1 08 HANDBOOK OF BRITISH BIRDS 



differ from Swallows and agree with Humming- 

 birds, and in regard to their "feather tracts" quoted 

 Nitzch's " Pterylography " in support of his views. 

 Dr. Shufeldt, however, whose opinion as a well- 

 known authority on avine anatomy carries weight, 

 has shown that, although there are undoubtedly 

 points of resemblance between Swifts and Hum- 

 ming-birds, in all the most important osteological 

 characters the former are more nearly related to the 

 Swallows [Journ. Linn. Soc. ZooL, xx. 1889). So 

 that the old view, after all, was not incorrect, al- 

 though the classification since objected to was based 

 upon external characters, and upon similarity of 

 flight, habits, food, nidification, and general mode 

 of life. The late Prof. W. K. Parker, than whom 

 no one was better qualified to express an opinion 

 on such a subject, published an important paper on 

 the systematic position of the Swifts (Zool., 1889, 

 pp. 91-95), in which he characterised Dr. Sclater's 

 expression that the Swifts have no relationship 

 whatever to the Swallows (Proc. Zool. Soc, 1865, 

 p. 593) as " too emphatic to be true." The Swifts, 

 says Prof. Parker, lie between two groups of birds 

 that differ in the most marvellous manner — the 

 Passeres and the Picarise, and certainly lie on the 

 Passerine border of the Picariw. He adds, " I 

 agree with my friend Dr. Shufeldt that the Swallow 

 and Swift are near akin." Mr. F. A. Lucas of Wash- 

 ington has shown [The Auk, vol. vi. pp. 8-13) that 

 the wing in the Cypselidse is extremely variable ; in 

 some it is modified as in the Humming-birds, in 



