Royal Microscopical Society. 
219 
This metamorphic fusion of parts, essentially distinct in morpho- 
logical origin, is very remarkable ; and to add to the mystery, the 
vomerine moieties are each of them formed in a distinct plate of 
cartilage, which, as a rule, does not exist in other birds. 
The “ Coracomorphse ” — five thousand known species there are 
of these — are characterized by this structure, at least as far as I 
can find, for I have worked out this part in scores of types,* not 
only of the natives of the Old World, but to an equal or even 
greater extent in South American, Malaysian, and Australian 
forms — the feathered denizens of the “ Notogaea,” or Southern 
World. 
The Swifts (“ Cypselus ”) have this structure as completely 
as their Passerine relations the Swallows. Just above the Ostrich 
order, the Hemipods (“ Turnicomorphse ”) show this structure on 
a very large scale, but the bony substance is only strongly tied to 
the cartilage. 
Leaving out the Tinamous, which are merely little Ostriches 
struggling to become of the winged order, there are certain climbing 
birds which refuse to conform to my friend’s Greek rules, “ and he 
whose heart is as the heart of a lion, did utterly melt ” in presence 
of this difficulty ; these birds, the Woodpeckers, retaining the 
strongest marks of any of a reptilian parentage, I beg to call the 
“ Saurognathae.” 
Differences of so remarkable a kind existing in the fore-face of 
the great groups of birds, and correlated with such exquisite 
specliazations as we find in the Woodpeckers on one hand, and the 
Singing-birds on the other — to say nothing of other groups, each 
member of which is a marvel of adaptive modification — such 
peculiarities as these may well decoy the student into these 
enchanting zoological territories. 
On the Development of the Shull and Face of the Genus Corvus. 
My youngest Crow-embryo is the Hooded Crow (C. cornix) at 
about the sixth day of incubation. The natural size of its head is 
shown in Plate XXXIV., Fig. 1. A palatal view of the skull 
(Fig. 2) at this stage shows that the first “ prae-oral arch ” (tra- 
beculae tr.) has coalesced throughout nearly its entire length, the 
posterior part (apices of the rods) alone being distinct. These 
apices diverge round the pituitary body (py.), and then coalesce 
with the “investing mass” ( i . v.) of the notochord (n. c.). The 
distal ends, besides coalescing by a continuation forwards of the 
median commissure, have sent forwards an azygous rostrum, the 
“pre-nasal cartilage”; this single cartilage answers to the double 
cartilages in which the mandible terminates. 
* Through the kindness of my friends, Osbert Salvia, Esq., and Mr. W. J. 
Williams, Assist. Sec. Zool. Soc. 
