Stromatoporoids and Eozoon. 345 



and cons of tlie opposing views, apparently inclines to a 

 belief in the mineral tlieoiy, and demands^ in view of the 

 antiquity of tlie rocks and the changes to which they have 

 been subjected, the clearest possible evidence of organic 

 structure before accepting the theory of the organic nature of 

 Eozoon. 



I consider that the sections made by the late Dr. Carpenter 

 yield abundant evidence of organic structure. 



Eozoon canadense is a Foraminiferan. Its calcareous 

 skeleton shows clearly the Foraminiferal structure of pores 

 and tubuli, and, further, chitinous rings and coils are present. 

 Dr. Carpenter's specimens must liave died peacefully on 

 the Lower Laurentian sea-bottom, and have been buried and 

 slowly metamorphosed by infiltration, but in such a way as 

 to preserve a good deal of their structure. Possibly igneous 

 irruptions may have occurred later within varying distances 

 of the dead specimens, leading to varying degrees of mineral- 

 ization. I suppose the theory of the mineral origin of 

 Eozoon is due to the existence of much metamorphosed 

 specimens. 



Fortunately Dr. Carpenter had several very fine examples 

 of Eozoon in his magnificent collection (now in the British 

 Museum, Nat. Hist.). About the time of his death he was 

 engaged in writing a monograph which would have finally 

 settled the whole question. A friend of mine who ktiew 

 him tells me that Dr. Carpenter could scarcely listen wit!i 

 patience to the arguments of the mineralists, and I can 

 appreciate this attitude when I look at his beautiful sections. 

 Sir William Dawson, too, had occasion to resent the charge of 

 "subjectivism" brought against him by an upholder of the 

 mineral theory. 



Sir W. Logan "^ was the first to notice the resemblance of 

 Eozoon to the Stromatoporoids. 



The recent Foraminiferan Po^ytrema cyUndricum, Carter, 

 recalls in certain respects both Be'itn'cea and Eozoon. This 

 pretty little branching Foraminiferan, of a brilliant yellow or 

 red colour, has a surface-layer of large chambers, but at the 

 same time the central axis of the branches is occupied with a 

 smaller vesicular tissue. A tiansverse section of Beatricea 

 has somewhat the appearance of that of a megalospheric 

 Foraminiferan. 



In the Stromatoporoids and Eozoon there is a many- 

 chambered (Polythalamous) calcareous skeleton with the 

 walli? of the chambers penetrated by fine tubuli. Altered 

 chitinous hoops and coils are found in the communicatiou- 



* Logan, W., ' Geology of Canada/ 18G3, p. 19. 

 Ann. & Mag. i\. Hist. Ser. 8. Vol. x. 2-i 



