Should it be remarked that I have commented 

 somewhat severely on certain parts of the Bio- 

 graphy of Birds, I answer, that I should only 

 have taken as much notice of that work as 

 would have been necessary to prove that the new 

 theory could not be depended upon, had not the 

 partisans of the author given me ample cause 

 of provocation. Had they continued under 

 arms, it was my intention to review the whole 

 of the Biography of Birds, together with the 

 author's " Introductory Address." 



The controversial papers which have appeared 

 on different subjects in Mr. London's Magazine 

 are not included in these Essays. Had mine 

 been introduced, those of my opponents must 

 equally have been admitted, for the sake of 

 perspicuity. 



These Essays chiefly treat on the habits of 

 birds. I cannot help observing, that too many 

 of our histories of birds are both defective and 

 erroneous. We can never expect to have a 

 complete history of birds, until he, who under- 

 takes the task of writing it, shall have studied 

 his subject with unceasing attention in the field 



