IN TROD UCTION log 



must have been morphologically inferior to these descendants, which on 

 evolutionary principles have gone on improving, while the Ratite branch 

 retrograded. That this last branch also may have improved and under- 

 gone specialization is true, but not to the point, for it can hardly have 

 improved up to the level at which was the parting of the ways, and thus 

 we are quite justified in continuing to regard the BatitsR as the lower 

 branch, and in beginning with them. They were shewn beyond doubt 

 by Huxley to form five separate groups, which we shall here, as before,^ 

 dignify by the name of Orders, adding to them a sixth, though little has 

 as yet been made known of its characteristics. Of this, which contains 

 the great extinct Birds of Madagascar, he did not take cognizance, as it is 

 here necessary to do. In the absence of any certain means of arranging 

 all these orders according to their affinities, it will be best to place their 

 names alphabetically thus — 



Ji^PYOBNiTHES. Fam. ^^injornithidae. (Roc). 



Apteryges. Fam. A])terygidx (Kiwi). 



Immanes. Probably two Families ^ — Dinornithidae (Moa). 



Megistanes. Fam. i. Casiiariidae (Cassowary) ; Fam. ii. Dromseidse 

 (Emeu). 3 



RHEiE. Fam. Rheidse (Rhea). 



Struthiones. Fam. Struthionidx (Ostrich). 



Some systematists think there can be little question of the Struthiones 

 being the most specialized and therefore probably the highest type of 

 these Orders. Nevertheless the formation of the bill in the Apteryges is 

 quite unique in tlie whole Class, and indicates therefore an extraordinary 

 amount of specialization. Their functionless wings, however, point to 

 their being a degraded form, though in this matter they are not much 

 worse than the Megistanes,^ and are far above the Immanes — some of 

 which at least appear to have been absolutely wingless, and were thus the 

 only members of the Class possessing but a single pair of limbs. 



Turning then to the Carinatse, their subdivision into Orders is attended 

 with a considerable amount of difficulty ; and still greater difficulty is 

 presented if we make any attempt to arrange these Orders so as in some 

 way or other to shew their respective relations — in other words, their 

 genealogy. In regard to the first of these tasks, a few groups can no 

 doubt be at once separated without fear of going wrong. For instance, 

 the Crypturi or Tinamous, the Impennes or Penguins, the Striges or Owls, 

 the Psittaci or Parrots, and the Passeres, or at least the Oscines, seem to 

 stand as groups each quite by itself, and, since none of them contains any 



^ See Ann. Nat. Hist. ser. 4, xx. pp. 499, 500. It must, however, be borne in 

 mind that what here is meant by an " Order " of Aves is a very different thing from 

 an " Order " of Reptilia. 



2 On this see Prof. T. Jeffery Parker's most instructive paper ( Traits. Zool. Soc. 

 xiii. pp. 373-431, pis. Ivi.-lxii.), in which, though admitting only a single Family, he 

 recognizes three Subfanjilies — Dinornithinx, Anomalopteri/ginm and Emeinw. 



^ Since this was in type Dr. Stirling has announced (Trans. B.oy. Soc. S. Austral. 

 XX. pp. 171-190) that fossil remains of a gigantic bird, Genymmis, found at Calla- 

 bonna in South Australia, prove it to have been allied to the Emeus, in which case 

 a third Family of Megistanes will probably be required. 



■* Nor, possibly, than the jEijyornithes {cf. Andrews, Ibis, 1896, pp. 376-389, pis. 

 viii. ix.). 



