258 CongloJiierates hi Gnclssie Terraiies. — A. Wlnchell. 
pebbles were reported as furnishing evidence of softening and 
distortion ; and the inference would be that if metamorphic 
agencies had effected such changes in times as late as the 
Coal-Measures, it. Avas probable that in earlier times, they had, 
in many situations, more completely softened once-consoli- 
dated sediments, and even reduced them to such state of 
molecular intermobility that crystallizing rearrangements of 
the molecules would have taken place. 
Professor Hitchcock affirms : "There is no support to your 
position to be derived from any of the cases cited from the 
East and the Black Hills." My "position'' was simply that 
congloriicratcs sometimes occur In uncissic terranes. I think 
Avhen professor Hitchcock attempts to show that the gneissic 
terranes of New England whicli enclose conglomerates are not 
Laurentian, he yields a clear implication in his own words, to 
serve as support to my "position." If he conceives my posi- 
tion to hnve been that Laurenti;in gneisses are all sedimentary 
in origin, I admit that the cases cited from New England and 
the Black Hills do not complete the proof of it, but the infer- 
ence lies so close to the facts cited that it is a mere matter of 
form to enunciate it. 
I desire also, to notice briefly a comment communicated by 
the honored Director of the Canadian Survey.' He says, " I 
entirely concur in 3'-our remarks. The facts you mention, how- 
ever, have been so long and so well known to us in Canada as 
to be considered scarcely worth discussing ; and I am a little 
surprised that among the authorities you cite you have not 
referred to Logan and the "Geology of Canada." *■ * * 
That the whole complex of the Archa-an or i)re-Cambrian 
rocks is a great series of mixed igneous, clastic and pyro-clas- 
tic rocks greatly altered, phj^sically and mineralogically. by 
various metamorphic agencies there can be no doubt." 
To this I beg to subjoin an expression of surprise that the 
obvious use of facts " so well known " has been so quietly 
overlooked, especially in Canada, where at least one of the 
officials of the survey is insisting that the gneisses are erup- 
tive, and not of sedimentary origin. If those facts are so old 
and familiar as to have passed the stage of appropriate com- 
"This comes in a personal communication, but I assume no objection can be 
made to public reference to it, since it concerns a geological question of gen- 
eral interest. 
