Miscellaneous. 355 
same form, but their structure is the same, or at least appeared to 
me to be so. They are wedge-shaped or parallelogrammic, about 
;isths of a millimetre in length, and from ;4,ths to ,$,ths in breadth. 
It is very difficult to ascertain their thickness, but I believe it to be 
about a third of their length. They are composed of at least two 
layers of two or three rows of broad cells on either surface, as vi- 
sible under the microscope. Their colour is a deep green verging 
on bistre. I know of nothing at all similar in the family of Mosses, 
and at least in a physiological point of view, the fact is not unim- 
portant. It must be observed that the capsules were quite ripe, 
having already lost their opercula, so that the question is not one of 
unripe spores. The species in which this curious structure was ob- 
served is Hucamptodon perichatialis, Mont.” 
Dr. Montagne kindly accompanied his observations with speci- 
mens, which has enabled me to confirm their correctness.—M. J. B. 
M. Aeassiz on the Geological Development of Animal Life. 
The Zoophytes, Mollusca and Articulata existed in the earliest pe- 
riod of the earth’s development, although all their classes were not 
numerously represented in the oldest members; but they do not al- 
low of our supposing that any progressive perfection to the present 
creation occurred. This is the case with the Vertebrata only, among 
which fish appeared in the first period, reptiles in the second ; mam- 
malia and birds did not appear for a long time after the former ; lastly 
came man, as lord of all: hence M. Agassiz denominates the corre- 
sponding periods, those of fish, reptiles and mammalia. 
The greatest change in the fish occurred at the end of the Jura 
period. All fish which existed prior to the chalk have a peculiar 
aspect and belong in general to extinct families; those of the later 
epochs resemble those now living, and many of them belong to fa- 
milies and genera at present in existence; but they all differ speci- 
fically, just as all Vertebrata in different geological epochs differ in 
species. —Jahrbuch fiir Mineralog. Geolog. &c., Part 3. 1845. 
EXPLORATIONS OF DR. SCHRENK. 
The extreme limits of the wild and remote regions of south-eastern 
Siberia and along the Chinese frontier have been successfully ex- 
plored by an able and enterprising botanist, Dr. Schrenk, who has 
recently returned to St. Petersburg. Remote and unfriended, this 
ardent naturalist has passed four years in a country, the greater part 
of which was never before trodden by an European foot. In addition 
to copious materials with which he will soon enrich botany, geology, 
and other branches of science, he has made most important obser- 
vations on the eastern extension of the mass of land which forms a 
portion of that vast depressed area so vividly brought before our con- 
sideration by Humboldt, and which is now found to extend eastward 
from the shores of the Aral to the Saissar and Balkash lakes ; though 
in approaching the latter region the ground rises to a few hundred 
feet above the sea. Thence penetrating to the lake of Issikul, sur- 
rounded by lofty mountains considerably south of the range of the 
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