174 REPORT OF THE AMERICAN COMMITTEE. 
Sir J. W. Dawson answers : " There are abundant evidences 
of plant and animal life as early as the Middle Laurentian ; but 
nothing definite as yet except Eozoon and a few other forms." 
Dr. Hunt : " Indirect evidences of organic life are the 
graphite and metallic sulphides found from the Laurentian up- 
wards. Direct evidences are also found in fossil forms." 
Prof. Le Conte: "I believe there are. — (1.) Graphite is 
probably of organic origin. (2.) Beds of iron ore are presump- 
tive evidence of existence of organic matter. (3.) The existence 
of limestone is also possible evidence of same." 
Prof. Irving: "Below the Huronian, doubtful; in the 
Huronian, certain evidences of life." 
Dr. Emmons: "No." 
Prof. Geo. H. Williams : " I know of no certain traces of 
life in the Archean, least of all the Eozoon." 
Prof. C. H. Hitchcock : " I will give up all signs of life in 
the Archean, unless it be the argument from iron ore in favor of 
vegetation. Yet it was no place for plants in the Laurentian." 
Prof. N. H. Winchell : "I do not believe in the organic 
nature of Eozoon, but there are evidences of organic nature in the 
Animikie, viz. : forms of irregular shape imprinted on the slates, 
as if of sea-plants, and a large per cent, of carV>on in the form 
of graphite. I do not myself know of any limestone in the 
Archean. None have been found in Minnesota except what 
may be of chemical origin." 
Prof. Wadsworth : " No, I do not think any have been 
established." 
Prof. Emerson answers " Yes," as to the evidences of or- 
ganic life, but he does not specify ^ where ' or ' what.' 
Prof. Pumpelly: "Nothing in the Laurentian except cal- 
cite, graphite, and iron-ore are such evidences," i.e., " Yes." 
Prof. A. Winchell: " I agree with those who think beds 
of graphite and iron-ore, as well as bituminous gneisses, are evi- 
dences of organic, probably vegetable life. It is to be presumed, 
also, that beds of Archean limestone sustained some dependence 
on the influence of animal life." 
Of those who have answered or whose views are published, 
Profs. Dana, Le Conte, Irving, Emerson, N. H. Win- 
chell, A. Winchell, Pumpelly, Sir J. W. Dawson, Dr. 
Hunt and Mr. Walcott (10), believe (some on one ground and 
