NOTES AND ABSTRACTS. 



521 



are native to the United States and the remainder foreign (China, 

 South Africa, Australasia, &g.).—G. F. S.-E. 



Seed Tests in Nebraska. By E. Mead Wilcox and Miss 

 Stevenson {U.S.A. Exp. Stn. Nebraska, Bull. 110; with 12 figs. ; 1909 ; 

 also Twenty-Second Annual Report of the same station, pp. 143-158 ; 

 Feb. 1909). — The paper gives an account of the weed seeds found, 

 percentages of purity and germination in over 1000 samples forwarded 

 to the laboratory and examined free of charge. Many of the seeds are 

 illustrated.~G. F. S.-E. 



Sex Inheritance in Lychnis. By G. II. Shull (Bot. Gaz. 

 vol. xlix. pp. 110-125 ; with 2 figs. ; Feb. 1910).— It was found that 

 liermaphrodites occur in Lychnis dioica to the extent of one in 1000 

 or less. He himself discovered six hermaphrodite individuals in 8000 

 examined, and last season eight in 10,320 individuals. Four (A, B, 

 C, D) of these were successfully used in breeding, with the following 

 results : When self -fertilized, A yielded 33 females, 25 hermaphro- 

 dites, and no males; B yielded 110 females, 95 hermaphrodites, and 

 2 males; 0 and .D gave no result. When pollen of A was used to 

 fertilize normal female flowers the results were 236 female, 161 her- 

 maphrodite, and 11 male flowers. When B was used as pollinating 

 parent the result was 162 female, 144 hermaphrodite, and no male 

 flowers. 0 as pollen parent gave 39 females and 55 males, all normal. 

 D as pollen parent gave 26 females and 18 males, all normal. When 

 pollinated by normal male pollen 0 and D gave no result ; A gave 

 21 females, 2 hermaphrodites, and 11 males (B apparently was not 

 investigated). The discussion of these results and of the general ques- 

 tion of Mendelian sex inheritance occupies most of the paper. 



G. F. S.-E. 



Soil Fertility. By G. G. Hopkins {U.S.A. Exp. Stn. Illinois, 

 Circ. 123 and 124). — The author in 1906 criticized with considerable 

 freedom certain conclusions published by Professor Whitney, Chief of 

 Bureau of Soils, U.S. Department of Agriculture. 



These conclusions are given as follows: — 



" 1. All ordinary soils, including so-called exhausted soils, contain 

 sufficient plant food for good crop yields, and this supply will be 

 indefinitely maintained without the addition of any of the plant-food 

 elements. 



"2. Most agricultural plants, and probably all of them, excrete 

 substances that are poisonous to the plant furnishing the excreta. 

 Weeds are poisonous, or excrete substances that are poisonous to 

 agricultural plants. So-called exhausted soils contain substances that 

 are poisonous to all agricultural plants. 



" 3. The fertilizers we add to the soil have their effect on these toxic 

 substances, and render the soil sweet and more healthful for growing 

 plants. It is through this means that our fertilizers act rather than 

 through the supplying of plant food to the plant. 



