322 LEISURE-TIME STUDIES. 



young salamander cannot be explained by any such phrases 

 as "adherence to type." "unity of type," "natural 

 symmetry," and the like, unless, indeed, we may suppose 

 that Nature imitates humanity in its anxiety for symmetry, 

 and supplies the young salamander with gills which never 

 were used, and which never were meant to be used, -on the 

 principle of an architect who places blank windows and 

 painted imitation blinds on a house under the idea of secur- 

 ing uniformity. Such a practice, admittedly far from aesthetic 

 in architecture, is positively degrading when applied to the 

 explanation of Nature's ways and works. It is an idea, 

 besides, which is founded on pure and baseless assumption, 

 and as such demands no further notice. The opposing 

 view, which regards the gills of the young Alpine salamander 

 as the representatives of organs which, at a former period in 

 the history of the species, were used for breathing in its 

 water-living stages of development, is, on the other hand, 

 not only reasonable and consistent, but also demonstrates 

 how great an alteration in the nature of a living organism 

 a change of surrounding conditions may induce. As Mr. 

 G. H. Lewes remarks, "this aquatic organisation has no 

 reference to the future life of the animal, nor has it any 

 adaptation to its embryonic condition ; it has solely reference 

 to ancestral adaptations, it repeats a phase in the develop- 

 ment of its progenitors." That the change in the Alpine 

 salamander's mode of development has, in reality, been one 

 entirely dependent upon external causes, is a suggestion 

 which, as made by Fraulein von Chauvin, carries weight 

 with it in support of the idea of the close relationship 

 between living beings and their environments. Want of 

 food would thus be a condition which could scarcely be 

 conceived as having driven the Alpine newt to its high 

 habitat, since the dietary would become scarcer and more 

 difficult to obtain the higher the altitude it reached. More 

 probable is the idea that slow elevation of the land surface 

 was the cause of the change in habits and development. A 

 slow rise of land would imply an equally gradual alteration 



