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greatly exaggerated by the necessary modification of the bones in 
the giant species, by their thickness, and by the size of the ridges 
and out-standing processes for muscular attachment; but the two 
birds are, nevertheless, near allies. In the skull, especially, is this 
difference exhibited; and any large bird may differ osteologically 
from its small relations from this cause, much more than from any 
necessary specific or generic distinction of character. 
Again, any peculiarity of habit in an aberrant species, or genus, 
will make, as it were, large demands upon the structure of those parts 
or organs which are subservient to this (as it regards the group or 
family) eccentric mode of life. The Secretary-bird (Serpentarius) 
amongst the Vultures, the Spoonbill (Platalea) and the Oyster- 
catcher (Hematopus), the Pelican and the Scissors-bill (Rhynchops), 
each form so different from its relations, are familiar instances of 
this law. 
Perhaps we ought to expect the skull of a bird to be the seat of 
more extensive teleological modifications than any other part of the 
skeleton, seeing that it must perform such varied duties, learn so 
many trades, and be the servant and caterer to the whole body; 
whilst the hands, which in some of the higher mammals minister to 
the necessities of the creature, are here necessarily restricted to one 
or two functions. Ifa rule like this could be clearly made out, it 
would go far towards settling many a disputed point of relationship ; 
the Hornbills and the Kingfishers would not then startle the student 
of the Insessores; and the Flamingo (Phenicopterus), notwithstand- 
ing its lamellirostral character, might be allowed to stalk amongst 
the Herons. 
The broad expanded occiput of the Baleniceps differs but little 
from that of the Adjutant ; but the upper surface of the skull, instead 
of being generally rough and convex, as in the latter bird, is smooth, 
flat, and even concave at its anterior half. In the Baleniceps, as in 
the Heron and Boatbill, the large eye-ball has elevated the upper or- 
bital margin above the level of the mesial part of the skull, whilst in 
the Adjutant that margin is some distance below. Moreover, the 
skull of the Baleniceps is very short as compared with that of the Ad- 
jutant, and in density and polish of the bone is more like that of the 
great Maccaws (Ara) ; its transverse hinge too, with the upper jaw- 
bone, is more like that of these birds than that of its own congeners. 
There is no bony bridge over the temporal fossee in this bird, in which 
respect it agrees with the Heron and Boatbill, and differs from the 
Adjutant. The eye-ball being very large and the skull very short, 
the anterior orbital margin is one-third of an inch in front of the 
great transverse hinge; whilst in the Adjutant, and even in the 
Heron, it is half an inch behind that hinge. This modification has 
caused a displacement of the lacrymal bones, which, although they 
form the anterior boundary of the orbit, as in other birds, are in 
front of the great hinge, instead of behind it. The nostrils are high 
up on the jaws, two-thirds of an inch in front of the hinge, and more 
than one inch apart ; at their anterior end they are continuous with 
the deep submesial grooves that mark out the strong bony ridge 
