1895.] DB. J. DE BEDEIAGA ON IlLE PYEENEA.N NEWT. 153 



of the dark area of the sides of the belly, and are partly placed on 

 the grey ground-colour and partly on the bright-coloui-ed median 

 area of the belly. The latter varies in its width ; it is pale yellow, 

 yellow with or without traces of orange and pink, orange or red. 

 Generally the whole middle portion of this area is entirely imma- 

 culate ; sometimes with very few spots, and these distinct, wide 

 apart, scattered, and entirely dark round ones, just as if they bad 

 been accidentally misplaced. The throat is immaculate or indis- 

 tinctly dotted with grey ; its ground-colour is similar to that of 

 the belly, but it has never the same rich tint, sometimes so 

 beautiful ; the lower edge of the tail on the contrary may 

 be even more brightly coloured than the belly. When collecting 

 these newts, I was quite struck by an orange or red line underneath 

 the tail which the aniuial seemed intentionally to exhibit, and 

 which looked just like the antenna of a boiled crawfish. The anal 

 prominence appears also often orange or reddish, and these colours 

 can extend over the lower surface of the limbs. The inner fingers 

 and toes are always lighter than the outer ones and as a rule 

 yellowish ; palms and soles are yellowish or partly yellow and 

 partly, on their external portion, grey. The transverse dark 

 stripes on the fingers and toes are more or less distinct. The tips 

 of the fingers and toes are generally dark. 



PupU oval, with a pale gold margin interrupted below in the 

 middle. Iris pale golden, strongl}' spotted with light and dark 

 brown. 



Variation in Colour. 



The ground-colour and the markings vary to a certain extent in 

 M. aspera, but these variations are mostly either merely individual 

 or due to sexual selection. In other cases light and bright 

 colours appear temporarily when the newt lives in water and dis- 

 appear as soon as it goes on land. Different combinations of 

 colours and shades as well as markings are also in so far tem- 

 porary as they vanish with the growth of the newt. As regards 

 the colom-s of the upper surfaces of the adult, both sexes are alike ; 

 the diverse modes of life affect them only to a certain extent, for 

 we know that this species is brightly coloured in summer and that 

 it gets a duller colouring in winter. The modifications of colours 

 of the lower surfaces are doubtless connected with the sexual 

 functions, and, strange to say, the greater brightness of colour is 

 shown by the females, whilst in all other species we find in the 

 female plain colours, whilst the males acquire a more intense 

 and brilliant coloration. 



As a rule the colours of both sexes are alike in the young, but 

 the older the newts get the more the colouring of their lower 

 surfaces is differentiated. The young ones are generally light 

 grey and more or less spotted with yellow or striped ; their belly 

 is pale orange. With the growth of the individual appears a 

 tendency to deeper and more intense colouring of its upper surfaces, 

 and the yellow markings very often disappear altogether or become 



