What constitutes a Museum Collection of Birds? 153 



Audubon, depicting on a large scale a flight of Passenger 

 Pigeons, a common sight of his day, hut which the world will 

 never see again, and of which no adequate portrayal exists. 



While claiming the attention primarily through their 

 beauty, groups of this nature permit of the display, in a 

 most satisfactory manner, of many facts pertaining to the 

 life-history of the species they include : for example, haunts, 

 courtship, nesting-site, nest, eggs, the care of and develop- 

 ment of the young, manner of feeding*, flight, relation of 

 colour to environment, molt, etc. 



It is, of course, implied that these groups shall be based 

 upon detailed field studies in which the camera, as a graphic 

 recorder, plays an important part. 



Special Groups. 



Elaborate reproductions of unusual scenes from bird-life 

 do not, however, offer the only means of halting the steps 

 of the casual stroller through our exhibition halls. Groups 

 which illustrate a fact, theory, or subject, appeal to every 

 receptive mind. Simplicity of treatment is here recom- 

 mended, in order that the object in view may not be obscured 

 by unimportant accessories ; nor should they, on the other 

 hand, be made too technical. 



Bird-life affords such a wealth of subjective material that, 

 unless one has unlimited means and space at one's disposal, a 

 selection is made with difficulty. Birds' plumage, as their 

 distinctive character, offers perhaps the most desirable, as 

 well as the most attractive, feature for subjective treatment. 

 Groups, therefore, which illustrate the relation between 

 colour and environment (protective coloration), colour and 

 habit (deceptive or aggressive coloration), colour and 

 climate, colour and age, colour and sex, colour and season ; 

 the molt, albinism, melanism, etc., naturally suggest them- 

 selves. 



Similarly, the relation between structure and habit may be 

 demonstrated by means of exhibits in which the uses of the 

 bill, wing, tail, and feet are shown. 



Yariation by artificial selection may be illustrated by 



