DISEASES OF PLANTS. 461 



Some results of the work which have been obtained in this country are briefly out- 

 lined, examples being cited in grape diseases, nursery stock diseases, diseases of 

 cereals, etc. 



Tlie diseases of cultivated plants, V. Peglion {Le malaUie crittogamiche delta 

 piante coltlvdti'. (hmli: (Mrln Ccmone, 1899, pp. VII^Sll). 



Plant diseases investigated at St. Petersburg in 1898, K. S. Iwanoff {Ztschr. 

 PflanzenkranJ:., 10 {1900), X<>. J, pp. 91-102). — A Ijrief report is given on 160 species 

 oJE fungi which were observed on 230 species of host plants. They are classified by 

 hosts as follows: Cereals and grasses, clovers and legumes, potatoes, garden, plants, 

 fruit trees, berries, ornamentals, forest trees, and weeds. Among the number of 

 fungi were several new species. 



Parasitic algae and fungi of Java, III, JVI. Raciborski {Batavia: Staaisdruck- 

 evei, 1900, pp. 49). 



A monograph of the Erysiphacese, E. S. Salmon [Mem. Torrey Bot. Club, 9 

 {1900) , j)p. 1-292, ph. 9) . — A monograph of the species of powdery mildews is given, 

 together with notes upon their morphology and life history, relation of host and par- 

 asite, and the distribution of the powdery mildews. The author limits the family to 

 the genera Podosi)hfera, Spluerotheca, Uncinula, Microsphfera, Erysiphe, and Phyl- 

 lactinia. Of these, 49 species and 11 varieties are recognized. Under the discussion 

 of the various species notes of their economic importance are given. The species of 

 Oidium are considered as conidial forms and for the most part are not described. 



Concerning the geographical distribution of rust fungi, P. Dietel {Naturw. 

 Wclmschr., 15 {1900), No. 19, pp. 2n-220). 



The depreciation of the yield of wheat due to rust, A. Geegoire {Bui. Sta. 

 Agron. Gemblniu; 1900, No. 67, pp. 14, 15). — An account is given of pot experiments 

 conducted to determine the loss due to rusts of cereals. Six series were grown, in 

 which the loss of straw was from 8 to 23 per cent, with an average of 17 per cent, and 

 in grain the depreciation was from 21 to 40 per cent, with an average of 35 per cent. 

 The number of grains per head and average weight of the individual grain was con- 

 siderably lower for the plants affected with rust. 



Recent investigations on rust of wheat, W. G. Smith {Nature, 62 {1900), No. 

 1606, pp. 352-356, figs. 2). — A review is given of the recent publications of Eriksson, 

 Klebahn, Carleton, and others on rusts of cereals. 



Investigations of the rust fungi of cereals in Austro-Hungary, H. Zukal 

 {Ztschr. Pfianzenkrank., 10 {1900), No. 1, p)p. 16-21). — A report is given of studies on 

 the cereal rusts of Austro-Hungary. The species observed were Puccinia graminis on 

 rye, P. glumarum on wheat, P. simplex and P. graminis on barley, and P. graminis 

 and P. coronata on oats. The author tentatively adopts the name P. glumarum for 

 the rust on wheat. Culture experiments were made of the different species, and 

 negative results were obtained in experiments for preventing the attacks of rusts. In 

 relation to Eriksson's mycoplasma theory the author is led to believe some infection 

 may possibly be secured through mycelium carried in the seed grain. Investigations 

 on alternate generations showed that the rust fungi are not confined to certain definite 

 transition hosts for their phases. 



Experiments with smuts of cereals, C. N. Grenfell {Agr. Gaz. New South 

 Wales, 11 {1900), No. 9, jyp. 742-747). — Inoculation experiments are reported with 

 Tilletia tritici, Urocystis occulta, and Ustilago segetum. Soaking seed in copper sulphate 

 as a means of preventing snmts was successfully investigated, the treatment tending 

 to reduce the amount of disease. It is claimed that ['.■^tilago segetiuii. decreases and 

 Urocystis occulta increases the tillering tendency of wheat plants. The infection of 

 the loose smut, U. segetum, is said to take place at an earlier stage of the plant than 

 the others, jirobably occurring in the seed. 



Infection experiments with some TJredinesB, E. Fischer {Bot. Centbl.,83{1900), 

 No. 3, pp. 75, 76) . — Successful inoculations of Acteea spicata with teleutospores of a 



