140 
Proceedings of the Royal Irish Academy. 
XXIV. — On The Mineral Origin of the so-called ^'Eozoon Cana- 
DENSE." Ey Professors "William King, Sc. D., and Thomas H. 
RowNEY, Ph. D. 
[Read April 10, 1871.] 
The only replies that have appeared to our former Paper"^' on ^ ' Eozoon" 
are by Drs. J. W. Dawson and T. Sterry Hunt.f As one confines 
himself to the discussion of the zoological aspects of the question," 
and the other to certain of its chemical and mineralogical relations, 
we shall consider their Papers separately. To begin with the first. 
"We intend to review Dr. Dawson's paragraphs seriatim ; of course 
omitting to notice any remarks that contain nothing of importance. 
1st. Pully believing that Dr. Dawson can employ his time more 
usefully on other subjects than that of Eozoon," we are quite will- 
ing to his renouncing the ''controversy" altogether. Eor our part, 
feeling convinced that we have irrefragably established the purely 
mineral origin of ''Eozoon Canadense," and considering the way in 
which the organic theory is maintained, we are quite as " reluctant" 
as Dr. Dawson appears to be in prolonging the discussion. It is only 
" in the interest of truth" that we commenced it, or keep it open. 
2nd. Dr. Dawson maintains the organic origin of certain structures ; 
and has a perfect right to represent them as such. On the other hand, 
we, contending for their purely mineral origin, claim an equal right 
to describe them according to our view. 
3rd. The statement respecting the Tudor specimen will be noticed 
under the 6th paragraph. 
4th. We totally repudiate the charge of having shown any 
"anxiety" to " ignore the specimens of 'Eozoon' preserved under 
different mineral conditions." We have fully discussed such speci- 
mens as far as the evidences enabled us, which may be considered to 
argue the contrary. 
5th. We have certainly admitted our "inability to explain satis- 
factorily the alternating layers of carbonate of lime and other minerals" 
in " Eozoon :" but how this is " fatal" to our " case" surpasses our 
comprehension ; as we have pointed out analogous examples which 
occur under circumstances proving that the alternation can only be a 
mineral arrangement. J The analogies we have adduced, Dr. Dawson 
may say "are clearly not parallel ;" but he has failed to make his 
statement clear to others. As we have no faith in the success of any 
" attempt" to explain the "connecting plates and columns" on any 
" hypothesis," clearly we are under no necessity to do 
* "Proceedings of the Royal Irish Academy," vol. x., pp. 506-551. 
t lb., New Series, vol. i., Part 2. 
X " Quarterly Jovirnal Geol. Soc," vol. xxii., p. 210 ; Proceedings Royal Irish 
Academy," vol. x., p. 532. 
