Reviews—Lapworth and Page’s Geology. 321 
reliability, and the attractive manner of its setting forth, will be best 
appreciated by the readers and students for whom the book is meant. 
We have purposely delayed to speak of the chapters on Igneous 
and Metamorphic rocks, as these chapters will be the ones to 
attract most attention. Both are treated from the point of view of 
the structural geologist, but one who is well acquainted with the 
minuter and microscopic characters of the rocks he speaks of. The 
classification of Igneous rocks adopted has a chemical and mineralo- 
gical basis, the minuter subdivisions being effected by differences in 
origin and texture. A notable passage suggests, “It is far more 
probable, however, that they (granitic bosses) are really laccolites 
or intrusive sheets upon a gigantic scale, the plane of intrusion and 
separation, instead of being confined toa single bedding-plane, cross- 
ing the bedding of the rocks of the district more or less irregularly 
and obliquely.” 
Fig. 55. Fie. 56. 
Figures illustrating the structures of the Schistose Rocks. 
Figs. 53, 54. Macro-structures. Fig. 53. Flaser gneiss (Flaser structure), natural 
size. Fig. 54. Augen-granulite (Augen structure), natural size. 
Figs. 55, 56. Micro-structures. Fig. 55. Mylonite (Mylonitie structure), highly 
magnified, Fig. 56. Mica schist (Granulitie structure), highly magnified. 
The metamorphic chapter derives great interest from the Survey 
paper read at the Geological Society a month ago, in which all Prof. 
Lapworth’s conclusions in the Highlands were confirmed. The terms 
DECADE III.—vVOL. V.—NO. VU. 21 
