THE ARCHEAN. 173 
Peof. N. H. Winchell says : " Partly one and partly the 
other." [i.e. (3.)] I can give examples if time and situation de- 
manded. 
Peop. Wadsworth says : "All these conditions occur, but 
the third is the more common." 
Capt. Button does not believe this question can be answered 
in the present stage of geologic knowledge. 
Peof. Pumpelly : " I am disposed to consider them to a 
large extent as metamorphosed sediments which, under some con- 
ditions, have been extruded and thus become eruptive :" that is, 
he believes the part of the question marked (1) correct. 
Peof. A. Winchell : " Wide observation and study have 
settled me pretty firmly in the conviction that nearly all of our 
crystalline bedded rocks were originally sedimentary. I have 
no doubt also, that most granitoid rocks were originally sedi- 
mentary. But this is not to deny that many granites had an 
eruptive origin, or that in many eruptives a bedded structure 
has been superinduced by mechanical stresses." 
A fair interpretation of the replies of Profs. Dana, Le Conte, 
Irving, Walcott, Hitchcock, N. H. Winchell, Wadsworth and 
Emerson (8), favors the view that the lower crystalline rocks 
consist partly of those which were originally sedimentary, partly 
of those which were originally igneous^ each class being more or 
less metamorphosed later. 
Dr. Hunt and Dr. Emmons regard these rocks otherwise, 
the former as aqueous or crinetic and indigenous, the latter as 
aqueo-igneous, and not a deposit of amorphous sediments like 
those of later formations. 
A very strong preponderance lean to the view that either of 
several kinds of origin may be ascribed to the lower crystalline 
rocks, depending upon the particular case — the sedimentary, 
the igneous, or the aqueo-igneous. 
K. Aee theee evidences of life in the Archean? If 
so, where and what ? 
Prof. Dana, in his Manual of Geology, 2d edition, p. 189, 
says: "There can be little doubt that Rhizopods existed in Arch- 
ean time," but he does not give his reason for thinking so, nor 
state whether they possibly existed in the Laurentian period. 
C 
