animal is excited. They occur in both sexes, but are best developed
when the male arrives at maturity, at which age the middle appendage is
sometimes twice as long as the head. Most of the species likewise have
a low crest running along the neck; and this is much more developed in
the full-grown males than in the females or young males. (67. All the
foregoing statements and quotations, in regard to Cophotis, Sitana and
Draco, as well as the following facts in regard to Ceratophora and
Chamaeleon, are from Dr. Gunther himself, or from his magnificent work
on the Reptiles of British India, Ray Soc., 1864, pp. 122, 130, 135.)
A Chinese species is said to live in pairs during the spring; and if
one is caught, the other falls from the tree to the ground, and allows
itself to be captured with impunity I presume from despair. (68. Mr.
Swinhoe, Proc. Zoolog. Soc. 1870, p. 240.)
[Fig. 34. Ceratophora Stoddartii. Upper figure; lower figure, female.]
There are other and much more remarkable differences between the sexes
of certain lizards. The male of Ceratophora aspera bears on the
extremity of his snout an appendage half as long as the head. It is
cylindrical, covered with scales, flexible, and apparently capable of
erection: in the female it is quite rudimental. In a second species of
the same genus a terminal scale forms a minute horn on the summit of
the flexible appendage; and in a third species (C. Stoddartii, fig. 34)
the whole appendage is converted into a horn, which is usually of a
white colour, but assumes a purplish tint when the animal is excited.
In the adult male of this latter species the horn is half an inch in
length, but it is of quite minute size in the female and in the young.
These appendages, as Dr. Gunther has remarked to me, may be compared
with the combs of gallinaceous birds, and apparently serve as
ornaments.
[Fig. 35. Chamaeleo bifurcus. Upper figure, male; lower figure, female.
Fig. 36. Chamaeleo Owenii. Upper figure, male; lower figure, female.]
In the genus Chamaeleon we come to the acme of difference between the
sexes. The upper part of the skull of the male C. bifurcus (Fig. 35),
an inhabitant of Madagascar, is produced into two great, solid, bony
projections, covered with scales like the rest of the head; and of this
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