282 ReporU and Proceedings — 



respect a comparison with Neumayr's book before mentioned shows 

 how much nowadays even the lapse of seven years may affect the 

 progress of science — but, what strikes us even more, so much 

 elaborate thought and such original views are displayed in every 

 chapter, that we admire the author as much when we dissent from, 

 as when we agree with, him. 



In the concluding chapter we are expressly told, what the attentive 

 reader must already have become aware of, namely, that the funda- 

 mental view which guided the author is a decided uniformitarian one. 

 The remainder and larger portion of the same chapter is dedicated 

 to a discussion of the Evolution theory ; here Dr. Koken strongly 

 opposes the overwhelming part ascribed to natural selection. 



The two maps are very acceptable, being reconstructions of the 

 continents and seas during the Cretaceous (plate i.), and during 

 the older Tertiary, together with an illustration of the extension 

 of the Pleistocene Ice period in the northern hemisphere (plate ii.). 

 They are in the main on the plan of Neumayr's reconstruction of 

 Jurassic continents, which is also added by means of black dotted 

 lines on the first map. Dr. Koken's maps serve not only as 

 illustrations to the respective chapters of the text, but they are, 

 as it were, graphic summaries of the same ; they will be particularly 

 appreciated by those who have hithei'to sought in vain for some 

 guidance of this kind when working on geographical distribution 

 of organisms. The figures in the text are first-rate. 



An English translation would prove a success to an enterprising 

 publisher, and it might not be indispensable to many scientific 

 workers, for the book ranks with Neumayr's Erdgeschichte and 

 Prof. Suess' Antlitz der Erde in its clear as well as fascinating 

 writing. 



Geological Society of London. 



I.— April 25th, 1894.— Dr. Henry Woodward, F.R.S., President, 

 in the Chair. 



Mr. A. R. Sawyer, referring to specimens exhibited by him from 

 the Transvaal, Orange Free State, Cape Colony, Mashonaland, and 

 Matabeleland (the last-mentioned collected during the recent war), 

 remarked that gneisses and gneissose granites cover a large portion 

 of Mashonaland, together with patches of schistose rocks and a few 

 stratified rocks. He drew attention to the fantastic shapes assumed 

 on weathering by the granitic gneiss, which he considered solely 

 due to atmospheric agencies, and not to ice-action or to the effects of 

 submersion. 



The schistose rocks are, for the most part, sheared and altered 

 igneous masses. There are numerous examples of dolerites and 

 epidiorites passing into hornblende-schists, and of more acid igneous 

 rocks. Masses of magnetite occur in various parts of Mashonaland, 

 and serpentinous rocks (which probably owe their origin to the 

 alteration of peridotites) in the north-west corner of the Victoria 

 Gold-field. 



