436 SUMMARY OF CURRENT RESEARCHES RELATING TO 



reaching the roots. Inoculation experiments were made on a tree 

 about thirty years old, towards the end of spring, 1909. In 1911 the 

 eruption of fungus pustules on the bark stretched from the height of a 

 few centimetres above the ground to 2*20 metres. The tree presented 

 the characteristic feature of " the ink disease." The entire covering, 

 leaves, etc., of the tree had died. 



C. E. Lewis * has published results of his experiments with fungi 

 occurring on apples. Sphseropsis malornm causes spots on the leaves of 

 apple trees. It was, he found, only parasitic on leaves. Other fungi, 

 PhyUosticta limitata, Coniothyrium pirma, and Coryneum foUicolum also 

 occurred on the leaves, but always on spots already killed by spraying. 

 A number of fungi occur on branches and twigs, and of these Sphseropsis 

 does the most damage. He proved by inoculation experiments that 

 Coryneum and Phoma would cause considerable injury. 



Charles Brooks and Caroline A. Black f have issued a second report 

 on the fruit-spot of apples and also on a similar spot on quince. They de- 

 scribe all their experiments, and have deteroiined a Phoma stage for the 

 apple-spot which they name P. Pomi. The spot on the quince is caused 

 by the same fungus, as was proved by cross inoculations. 



Perley Spaulding % has pul)lished notes on tree diseases in the 

 United States. The chestnut blight, he writes, has now spread beyond 

 control in the Connecticut Valley. He thinks its widespread dissemina- 

 tion is intimately connected with the distribution of diseased nursery 

 stock. A serious disease of balsam-fir was found to be caused by 

 Lopliodermium nervisequum. It attacks the fir-needles at any stage of 

 growth ; the affected needles turn yellow and die, and, in time, the fruit- 

 ing stage of the fungus forms along the middle of the leaf on the under- 

 side. 



Maple-trees were killed by Myxosporium acerinum. It starts on 

 small branches and works back to those that are larger. Pruning 

 the affected parts was recommended. A new disease of Norway spruce 

 {Picea excelsa) was caused by a fungus which seemed to be identical with 

 Phoma piciena, discovered first on red spruce. The disease causes de- 

 foliation, and very often the death of the trees. 



F. D. Heard § has given notes on new or little-known plant-diseases 

 reported in North America for the year 1910. On fruit-trees he records 

 Endomyces mali from decaying apples, a new apricot disease caused by 

 Botrytis cinerea, and others. Fusisporium Rubi caused a witches-broom 

 effect on the flowers of the dewberry. Among vegetables, cabbage- 

 plants suffered from Phoma oleracea, chives were attacked by Puccinia 

 Porri,'dud hops by a new form of m\]de\Y, Pseudojwronospora Geltidis var. 

 Humidi. Mycogone perniciosa, a pest of mushroom-beds, was reported 

 for the first time in America. Diseases of cereals, forage crops, tropical 

 plants used in commercial industries, and of trees and shrubs, are also 

 reviewed by the author. A full bibUography of the papers cited is given. 



C. W. Edgertou || has proved that the fungus Glomerella Gossypii 



* Phytopathology, ii. (1912) pp. 49-62. 



t Phytopathology, ii. (1912) pp. 63-72 (2 pis.). 



+ Mycologia, iv. (1912) pp. 148-51. 



<} Phytopathology, ii. (1912) pp. 5-22. 



II Phytopathology, ii. (1912) pp. 23-7 (Ipl.). 



