150 EXPERIMENT STATION RECORD. 



In another publication (E. S. R., IG, p. 885) it has been shown that the first 

 entrance of the germ-tube was probably clue to some positively chcmotropic 

 body which is common to all plants. To determine the identity of this sub- 

 stance the author tested the germination of spores placed on a membrane of thin 

 rubber, perforated with holes comparable in size with stomata. This membrane 

 was arranged with one side exposed to air saturated with watei- vapor and the 

 other to the air of the laboratory. On the latter side spores of Pucchua ghi- 

 marum hordei were sown, and after 2 days the membranes were microscopically 

 examined and the germ-tubes were found entering the majority of these arti- 

 ficial stomata. 



It is believed that other circumstances may possibly share in attracting the 

 germ-tube to the stomata of the plant, but the attraction of the water vapor is 

 believed to account for the first entrance of the germ-tube. 



Smut in wheat, barley, and oats, and how to prevent it, I. B. P. Evans 

 {Transvaal Agr. Jour., J, (1906), No. IJf, pp. 389-306, pi. 1). — The author reports 

 on the abundance of smut in wheat, barley, and oats in the Transvaal, and de- 

 scribes the copper sulphate, hot water, and formalin methods of treatment for 

 its prevention. 



Smut treatment, A. Mackay {Canada Expt. Farms Rpts. 1905, p. 364). — At- 

 tention is called to the serious loss due to the presence of the bunt or stinking 

 smut of wheat, and the author recommends the treatment of the seed wheat with 

 solutions of formalin or copper sulphate before seeding. Formalin solutions are 

 also recommended for the treatment of seed oats and barley. 



Preventives of smut in wheat, S. A. Bedford {Canada Expt. Farms Rpts. 

 1905. pp. 32 'i. 325). — According to the author, about G per cent of the wheat re- 

 ceived at Winnipeg during the past year was rejected by the inspectors on ac- 

 count of the large amount of smut prevalent. 



Attention is called to the desirability of treating seed, and the results of 

 treating seed with formalin and copper sulphate are shown. In the experi- 

 ments reported different lots of seed wheat were sprinkled and soaked with 

 solutions of formalin and copper sulphate and the resulting crop was entirely 

 free from smut, although the untreated wheat contained more than 12, per cent 

 smutted heads. The increase in yield attributed to the treatment was from 2 

 to 5 bu. per acre on the different plats. 



Notes on brusone, U. Brizi {Agr. Mod., 11 {1905), pp. 380, 394, 4'i2; ahs. in 

 Centhl. Bald, [c/c], 2. Aht.. 15 {1906), No. 21, pp. 653, 654).— A study is given 

 of brusone or smut of rice, in which the author reviews various theories regard- 

 ing its cause and gives the results of his own Investigations regarding it. 



Yoglino is said to have considered it primarily due to bacteria attacking the 

 plants from the soil, while Ferraris and Farneti consider Piriciilaria oryza' the 

 cause of the disease. According to the author the injury to the plant is first 

 shown on the finest rootlets, a fact which apparently escaped all previous 

 investigators except Vogliuo (E. S. R., 15, p. 590). 



The first indication of the disease may be seen in the browning of the paren- 

 chymatous tissues of • the fmest- roots, followed by the discoloration of the epi- 

 blem and the central cylinder and later by the destruction of the protoplasm in 

 the parenchyma cells. The appearance of the disease on the aerial parts of the 

 plant follows after a considerable interval. If rice is grown in poorly aerated 

 water cultures, typical brusone will develop on the roots, stems, and leaves 

 within a few days, but the author takes this as an indication that the disease 

 is not of parasitic origin, but that it results from the destruction of the roots in 

 a poorly aerated soil. The disease is always worst in heavy soils accompanied 

 with a high temperature. 



