930 EXPERIMENT STATION RECORD. 



r;iiliiiiu had in fjciicral a sliimilntin;; cflcct on Lri-owlli. Tlioriiini rays froni 

 a Wt'lsltacli IninuT bad practually tlii' saint' elTt'c-t as ladinni rays. Tbo ex- 

 posure of leaves to radinni tubes resulted in a retardation of starch formation 

 innnediately mider the radium coated rods. Anaerobic respiration was retarded 

 and normal aerobic resiiiration accelerated by radium rays. 'Alcoholic fer- 

 mentation was aceelerattnl when radium tubes were placed in fermenting 

 mixtures, and the buddinjj of yeast cells was considerably increased. 



In experiments on trojiistlc response the author found that neither roots nor 

 shoots si'fm'inj: in air showed the slightest tendency to curvature to or from 

 sealed tubes containing radium of various activities. 



AVliere exposure to radium rays was followed by retardation of growth, 

 histological examination showed a cessation of cell division, an acceleration of 

 tissue differentiation, a decrease in tlie size of cells, and a lack of coordination 

 in histogenesis. 



Experiments with radioactive air indicated that radium acts as a stimulus to 

 protoplasm. Where retardation of growth is observed, it is l)elieved to be an 

 expression of overstiuuilation. Acceleration of gi-owth is held to indicate a 

 stimulation between the minimum and optinnim. 



An extensive bibliography is included in this report. 



Influencing the growth of plants by electricity, M. Breslauer and 

 C. Schmidt (Mitt. Deut. Ijtnthv. (Ic.srU., 2,i (I'JOS). \o. 50, i)i,. .',J,l-U3, fig.t. S; 

 Vmschau, 13 (1909), No. 2, pp. 23-30, figs. 9; Dcut. Landa: Presse, 36 (J90H), 

 No. 90, pp. 943, 9>,-',; al)s. in Mark TAine Exprcxs, 99 (190H), No. J,031, p. 131; 

 Chem. AJ}s., 3 (1909), No. 6, pp. OS^, 685). — These articles discuss experiments 

 by liemstrom and Lodge (E. S. R.. 20, p. 630) and by one of the authors. 

 Breslauer, of the Technical High School of Charlottenburg. They describe an 

 installation similar to that of Lodge's, which was set up on a farm near Berlin 

 with the object of testing the practical character of the method. It is esti- 

 mated that the necessary apparatus may be installed and operated for about 

 S21 per acre annually. 



On wind injury to plants, F. Noll (Sitzlxr. Natiirliist. Ver. Preuss. Rhrin- 

 landc II. Wcstf ulcus, 1901, No. 2, Sect. A, pp. 5S-68, fiy. 1). — A preliminarjk' 

 account is given of some experimental investigations on the effect of prevail- 

 ing winds on plants. 



The formation of red wood in conifers, Jean White (Proc. Roy. Soc. Vic- 

 toria, II. ser., 20 (1907), No. 2, pp. 107-12Ji). — A study was made of a number of 

 species of Australian and other conifers to determine the cause of the formation 

 of red wood, which is sometimes conspicuous in parts of the trunks of these 

 trees. It has been previously suggested that the formation ot rvd wood is due 

 to a morphogenic response to a gravitational stimulus, and the experiments 

 described were conducted with plants so rotated on a klinostat as to remove 

 the action of gravity. 



So far as the author's investigations go, they seem to confirm the theory that 

 the formation of red wood is due to the stimulus of gravity. Where the lesser 

 tliickness shown by the walls of the red wood tracheids was compared with 

 similar tissues in the white wood, the stimulus seemed to be photomorphic, the 

 response being somewhat similar to etiolation in character. 



The distribution and occurrence of races of mistletoe in Bavaria, K. von 

 TuBEUF (Naturw. Ztschr. Forst n. Landto., 6 (1908), No. 12, pp. 561-599, figs. 

 28, map 1). — A study was made on the occurrence and distribution of mistletoe 

 (Viscnm alhnm) in Bavaria. The author claims that there are 3 biological 

 races of this species, one occurring on the pine, a second on firs, and a third on 

 deciduous trees. Among the latter species, much injury is done to the apple, 

 poplar, willow, and maple. 



