CONTENTS. 



PAGE 



Contributions to the Knowledge of the Life History of Pinus 

 with special reference to Sporogenesis, the Development of the 

 Gametophytes and Fertilization; by Margaret C. Ferguson . i 



Studies of Variation in Insects; by Vernon L. Kellogg and Ruby 

 G. Bell ^°3 



Hopkins-Stanford Galapagos Expedition.-XVH. Shore Fishes 

 of the Revillagigedo, CHpperton, Cocos and Galapagos Islands; 

 by Robert Evans Snodgrass and Edmund Heller . • -333 



Some interesting Beaver Dams in Colorado; by Edward R. 

 Warren ^^^ 



Organization and Membership of the Washington Academy of 

 Sciences ^^^ 



Index '^^^ 



