148 F. M. Chapman: 



be represented, but duplicates should be displayed only when 

 it is required to show all the parts of the body to equal 

 advantage. It is, of course, desirable, but by no means 

 essential, that the specimens should be taken in the region 

 under consideration. 



The seasonal collection of birds, on the other hand, should 

 contain only the birds of the month. The collection will, 

 therefore, be composed of two parts : the first will contain 

 Permanent Residents, or those species which are present 

 throughout the year ; the second part will contain migrant 

 species. These should be removed or replaced as circum- 

 stances require, the change being made at the first of each 

 month to represent the changes, if any, which we may expect 

 to occur in that month. In January, for example, the seasonal 

 collection of Birds Found Within 50 Miles of New York 

 City, which is displayed in the American Museum of Natural 

 History, contains, in addition to the ever present Permanent 

 Residents, only the Winter Visitants, the two combined form- 

 ing the local avifauna of the month. 



February 1, there will be added to the migrant group the 

 few species which we look for from the south in that month. 

 One month later, the March migrants will be included, and, 

 at the proper time, those due in April and in May. Mean- 

 while, as the winter birds and transient migrants pass onward 

 to more northern breeding grounds, they are removed, and at 

 the conclusion of the migration in June we shall have left in 

 our migrant group only the Summer Residents, or birds which 

 have come from the south to nest, and these., with the Perma- 

 nent Residents, constitute our summer bird-life. The com- 

 position of the collection now remains unchanged until the 

 autumnal migration necessitates further alterations. 



Such a collection thus not only graphically illustrates the 

 migration of local birds, but at all times represents the 

 existing conditions, and thereby greatly facilitates identifica- 

 tion of local birds by narrowing the field of possibilities. 



In addition to the individual labels already mentioned, 

 labels should be provided here for each seasonal group of 

 birds, as, for example, Permanent Resident, Winter Visitant, 

 etc., while labels for each month should emphasize the 



