NOTES AND ABSTEACTS. 



563 



which form loose masses of black spores in the inflorescences, which are 

 set free at flowering time. The fungus in the case of wheat is Ustilago 

 tritiei (Pers.) Jens., that on barley U. nuda (Jens.) Kell. and Sw. 

 Cross inoculations with these two fungi failed to produce the disease, but 

 when the spores were introduced into the flowers of the wheat and barley 

 respectively infection always followed. The fungus, therefore, attacks the 

 embryo in the flower and no infection follows the presence of ripe spores 

 on the seed as it does in the case of the covered smuts of wheat and 

 barley. 



Various methods have been suggested for dealing with these smuts 

 and they have been subjected by the authors to trial. The method of 

 roguing met with some success, but it was not entirely successful and 

 was so laborious as to render it impossible to carry out even in a small 

 field. The modified Jensen treatment with hot water gave the most 

 excellent results. The recommendations are briefly as follows (reference 

 should be made to the Bulletin for full details) : A seed bed, capable of 

 producing at least twice as much seed as is required, should be selected 

 and well cultivated. The bed must be isolated from all chance of 

 infection by smut spores from a similar crop. The seed to be sown is to 

 be steeped first (in small parcels of about \ peck in canvas bags) in water 

 at room temperature for five to seven hours and immersed for ten 

 minutes in the case of wheat in water at 54° C. (129"2° F.) and for barley 

 fifteen minutes at 52° C. (125*6° F). It is extremely important that the 

 temperatures should be exactly maintained. Water at 51° C. is ineffec- 

 tive ; above the temperatures mentioned there is risk of danger to 

 germination. — F. J. C. 



Snowdrops from Seed (Garden, March 20, 1909, p. 142).— The 

 seed is directed to be sown when ripe in boxes to be left outside. Some 

 will come up the first spring, others not till the second or third. To 

 select the seedlings they should be kept in the boxes till they bloom ; the 

 first seedlings will usually bloom the fourth year from sowing the seed. 



H. B. D. 



Sodium versus Potassium (Bot. Gaz. vol. xlviii., No. 2, pp. 98-104, 



August 1909). — Professor W. J. V. Osterhout shows that so far as their 

 toxic action upon plants is concerned, these salts resemble one another 

 very closely. The method used by this author consists in growing wheat 

 for thirty days in solutions of various proportions of NaCl and KC1, and 

 plotting the results as estimated by the growth of roots. Tables are 

 also given showing the results when magnesium,, ammonium and calcium 

 chloride were used along with these salts in varying proportions. 



G. F. S.-E. 



Soil Bacteria, Effect of Salts upon (Bot. Gaz. vol. xlviii., No. 2, 

 pp. 105-125, August 1909). — Mr. Chas. B. Lipman tested the effects of 

 various concentrations of calcium, magnesium, potassium and sodium 

 chlorides upon the ammonifying action of Bacillus subtilis (this form is 

 capable of changing 19 per cent, of nitrogen into ammonia within a given 

 time). He found that these salts were toxic in the order given above, the 

 first being the most poisonous and the fourth the least. As regards the 



p p 2 



