6oo Summary of Agricultural Experiments, [oct., 



retain their germinating capacity in the soil. For this purpose pots 

 containing 100 seeds of each weed were placed at a depth of 12 in. 

 below the surface of the ground. From 1900 onwards a pot was dug 

 up each year and the seeds allowed to germinate. In the case of 

 Plantago lanceolata two-thirds of the seeds were dead by 1900, but 

 after ten years 8 per cent, still retained their germinating capacity. 

 The germinating capacity of seeds of Sinapis arvensis was as high 

 after ten years (87 per cent.) as after one year. For purposes of com- 

 parison seeds kept in dry storage since 1899 have been allowed to 

 germinate in each year from 1900 onwards. The seeds of Plantago 

 lanceolata retained their germinating capacity very well in the first 

 few years, but by 1909 were all dead. The percentage of seeds of 

 Sinapis arvensis germinating after one year was 82 per cent., and 

 after ten years 24 per cent. 



With a view to ascertaining the extent to which seeds will retain 

 their germinating capacity when placed at different depths in the soil, 

 pots containing seeds were placed at depths of 3 in., ^in., and 12 in. 

 below the surface. The trial lasted over six years, and showed that 

 seeds placed at the greatest depth retained their germinating capacity 

 best. The seeds of cultivated plants, especially grasses, lost their 

 germinating capacity in the soil much more quickly than the related 

 weed seeds. A few weed seeds, e.g., Agrostemma Githago, entirely 

 lost their germinating capacity in the soil in the first year. 



Weed seeds were found to retain their germinating capacity after 

 passing through the digestive tract of a cow and pig. Of the seeds 

 of Plantago lanceolata and Matricaria inodora fed to a cow, the number 

 of the seeds in the manure which were found to germinate was 51 per 

 cent, and 26 per cent, respectively of the quantities fed. About 50 per 

 cent, of the seeds of Rumex Acetosella and Cheno podium album passed 

 unharmed through the digestive tract of a pig. Seeds eaten by fowls 

 were, as a rule, found to be destroyed, but in the case of these two 

 latter weeds about 15 per cent, were unharmed. 



Resemblance between Grown Gall and Mitrogen-Fixsng Nodules (U.S. 

 Dept. of Agric, Bureau of Plant Industry, Circ. 76). — Specimens of 

 lucerne, and crimson and alsike clover, were forwarded to the Labora- 

 tory of Soil Bacteriology with a statement that although they appeared 

 to possess the nitrogen-fixing nodules on their roots, the crop was not 

 satisfactory. Investigation showed that these nodules, though re- 

 sembling the normal nitrogen-fixing nodules, were really tumours 

 formed by the crown gall organism. Although not apparently destruc- 

 tive to clover, the organism might be transmitted through this host 

 to sugar-beet or to fruit trees. 



An account of the occurrence of crown gall in England was given 

 in this Journal for November, 1910, p. 617. 



Prevention of Finger-and-Toe in Turnips (West of Scotland Agric. 

 Coll., Bull. 56). — In 1902 plots in a field that was very badly infected 

 with finger-and-toe were set aside for experiments in preventing the 

 disease. The soil is a light loam in good condition, distinctly poor 

 in lime. In 1903, 1904, and 1905 turnips were grown, and in 1909 

 swedes, the three years interval being taken up with a rotation of 

 wheat, seeds, and oats. In all these four years the disease kept up 

 ; ts virulence, the crop on the untreated part of the land being almost 



