223 AVES. 



yoke-footed geneva. The species \a'1uc1i possess cccea closely accord ivith the Cuculoides in 

 their anatomy, but all of them possess the accessory yilume to the clothing feathers, in whicli 

 they differ from that grovip. We sulidividc tlicni into Tror/onoiihs and Ci/pseloiOes. 



The TrnrjnnniJes consisting of the Tnigons only, it iviU be suificicnt to refer to the generic 

 head (p. 2\G). They liave twelve tail-feathers. 



Tiie Cypseloides have only ten. They divide into two triljes, i\liich may be termed Parvi- 

 roslres, containing the family of Podargues and i\Ioth-liunters, nocturnal s]ieeies with great 

 cocea, and \\hich hiv mottled eggs ; and Tenuirostres, comjirising the two distinct families of 

 the Swifts and 1 lunimiiig-birds, whieh have no eccca, and lay ivhite eggs, the last-named 

 family dilfering remarkably from all the pireceihiig S/rcpilores in having a conqilieated niferior 

 lar\'iix, wliidi character ulitains throughout the next onles', "without a single known execjition. 



Althiingh the foregoing long series of groups, more or less subordinate, cMiiee a decided 

 mutual attinitv and tolcrablv regular suecessiousliip, to those wlio have practically studiei! 

 them, we have been unable to detect a single character that n\\\ apply to all, and the onh' one 

 \\hieh approximates to being general, consists in the lo\\er laiMix being piroviiled witli onh" 

 the stenio-tracheal pair of muscles, save m the single family of the Ilunimiug-birds ; hence 

 these birds are nnaliie to inflect the voice, and siiiij; and they are generally very inferior in 

 mtelligenee and docility to the members of either of the three other orders with ^\liich Me are 

 now engaged ; the Picoides and Ilooijocs constituting the chief exceptions to this geneiahzation. 

 Linnaeus obtained a glimpse of their distinctness from the Paxscrina, when he instituted his 

 ordinal divisions Piece and Passeres; but lie fell into error in assigning a position among the 

 former to the Crows, which alone could have induced Cuvier to remark that he could discover 

 no distinctive character to seianatc the Pica' and Pnsseres of his great predecessor. 



The series of SlrejiUnres can accordingly be dclined only by negative cliiiracters, derhed 

 principally from comiiarison of them with the Passerince. Perhaps the most remarkable fact 

 connected with their anatomy, consists in the ctt'ca being invariably either altogether absent, 

 or, if present, developed to a considerable but fixed size, which never varies; this diversity 

 being found to exist in groups that are nearly alhcd, as in the Swifts and Moth-hunters, the 

 Kingfishers and Todies, &e. 



IV. C.VNTORES, or the restricted PasseriDce. — It is impossible for a greater contrast to be 

 afforded than is furnished by this ordinal division and the preeeiliug one. Although cuni- 

 prising many more species and received generic divisions than the three foregoino- orders 

 collectively, there is absolutely no essential difference of structure percc|)til)le thmueliout the 

 whole immense series; the only dilfcreuces consisting in the degrees of developenieiit of parts 

 common to all : the pecnhar type of skeleton, digestive and vocal organs, &c. being mvarialjlv 

 one and the same, just as the Ilnmming-f'ird or Parrot model is analogously varied, in a miiicn- 

 degree. There are no subdivisions equivalent to those which have been indicated as families 

 even of the StrepiUircs, iiowever the beak may vary in magnitude and form; the most dissi- 

 milar beaks being often unaccompanied by other mailvcd diversities, so that a dead specimen 

 deprived of its head, although at the first glance it might be referred with certainty to the 

 present order, could oul\ In a f '» instances be assigned, even on anatomical examination, to 

 any |)artieular group of it, and the plumage and style of colouring would even then afl'ord the 

 surest indication of its affinities, in the great majority of cases. In the Slrepi/ares, on the 

 contrary, any one organ, and very commonly a single ordinary clothing feather, woiUd snttice 

 to indicate the very genus from which it had been taken; the varieties in the form of the 

 sternal apparatus may be cited as one illustration of the considerable diversities observable in 

 the wliole structure of the S?rpy;i/or£'S; whereas a single sternal a]iparatus (fig. Sfi, p. 17''^), 

 we have deemed fully aihapiate to represent the form of this ini|)ortant portion of the skeleton 

 throughout the amazingly extensive series of the present division.* There are, in fact, no 



* Tliu itcrtial ai)p/ir;ilUb uf ijunicnjiis guntra ^.f r„,>t(,rcs arc bcaiUUully ll^'urccl in I\lf. V;irrtirs Jli^luy;/ c/Biiti.J' ''-''■, 



