Perry.] 204 [April 19, 



calcareous masses in eastern Massachusetts, which are known to 

 hold "Eozoon," points which each should verify by an actual exam- 

 ination of the masses in question, and of similar rocks so far as 

 accessible and as they occur in place. Whether all the limestones 

 noticed be exactly identical in origin, in structure and in age, or 

 not, they certainly have very many features in common, and are so 

 essentially alike, if one may judge from their appearance, as to serve 

 well to illustrate each other. The question as to the mode of their 

 origin, whether it were by infiltration, segregation, or sublimation, I 

 leave undiscussed for the present, proposing to take it up in detail 

 on some future occasion. Enough, I think, has been said to show 

 that the limestones to which reference has been more especially made, 

 particularly those of Chelmsford, have truly a vein-like structure and 

 are really vein-rocks. 



But there is another point, of no small importance, to be briefly 

 noticed. It is a fact, which no one can successfully gainsay or deny, 

 that genuine ''Eozoon" — " Eozoon," which has been recognized and is 

 accredited as genuine by those who hold to the organic nature of this 

 marvellous form, and as advocating it are supposed to be best quali- 

 fied to judge of its character — actually occurs in great profusion, in 

 some of the limestones of Chelmsford. 



Meanwhile, the evidence now presented, evinces, so far as it is read- 

 ily possible to evince, the inorganic character of the limestones under 

 consideration. And while it seems thus clearly to show that the so- 

 called "Eozoon" of Chelmsford is not an organic structure, it at the 

 same time indicates the probability that the "Eozoonal" forms fur- 

 nished by limestones of the Grand Calumet in Canada, of Bavaria 

 and Bohemia, of Ireland and of other regions, have the same or a 

 kindred origin, and therefore that they are likewise inorganic. In- 

 deed, so far as I can see, the evidence casts discredit upon the as- 

 sumed organic character of the "Eozoon" generally, and fixes the 

 burden of proof upon its advocates, to whom it originally belonged, 

 and with whom of good right ii should have always remained. It 

 with equal certainty suggests that the resemblance which the "Eo- 

 zoon" bears to animal structure, is, like that of "Dendrites" to vege- 

 table forms, merely the result of chemical agency ; in other words, 

 that the "Eozoon" properly belongs to the department of Mineral- 

 ogy, and not, as lias been claimed, to that of Palasontology. 





