1880.] 3TT [Crosby. 
and the number of these localities will probably be increased by 
more extended and careful observation. These conglomerates are 
probably of several different ages; and yet the metamorphic process 
appears to have been substantially the same in every case. As a 
rule, the altered conglomerate is closely associated, geognostically, 
with eneiss or mica schist; and in every such instance the product 
approximates to one or the other, or both of these rocks. Nearly 
all observers agree that these remarkable passages of sandstone and 
conglomerate toward mica schist and eneiss, are due to alteration 
and not to derivation; there seems little room for doubt on 
this point. And yet, as previously stated, the gneiss-like pro- 
ducts of the alteration of the conglomerate are frequently difficult 
to distinguish from the schistose gneisses forming a large part of this 
great gneissic formation.‘ Such identity in the effects seems to imply 
similarity in the causes, some community of origin; and I am some- 
what inclined to regard the small area of semi-crystalline rocks in 
Bellingham as essentially a part of the gneiss and mica schist forma- 
tion, and to see in the more conglomerate portions an indication of 
the condition of a large part of our schistose gneisses at some time 
in the remote past,—a small sample arrested in its development, 
and now available as a key to the origin of thousands of square 
miles of crystalline rocks. 
I am aware, however, that altered conglomerates have not been 
studied sufficiently to justify positive statements with regard to their 
bearing on the problem of the genesis of crystalline schists; and all 
that I wish to do in this connection is to suggest that, unless the alter- 
ation of conglomerates is granted, it becomes a very difficult question 
to account for the almost complete absence of this class of rocks 
from the stratified crystalline formations. For we know that the 
stratified crystallines have, in the aggregate, an enormous volume; 
and this, as well as many other characteristics, shows that they must 
be regarded, in large part, as shore deposits. We know, further, 
that the seas, even in the earliest times of which geology furnishes 
any material record, were sufficiently near their present status, both 
physically and chemically, to permit the existence of life — probably 
both animal and vegetable. Now it is simply impossible ‘to believe 
that an ocean which permitted the formation of vast beds of limestone, 
graphite, and iron ores, and the existence of life, did not deposit 
extensive formations of conglomerate; the sediments of early times 
‘must have included nearly, if not quite, as large a proportion of frag- 
