x The Biological Society of Washington. 



Frederick V. Coville : Plant Food of the Wild Ducks in Chesa 

 peake Bay. 



Frederick V. Coville : The Water Hyacinth, Piaropus crassipes, 

 as an Obstruction to Navigation in Florida. 



L. H. Dewey : The Eastward Migration of Certain Weeds in 

 America.* 



May 8, 1897 -277th Meeting. 



The President in the chair and 56 persons present. 



The following communication was presented : 



C. Hart Merriam : Suggestions fora New Method of Weighing 

 Species and Subspecies.f 



By invitation, Hon. Theodore Roosevelt, Assistant Secretary 

 of the Navy, presented an address on the same subject. 



May 22, 1897 278th Meeting. 



Ex-President Theodore Gill in the chair and 23 persons present. 

 David White exhibited eroded quartz pebbles found on the 



summit of a mountain, commenting on the probable cause. 

 The following communications were presented: 

 Erwin F. Smith : A Bacterial Disease of Cruciferous Plants J 

 B. T. Galloway : The Effects of Environment on Host and 



Parasite in Certain Diseases of Plants. 



V. K. Chesnut : The Poison of the Common Black Nightshade. 



October 9, 1897 279th Meeting. 



The President in the chair and 29 persons present. 

 L. 0. Howard exhibited a specimen of Belostoma colossicum 

 from Cuba, comparing it with the native Benasus griseu*. 

 The following communications were presented : 

 R. T. Hill : Notes on Antillean Faunas, Past and Present. 

 B. W. Evermann: The Catfishes of Louisiana. || 

 Theo. Gill : The Insufficiency of the Order Bunotheria. 



* Asa Gray Bulletin, v, pp. 31-34, June 11, 1897. 



t Suggestions for a New Method of Discriminating between Species and 

 Subspecies. < Science, n. s., v. pp. 753-758, May 14, 1897. 



\Pseadomonas campestris (Pammel) : the Cause of a Brown Rot in Cru 

 ciferous Plants. <Centralb. fur Hakteriologie Abt. ii, Band 3. 1897. 



| To be published in a Farmer's Bulletin, U. S. Dept. of Agriculture, 

 with descriptions of other poisonous plants. 



|| To be published in Bull. U. S. Fish Commission for 1898. 



