Geology and Mineralogy . 501 



those found in a series of intrusions in the neighborhood of 

 Wausau, which consist of syenites and nephelite-syenites. One 

 of the latter is noteworthy in that its pyroxene is a hedenbergite 

 and it contains fayalite. As is so often the case, these rocks in 

 their pegmatitic developments contain many interesting minerals. 

 These have been carefully investigated and many of them have 

 been analyzed, as well as the rocks and rock-minerals. The whole 

 makes a very thorough and excellent piece of petrographic inves- 

 tigation. It is an interesting fact that the intrusion of the alkalic 

 rocks has no accompanying retinue of differentiated dikes and satel- 

 lite masses which are so common a feature in such occurrences else- 

 where. 



Following the petrography, the matter of chief interest is the 

 result of the study of the glacial geology. The various characters 

 of the ice invasion and of the deposits it left are described in 

 detail for all parts of the area. The writer finds evidence of 

 four distinct glacial formations, each believed to have been formed 

 by a separate ice invasion. One part of the region is driftless 

 and nonglaciated, and the author, in explanation of this, adopts the 

 view of Chamberlain for the larger areas to the southwest, that is 

 the diversion of the ice currents by the highlands of northern 

 Wisconsin and Michigan. 



The work concludes with a description of the topographic fea- 

 tures of the region and a discussion of its physiographic develop- 

 ment. The volume is well printed and embellished by many fine 

 half-tones, and as a whole, both in the results obtained and in 

 the manner in which they are presented, it is an excellent work, 

 of general as well as of local interest, reflecting credit on the 

 author and on the State survey. l. v. p. 



2. Research in China {in 3 vols, and atlas) : Vol. I, Part II • 

 Petrography and Zoology; by Eliot Blackwelder. 4°, pp. 357- 

 528, plates 12. Washington, 1907 (published by the Carnegie 

 Institution). — Some years since, as is well known, the Carnegie 

 Institution despatched to China an expedition under the leadership 

 of Mr. Bailey Willis of the United States Geological Survey. 

 One of its chief purposes was the study there of the earliest strati- 

 fied rocks, in the hopes of throwing light on important questions 

 concerning Cambrian andpre-Cambrian geology and paleontology. 

 While the success of the expedition in this particular direction 

 was perhaps not greater than that which has attended the study 

 of these strata in other places, a considerable amount of material, 

 valuable in several branches of science, and of interesting infor- 

 mation concerning the regions traversed, was obtained and, under 

 the auspices of the Carnegie Institution, these have been studied 

 and collated and the results are now being published. 



The present volume by Mr. Blackwelder, who was Mr. Willis's 

 chief assistant, describes the petrography of the rock specimens 

 collected along the route of travel. They represent a large var- 

 iety of types, igneous, sedimentary and metamorphic, which have 



