FASCICULI MALATENSES 
1 57 
where the adult only displays different shades of inconspicuous brown ; the 
dorsal cross-bars of black or dark green on several of the Hydrophinae 
disappear with age, leaving an almost uniform dull green or grey coloration. 
These are only a few instances, taken from a comparatively small number 
of species from a very limited area ; but, even from them, it is clear that the 
young of reptiles lose their characteristic juvenile coloration in one of two 
ways, either by the fading of brilliant or intense colours, or by the growth of 
dark pigment, which encroaches upon pale areas, either obliterating them 
altogether or breaking them up in such a way that they arc no longer con¬ 
spicuous, In some genera the conspicuous coloration persists, in a more or 
less marked way, through life in certain species, being confined to the young 
in others, so that it is more probably a vestigial character than a new develop¬ 
ment ; for example, the yellow streaks on the head which disappear in the 
adult of Cyclemys annmdalii , normally persist through life in C . amboinensis. , 
while the lateral bars in Cables versicolor are only occasionally visible in this 
species in the adult (when it is in a state of irritation), generally present in the 
young, and at any rate closely paralleled in the adult of C , emma even when 
the animal is undisturbed. Of course, sexual coloration, such as the cross-bars 
on the sides of Liolepis bellii , has no connexion with this phenomenon of the 
juvenile livery, and, equally of course, there are many reptiles which retain a 
conspicuous or intense coloration, however old they may be, and others which 
develop such a coloration after their extreme youth is past, for reasons possibly 
other than sexual. Among Batrachians, conspicuous coloration is rare in 
youth ; frogs and toads endowed with bright pigment, like Ixalus horridus , 
do not possess it when first they lose their tails, though its extent in later 
development may be indicated, while almost adult specimens of Ichthyopkis 
glutinosuSy which l have seen alive in a stream in the Malay Peninsula, have 
had both the yellow and the black of their characteristic coloration less intense 
than was the case with larger individuals/ 
VARAN1DAE 
38. Varanus nebulosus, D. & B. 
Jalor, and Batang Padang, South Perak, 
39. Vcranus sal vat or, Laur. 
Jalor. 
* On the coast ot the Pa tan i States both Faranus nebulosus and F t salvator 
are very common, especially on the mud-flats near Jambu, where they stalk 
