FRIG A TE-BIRDS. 



183 



on its lioad, to draw out the long tail-foatlu'is. It resents this insult by screaming and 

 sna))|iing, but never tries to escape by flying or shuffling along the ground ; in fact, 

 like all birds which have their legs placed so far behind, they cannot rise off a flat 

 surface, but re()uire a drop of a few feet to give them an imjjetus." Where rocks are 

 wanting, however, the trojjic-bird breeds in trees. The same gentleman, during a 

 mountain ascent on one of the Seychelles, observed a yellow-billed trojjic-bird (T'. 

 JlaiJi'rostris) enter a Iiole in the stump of a dead tree. " On returning," he says, " I 

 made for it. After a scramble over dead wood and granite boulders, I got to it. The 

 hole was about fifteen feet from the ground, and my man soon ascended, not, however, 

 without fears on my part that the rotten old stem would come down with liis weight. 

 Unfortunatelj- there was only a young bird inside it. Tiiis I took home and endeav- 

 ored to rear, but it only lived four days." Tlie young is cov- 

 ered with ]>ure white down, and consequently is very unlike the 

 downy youngs of the LaridiB. The chick, like that of all the 

 members of the order, is reared in the nest, or rather on the spot 

 where the egg was hatched, until able to fly. 



Only three species are known, — the two above mentioned, 

 and the red-billed, white-tailed P. cethereus, which is the species 

 represented in our wood-cut. 



In Fig. 89 is shown one of the more ob\ious characters of the 

 FREGATOIDE.E, namely, the remarkably short tarsus, the sliort- 

 ness and breadth of which is absolutely uuicpie amongst the Euor- 

 nithes. It is only equalled by the corresponding bone of the pen- 

 guins, in which, however, the three component metatars.ils are 

 nearly se]iarated, and equally well developed. On the whole, the 

 foot of the frigate-bird is short, and abnormally developed, for 

 the "webs" are so deeply excised that they hardly deserve their 

 name, and the tarsus is feathered to the legs and feathered to the 

 toes, — a very extraordinary feature in a " water-bird," it lu-ing, in 

 fact, the only one among all the birds so designated that exhibits 

 this cliaracter. The abnormal ratio of the phalanges of the middle 

 toe has already been mentioned. 



The wings are hardly less remarkable, since the culiitus is 

 longer than tlie upper arm bone by one third of its length ; and 

 as the humerus itself is very long, the stretch of the wings becomes quite excessive in 

 j)ro]iortion to the size of the body. In n'gard to the breast-bone we remark that the 

 hind border is described as truncate, without any notehes or lateral ]irocesses. Peculiar 

 to Fref/uta is also the fact tliat there is no interval between the lumbar and caudal ver- 

 tebne, as the transverse processes are continuously developed throughout these verte- 

 bra. As to the j)elvis, it may be remarked that the ilia do not meet together medianly in 

 front of the acetabula at all, as they do in both the other super-families. The caudal 

 vertcbriB have very strong transverse processes, and the external tail is long and very 

 forked. In many other external characters tlie frigate-birds show affinities to the 

 cormorants; for instance, in the shape of the bill, which is composed of several pieces 

 separated by grooves, ending in a strongly-hooked nail, in tlie naked gular pouch, and 

 also in tlie pectination of tlie claw of llie third toe. The jtterylosis ap]>roaclies that of 

 the cormorants, but is peculiar on account of the remarkable sparse arrangement of the 

 contour fcathcre. 



Fio. 89. — Leg bonoB of 

 Frtfiata aqnllit, from 

 the' knee, tb, tibia ; 

 mt^, turso-metatarsus. 



