OF GALLINACEOUS BIRDS AND TINAMOUS. 201 
Rhea, Tinamus, Hemipodius, Dendrortyx, Perdix, Phasianus, Gallus, Pavo, Meleagris, 
Oreophasis, Crax, Talegalla, Goura, Syrrhaptes, Columba, Pterocles. Here we see that the 
Syrrhaptes (Pl. XXXVIII. & Pl. XLI. fig. 4) stands high in this respect, standing 
between Goura and Columba. That, however, must be qualified by showing that whilst 
there is, as it were, a sudden rise towards perfection of growth, yet nevertheless there 
are deficiencies in detail that modify this anomalous sternal completeness in so low a 
bird. Iam not more surprised at finding such long-wingedness in the almost struthious 
Syrrhaptes, than in seeing birds related to the Thrush and the Sparrow with scarcely 
the power to fly: sudden arrest or over-development of some particular organ is not at all 
uncommon in nature. Zoologically, the Stilt-Plover is but a somewhat absurd Dotterel ; 
and the shanks of the Flamingo only serve him to stalk about between the stilted Cranes 
and the clacking Geese. Were not the graduation of the sternum from the Gallinaceous 
to the Pigeon-group very gentle, that of the Syrrhaptes might cause surprise ; but the 
change is easily made, and the clinging of the inner hyposternal process (Pl. XLI. fig. 4) 
to the entosternum for most of its length, and then its rejoining the mesial piece at the 
end, is all soon done in actual nature by allowing the bony matter to creep further and 
further along the membranous spaces between the cartilaginous bands. ‘The great 
distance of the external fork of the hyposternum from the end of the bone is very extra- 
ordinary in the Galline (Pl. XLI. figs. 9 & 10) and the Pigeons. In many water-birds, 
in Owls, Giant Goat-suckers (Podargus), in Woodpeckers, Toucans, Kingfishers, Rollers, 
where the hyposternum is double, the outer piece comes very nearly to the same trans- 
verse line as the xiphisternum. This is not always the case in water-birds, as may be 
well seen in Numenius arquatus ; so that the hiatus between Syrrhaptes and the Pluvia- 
lines is somewhat filled up even as to this character. 
In the individual now under description the inner hyposternal fork of the right side 
is as free from the body of the sternum as in Goura; on the left side there is an 
ossified tendinous band, which, as in the growing Pigeon, converts the notch into a 
fenestra (Pl. XLI. fig. 4, hys. xs.). That which strikes the eye at once is that neither 
of the hyposternal forks diverge nearly so much as in the Pigeons: there is a much 
greater tendency to that parallelism which is so marked in the Lapwing’s sternum, and 
which, having a certain amount of filling up, is tending towards the curious, oblong, 
complete sternum of the ‘‘ Gruinz.” As in the Plovers, these processes of the sternum 
of Syrrhaptes are not nearly so pedate as in the Fowls and Pigeons. The great ento- 
sternal keel (Pl. XXXVIII, es.) is quite equal to that of the Pigeon; but it does not 
stand forward so well as in that bird or the Plover, but falls back in a very gallinaceous 
manner (Pl. XLI. fig. 10, es.), although not so much as in the purer types. Its ante- 
rior margin is very thick, and it suddenly thickens, as in the Plover and Curlew 
(Numenius), not gradually as in the Pigeons and Fowls. The broadest part of the space 
on the keel for the ‘“‘ pectoralis major ” is scarcely 3 lines ; in the sternum of Columba 
livia it is 4} lines,—the two sterna being nearly of the same size, and the greatest 
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