330 EXPERIMENT STATION RECORD. [Vol. 35 



Amphiclinous hybrids, H. de Vbies (Ber. Deut. Bot. Gesell., SS (1915), No. 

 8, pp. 461-468). — The author has found that the crossing of (Enothera lamarck- 

 iana with CE. lamarckiana nanella gives, according to cultural conditions, from 

 to 90 per cent of dwarfs in the progeny. The percentage is usually below 50 

 per cent in the progeny of the first year, but above that figure in that of the 

 second. These figures may be raised by early planting or abundant water 

 supply during the period of root formation. The percentage of dwarfs in the 

 progeny is thus not constant, depending greatly upon cultural conditions. 



Recent mutations of Solanum commersonii, Labeegekie {Rev. Vit., 4S 

 {1915), No. 1117, pp. 406, 407). — An account is given of the sudden appearance 

 in 1914 of two mutants, which are described, in the progeny of two plants of 

 S. commersonii grown for several years in contact with a domestic variety of 

 potato. The phenomena noted are compared with those reported by Planchon 

 (E. S. R., 28, p. 130) and Heckel (E. S. R., 33, p. 222). It is suggested that 

 solar illumination may be a factor in such cases. 



A case of leaf etiolation due to cold, G. Gassneb (Ber. Deut. Bot. Gesell., 

 33 (1915), No. 8, pp. 478-486, pi. 1). — Studies previously reported by the author, 

 partly in connection with Appel (E. S. R., 19, p. 345), have been followed up 

 with tests of the aftereffects of low temperatures on germinating oats. Plants 

 germinated at from 1 to 2° C, as compared with those sprouted at 5 to 6° or 

 20°, remained pale and backward in growth under favorable conditions of heat 

 and light. 



Experimental production of tuberous growth at the expense of the root 

 in potato, M. Moli.iakd {Compt. Rend. Acad. Sci. [Paris], 161 {1915), No. 18, 

 pp. 531, 532). — The author produced in potato seedlings grown in tightly closed 

 tubes tuberous development containing starch on the lower part of the stem, 

 apparently at the expense of other portions of the plant. These conditions 

 showed marked contrast with those in plants similarly kept, except that air was 

 freely admitted. 



The question of a physiological unity constituted by a leaf with its inter- 

 node, J. KuiJPEB (Kuyper) {Arch. Suikerindus. Nederland. Indie, 23 {1915), 

 No. 34, pp. 1285-1293, fig. 1). — The question regarding a possible physiological 

 unity constituted by the leaf blade, the leaf sheath, and the internode having 

 arisen in the course of previous work (E. S. R., 34, p. 627), the author has 

 investigated different varieties of sugar cane. From this work he has concluded 

 that the view of a purely local physiological influence in case of a given leaf is 

 not supported by the evidence obtained. 



Contributions to the physiology of stomata in Saccharum officinarum, J. 

 KuiJPEU (Kuyper) {Arch. Suikerindus. Nederland. Indie, 23 {1915), No. 44, pp. 

 1673-1700, pi. 1). — Studies previously noted regarding stomatal structure in 

 sugar cane (E. S. R., 34, p. 628) have been followed up with investigations 

 of the influence on stomatal behavior of light, temperature, and humidity. 



It is stated that while direct sunshine is very effective in causing the stomata 

 to open, darkness causes them to close, although in prolonged darkness 

 the stomata sometimes open to a very small but constant degree. In moderate 

 illumination from a clouded sky, the stomata open slowly and slightly as com- 

 pared with the behavior in strong sunshine, sunny mornings appearing to be 

 valuable from the standpoint of cane culture. When temperatures of from 48 

 to 45" C. (109.4 to 113° F.) were produced by the absorption of sunshine by 

 the dark clotli covers the stomata were opened by the heat, but when a shelter 

 was provided the stomata closed normally as in darkness. So far as it was 

 possible to ascertain the influence of air humidity free from complication by 

 other- factors, a high humidity of the air ai)|)(iirs to increase stomatiil opening. 



