DISEASES OF PLANTS. 765 



use of diseased tissue or masses of mycelium. The results obtained 

 in these experiments show that the cause of this disease is an active " 

 parasite capable of causing- the disease at any age of the plants, but at 

 the same time the organism is able to flourish under purely sapro- 

 phytic conditions. It was found that sterilizing the soil to a depth 

 of 3 in. completely prevented the occurrence of this t3^pe of disease. 



The third type in its etl'ect upon the host is similar to those just 

 described, but no Botrytis appeared. From the sclerotia placed in 

 wet sand numerous trumpet-shaped Peziza apothecia appeared, and 

 the fungus was determined as a typical form of Sclerotinia Uhertiana. 

 The author's conclusions are that the lettuce "drop'' in Massachusetts 

 is caused by 2 distinct species of fungus, Botrytis vulgaris and Sclero- 

 tinia Uhertiana. These 2 fungi are remarkably alike in many respects, 

 and have a similar effect upon the host plant. Most of the diseases 

 were caused by degenerated forms of Sclerotinia which have almost 

 entirely lost the abilitv to reproduce themselves b}^ spores and have 

 become highly specialized as a vegetative facultative parasite. The 

 disease caused by Botrytis vulgaris and the typical form of Sclerotinia 

 Uhertiana in mature plants is rare. 



Notes are given on a number of diseases which have been attributed 

 b\' difl'erent authors to Sclerotinia and Botrj^tis. Among those 

 described are diseases of hemp, rape, potato, cucumber, and various 

 rots of vegetables and fruits. Of diseases due to Botrytis alone the 

 author describes a new disease of the linden, in which the branches 

 and upper part of the stem show no abnormal symptoms, while the 

 lower part from the surface of the ground to a height of several 

 inches showed numerous excrescences breaking through the epidermis. 

 This disease seems to be, as far as the author's observations go, a nur- 

 sery stock disease that results in the bark of the lower part of the 

 stem being destroyed and the wood laid bare. It is believed that this 

 disease is caused solely by Botrytis cinerea., which in this case is a true 

 parasite. A disease of rose twigs in hothouses, due to Botrj^tis, is 

 briefly described, and a number of other diseases due to this group of 

 fungi is mentioned. 



The author concludes that there is no connection whatsoever between 

 Sclerotinia Uhertiana and Botrytis cinerea. The connection between 

 the 2 species which has been f requentl}" claimed is due to their simul- 

 taneous occurrence and similarity of mycelium as well as their effect 

 on the host. 



T-wo diseases of red cedar, caused by Polyporus juniperinus 

 11. sp. and P. carneus, H. vox Schrexk {U. S. JJtpt. Agr.. Dii'lslon 

 of Vegetahle Physiology and Pathology Bui. 21,2)p- ^^,i->^'S. 6').— Exam- 

 ination was made b}- the author of the cause of a diseased condition 

 noticed in the wood of the red cedars of the United States, Juniperus 



