The Life and Writings of Agassiz. 19 



he prepared registers, in which he entered the names of all 

 the animals as they occurred to him in his studies. After 

 having continued this practice for more than ten years, he 

 arranged the names methodically, and published the nomen- 

 clature of each class separately, after having it revised by 

 the naturalists most distinguished throughout Europe in each 

 special branch. " The Nomenclator ZoUogicus" is preceded 

 by an introduction in Latin, in which the general principles of 

 nomenclature are profoundly discussed, and it has become an 

 authority universally acknowledged. In connection with this 

 work we must mention another publication, more extensive 

 and not less important — the " Bibliographie Generate d' His- 

 toire Naturelle ; " which grew up in a similar manner by the 

 side of the Nomenclator. It contains a list of the authors 

 cited in the former work, with bibliographical notices, and is 

 in course of publication at the expense of the Ray Society. 

 This work will form several large volumes ; the first num- 

 bers, containing a list of the publications of scientific institu- 

 tions, have recently appeared. 



We now come to speak of a series of discoveries which 

 have particularly tended to make the name of Agassiz known 

 to the public in general, and from which resulted his Glacial 

 theory. This theory is so generally known, that it may be 

 interesting to relate, in a few words, its origin, and the dif- 

 ferent phases in which it has appeared. Although now of so 

 wide application (extending to the whole northern hemi- 

 sphere, as far as erratic boulders and polished rocks are 

 found), its origin is to be sought in the Alps. It was among 

 the chamois-hunters of the Valais that the idea arose, that 

 masses of rock were transported to a distance from their 

 original position by the glaciers. These men, accustomed to 

 live in the high regions of the Alps, and seeing every year 

 enormous masses of rock transported to a distance from their 

 original positions by the glaciers, found no difiiculty in sup- 

 posing that all the boulders which are found in the valleys 

 had been transported thither in the same manner ; and as 

 they had observed the oscillation of the extremities of the 

 glaciers, — that is to say, their advance in one year and their 

 recession in the next, — they concluded, in like manner, that, 



