DISEASES OF PLANTS. 249 



This was first observed in the vicinity of Chicago in 1913, and in 1914 was 

 reported in a number of localities in Ohio and Indiana. 



The rust appears on the plants in the field about the last of July, the uredo 

 stage persisting until fall, when the teleuto pustules may be found on the stems 

 and branches. The uredo stage may be also found in the greenhouse throughout 

 the winter on cuttings and seedlings, and later on mature plants. Toward 

 spring the rust seems to die out in the house, reappearing in the summer. The 

 fungus was first described as Puccinia antirrhini In 1895, but there seems to 

 be no reference to the rust since that time. 



A Nectria parasitic on Norway maple, M. T. Cook (A 6.9. vi Phyotpatlwlogy, 

 It (IDlJf), Xo. 6, p. 390). — The author reports having observed for the past two 

 years a disease of Norway maple, symptoms of which bear striking resemblance 

 to those of the chestnut bark disease due to Endothia parasitica. 



The leaves of the infected maple trees wilt and the branches die. Observa- 

 tions showed that the trouble was due to a canker which girdled the branches. 

 The infection usually occurs through a wound. The causal organism is con- 

 sidered probably X. cinnaharina or N. coccinea. On an isolated group of Nor- 

 way maples the disease has proved very destructive. It was also found in a 

 nursery, but here the fungus was apparently saprophytic. 



Thrombotic disease of maple, W. H. Rankin (Abs. in Phytopathology, 4 

 (1914), No. 6, pp. 395, 396).— The first indication of this disease, found near 

 Claverack, N. Y., is a withering and drying of the leaves without change of 

 color except a slight blanching. After one limb of a tree becomes affected, 

 other limbs either directly above or below are killed, the disease progressing 

 until within a month or two the tree is dead. 



An examination of a diseased limb showed no fruiting bodies of a fungus, 

 and the bark on recently killed limbs was found apparently healthy. Upon 

 cutting into the sapwood of the current season's growth, it was found to be 

 streaked with dark-green lines. The mycelium of a fungus was abundant, 

 and the dark-green streaking isssaid to be due to the abundant production of 

 selerotia, which were packed in the vessels. The causal fungus was found to 

 be a species of Acrostalagmus. 



Inoculation experiments and other investigations are said to be in progress. 



A mutation in Phyllosticta, C. H. Crabill (Ais. in Phyot pathology, 4 {1914), 

 No. 6, p. 396). — The author reports observing in studies of several species of 

 fungi isolated from frog eye leaf spot of apple one which answers closely to the 

 descriptions of Phyllosticta, except that it produces chlamydospores. This is 

 believed to be a mutant from the usual form of the fungus. 



The perfect stage of Phyllosticta paviae, V. B. Stewart (Ahs. in Phyto- 

 pathology, 4 {1914), No. 6, p. 399). — The author reports observing the mature 

 perithecia in May, 1914, on the underside of diseased horse chestnut leaves 

 that had been exposed to the winter. Cultures made from the perithecia and 

 transferred to horse chestnut seedlings produced the characteristic lesions 

 of the leaf blotch within 10 days, indicating that the perithecia are the perfect 

 stage of the fungus P. pavice. 



Comparing this stage of the fungus with one previously described by Peck, 

 the author finds that they are identical, so that the name for the sexual stage of 

 the fungus should be Lwstadia cesculi. 



The longevity of pycnospores and ascospores of Endothia parasitica under 

 artifiicial conditions, F. D. Heald and R. A. Studhalter {Phytopathology. 5 

 {1915), No. 1, pp. 35-44, Pl' 1; a^s. in Phytopathology, 4 {1914), No. 6, p. 401).— 

 The author states that pycnospores in suspension in water show a slow but 

 gradual reduction in the number remaining viable. At temperatures from 



