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Show 1895.] DE. J. DE BEDEIAGA ON THE PYEENEAN 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-coloured 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 immaculate ; sometimes with very few spots, and these distinct, wide apart, scattered, and entirely dark round ones, just as if they had been accidentally misplaced. The throat is immaculate or indistinctly 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. W h e n collecting these newts, I was quite struck by an orange or red line underneath the tail which the animal seemed intentionally to exhibit, and which looked just like the antenna of a boiled crawfish. The aual 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. Pupil oval, with a pale gold margin interrupted below in the middle. Iris pale golden, strongly 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 disappear as soon as it goes on land. Different combinations of colours and shades as well as markings are also in so far temporary as they vanish with the growth of the newt. As regards the colours 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 iu 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 |
