OPPONENTS AND OBJECTIONS. 189 



crystals not unfrequently cross and interfere with the struc- 

 tares in such specimens. 



6th. On the contrary, the Canadian specimens prove clearly 

 that the veins of chrysotile have been filled subsequently to 

 the existence of Eozoon in its present state, and that there is 

 no connection whatever between them and the iJTummuline 

 wall. 



7th. This I have never seen in all my examinations of 

 Eozoon. The writers must have mistaken veins of fibrous ser- 

 pentine for the nummuline wall. 



8th. Only if such grains of chondrodite are themselves 

 casts of foramini feral chambers. But Messrs. King and 

 Eowney have repeatedly figured mere groups of crystals as 

 examples of the nummnline wall, 



9th. Dr. Carpenter has shown that this objection depends 

 on a misconception of the structure of modern Foraminifera, 

 which show similar appearances. 



10th. That disseminated crystals occur in the Eozoon lime- 

 stones is a familiar fact, and one paralleled in many other 

 more or less altered organic limestones. Foreign bodies also 

 occur in the chambers filled with loganite and other minerals ; 

 but these need not any more be confounded with the pillars 

 and walls connecting the laminae than the sand filling a dead 

 coral with its lamella. Further, it is well known that foreign 

 bodies are often contained both in the testa and chambers even 

 of recent Foraminifera. 



11th. The canal system is not always filled with serpentine 

 or malacolite ; and when filled with pyroxene, dolomite, or 

 calcite, the forms are the same. The irregularities spoken of 

 are perhaps more manifest in the serpentine specimens, 

 becanse this mineral has in places encroached on or partially 

 replaced the calcite walls. 



12th. If this is true of the Aker marble, then it must con- 

 tain Eozoon; and specimens of the Amity limestone which 

 I have examined, certainly contain large fragments of Eo- 

 zoon. 



13th. Tbe configuration of the canal system is quite 

 definite, though varying in coarseness and fineness. It is 



