HOMRAI OF THE HIMALAYA. 



179 



1 



much excited. The female and young of a year old have the legs and I 



plumage coloured exactly like the male ; from which the former differs by 



being smaller ; by having the irides of her eyes, pure hoary ; the naked 



skin of the ophthalmic region, pale purpurescent dusky; and lastly, by 



wanting the black colour which distinguishes the casque, and ridge, cutting 



edges, and interior surface of the bill, in the male; those parts of the 



casque and bill of the female, being red, like the sub terminal portion of 



the upper mandible of both sexes. The mature female's bill and casque j 



are shaped like those of the old male, but are both smaller in proportion. 



The young have the bill much less arched, and thicker in proportion 



to the length ; the cutting edges are entire, void of brittle substance or 



serration ; and there is no casque, or rather the casque has no develope- 



ment or separation from the bill, anteriorly : for, posteriorly, it has both, 



very soon after birth. In the second year the anterior portion of the 



casque begins to separate itself from the ridge of the bill, exhibiting a 



wedge form ; the apex of which, gradually receding during the third year, \ 



in proportion as the casque acquires more breadth and height in front, 



comes at length, in the mature state to form the centre of that inward 



curve or crescent, the ends of which are the hoiiis of the old bird's casque. 



The younger the bird, the narrower the casque in front. Old age alone 



makes it nearly as broad before as behind. The sketches appended to 



this paper will complete the illustration of this point, which is of importance 



as a guard against the multiplication of imaginary species, derived solely 



from diversities in the shape of the bill and casque. The bill of the young 



is at first of an uniform pale greenish yellow, with a small portion oi' hlack 



at the base only. Their iris, whatever the sex, is at first, hoary, like the 



females; and the ophthahnic region, })alc dnsky. Posleriorhj, tlicir 



casque is soon darkened, it'thcy be males — red(l( lud, if iht>y i)o females: 



but the black or red space (KMiniiiL;- the sopaialion of the casque and hill, | 



anteriorly, is later manii'osted; because^ its manil'i'sliu ii>ii (IcpriuU \\\nn\ the 



developemcnt of tlic castpic itself m iluiL ilic la^i i.K \ l K)[)ctl purl of ii. 



I 



