WHAT IS EOZOON ? 81 



C. W., which show more regular lamiiiEe, and in which the 

 tubuli have nofc yet been observed; and a specimen from 

 Burgess, C. "VY., contains some fragments of laminae which 

 exhibit, on one side, a series of fine parallel tubuli like those 

 of Nummulina. These specimens may indicate distinct 

 species ; but on the other hand, their peculiarities may de- 

 pend on diflferent states of preservation. 



" With respect to this last point, it may be remarked that 

 some of the specimens from Grenville and the Calumet show 

 the structure of the laminae with nearly equal distinctness, 

 whether the chambers are filled with serpentine or pyroxene, 

 and that even the minute tubuli are penetrated and filled with 

 these minerals. On the other hand, there are large specimens 

 in the collection of the Canadian Survey in which the lower 

 and still parts of the organism are imperfectly preserved in 

 pyroxene, while the upper parts are more perfectly mineral- 

 ized with serpentine." 



[The following note was added in a reprint of the paper in 

 the Canadian Naturalist, April, 1865.] 



" Since the above was written, thick slices of Eozoon from 

 Grenville have been prepared, and submitted to the action of 

 hydrochloric acid until the carbonate of lime was removed. 

 The serpentine then remains as a cast of the interior of the 

 chambers, showing the form of their original sarcode-contents. 

 The minute tubuli are found also to have been filled with a 

 substance insoluble in the acid, so that casts of these also 

 remain in great perfection, and allow their general distribu- 

 tion to be much better seen than in the transparent slices 

 previously prepared. These interesting preparations establish 

 the following additional structural points : — 



" 1. That the whole mass of sarcode throughout the organ- 

 ism was continuous ; the apparently detached secondary 

 chambers being, as I had previously suspected, connected 

 with the larger chambers by canals filled with sarcode. 



" 2. That some of the irregular portions without lamination 

 are not fragmentary, but due to the acervuline growth of the 

 animal ; and that this irregularity has been produced in part 



G 



