842 EXPERIMENT STATION RECORD. [Vol. 37 



laboratory. The plants showing these symptoms put forth normal foliage again 

 in September with the advent of cooler weather. 



Histological studies showed that the crinkling of the leaves was due to ne- 

 crosis of certain epidermal and cortical cells of the veins, followed by the 

 growth of the parenchyma cells which Induced buckling of the leaf surface. 

 Transpiration experiments indicated that dwarfed plants transpire more rap- 

 idly than normal ones. 



Notes on mosaic symptoms of Irish potatoes, I. E. Melhijs (Abs. in Phyto- 

 pathology, 7 (1917), No. 1, p. 71). — The author gives a description of the mosaic 

 disease of potatoes and its effect on the production of tubers. 



Frost necrosis of potato tubers, L. R. Jones and E. Bailey {Abs. in Phijl>- 

 pathology, 7 (1917), No. 1, pp. 71, 72). — A type of uoninheritable net necrosis of 

 potato tubers is described, of which frost Injury is apparently the primary 

 cause. Experiments under artificial conditions have shown that exposure to 

 freezing temperature may produce either ring or net necrosis. The stem end 

 of the tuber is reported to be always more sensitive to injury than the other. 



A bacterial blight of soy beans, A. G. Johnson and Florence M. Coerpeb 

 (Abs. in Phytopathology, 7 (1917), No. 1, p. 65). — The authors report having 

 had a bacterial blight of soy bean under investigation at Madison, Wis., for 

 several years. The disease has become quite common, occurring especially 

 on the leaves, on which the organism causes the production of small, angrular 

 spots which, in later stages, become dark in color. liepeated i.solation cultures 

 have yielded a characteristic organism which is referred to the genus Pseudo- 

 monas. Studies on the physiological characteristics of the organism and Its 

 pathogenicity are said to be in progress. 



Further note on a parasitic saccharomycete of the tomato, A. Schneidek 

 (Phytopathology, 7 (1917), No. 1, pp. 't2, 5S). — In continuation of investigation.s 

 of a disease of tomato previously reported (E. S. K., 36, p. 749), the auth.>r 

 has concUuletl that the fungus is a new species, and it is technically described 

 under the name Nematospora lycopcnici. 



Host limitations of Septoria lycopersici, J. B. S. Norton (Abs. in Phyto- 

 pathology. 7 (1917), No. 1, p. 65). — In(xulation experiments in humid iuclosures 

 on seedlings of a number of species of Solanacese and SO varieties of tomato 

 with Septoria from tomato are said to have resulted in infections on several 

 species of Solanuni, eggplant, Datura tatula, potato, currant tomato, and &'. 

 carol inense. With larger plants outdoors, infection rarely occurs excejU on 

 Lycopersicuui. 



Note on the genus Coniothecium, with special reference to C. chomatos- 

 porum, P. A. van deb Bijl (So. African Jour. Set., 12 (1916), No. IS, pp. 6-i9- 

 657, pis. 6, figs. 2). — In view of a statement made by Massee (E. S. It., 34, p. 

 543), the author here pre.'<ents more fully the results of an investigation, previ- 

 ously noted (E. S. R., 32, p. 314), wlucli has not yet been completed. 



This paper notes certain cultural characters of C. choinatosporum, tlie cause 

 of a branch blister di.<:ease on apple and pear. The fungus develops between 

 the cells, invading the middle lamella? and rupturing the skin to produce the 

 black blisters and fruit russeting. Evidence obtained is said to show (hat this 

 organism is only a stage in the life cycle of Phomu malt. 



Control of peach bacterial spot in bouthern orchards, J. W. Rorkrts (V. S. 

 Dept. Agr. Bui. 54S (1917), pp. 7, pi. 1). — A description is given of the bacterial 

 spot of peaches caused by Bacterium pruni. The disease, which Is also known 

 as bacteriosis, is said to occur in practically all the peach-growing sections of 

 the eastern half of the United States, Its most serious injury being confined 

 to the most southerly portion of this district. Twigs, fruit, and leaves are 

 affected, but the greatest amount of injury is done to the leaves. 



