530 EXPERIMENT STATION EECORD. 



It was discovered that the ginning percentage was not directly measured by 

 any single one of the characters of volume of seed, specific gravity of seed, 

 number of fibers arising from a single seed, or the weight of the individual 

 fibers. By using the coefficients of correlation between the characters of num- 

 ber of fibers per seed, weight of 1,000 fibers, and volume of seed, it was found 

 that one, the number of fibers per seed, had a marked effect on the value of the 

 ginning percentage. 



Fiber industry of British East Africa, A. Wiggles worth {London: John 

 Bale, Sons d Danielsson, Ltd., 1915, pp. 15, fig. 1).—A paper read at the Third 

 International Congress of Tropical Agriculture, held at London in June, 1914. 

 and giving an account of the methods of production and manufacture of fiber 

 from Sansevieria and sisal. 



The growth and preparation of Italian hemp, A. Wiggles worth (London: 

 [Author], 1914, pp. 39, figs. 18). — This gives methods employed in Italy in the 

 production of hemp and the manufacture of the fiber. 



Investigations on hops.— V, On the aroma of hops, J. Schmidt (Compt. 

 Rend. Lab. Carlsberg, 11 {1915), No. 3, pp. 149-163).— This describes experi- 

 ments in growing and breeding hops in connection with work previously noted 

 (E. S. R., 31 p. 526). The results have been summarized as follows: 



" In exact investigations as to hops, whether of botanical or chemical, prac- 

 tical or scientific nature, the work should be based upon clones, as otherwise 

 the results may be liable to justifiable criticism. 



"Among the hop plants cultivated in the experimental garden of the Carls- 

 berg Laboratory, there were in 1911 two American plants (labeled Oregon 

 Cluster and New York Spaulding English Cluster), the hops of which exhibited 

 a very peculiar turpentine-like aroma, so widely different from that of all 

 European varieties that a single hop could at once be recognized by the smell 

 among hundreds of others. Cultivation experiments made during the years 

 1911, 1912, 1913, and 1914 showed that this aroma remained apparently con- 

 stant in our climate in these two plants and their clones. 



" Crossing experiments made in 1912, 1913, and 1914 with the two American 

 plants and Danish males showed that the turpentine-like aroma was trans- 

 mitted to between one-half and three-fourths of the offspring plants, without 

 regard to whether the hops themselves retained the appeai-ance peculiar to 

 those of the mother plant. 



" From the experiments already mentioned, as well as from several others 

 made with European varieties (e. g., those from Saaz in Bohemia) it would 

 seem that the aroma of hops is not to be regarded as so volatile a character, 

 or so entirely due to purely local conditions, as has generally been believed." 



Investigations on hops. — VI, On the amount of lupulin in plants raised by 

 crossing, J. Schmidt {Compt. Rend. Lab. Carlsberg, 11 {1915), No. 4, PP- 165- 

 183). — In experiments in breeding hops to increase the lupulin content, 21 

 females of Danish, English, German, and Austrian origin, all cultivated plants, 

 • were crossed with wild Danish males in 1911. The lupulin (total content of 

 hard and soft resins) contents of the seedling offspring ranged from 7.3 to 19.7 

 per cent as maximums of the several groups of different parentage. The 

 average lupulin content of the oft'spring of any given parentage showed lower 

 than that of the mother plant, but there were a few individuals that showed a 

 higher content. This was true in spite of the fact that wild males, " pre- 

 sumably genotypically poor in lupulin," were used. 



Thus by vegetative propagation the author sees a method of improvement 

 by using the highest plus variant among the offspring. 



Investigations on hops. — VIII, On the flowering time of plants raised by 

 crossing, J, Schmidt {Compt. Rend. Lab. Carlsberg, 11 {1915), No. 4> PP- 188- 



