DISEASES OF PLANTS. 247 



July and August, and by overrunning the millet plants i-etards their growth and 

 development. 



A new chytridiaceous parasite of rye grass, E. Griffon and A. Maublanc 

 (Bui. Trimest. Soc. Mycol. France, 26 {1910), No. 3, pp. 317-321, pi. i).— The 

 authors describe as nevp Cladochytrium ccespitis n. sp., a fungus which first 

 attacks the sheaths and adjacent tissues of the young stems of rye grass (Lolium 

 perenne) near the ground, producing a species of brown rot which soon invades 

 the roots, and finally causes the death of the plants. 



Notes on the occurrence of fung'us spores on onion seed, G. H. Chapman 

 (Massachusetts Sta. Rpt. 1909, pt. 1, pp. 16-'f-167). — In 10 samples of onion 

 seed examined. 2 were found contaminated with onion smut spores ( Urocystis 

 cepulw). Spores of onion brown mold (Macrosporium porri) and downy mildew 

 (Peronospora schleideniaiia) were also found, as well as the spores of several 

 species of fungi not parasitic on the onion. 



Scab and eelworm in potatoes, E. S. Holmes (Jour. Dept. Agr, Victoria, 

 8 (1910), No. 9, pp. 570-582). — The results are reported of experiments for the 

 prevention of scab and nematodes in potatoes in various parts of Victoria, in 

 which the use of formalin, green and artificial manures, iron sulphate, and 

 spraying for the scab (the term being used here in its widest sense), and the 

 use of green manure, formalin, and spraying for combating the nematode, were 

 tested. 



It was found that soaking the seed tubers in a 1 : 30 solution of formalin for 

 2 hours before cutting and planting was efficacious in preventing the scab 

 in that form, at least, which occurs in the Ballarat district, while clean seed 

 and artificial manures were also factors in the production of a clean crop. For 

 combating the nematode, green manure and the use of artificial manures, 

 especially the latter, are worthy of consideration for future experiments, while 

 the formalin treatment did not prove as eflicacious as in the case of the scab. 



A tabulated statement of the results obtained from 5 experimental plats 

 is appended. 



The symptoms of internal disease and sprain (streak disease) in potato, 

 A. S. HoRNE (Jour. Agr. ^Sci., 3 (1910), No. 3, pp. 322-332, i)ls. 2).— The author 

 describes the symptoms of two obscure diseases of the potato now found in 

 England. One, known as internal disease, was originally described from 

 Germany by Frank in 1897 (E. 8. R., 9, p. 61) as " buntwerden " or " eisen- 

 fleckigheit," and the other from England and Scotland called " sprain in pota- 

 toes " was described in 1909 (E. S. R., 22, p. 347). 



The results are also given of experiments on growing potatoes from seed 

 tubers affected with both diseases, and their subsequent development in stor- 

 age. As a result of these investigations the author claims that the internal 

 disease attacks certain varieties of potatoes, occurring even in the very young 

 tubers, while sprain, or streak disease, as the author proposes to rename it, 

 occurs in other varieties. 



The markings in the diseases may or may not form a connected system in the 

 tissues of the potato. Sometimes the discolored areas are quite isolated, and 

 the diseased cells can easily be traced to within a few cells of the cork layer 

 (skin), terminating occasionally in a slight injury to the surface of the tubers 

 in the case of the streak disease. 



No trace of a hyphal organism was found within the cells or intercellular 

 spaces of the diseased tissues. The dead cells often retain their starch in an 

 unaltered condition. Neither disease spreads in storage under the experimental 

 conditions described. In every experiment, samples of potatoes affected with 

 either disease produced a certain proportion of tubers affected with these 



