ISO EXPERIMENT STATION RECORD. 



doors, cutting across the stems iu the iuteruodes, etc. lu rearlj' every iustance 

 the stem was cut off at the next or some lower node by the formation of an 

 absciss-layer. 



The survival of plant tissues after freezing, W. Russell (Compt. Rend. 

 Acad. Sci. IParis], 158 (1914), No. 7, pp. 50S-510).—ln a study of the effect of 

 freezing on a number of plants, the author found that while after thawing the 

 plants might show a wilted condition the ultimate death of the plant might 

 be delaj-ed for several days and even weeks. He claims that where thickened 

 secondary tissues were present among thin-walled parenchyma cells the former 

 were very slow iu showing the effect of freezing. He concludes that the death 

 of a plant from freezing is rarely immediate, but that it is delayed in propor- 

 tion to the uninjured elements, the destruction proceeding with more or less 

 rapidity from cell to cell. 



The frost problem up to date, C. Frazer (Country Gent., 79 (1914), No. 8, 

 pp. 360, 392, fig. 1). — This is a brief statement of two recent theories of frost 

 injury to fruit, and of selected results of experiments and observations sup- 

 porting the conclusion that both the duration of the frozen state and the rate 

 of defrosting are important in determining the effect of cold on the fruit. It 

 is held that even if orchard heating has been delayed until after a freezing 

 temperature has been reached, there may be time to save the fruit. Tabular 

 results of studies on resistance of various fruits at different stages are quoted. 



Can selection improve the quality of a pure strain of plants? C. and. A. 

 Hagedoorn {Jour. Bd. Agr. [London], 20 (1914), No. 10, pp. 857-860, pi. 1).— 

 As bearing upon the common belief that unselected seed automatically deteri- 

 orates, the author cites the results of selective breeding of wheat carried on 

 by L. de Vilmorin and descendants since about 1850, showing reproductions of 

 photographs of a dozen specimen ears of the present generation side by side 

 with those of the original parents. The long-continued selection has produced 

 no apparent change, thus supporting experimentally the statement that in a 

 strain once pure of a self-fertilized plant, no amount of selection can produce 

 amelioration or deterioration, as is possible with habitually cross-fertilized 

 plants. 



Coloration of the seed coat of cowpeas, A. Mann ( U. S. Dept. Agr., Jour. 

 Agr. Research, 2 (1914), No. 1, pp. 33-56, pi. 1, figs. 2).— This is a detailed 

 account of an investigation previously noted (E. S. R., 27, p. 632), in which a 

 study was made of the seed coats of various cultivated cowpeas to determine 

 whether the diversity in the color scheme and kinds of jiigments in the seeds 

 have a direct bearing on the problem of heredity. 



On the appearance of sterile " dwarfs " in Humulus lupulus, E. S. Salmon 

 (Jour. Genetics, 3 (1914), A^o. 3, pp. 195-200, i)ls. 2).— The author reports the 

 occuri'ence, in a large number of crosses made between similar varieties of hops 

 and various individual male hops, of certain individuals which are character- 

 ized by their total or almost total inability to climb and their complete sterility, 

 no flowers being produced. 



FIELD CROPS. 



A table for estimating the probable significance of statistical constants, 

 R. Pearl and J. R. Miner (Maine Sta. Bui. 226 (1914), pp. S.5-SS).— This paper 

 discusses the significance usually put upon the probable error in any given 

 case by biometric workers and points to errors in such considerations. A 

 table is presented, designed to be useful to statistical workers, which sets 

 forth, for a series of ratios between a statistical deviation and the " pi'obable 

 error " of the error distribution, first, the probability that a deviation as great 



