Dr. W. B. Carpenter on Eozoon cauadense. 463 



mode ill wliicli it ministered to the deposition of tlie inter- 

 mediate skeleton. 



The tJdrd of the additional probative facts I have now to 

 adduce is the existence of a canal-system in the calcareous 

 lamellcBy anteriorly to the intrusion of any foreign mineral ; 

 as is distinctly proved by the fact stated in my previous " Re- 

 marks" (p. 283), that the minuter part of the canalicular system 

 is often not intiltrated with any foreign mineral at all. As I 

 hold this fact to be of cardinal importance, and as I cannot see 

 that it has been met, either by Professors King and Rowney, or 

 by Mr. Carter, in their replies to my previous Remarks, I now 

 present an exact representation (PI. XIX. fig. 5) of the aspect of 

 such a portion of the canalicular system — showing by its semi- 

 opacity in one part the extent to which the serpentinous in- 

 filtration has proceeded, and by its transparence in the rest 

 that the canalization is not the result of any foreign infiltration 

 whatever. These canals (as formerly stated, p. 283) are filled 

 with calcite having the same crystalline axis as that of the 

 matrix — just as is the reticular structure of fossilized skeletons 

 of Grinoids, spines of Cidaris^ &c. It would be just as logical 

 to refuse to that reticulation the character of an organic 

 structm-e, because it possesses (even in the recent state) a crys- 

 talline arrangement, as to say that this canalicular system is 

 not an evidence of the organic origin of the calcareous lamella? 

 in which it presents itself. '^ Is it possible," said one of our 

 most distinguished Naturalists to me a few days since, " that 

 it is seriously maintained that these canaliculi do not pre- 

 exist ?" As I know them to be contained in the section which 

 I long since forwarded to Prof. Rowney, the only conceivable 

 reason for the non-recognition of them, alike by the two Galway 

 Professors and by Mr. Carter, is that they have not used the 

 reduced light, which, through the extreme transparence of the 

 minuter canaliculi, is necessary to bring them into clear view. 

 I liave thus shown : — (1) that the " utter incompatibility " 

 asserted by my opponents to exist between the arrangement of 

 the supposed " nummuline tubulation " of Eozoon and time 

 Nummuline structure, so far from having any real existence, 

 really furnishes an additional point of conformity ; and (2) that 

 three most striking and complete points of conformity exist be- 



in its viscid " glaze,'' and held in an inclined position, a brush dipped in 

 a viscid pigment was brought into contact with it at the proper point ; 

 and the pigment ran down into the glaze, first forming a stem, and then 

 spreading out in an arborescent raniihcation. The success of the opera- 

 tion depends on a very nice adjustment between the viscidities of the 

 two liquids. 



