cussion. Nor is it our present purpose to critically ex- 

 amine his ornithological writings, but rather to draw at- 

 tention to the fact that Dr. Cooper is one of our best or- 

 nithologists, because, to many, the conchologist has over- 

 shadowed the ornithologist in his work. We wish now 

 to refer directly to the work that in reality was the result 

 of his meteorological observations and directed his atten- 

 tion to the question of the geographical distribution of 

 plants and animals. This subject has been distinctive of 

 all of his later work, and if we are not in error, he was 

 the first to note the particular laws governing the envir- 

 onment of bird-life. 



At the time he presented his essay on the geographical 

 distribution of plants, no one in the United States, and 

 only De Candalle, Richard and Humboldt in Europe, had 

 critically examined this subject, and Michaux, on the ba- 

 sis of the forest growth of a portion of the United States 

 had noted it. While Purrsh, Bartram, Nuttall, Barton 

 and Torrey had preceded him, they are silent on the laws 

 or conditions governing the distribution, and while Doug- 

 las and Eschscholtz preceded him on the West Coast and 

 noted cases of geographical distribution, they were from 

 the very paucity of systematic observations unable to for- 

 mulate any scientific generalizations. Then we regard 

 this essay as the first systematic presentation ol this sub- 

 ject in the United States. From the plants he carried 

 this question into the life history of the Mollusctz, and 

 thence he laid the foundation of his generalizations re- 



