CHAPTER II. 



SECOND ORDER. PICARI^E.* 



THIS order is a " wayfarers' home," established to receive 

 those birds who do not belong elsewhere (in science, a poly- 

 morphic group). The (North American) birds composing it 

 are characterized by the combination of a bill without any cere 

 or soft membrane, and one of the following features: tail- 

 feathers, ten ; foot, syndactyle by the union throughout of the 

 middle and outer toe ; front toes, two in number. There are 

 also internal and other features which are more or less charac- 

 teristic. Either the bill or the toes always present certain 

 peculiarities. 



There is an important element in classification which is 

 often overlooked : that of latent features. These are frequently 

 undeveloped. For instance, the chief, and let us momentarily 

 suppose, the only, difference between the typical Thrushes and 

 Mocking-thrushes is in the tarsus, or so-called " leg." In the 

 latter group it is always scutellate (or divided into scales) at 

 least, in front ; whereas in the former Thrushes, when adult, it 

 is " booted " (i. e., without scales, unless near the toes). Yet a 

 young Robin with scutellate tarsi is no less a typical Thrush ; 

 his tarsi are virtually " booted," and will become so upon nor- 

 mal growth. Those of a young Catbird never will. Is not 

 abnormal growth frequently due to the persistent latency of 

 normal features ? As another example, the females of two 

 closely allied species may be exactly alike in coloration, size, 



* In the A. 0. U. Check-List this or- it impracticable to make the change 



der is not used, the Goatsuckers, Swifts, here, since it would have necessitated 



and Hummingbirds being placed in the rewriting of much of the original 



the order MACROCHIRES, the King- text, relating to ordinal and family 



fishers and Cuckoos in COCCYGES, and characters, which, of course, was not to 



the Woodpeckers in PICI. I have found be thought of. W. B. 



