OPPONENTS AND OBJECTIONS. 187 



phenomenon by the fact that a similar alternation occurs in 

 amphiboline-calcitic marbles, and gneissose rocks. 



" 16th. In order to account for certain untoward difficulties 

 presented by the configurations forming the ' canal system,' 

 and the aciculi of the ' nummuline layer' — that is, when they 

 occur as ^ solid bundles' — or are ' closely packed^ — or Ufpi^ear 

 to he glued together ' — Dr. Carpenter has proposed the theory 

 that the sarcodic extensions which they are presumed to re- 

 present have been ' turned into stone' (a ' silicious mineral') 

 'by ^Nature's cunning' ('just as the sarcodic layer on the 

 surface of the shell of living Foraminifers is formed by the 

 spreading out of coalesced bp-udles of the pseudopodia that 

 have emerged from the chamber wall ') — ' by a process of 

 chemical substitution hefore their destruction by ordinary 

 decomposition.' We showed this quasi-alchymical theory to 

 be altogether unscientific. 



"17th. The 'silicious mineral ' (serpentine) has been ana- 

 logued with those forming the variously-formed casts (in 

 ' glauconite,' etc.) of recent and fossil Foraminifers. We have 

 shown that the mineral silicates of Eozoon have no relation 

 whatever to the substances composing such casts. 



" 18th. Dr. Hunt, in order to account for the serpentine, 

 loganite, and malacolite, being the presumed .in-filling sub- 

 stances of Eozoon, has conceived the 'novel doctrine,' that 

 such minerals were directly deposited in the ocean waters in 

 which this ' fossil ' lived. We have gone over all his evidences 

 and arguments without finding one to be substantiated. 



"19th. Having investigated the alleged cases of ' chambers ' 

 and * tubes ' occurring ' filled with calcite,' and presumed to 

 be ' a conclusive answer to ' our ' objections,' we have shown 

 that there are the strongest grounds for removing them from 

 the category of reliable evidences on the side of tjie organic 

 doctrine. The Tudor specimen has been shown to be equally 

 unavailable. 



" 20th. The occurrence of the best preserved specimens of 

 Eozoon Canadense in rocks that are in a ' liiglihj crystalline 

 condition ' (Dawson) must be accepted as a fact utterly fatal 

 to its organic origin. 



