110 MASSACHUSETTS HORTICULTURAL SOCIETY. 



which he cannot direct himself at all, birds escape all persistent obser- 

 vation, although their habits present some facts worthy our careful consid- 

 eration, as well in a purely scientific point of view as in respect to their 

 relations to man. To consider only their creation in itself, abstracted from 

 our wants and our interests, what more worthy the study of the naturalist 

 than the regular migratory habits of the greater part of birds. What mys- 

 terious necessity, or what supreme will, guides across vast countries those 

 flocks of birds which each year, at the same epochs, return — expected 

 passengers and always faithful — along the coasts of our seas, in the gorges 

 of our mountains, or through the length of our valleys. What necessity 

 assembles, or disperses, according to the season, the individuals of the same 

 species ? All these questions can be elucidated only by observation ; and their 

 solution will require us to wait yet for a long time. But in compensation, 

 each of the facts which are revealed to us has its immediate utility in 

 making us acquainted with some new enemy of our harvests, or some hith- 

 erto unknown auxiliary which runs to protect them ; for there "exists a 

 constant harmony between the instincts of animals and their mode of 

 alimentation, and the search after their food exercises an immense influence 

 upon their actions. To these two classes of ideas appertain the questions 

 with which now for a long time I have charged myself, concerning the 

 habits of birds ; and in the hope of being useful, both to Ornithology and 

 to Agriculture, I have followed during long years the observations which 

 have appeared to me appropriate to advancing the solution. I must declare, 

 first of all, that a labor of this kind cannot be considered as a finished 

 work. By its very nature it demands to be pursued, and can give results 

 in the least satisfactory, only after a prolonged application of the method 

 which I have followed. It is especially this method, and its first results, 

 which I desire briefly to make known to-day. 



One can formularize, in the following manner, the questions to which my 

 observations reduce themselves : — 



1st. What are the causes of the changes in the alimentary regimen, 

 which, following the seasons, one observes at honie in many species of 

 birds ? 



2d. Whence proceed these reunions, often con?iderable, of birds of the 

 same family, or of the same species, at a single point? 



3d. Why do certain birds quit, in a moment, onr country to return soon, 

 and that many times in the course of the year ? 



. 4th. What is the cause of these periodical emigrations, executed by cer- 

 tain species with a regularity Avhich nothing seems able to alter ? 



5th. What are the species useful or injurious to the harvests ? 



6th. What are the species of exotic birds which it would be possible and 

 useful to introduce and acclimate in our country ? 



The alimentary regimen, and the necessities wjiich it creates for each 

 species, seems to me to have a decisive influence upon the kind of habits 

 which concern the preceding questions ; and it has appeared that it would 

 be of great interest to gather, at different periods of the year, the stomachs 

 of all the birds which it might be possible for me to procure, to examine 



