. 
NATURAL HISTORY MISCELLANY. i 44T 
practical observer. This, said Dr. Hunt, was going back to the 
notions of those, who, rather than admit that mountains had been 
formed beneath the sea, imagined that the fossil shells which they 
often contain were not the real shells of animals, but the result of | 
some freak of nature. The argument of Messrs. King and Rowney 
that the Eozoon rock is a result of pseudomorphic alteration be- 
cause it contains serpentine, is a begging of the question at issue, 
by asking us to admit that the presence of serpentine is an evi- 
dence of metamorphic change, which is denied. He then remarked 
that the specimens of this organic limestone, with its injected cri- 
noids, differed from Eozoonal rock only in containing at the same 
time recognizable fragments of other organic remains, and in pre- 
senting in its injected portions the differences which distinguish 
the minute structure of a crinoid from that of a calcareous rhizo- 
In conclusion, he again adyerted to the views which he had 
long maintained as to the origin of great masses of silicated rocks 
by a direct process of deposition from watery solutions, in which 
they were formed by chemical reactions. 
Dr. Dawson spoke, confirming the observations of Dr. Hunt, 
which he had yerified by microscopic examinations. He alluded 
to the structure of crinoids, which in the fossil state were gener- 
ally filled with carbonate of lime so as to obliterate their pores. 
The infiltrating silicate in the present case however, showed, es- 
pecially in decalcified specimens, that these ancient crinoids closely 
resembled in their minute structure, the modern forms lately 
studied by Dr. W. B. Carpenter and Professor Wyville Thompson, 
especially Comatula. Figures of these decalcified specimens were 
exhibited and will be published. Dr. Dawson alluded further to 
the process of filling up the porous calcareous skeleton of the cri- 
noids, which was clearly shown to be prior to the cementing and 
consolidation of the fragmentary limestone. 
MICROSCOPY. 
Tur Susmersion Microscope.—R. E. Dudgeon, M.D., de- 
scribes under this name, in the Quarterly Journal of Microscopical 
Science for July, 1871, a contrivance by which the objective of an 
ordinary microscope can be plunged in water without affecting its 
optical qualities. A brass tube with its lower end closed water- 
tight by a flat disc of glass is slipped over the objective from 
