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 Cei'tain Weeds in 

 America.* 



May 8, 1897 - 277th Meeting. 



The President in the chair and 56 persons present. 



The following communication was })resented: 



C. Hart Merriam : Suggestions for a 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 X 

 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. 

 Tj. 0. Howard exhibited a specimen of Belostoma colossicuvi 

 from Cuba, comparing it with the native Benseus griseu-<i. 

 The following communications were {)resented : 

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

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

 Theo. Gill : The Insufficiency of the Order Bunotherja. 



* Asa Gray Bulletin, v, i)p. 31-34, .Tune 11, 1S!)7. 



t Suggestions for u New Method of Discriminating between Species and 

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



XPseadomonas campesiris (Pammel) : the Cause of a Brown Rot in Cru- 

 ciferous Plants. <Centralb. fiir I'akteriologie Abt. ii. Band 3. 1807. 



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

 with descriptions of other poisonous plants. 



II To be published in Bull. U. S. Fisli Commission for 1898. 



