436 



NATURAL HISTORY OF BIRDS. 



present super-family from tlie Cain-imulgidie. Osteologic.illy the swifts and humming- 

 birds resemble each other closely iu all respects except in the shape of the bones of 



the face. The breastbone 

 is liiglily cliaracleristic, 

 having a high keel, and 

 an entire, unnotched pos- 

 terior margin. The ]>ro- 

 ]>ortion.s of the different 

 sections of the wings are 

 also noteworthy, the hu- 

 merus being very short, 

 the forearm longer, and 

 the hand extremely long, 

 whence Kitzseh's name 

 of the group. The myo- 

 logical formula is A-i-, 

 nniijue amongst Piearian 

 aiicl Passerine birds, and 

 only shared l)y the owls. 

 The tensor patagii brevis 

 is fjuite peculiar, no ten- 

 don being developed, and 

 the fleshy belly running 

 on to a special tendon 

 which springs from the 

 lower end of the outer surface of the humerus, ami is 

 continued, ]iaralk'l to the forearm, along the radial 

 margin to tlie hand (Fig. -111). As to the visceml an- 

 atomy we onlyinention the .absence of ca'cn, concom- 

 itant witli till' aV)sence of tuft to the oil-gland, a 

 feature wliich leads us to the ]it(rylography, in regard 

 to « hich we ])oint to the unicjuely small number of 

 secondaries, six to seven. 



From all this it is evident that the swifts and liuiu- 

 ming-birds are very closely allied, notwitlistamling the 

 extreme specialization of the facial ])art of the head 

 in two oi)])osite directions. The swifts have the 

 mouth sjtlit to beneath the eyes, and the bill is ex- 

 tremely short, broad at base, and the gajte extraordi- 

 narily wide; the ]ialate is built on the princijile of 

 complete iegithognathism, "the vomerine bones being 

 p-afted ii])on the nasal wall." In the humming-birds, 

 on the other hand, the bill is long and narrow, the 

 month not split, consequently the gape also narrow, 

 and the jialate is, according to P.avker, schizognathous, 

 the vomer being pointed anteriorly, and only tied to the alinasal wall by a fibrous liga- 

 ment, but not grafted upon it. But even in the pal.atal structure the relationship 

 between swifts and humming-birds is manifested by the development of the niaxillo- 



Fio. 218.- 



■ Apalmlerma narina, African 

 trogoii. 



