OF GALLINACEOUS BIRDS AND TINAMOUS. 153 
fourth. His fifth Order, ‘‘ Grallatoriz,’”’ and his sixth, or “ Palmipides,” are named 
after a different principle. Cuvier’s ‘‘ Families” are named in the first class from the 
habits of the birds—‘‘ Accipitres Diurne” and ‘‘ Accipitres Nocturne ;” the third 
‘‘ Order,” the ‘‘ Scansoriz,”’ is also named on the same principle, or from the habits of 
the birds. He has no “ Families ” in the scansorial and gallinaceous ‘‘ Orders ;”? and 
the Families of the ‘‘ Passerine ” are all named from the beak, viz. “ Dentirostres,” 
‘« Fissirostres,” ‘‘ Conirostres,” and ‘‘ Tenuirostres:”’ this last “ Family ” is a curious 
assemblage of genera; it contains Sitta, Certhia, Trochilus, Upupa, Merops, Prionites, 
Alcedo, Todus, and Buceros. After this, let no modest young ornithologist be afraid of 
thinking for himself, when this great zoological chief has left us such a jumble. 
The “‘ syndactyle ” division of Cuvier’s ‘‘ Tenuirostres,” the ‘‘ Fissirostres,” and the 
Scansorial birds ought to be placed in very close contiguity ; and I have been more 
struck with the dovetailing of these very interesting groups than with that of any others 
in the class. One of the first things to be done in the study of these three conter- 
minous families is, for the time, to forget the peculiar modifications of the bill and the 
feet, and to look a little more deeply into the matter. Take the sternum alone in 
these three groups, and how large an amount of modification do we have! and yet the 
study of its development shows how slight and how gentle are the changes—how much 
is due to arrest in one, to overgrowth in another. The breast-bones of Caprimulgus 
and of Cuculus are almost identical in shape: the same part in Buceros is like that of 
the fledgeling Cuckoo,—the inner portion of the hyposternal piece not being lost along 
the margin of the entosternum. The sternums of the Toucan, the Woodpecker, the 
Plantain-eater, and of the Kingfishers (Dacelo, Alcedo) are very nearly alike ; that of 
Podargus belongs to the same style, but is especially like the sternum of some of the 
more delicate-billed Kingfishers. All these latter species have the hyposternal element 
forked. But the pelvis and the skull show just the same kind of facts, and prove the 
close relationship of these groups; and it would require the space of a goodly volume 
to give the matter in its fulness. 
The “‘ Fissirostres ” are not a little heterogeneous. The Swift (Cypselus) seems to 
have barely escaped being a Swallow ; and the abortion of the inferior laryngeal muscles 
and of the symmetrical czca coli is rather startling to one who has just been studying 
the true sylviine Hirundines. Must we set down to ‘‘ teleology” alone the sudden 
overgrowth in the Swift of the sternum and the wing-bones, and the abortive develop- 
ment of its legs and feet ? Without leaving the family of the Warblers, the Swallows 
and Martins have taken on the gaping mouth, the long wing, the forked tail, and the 
tiny feet of the Swift, but not to the same degree. Whilst they retain all the true 
sylviine structures, they overlap the ‘‘ Fissirostres” on their cypseline border, and 
might receive the title ‘‘ Swift-like Flycatchers ” (Muscicape cypseliformes). 
A very large amount of work has to be done for the ‘‘ Scansores ”’ and their ornithic 
neighbours, not merely in tracing the development of the skeleton, and especially the 
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