Reviews — W. 0. Dietrich — Origin of African Eleiihants. 93 



discussed. Tlie chemistry of enrichment is considered : firstly in the 

 light of experimental data ; secondly from considerations of the 

 composition of mine waters, thirty-seven samples having been analysed. 

 Yery valuable are the contributions on the chemical relations and 

 occurrence of the minerals of copper, silver, gold, lead, zinc, and 

 iron, and of certain gangue minerals, including felspars, kaolin, 

 sericite, alunite, sulphates, and carbonates. There is a brief review 

 of the several classes of sulphide deposits in the States, and a 

 detailed review of the various mining districts. While having very 

 important bearing on the economic side of mining geology, the 

 bulletin forms a valuable contribution to the mineralogical chemistry 

 of the sulphide minerals. 



IX. — Probable Origin of the African Elephant. 

 W. 0. Dietrich. — Zur Stammesgeschichte des afrikanischen 

 Elephanten. Zeitsch. f. induktive Abstammungs- und Yerer- 

 bungslehre, vol. x, p. 49, with 7 text-figures, 1913. 



IN this paper tlie author discusses the probable origin of the African 

 Eiepliant. He first points out how very little material there is 

 at present upon which to base an opinion, and gives a useful list of 

 the principal discoveries. He then discusses at some length the chief 

 dental characters which are of importance in determining relationships 

 within the group. From tlie nature of its tooth structure he concludes 

 that the African Elephant, while in some respects highly specialized, 

 is an arcliaic type, and expresses liis belief that its primitive characters 

 cannot be the result of retrogressive changes in a more advanced type 

 such as Elephas mitiquiis, but on the other hand prove an independent 

 descent from some at present unknown type of Mastodon. It is 

 important to note, however, that although a Mastodon has been 

 recorded from South Africa, all the true elephants at present known 

 from deposits of Pliocene or Pleistocene age in Africa (the Sudan, 

 Zululand, and recently British East Africa) possess teeth of a more 

 specialized type than those of E. africanus. It seems, therefore, by 

 no means certain that this species may not have acquired the peculiar 

 characters of its dentition as a result of retrogressive changes, possibly 

 in consequence of some peculiarity in its food. 



A table is given, showing at a glance the various views that have 

 been expressed on this subject. 



C. \Y. A. 



X. — Brief Xotices. 

 1 . Wisconsin Geological and Natural History Survey, — An 

 instructive work on "The Geography and Industries of Wisconsin ", 

 by Professor 11. H. Whitbeck, has been issued by this survey 

 ( Bulletin No. xxvi. Educational Series, No. 3, 1913). The mineral 

 industries include, in order of importance, iron-ore, zinc-ore, stone, 

 clay, mineral water, lime, sand, and lead-ore. The annual output is 

 valued at about twenty million dollars. No coal occurs, the bed-rocks 

 being all older than any coal-bearing formations. In the value of com- 

 mercial mineral waters Wisconsin is foremost among the States. More 



