FIELD CROPS. 139 



Further experiment aud larger numbers may show that selection can always 

 cause a shift in the mean, but will necessarily be a shift so slight that it can 

 be detected only by a long continued experiment and enormous numbers." 



It is noted that "mutations may occur. We have shown the origin of one 

 family by a very wide mutation. In this particular case it was not difficult to 

 show that a constitutional change toolc place in a single germ cell of the 

 mother plant." 



Field experiments with wheat, 1912, H. K. Chapman, R. W. McDiarmid, 

 J. W. Shaw, H. Bartlett, and H. J. Kelly {Agr. Gaz. N. S. Wales, 2Jf (1913), 

 No. 12, pp. 1039-1050) . — This paper reports work in progress on the compara- 

 tive value of bone dust, superphosphate, rock phosphate, bone charcoal, and 

 Thomas phosphate as wheat fertilizers at the Cowra, Wagga, Bathurst, Glen 

 Innes, and Nyngan experimental farms. 



Seed tests made at the station during 1913, M. T. Munn {'New York State 

 Sta. Bui. 378 {191J,), pp. 113-131).— Thxa bulletin describes the methods em- 

 ployed in making a purity test by " count," and states that " during the year 

 292 official samples of seed were drawn from dealers' stocks by authorized rep- 

 resentatives of the commissioner of agriculture. Analyses of these samples 

 showed 17.5 per cent to be violations of the seed law, i. e., they contained in 

 excess of 3 per cent by count of foul or foreign seed and were not so labeled. 

 Lawn grass and grass seed mixtures were the most frequent violations, with 

 alsike clover, red clover, and redtop grass, respectively, coming next in 

 order. . . , 



" From correspondents, 975 seed samples were received during the year, and 

 a practical report covering the quality, noxious weed-seed content, adulterants, 

 and general appearance of each sample was given. These voluntary examina- 

 tions reveoled apparently the same seed-trade conditions as did the seed exami- 

 nations of the previous year." 



Purity of farm seeds in 1913, F. H, Hall ^Neio York State Sta. Bui. 378, 

 popular ed. (1914), PP- 2-.J). — A popular edition of the above. 



Results of seed tests for 1913, F. W. TzVylor and F. App {ISleic Hampshire 

 Sta. Bui. 166 {1913), pp. iS).— This bulletin gives tabulated results of testing 

 107 samples of seeds from December 1, 1912, to September 1, 1913, the text of 

 the seed law of New Hampshire, and suggestions regarding sampling and the 

 handling of samples. 



Report of seed tests for 1913, J. L. Burgess {Bui. N. C. Dcpt. A'gr., 3J^ 

 {1913), No. 9, pp. 48, figs. 2).— This bulletin gives the results of testing 732 

 samples of seeds, lists the weed seeds that commonly occur in certain commer- 

 cial seeds, aud notes the effective working of the North Carolina seed law. 



Better seed, F. S. Harris {Vt^Jli Sta. Circ. 16 {1914), PP- 47-52).— The need 

 of seed improvement is pointed out, and some directions are given for growing 

 and storing better seeds on the farm. 



Homemade seed corn testers, H. D. Hughes (Iowa Sta. Circ. 1 (1912), pp. 

 4, figs. 2). — This gives directions for making and using the sawdust box tester 

 and the rag doll tester. 



Unlawful Iowa weeds and their extermination, L. H. Pammel and Char- 

 lotte M. King {Iowa Sta. Circ. 5 (1912), pp. 3-18, figs. 15). — This circular 

 gives part of the text of the Iowa weed law, including penalties, and describes 

 and gives methods of eradication of quack grass, Canada thistle, cocklebur, 

 mustard, milkweed, dock, buckhorn or rib grass, wild parsnip, horse nettle, 

 morning-glory, Indian mallow or butter print, burdock, wild timothy or drop- 

 seed grass, squirrel tail or wild barley, foxtail, shoofly, chicory, dodder, and 

 wild carrot. 



50128°— No. 2—14 4 



