DISEASES OF PLANTS. 885 



showed any predisposition to attacks of smut, being less subject to the wheal smut 

 than varieties of spring wheat. 



Early sowing of cereals when the soil temperature is low gave in the author's 



experiments with barley, oats, and spring wheat less smut than late sowings. In a 

 similar manner, less smut will be found on those cereals grown on a cold clay soil 

 than on a loamy soil, and as a rule the greatest amount of disease will he found in 

 cereals grown on sandy humus soils. A high temperature of the soil during the first 

 week after sowing favors the germination of the smut spores and consequently the 

 infection of the cereals. Cereals will germinate and begin their growth at a temper- 

 ature below that at which the fungus can develop. 



The use of excessive quantities of Chile saltpeter tended to delay the development 

 of smuts and also to hasten the appearance of the heads, especially in barley and oats. 



In the experiments for combating the diseases the author tested a fungicide known 

 as kreolin. This was employed in ] and 1 percent solutions, in which barley, oats, 

 and spring wheat were soaked from It) to 20 minutes. This treatment successfully 

 prevented the appearance of smut and at the same time protected the seed against 

 birds, worms, etc. The use of kreolin, while rather expensive as compared with 

 some other treatments, is recommended as entirely practicable in the ordinary 

 farm practice. 



Notes on infection experiments with various Uredinese, Miss C. M. Gibson 

 (New Phytol., 3 ( 1904), No. 8, pp. 184-191, pis. 2). — The results of an extensive series 

 of infection experiments are given, the investigation being begun with the inocula- 

 tion of Ranunculus ficaria with uredospores of the chrysanthemum rust. Laterother 

 host plants were introduced, and in many cases the germ tubes seemed to penetrate 

 the stomata, but in most instances failed to set up any definite infection. The hyphas 

 in many cases were found to be destroyed after entering the host, and this is believed 

 to have been due to the poisonous properties of substances secreted by the cells. 



Certain varieties of chrysanthemums were found not to be infested with the rust, 

 although growing among plants that were badly rusted, and a number of experiments 

 were conducted with these. An attempt to transfer immunity by grafting failed, 

 the shoots of the resistant variety being as freely infested with the rust as the plants 

 growing upon their own roots. 



The effect of temperature on the germination of the spores of chrysanthemum rust 

 is show n, and it is said that the uredospores kept for 71 days in a test tube in a cool 

 room retained about 25 per cent vitality. 



Notes on some species of TJromyces frequenting various species of legumi- 

 nous plants, E. Jordi ( Cenibl. Unit. v. Par., 2. Abt., 11 {1904), No. 24-25, pp. 763- 

 795, figs. 7). — The results of an extended series of inoculation experiments with the 

 different species of 1'romvces are shown. 



The author used in the first series of experiments forms of U. fabse from Yicla faba 

 V. cracca, Lathyrus montanus, and L. vermin, inoculating a dozen or more different 

 species of leguminous plants with the spores of the different forms. It was found 

 that certain biological forms existed which were not capable of infecting species that 

 were frequently closely related. 



Similar results were .obtained in studies of U. ervi from the hairy vetch, U. hedysari 

 obscuri, U. pisl, U. astragali, and U. anthyUidis. The experiments with U. astragali 

 are reported at considerable length, and the relationship of this fungus with the 

 secidial form growing on Euphorbia cyparissias is pointed out. 



Based upon some biological differences, the author describes U. euphorbix qMragdH 

 and U. euphorbix corniculati as new species. 



Investigations on the diseases of sorghum, W. Busse (Arb. K. Gesundheit- 

 samte, Biol Abt., 4 [1904), No. 4, pp. 819-426, pis. 2, figs. 12).— Compiled notes on 

 the results of original observations and experiments on diseases of sorghum are given. 

 The author's investigations were, for the most part, carried on in German East 



