PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 



BIOLOGICAL SOCIETY OF WASHINGTON 



The 574th regular meeting of the Society was held in the Assembly- 

 Hall of the Cosmos Club, Saturday, November 17, 1917; called to order 

 by President Hay at 8 p.m.; 78 persons present. 



On recommendation of the Council the following named persons were 

 elected to membership: Miss Katherine A. Stuart, Alexandria, Va.; 

 H. C. Fuller, Institute for Industrial Research, Washington, D. C; 

 Herbert Popenoe, Assistant Editor, Journal of Heredity, Washington, 

 D. C. 



Under the heading brief notes and exhibition of specimens. Dr. R. W. 

 Shufeldt exhibited two grasshoppers, the black Louisiana form of 

 Rhomaleum micropterum, and a specimen of the same species from 

 Florida, the latter being much lighter in color, a sort of tan with a ten- 

 dency in places to pinkish and greenish. 



The regular program was a symposium : Recently introduced pests 

 and the problem of accidental introductions. 



1. C. L. Marlatt: The pink bollworm of cotton, illustrated by lantern 

 slides. (No abstract.) 



2. A. L. Quaintance: Recently introduced fruit insects, illustrated 

 by lantern slides. (No abstract.) 



3. Perley Spaulding: Some biological aspects of the spread of the 

 white-pine blister rust, illustrated by lantern slides. Mr. Spaulding 

 said that the white-pine blister rust probably originated in Asia, spread 

 thence to Europe, and more recently to North America. The factors 

 concerned in its distribution are: (1) Man aids distribution by exten- 

 sive long distance shipment of nursery stock of pines and possibly of 

 Rib3s infected by this disease. He hinders distribution by quarantines 

 and inspections of nursery stock shipments. (2) Animals and insects 

 carry the spores about on their bodies thus aiding local spread of dis- 

 ease. They also hinder the production of spores by eating the fruiting 

 bodies and the surrounding host tissues. Gypsy moth larvae which are 

 known to be blown for miles feed freely upon the spores and in infected 

 areas the spores stick in great numbers to their bodies. (3) Wind blows 

 the spores freely about, as well as gypsy moth larvae which bear spores 

 upon their bodies. Rain hinders spread by beating down spores which 

 are floating about in the air. Sunlight within a short time destroys the 

 viability of exposed spores. 



This disease is but one of many which has spread from one country to 

 another and in many cases from one country throughout the world. 

 A list of thirty such diseases caused by bacteria and by representatives 



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