26o ' TJie American Geologist. April, i9oo 
b)' professors Duparc and Mrazec in their late interesting- 
work. 
These authors have demonstrated that Mont-Blanc is 
made up of a series of anticlinal and synclinal layers which 
have influenced the crystalline schists, and that at a later 
date the granite penetrated the arches formed thereb)- caus- 
ing the phenomena of metamorphism. Mont-Blanc is there- 
fore well adapted to the study of the metamorphic action of 
deep lying volcanic rocks on the schists of the crystalline 
layer. 
It has been demonstrated that the granite of which an 
important part of the Mont-Blanc mass is composed pre- 
sents a large number of special facies due to the profound 
modifications that it has undergone b}- its invasion of the 
schists of which the sedimentary layer is composed. 
Protogine was considered b}' former geologists only as 
an intermediar}' type between granite and the crystalline 
schists. In certain parts of the mass one is able to follow 
the gradual transformation that the modified cr)'stalline 
schists have undergone, and their development into real 
granite. 
Besides granite and its numerous variants, many volcanic 
or crystalline rocks, of an extremely interesting character, 
are to be found in the Mont-Blanc mass. 
The specimens will be carefully collected, under the su- 
pervision of Dr. F. Pearce, assistant to professor Louis Uu- 
parc, and the latter gentleman will himself superintend the 
arrangement of them. 
The Mineralogical and Geological Bureau will supply 
purchasers with collections of geological specimens, with or 
without thin slices. 
These crystalline rocks have been specially described by 
professors Duparc and Mrazec, in a fine volume containing 
sixteen zincographic plates and two colored elevations, the 
price of which is 25 francs. 
The same institution is also charged with the important 
task of collecting the rocks of the Simplon tunnel which 
will connect Switzerland to Italy. The Jura Simplon Rail- 
way company designated a commission, consisting of doc- 
tors Renevier, Pleim, and Schardt for the purpose of institu- 
ting and directing a geological, mineralogical, and geother- 
mal survey of the tunnel as the work progresses. Suites of 
the rocks encountered, with proper descriptions, and finally 
a complete memoir, will be furnished to such geologists as 
enter their subscriptions. These monographs cannot fail to 
furnish new light on many of the petrological problems now 
so much mooted as to metamorphism and differentiation. 
