174 Allen, Habitat Groups of North American Birds. [ April 



from Mr. Chapman's 'Guide Leaflet,' already cited: "Each group 

 has demanded its own special treatment, and, in the construction 

 of the series, the many novel problems encountered have resulted 

 in the development of original methods. This is particularly true 

 of the manner of installation and illumination of the groups at the 

 sides of the hall The background is curved [convex back- 

 ward] with the front opening so reduced in size that at the proper 

 distance, or 'correct view-point,' neither the ends nor the top of the 

 group can be seen. By thus leaving the actual limits of the group 

 to the imagination the illusion of space and distance is greatly 

 heightened." Furthermore, the groups are lighted from the top by 

 diffused light; electric lighting is employed at night, or whenever 

 the daylight is insufficient, but in either case the light comes from 

 the same diffusing surface. The reflection of outside objects in 

 the case fronts has been wholly prevented by the erection of a screen 

 consisting of a low wooden partition placed at the inner edge of the 

 gallery which serves not only to cut off reflections but tends to con- 

 centrate the attention of the observer upon the special and thus 

 wholly isolated exhibit before him. 



It is needless to say that the cost of this unique series of bird 

 groups has been heavy, and the work could never have been under- 

 taken by the Museum on the basis of its ordinary sources of income. 

 It is therefore fitting to close this sketch with a list of the names of 

 the friends of the Museum who have made these results possible, 

 as follows: 



Mr. John L. Cadwalader. 



Mrs. Morris K. Jesup. 



Mrs. Philip Schuyler. 



Mrs. John B. Trevor. 



Mrs. Robert Winthrop. 



Mr. F. Augustus Schermerhorn. 



Mr. H. B. Hollins. 



Mr. Henry Clay Pierce. 



Mr. Henry W. Poor. 



Mr. Courtenay Brandreth. 



