THE NATURALIST'S VISION 361 



Now, it is not necessary for me to state that 

 here was an astronomer of eminence, and an 

 ornithologist of varied experience, and up to that 

 moment I do not believe that either of them (and 

 I know one never had) apprehended that there 

 was any connection whatever between the two 

 sciences. Further inquiry elicited from Professor 

 Young the fact that he did not realize that it 

 was anything of consequence to see a bird fly 

 at night ; and moreover, he was not well enough 

 acquainted with birds to be able to determine 

 anything definite as to the special kinds observed. 



I did not go away from the astronomical labo- 

 ratory that night until I had seen many birds sil- 

 houetted on the background of the moon as they 

 flew by, and before leaving I knew definitely 

 that I had seen a number of birds of whose 

 identity I was as sure as if they had passed 

 close to me in broad daylight. I saw a barn- 

 swallow, a goldfinch, a purple grackle, birds that 

 I could refer to the family of sparrows, others to 

 the family of wood-warblers, and at least two dif- 

 ferent species of woodpecker, one of which, I have 

 no doubt, was the yellow-bellied sapsucker. I 

 refer such of my readers as care for details, to 

 a paper cited in the appendix, published on the 

 subject, which sets forth the observations. 



This is what I mean by opportunity; and I 

 conceive that the possibility of observing things 



