1906] CURRENT LITERATURE 399 
Scion and stock.—By grafting Nicotiana Tabacum on N. affinis (which 
contains little or no nicotin), and N. affinis on N. Tabacum, GRare and Lins- 
BAUER have succeeded in showing,'* in a more convincing way than before, 
the effect of the scion on the stock in respect to products of metabolism. Nicotin 
was found abundantly in N. affimis, whether it was functioning as stock or scion. 
Indeed, it attained almost the maximum amount found in N. Tabacum and 
scarcely fell below the limits of variation in that species. When N. Tabacum 
was the stock, and the scion, N. affinis was cut away completely, the new shoots 
produced contained even less nicotin than the N. affinis leaves had; so that the 
authors believe the scion had even increased the capacity of the N. Tabacum 
stock to form this alkaloid. Further researches are in progress.—C. R. B 
Tobacco.—In a long and somewhat controversial paper, excellently illus- 
trated by fallen of various races of tobacco, ees 12 concludes that there 
are four varieties within which may be grouped all the races of commerce. 
Three of these, vv. nap ss. wrisilnada 8 virginica, are the offspring 
of Nicotiana Tabacum, and one owes its origin to hybridization between N. 
Tabacum and an unknown ai of Nicotiana. eg ANASTASIA is desirous of 
securing seeds of certain races cultivated in the U.S. We bespeak the co- 
Operation of those living in tobacco-raising sections. He may be addressed at 
the Experiment Station, Scafati, Salerno, Italy.—C. R. B. 
Phototropism.—Further proof that the epidermal cells of phototropic leaves 
act as lenses, thus enabling them to function as receptive organs for adjustments 
fo light, is adduced by HaBerLanpt*3. On covering young leaves of Begonia 
Semperflorens with a layer of water, held in place by thin mica, he found no response 
to oo light, though control leaves had attained the usual transverse posture, 
the water-covered leaves gained it, though not perfectly, after removal of 
a oust of water.—C. R. B. 
MOND 
Nicos G , V., and Linssaver, K., Uber die wechselseitige Beeinflussung 
icottana Tsbasins und WN. afinis bei der Pfropfung. Ber. Deutsch. Bot. Gesells. 
1906. 
1 ANASTASIA o, Le variet& typiche — Nicotiana Tabacum L. R. 
Istituto Sperimentale Tabacchi in Scafati. Ministero delle Finanze. Imp. 8vo. 
PP. 122. figs. and plates 31. 1906 
LANDT, G., Ein experinientelie Beweis fiir die Bedeutung der papillosen 
Laubblatepiderms als Lichtsinnesorgan. ge . Deutsch, Bot. Gesells. 24:361-6. 
13 
] *4 BREAZE EALE, ne F., The relation of sodium oO potassium in soil and solution 
Sutures. Journ. Amer. Chem. Soc. 37: pages 1906. 
