DISEASES OF PLANTS. 547 



charred posts ranked third. It is stated tliat under the conditions untreated 

 good pitch pine posts should last from 12 to 2.5 years after being set in the 

 ground. The use of bands of either oil or tar applied to the post where it conies 

 through the ground, while helping to preserve the post, is believed to be more 

 expensive than dipping the entire lower end. 



The text is accompanied with a series of figures illustrating the results 

 securetl. 



Exports and imports of forest products, 1906, R. S. Kellogg ( U. *S'. Dept. 

 Agr., Forest Serv. Circ. 110, pi). 28). — This circular consists of a series of 25 

 tables taken chiefly from a rei)ort of the Bureau of Statistics of the iJepart- 

 ment of Commerce and Labor upon the Foreign Commerce and Navigation of 

 the L'nited States for the year ending June 30, lOOti. The information here 

 given includes summaries and detailed data relative to the exi)orts and im- 

 ports of forest products, including both raw and manufactured material of 

 various kinds. 



The total value of the exports of forest products and manufactured mate- 

 rials increased from $70,H06,994 in 1903 to $89,602,637 in 1906, while during 

 this time the corresponding imports increased in value from .$74,578,674 to 

 .$10(J,065,394. Of the imports the most important item showing an increase is 

 India rubber, of which 55,010.571 lbs., worth $30,436,710, was imported in 1903 

 as comparetl with 57,844,.345 lbs., valued at $45,114,450, in 1906. This was an 

 increase in value per pound of from 55.3 cts. to 78 cts. 



DISEASES OF PLANTS. 



Notes on some plant diseases, A. W. Bartlett (Rpt. Bot. CJarcl. Brit. Guiana, 

 1906-7, pp. 20-22). — Among the diseases described is a root disease of mango, 

 in which the roots of the mango tree were attacked by a fungus which pro- 

 duced felted mycelium between the wood and the bark. The wood in the 

 affected places had become black as though charred, but as the fruiting state 

 of the fungus has not been observed it could not be identified. The same dis- 

 ease is said to have been observed on roots of mango trees in Grenada and 

 Dominica. Tlie cutting and burning of the trees and isolation by trenching of 

 the places occupied by them are recommended as measures to pi'event the 

 spread of the disease. 



Brief accounts are given of anthracuose of cotton, an undescrlbed boll 

 disease, and cotton rust due to Uredo gossypii. The type of anthracnose ob- 

 served in Dominica resembles, more closely that occurring in the United States 

 than the variety reported as prevalent in the West Indian Islands. The disease 

 which the author calls boll rot has proved quite destructive, particularly to 

 varieties of Caravonica and Sea Island, as it completely destroys the contents 

 of the bolls. The cotton rust was found abundant, but it apparently caused 

 little injury to the plant. 



A root disease of Lil)erian coffee is reported, but an examination failed to 

 reveal the presence of fungus or insect in the parts above ground, while the 

 roots were blackened and decayed. From examinations it is believed that the 

 fungus is a form of Basidiomj'cetes. The early indications of the presence of 

 the disease are shown by the leaves turning yellow, afterwards dropping off, 

 and the berries becoming dried and shriveled, followed in a short time by the 

 death of the tree. The disease seems to spread from tree to tree, but by deeply 

 trenching about the diseased trees its spread has been successfully checked. 



Notes on the parasitism of Botrytis, F. T. Brooks {Proa. Cambridge Phil. 

 Koc, I'l (1!)07), Xo. .3, p. 298). — In an abstract of a paper presented by the 

 author it is stated that the conidia of Botrytis are unable to infect healthy 

 green leaves, whereas if a young mycelium that has been nourished saprophyt- 



