close rela- 

 tion between the amount of mobile starch and geo-sensitivity in the coleoptile 

 of grasses. — Wm. Crocker. 



Fat storage in evergreen leaves. — A number of investigators have stated 

 that there is considerable storage of fats in evergreen leaves during the winter. 

 Meyer'' finds that the droplets that were supposed by these former workers 

 to be fat droplets are not fat, and that the total volume of these does not rise 

 and fall with winter and summer, but that it increases continuously with the 

 age of the leaf. He speaks of the droplets as "mesophyllsekret," and points 

 out that little is known of their origin and composition. Some of the forms 

 studied were Ilex aqiiifolium, Taxus baccata, and Vinca minor. The methods 

 used by Meyer, as well as by former workers, are exclusively microchemical. 

 It is evident that these ought to be checked up by quantitative determina- 

 tions. — Wm. Crocker. 



Light and germination. — Lehmann'* finds in a germinator at 30° C. o. i 

 second illumination with 730 H.K. is sufficient to cause 50 per cent of the 

 seeds of Lythrum Salicaria to germinate within 24 hours, whereas only 6-7 

 per cent germinate in similar condition in darkness, and not more than 7 per 

 cent after 10 days. — Wm. Crocker. 



Osmotic pressure of epiphytes. — Harris"' finds that the epiphytes ^Bro- 

 mehaceae, Orchidaceae, and Peperomia) of the Jamaican montane forest 

 have 37-60 per cent of the osmotic pressure shown by the herbaceous terrestrial 

 vegetation of the same region, and 28-45 P^r cent of that of the ligneous 

 terrestrial vegetation. — Wm. Crocker. 



'fi ZoLLiKOFER, Clara, tjber das geotropische Verhalten entstarkter Keimpflanzen 

 und den Abbau der Starke in Gramineen-koleoptilen. Bar. Deutsch. Bot. Gesells. 

 36:30-38. 1918. 



'7 Meyer, Arthur, T)ie angebliche Fettspeicherung immergruner Laubblatter. 

 Ber. Deutsch. Bot. Gesells. 36:5-10. 1918. 



'* Lehmann, Ernst, tJber die minimal Belichtungszeit welche die Keimung der 

 Samen von Lythrum Salicaria. Ber. Deutsch. Bot. Gesells. 36:157-163. 1918. 



'9 Harris, J. Arthltr, On the osmotic concentration of the tissue fluids of phanero- 

 gamic epiphytes. Amer. Jour. Bot. 5:490-506. 1918. 



