the instance of the Christiania distriet, where a similar con- 
nection was pointed out by Bréccer in his classical investiga- 
tions several years ago!. Without entering into a detailed 
comparison it may be mentioned that the subsidence connected 
with the igneous action is much more marked at Julianehaab 
than at Christiania; for, while tbe depressed strip at Juliane- 
haab is only about half as broad as the corresponding belt at 
Christiania Fjord, the amplitude of the subsidence is as great 
or greater than at the former place. It is further worthy of 
mention that the original covering of the Plutonie rocks of 
llimausak had a decided concave or trough-like form, while in 
the Christiania distriet the stratified rocks originally overlying 
the Plutonic masses had a convex or arch-like surface, accord- 
ing to the reconstruction given by Brécerr. 
MECHANISM OF INTRUSION OF THE BATHOLITES. 
Introductory. — Owing to the world wide distribution of 
Plutonic rock bodies of batholitic habit the question of the pro- 
cesses by which these bodies have invaded the upper part of 
the earth crust is of great interest. Recent investigations by 
Surss, Ippives, Barrots, Micnet Lévy, BroGGer, Dary, and many 
others have added largely to our knowledge in this respect, but 
the question is in most cases unsettled, and the hypotheses 
which have been put forth are not generally accepted. The dif- 
ficulties arise partly from the complex nature of the intrusion, but 
they are also partly due to the fact that the present shape of 
the batholites is commonly so modified by erosion, that the 
original form cannot be made out with certainty. Very often, 
too, the exposures are so inadequate, and do not give any clear 
idea of the character of the junction with the invaded rock. 
1 W. С. BRÖGGER, Ueber die Bildungsgeschichte des Kristianiafjords. Nyt 
Magazin for Naturvidenskaberne XXX, 1886. — Idem, Die Eruptivgesteine 
des Kristianiagebietes И, 1895, р. 133. 
