336 Review of Recent Geological Literature. 
The author supposes that the rock was originally puddingstone, in 
which the fragments have mostly consisted of gneiss and granite ; those 
only have been left that contained most quartz ; the rest have changed 
into a granitic mass." 
He regards the Scandinavian mountains as constituting with those 
in the northern part of the British islands, a single system, and to have 
originated, or to have participated in, a great post-Silurian folding 
process, the folding axes running S. W. and N. E. " The forces acting 
during the folding process have changed the form of great rock-masseS) 
as well as of single mineral grains. The changes are not explained 
merely by assuming the whole to have been made ' molecular plastic ;' 
on the other hand all superinduced structures are not cataclastic, 
neither is it possible to account for the changes by chemical processes 
only. If for instance we observe bending of the twin-lamels in plagio- 
clase we must needs regard the mineral as having been plastic to a 
certain degree. If a plagioclase individual is divided into small parts, 
we have a cataclastic phenomenon. If the mineral is seen to be filled 
with epidote microliths, we must suppose chemical processes." 
The author adheres to the origination of granite masses in situ by 
metamorphism from sedimentary beds, and also "that in some cases 
originally sedimentary rocks may be, regionally metamorphosed, and 
at last protruded as true eruptives." 
Shall ive teach Geology! . By Alexander Winchell. [S. C. Griggs 
& Co., Chicago, 218 pp. 12mo 1889.] 
The author first states what position geology really occupies in the 
schools and colleges of the country and all countries. He claims that 
it should be taught in both schools and colleges for many reasons, among 
which are : that it has a high educational value, considerably higher 
than such studies as geography, history, and literature, that childhood 
is the period of observation and that geology is pre-eminently an ob- 
servational study ; that it promotes ethical culture from its broad scope 
and character and constantly recurring evidences of one guiding influ- 
ence, that it is of value in everyday life and that the course of govern- 
ments in respect to it proves that they think it very valuable, that it 
has a very good moral effect in that it produces a strong love for truth 
and avoidance of error, which, brought into life, prevents misunderstand- 
ings. He severely critisizes Chancellor Payne's positions in regard to 
education, not without cause, and compares geology to the latter's 
"culture trivium." Coming to the practical side of the question as to 
how to get geology into the schools he seems to think it is going there, 
though this is a change, and as such will be opposed for some time. 
His examples for teachers are very good and, although his position 
will be considered radical, he answers his topic very decidedly, yes. 
