REPTILES. 



403 



is excited. They occur in both sexes, but are best devel- 

 oped 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.* 



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 im- 

 punity, I presume from despair, f 



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 ter- 

 minal scale forms a minute horn 

 on the summit of the flexible 

 appendage; and in a third species 



d.Stoddartii (fig. 34), the whole 

 appendage is converted into a horn, 

 which is usually of a white color, 

 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. Giinther has 

 remarked to me, may be compared with the combs of gall- 

 inaceous birds, and apparently serve as ornaments. 



In the genus Chameleon we come to the acme of differ- 

 ence 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 



* All the foregoing statements and quotations in regard to Copho- 

 tis, 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. 



fMr. Swinhoe, " Proc. Zoolog. Soc.," 1870, p. 240. 



figure, female. 



