62 NATURE AND THE CAMERA 



be collected in this way. The reader, if a bird stu- 

 dent, will readily realise that. 



A word as to the method which should be employed 

 in making these series: Each photograph of a set 

 should be made with exactly the same distance between 

 the lens and the object; this will insure accuracy as to 

 the size of the bird during each step of its develop- 

 ment. Another way is to place the bird on a piece 

 of paper or wood marked off in small squares of equal 

 size; by these squares the bird may be measured. 

 On account of the constant movement of very young 

 birds, caused by their breathing, it is necessary to 

 make the exposure as short as possible. As the 

 birds develop, their respiration becomes slower and 

 less laboured, consequently the exposure may be in- 

 creased. It will be noticed that the gallinaceous 

 birds, even when but a day or two old, breathe with 

 less apparent effort than the helpless young of the 

 thrushes, warblers, and others that are born blind 

 and naked; their whole body throbs at each breath. 

 Especially is this noticeable when the weather is 

 warm. 



On no account should birds be handled more 

 than is absolutely necessary. If they are very young 

 the soft pin-feathers are easily injured, and if they 

 are feathered the warmth of the hand will moisten 

 and disarrange the feathers. When carrying a bird, 

 if it is able to perch, let it sit on your finger (they 



