772 EXPERIMENT STATION RECORD. 



that the timothy rust was originally identical with P. graminis, but that it has 

 l)ecome specialized on timothy and can only rarely be induced to grow on oats and 



rye. 



The relation between host and parasite, II. Marshall Ward {Ann. Bot., 16 

 {190J), pp. 333-315; abs. in Jour. Roy. Micros. Svc. \_Loiidon'], 1902, No. 5, p. 593). — A 

 stu(l\' lias been made of the relation between the brome grasses and the rust Puccinia 

 dispersa that occurs abundantly on the different species of Bromus. After a general 

 introduction the different rusts that have been found on brome grasses are discussed 

 and an account given of the efforts made to secure the proper sterilization of plants 

 in rust infection experiments. The methods of infection and progress of the various 

 experiments are given in detail. Pot plants were used, and the results obtained seem 

 to differ for the different species of Bromus. Spores taken from one species would 

 not infect others unless they were of closely allied forms. A comparison is drawn 

 between the germination of the uredospores and that of pollen grains as observed in 

 attempts at cross breeding, and the author l)elieves it possible to grow species of 

 grasses immune to rust infection. 



Concerning- pure cultures of the rust Puccinia dispersa, H. Marshall Ward 

 ( Centbl. Bali. u. Par., 2. AbL, 9 {1902), Nos. 5, pp. 161-168; 6-7, pp. 242-246, figs. 3).— 

 During the course of a series of experiments on the relation between the host and 

 parasite in the case of certain species of Bromus and the rust fungus Puccinia dispersa 

 the author devised a simjile methoil of obtaining pure cultures of both host and para- 

 site which are described in detail. Inocidation experiments are described and, so 

 far as the author's observations go, there does not seem to be any chance of infection 

 through mycelium or other agencies within the seed. The only source of infection 

 appears to be spores attached to the seed, as in none of his experiments was he able 

 to discover any trace of mycelium within the seed. 



A contribution to the study of cereal smuts and their prevention, C. von 

 TriJEUF {Arb. K. Gi'simdheltsamte, Biol AbL, 2 {1902), No. 3, pp. 4^^7-467, fig. 1).— 

 Studies are reported in which, by inoculation experiments, it is shown that in the 

 case of the stinking smut of wheat the fungus winters over as a mycelium in the 

 young plants. So far as the oat smut is concerned, it does not appear to retain its 

 vitality over winter in the soil. Winter oats treated with hot water and sown in 

 infested soil were without any disease in the subsequent croj). Experiments are 

 reported which seem to indicate that smut spores which have passed through the 

 alimentary canal of animals retain their germinative ability to a considerable degree. 

 Tables are given which apparently show marked differences in the susceptibility of 

 varieties of wheat to smut diseases. The results of experiments with fungicides for 

 the prevention of smut are reported in which seed treated with a copper-soda solu- 

 tion, wet and dusted with a copi^er-soda powder, and those treated with Bordeaux 

 mixture gave crops nearly free from smut, while seed wet and rolled in superphos- 

 phate, copper sulphate and lime powder, and in kainit gave the worst infected crops. 

 Negative results were obtained in experiments in which the effect of smut and rust 

 on the health of animals was investigated by feeding the infected straw, grain, etc. 



Experiments in the prevention of stinking smut of wheat, D. McAlpine 

 {Jotir. Dept. Agr. Victoria, 1 {1902), No. 4, pp. 413, 414). — The results of preliminary 

 treating of the seed grain with copper sulphate, corrosive sublimate, and formalin 

 are shown, the different treatments completely preventing the occurrence of diseased 

 plants. In check i)lats which were otherwise treated in the same manner only 5 per 

 cent of the plants were free from disease. The effect of the different treatments on 

 the germination of the seed is shown, corrosive treatment being the least injurious, 

 and copper sulphate the most so of the methods tested. 



Some biological phenomena of ITstilago maydis, J. Gruss {Ber. Deut. Bot. 

 GeselL, 20 {1902), No. 4, pp. 212-220, pil. 1; abs. in Jour. Roy. Micros. Soc. [^London:], 

 1902, No. 5, pp. 591, 592). — When spore formation takes place in corn smut, the spore- 



