212 THE ZOOLOGIST. 



In a stone -quarry near Cette (S. France) I was struck by a 

 Hyla whose upper surfaces, of a rich gold colour with small, 

 darker speckles, were wonderfully adapted to the limestone block 

 on which it was sitting. Curious to say, another one, on a rock 

 of the same colour, was of the usual rich green tint. I presume 

 the eyes of the latter were shut at the time, and the adjustment 

 of the colour therefore impossible. 



It is also sensitive to atmospheric changes, and more so to 

 moisture and dryness than to actual heat or cold. An individual 

 brought from the Rhine-woods one afternoon to the drier air of 

 the capital changed the same evening to a dark green ; next day 

 the colour was grey with small light spots, and afterwards it 

 became dark brown with yellow blotches. The skin had also 

 become rough and leathery — a condition which might be taken 

 to indicate complete prostration of the nervous system, and a 

 temporary reversion to ancestral colours. During a rainy night 

 it changed to its original smooth green appearance. 



Such observations will have been made by everyone who has 

 kept this species in confinement, but they lose some of their 

 value when it is remembered that the colour is equally affected 

 by desquamation, change or lack of food, light, mental depression 

 and ill-health of every sort, and that, besides, different individuals 

 vary in this respect. Hence it is generally impossible to decide 

 to what influence the change of colour, in most instances, is 

 due. To obtain anything more than a superficial knowledge of 

 the action of these different agents would require a long series 

 of experiments, pursued on a more systematic basis than has 

 hitherto been attempted. 



V. Fam. Discoglossid^e. 



1. Alytes obstetricans, Laur. — This is most probably a French 

 immigrant. It was first observed in the western districts of 

 Germany (Lower and Middle Rhine, Westphalia, Eifel, Nassau, 

 valleys of the Moselle, Saar, Nahe and Lahn), but is now being 

 discovered in various Central and Northern parts of the country 

 (llartz Mountains, Brunswick, Hanover). 



Its distribution in Baden is not determined as yet. Bona- 

 parte notes its occurrence at Mannheim, Niisslin at Freiburg. 

 It' it reached this point from the northern cantons of Switzerland, 

 as is quite likely considering its abundance there, there is reason 



