INTRODUCTION 13 
the Alectoromorphe [Gallinx] and the Peristeromorphe [Columbz]. They 
cannot be included within either of these groups without destroying its 
definition, while they are perfectly definable themselves.” Hence he 
would make them an independent group of equal value with the other 
two. Both Prof. Fiirbringer and Dr. Gadow consider the Pigeon- 
alliance the strongest, and indeed the general resemblance of most parts 
of the osteology of the two groups, so well shewn by M. Milne-Edwards, 
combined with the Pigeon-like pterylosis of the Sand-Grouse, leaves no 
room for doubt; but the many important points in which they differ 
from the more normal Pigeons, especially in the matter of their young 
being clothed with down, and their coloured and speckled eggs,! must be 
freely admitted. Young Sand-Grouse are not only “‘ Dasypzdes” but 
even “ Precoces” or Nidifuge at birth, while of course every one knows 
the helpless condition of “ Pipers”—that is, Pigeons newly-hatched from 
their white eggs. Thus the opposite condition of the young of these 
two admittedly very near groups inflicts a severe blow on the so-called 
“ physiological” method of dividing Birds before mentioned (page 74), and 
renders the Pteroclidx so instructive a form. The Colwmbzx considered in 
the wide sense suggested, possessed another and degenerate subdivision in 
the Dopo and its kindred, though the extirpation of those strange and 
monstrous forms will most likely leave their precise relations a matter of 
some doubt ; while the third and last subdivision, the true Columbz, is 
much more homogeneous, and can hardly be said to contain more than 
two Families, Colwmbide and Didunculide—the latter consisting of a 
single species (the absurdly-named “DopLEer”), and having no direct 
connexion with the Dididzx,? though possibly it may be found that 
the Papuan genus Otidiphaps presents a form linking it with the 
Columbide. 
The Galline would seem to hold a somewhat central position among 
existing members of the Carinate division,? whence many groups diverge, 
and one of them, the Opisthocomi or Heteromorphe of Huxley, indicates, 
he hinted, the existence of an old line of descent, now almost obliterated, 
in the direction of the Musophagide and thence, it has been inferred, to 
the Coccygomorphe of the same authority. But these ‘“‘Coccygomorphs” 
would also appear to reach a higher rank than some other groups that 
we have to notice, and therefore, leaving the first, we must attempt to 
trace the fortunes of a more remote and less exalted line. 
It is impossible with our present knowledge to thread the maze in 
which the taxonomer now finds himself. The Pelargomorphe of Huxley 
will be seen to differ much from Dr. Gadow’s group of the same name ; 
and, though it has been shewn that “ Desmognathism” must be aban- 
doned asa bond of union, just as “ Schizognathism” has to be relinquished 
as a broken alliance, the difficulty of finding a place for the Anseres seems 
as hard as ever. That ancient form, Palamedew (ScREAMER), which is 
1 This fact tells in favour of the views of those who hold the Sand-Grouse to be 
allied to the Plovers ; but the eggs of the Pigeons tell as strongly the other way, as 
do the young. 
2 Phil. Trans. 1867, p. 349. 
3 Of. Parker (Phil. Trans. 1850, p. 755). 
