202 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 10, 



beyond the lines reached by others. He made discoveries which, 

 followed to their legitimate issue, clearly show that the explanation 

 advanced by Dawson and Sterry Hunt as to the filling in of the 

 "chambers^' and other presumed sarcode-encasements is at fault. 



The " amorphous masses," as wiU be seen by referring to fig. 17, 

 PI. XY., occasionally assume a prismatic structure, with the prisms 

 closely adherent to one another laterally. We presume that this 

 example, if not strictly identical with, is closely related to those 

 which have been described as consisting of " parallel lamellae dis- 

 posed like the leaves of a book," or of " sohd bunches of rounded fila- 

 ments, reminding one of a sailor's ' swab.' " The ^' nature " of these 

 bodies "was for a long time a puzzle" to Dr. Carpenter; but, 

 doubtless perceiving that they are often compact and solid — that their 

 " parallel lamellae " and " rounded filaments " have not been bounded 

 by walls, the conclusion is drawn that they are " are in each case 

 but a mere aggregation of the elementary forms of sarcode-prolonga- 

 tion : " in what way wiU be seen immediately. Thus the same diffi- 

 culty or puzzle meets us here which we encountered when consider- 

 ing the nature of the asbestiform layer, numerous examples of which, 

 it wiU be recollected, showed no appearance of its presumed pseudo- 

 podial tubules having been separated by parietal partitions. 



Now, considering that, on the foraminiferal view, all the parts of 

 " Eozoon Canadense,^' with the exception of the " intermediate skele- 

 ton," must be regarded as the result of infiltration, mechanical or 

 chemical, it is obvious that the mode in which this process has been 

 effected is of primary importance in the main question under discus- 

 sion ; we may therefore be excused acceptiug auy explanation of the 

 process, unless it accounts for the present appearances of aU the 

 presumed sarcode-encasements. 



Dr. Dawson and Dr. Sterry Hunt's explanation, although simple, 

 scientific, and supported by numerous' cases among existing and 

 fossil foraminifers, becomes'a failure if carried beyond the " chamber- 

 casts " and the ramose or branching representative of the " canal- 

 system." Dr. Carpenter has proposed another, which, although in- 

 tended toaccountfor the usual appearances of the " amorphous masses" 

 and the "asbestiform layer," has failed in our opinion more 

 signally — no known fact or principle of geology, mineralogy, palae- 

 ontology, and chemistry being known, as far as we are cognizant of 

 them, to support the view that " the siliceous mineral found its way 

 into the cavities of the Eozoon, not by mere mechanical infiltration 

 occasioned by pressure from without, but by a process of chemical 

 substitution,whiGh took place, particle by particle, between the sarcode- 

 body of the animal and certain constituents of the ocean waters, 

 before the destruction of the former by ordinary decomposition"*. 



* The italics are Dr. Carpenter's. This hypothesis is more fully given in 

 the Intellectual Observer, vol. vii. p. 290, and p. 294 (upper paragraph) ; also 

 in the Proceedings of the Hoyal Society of London, vol. xiii. p. 546. Having 

 never seen any account of the suggestion made by Professor Milne-Edwards 

 '* with regard to the infiltration of fossil bones and teeth, in the course of the 

 discussion which took place on the Abbeville jaw," we are necessarily unac- 



