Dr. W. B. Carpenter on Eozoon canadense. 461 



careous layer, representing the intermediate skeleton," with 

 which it is continuous. And it is shown also by the effect of 

 dilute acid on any true "nummuline layer" of which the tubules 

 have been filled with serpentine ; for it is only after the removal 

 of the calcareous matrix that the internal casts of its tubules, 

 remaining as separate acicul«, present the least resemblance 

 to the chrysotile fibres to which Professors King and Rowney 

 persist in likening them, notwithstanding my repeated assertions 

 that the two things are altogether different. I can show a 

 precisely similar arrangement of vertical aciculge on the surface 

 of a chamber-cast of a recent Amphisteginaj and knoio them 

 to be the internal casts of the tubuli of its Nummuline wall. 

 But Professors King and Rowney's argument would make 

 out these also to be mere products of mineralization, because 

 they resemble chrysotile-fibres. I am perfectly acquainted 

 with the mineral pseudomoi-phs to which they refer, and freely 

 admit their resemblance to certain forms of the " acicular 

 layer " left after the decalcification of the " nummuline layer ;" 

 but I cannot believe that any microscopist who is familiar 

 either with dentinal or any other form of tubulation, can 

 entertain the slightest doubt that if figs. 2, 3 be correct, the 

 unaltered structure they represent is organic. If it be one 

 that any kind of mineralization can produce, I do not see 

 why we are to call Bones and Teeth any thing else than in- 

 organic concretions. The only alternative hypothesis is, that 

 not only Mr. George West and I, but all the Microscopists 

 who have verified our representation, are suffering under 

 "tubulation on the brain;" and this the Gal way Professors 

 and Mr. Carter are quite welcome to assert, if they think pro- 

 per, when they shall have examined the specimen itself which 

 is open to their inspection at any time. At present they are 

 in the position of the opponents of Galileo, who would not 

 look through the telescope which showed the Satellites of 

 Jupiter. 



I now pass on to a second probative fact of at least equal 

 cogency, — the relation exhibited in the same specimen be- 

 tween the " canal-system " and the tubuli of the " nummuline 

 layer." 



In my original description of Calcarina (Phil. Trans. 

 18G0) — the ty|:)e to which, as regards the general distribution 

 of its canal-system and its relation to the intermediate skeleton, 

 Eozoon has the closest resemblance — I gave the following 

 account of that relation (p. 554) : — " The proper walls of the 

 chambers are unifoiTnly perforated, like those of the chambers 

 of Botalia, by foramina of considerable size (averaging above 

 1 3000th of an inch in diameter) ; with these the canals of the 



