624 EXPEKIMENT STATION RECORD. 



Hybridization of wild plants, D. T. MacDougal (Bot. Gas., JfS (1907), No. 

 1, PI). .'fJ-58, flfjfi. 4). — The author discusses the hybrid origiu of a number of 

 so-called natural hybrids that exist wild, and In some instances he thinks the 

 evidence favors such hybridity. The various conditions under which hybrids 

 can be formed are deseril)od, and a list Is given of natural hybrids that have 

 boiMi reported as occurring in the indigenous flora of North America. 



The action of ozone on germination, 11. Micheels and P. De Meen (Acad. 

 Roll. BcJf)., Bui CI. Hci., 1!H)6, No. 6, pp. S6',-SG1, pU. 2).— The general interest 

 in the physiological action of ozone, due not only to the radio-activity and other 

 properties of the gas, but also on account of its frecpient production in the air. 

 led the authors to study its effect on the germination of wheat. A specially 

 devised apparatus was constructed to cut off the effects of static electricity, 

 and after a preliminary soaking for 24 hours in tap water the seeds were placed 

 to germinate, checks being maintained without ozone. In every instance the 

 ozone had an injurious effect as shown not only in a decreased nuujber of 

 germinations, but also in a marked diminution in the weight and size of the 

 seedlings. 



The stimulating action of manganese on germination, II. Micheels and 

 P. I)E riEEN (Acad. Roy. Bchj., Bill. CI. HcL, 1906, No. .5, pp. 2SS, 2cS\9).— Various 

 investigators having shown the stimulating effect of manganese sulphate on rice 

 (E. S. R., 16, pp. 42, 43) and on oats (E. S. R.. 17, p. 954), the authors carried 

 on experiments to d'^termine the effect of a colloidal solution of manganese on 

 the germination of wheat, comparisons being made with a colloidal solution 

 of tin. 



In other experiments of the authors « a colloidal solution of tin was found to 

 stinuilate the gcrminaticjn of peas and wheat. Not only was a gi'eater percent- 

 age of germination oljtained, Imt there was a decided increase in the weiglit of 

 the seedlings and tlie length of the root development. In tlie experiments with 

 the colloidal solution of manganese even more marked stimulating effects were 

 observed. These colloidal solutions are believed to act ui)on the reserve mate- 

 rial of the seed, having a sort of diastatic role. 



Tlie effect of different solar radiations on the nitrogen content of wheat, 

 J. DUMONT (Coiiipt. Rend. Acad. Hci. [Parish, l.'i3 {1901)). No. 2(!. pp. 1179- 

 1181) — In continuation of previous experiments (E. S. R., 17. p. 1141")), the 

 author has studied the effect of different colored screens on the nitrogenous ma- 

 terial in wheat. 



In the experiments reported equal areas of wheat in full flower were covered 

 with frames containing different colored glass, and the effect of the different 

 radiations on the total yield of straw, chaff", and grain, as well as the difference 

 in tlie nitrogen content, was noted. Comparisons were made with equal areas of 

 wheat grown in the open air and under frames containing clear glass. 



The total yields per square meter of straw, chaff, and grain for the different 

 lots were as follows : Open air 666 gm., under clear glass 670 gm., black, or 

 where all the visible spectra were cut off, 846 gin., green 856 gm., red 912 gm.„ 

 and blue 952 gm. 



The nitrogen, albuminoids, and gluten were determined. There was found to 

 be a progressive increase in the amount of nitrogen tlirough the clear, red, and 

 green glass to the blue, after which there was a falling off" toward the other end 

 of the spectrum. An examination of the figures i)resented shows that there is 

 a decided influence on the nitrogen content of the plant on the part of the more 

 refrangible rays of the spectrum. By reducing the amount of nitrogenous mate- 



^ Acad, Roy. Belg., Bub CI, gcb, 1905, No. 7, pp. 310-318. 



