358 REVIEWS AND BOOK NOTICES. 
it on every side. The water of the lake has at all seasons nearly 
the temperature of cold spring-water.” 
Happily this wonderful basin, or Yellowstone Park, has by Con- 
gress been set apart as a National Park, and thus its attractions 
will remain forever free to all, and we trust safe from injury by 
curiosity venders et id omne genus. 
Before leaving Prof. Hayden’s report we may call attention to 
the soda springs at the bend of Bear river, describing them in the 
words of the report. 
“At the bend of Bear river is located the most interesting group 
of soda springs known on the continent. They occupy an area of 
about six square miles, though the number is not great. At this 
time they may be called simply remnants of former greatness. 
Numerous mounds of dead or dying springs are scattered every- 
where, and only a few seem to be in active operation. So far as 
the manner of building up the calcareous mounds is concerned, it 
does not differ from that of the hot springs in the Yellowstone 
2r 
® 
bling spring, Bear river cross-cuts a number of the 
mounds, thus revealing the secret of their structure. The mounds 
vary from a few feet to twenty or thirty feet high, built up, in the 
same way as the hot spring cones, by overlapping layers. There 
are many of these mounds, which show, by the steepness of the 
sides, the amount of hydrostatic pressure. Many of the chimneys 
are nearly vertical, with the inner surface coated over with a so 
of porcelain.” 
The second, third and fourth parts of the reports contain valua- 
ble contributions from Messrs. Thomas, Lesquereux, Cope, Leidy, 
Meek, Horn, Uhler, Edwards, Porter and Beaman. 
Mr. Lesquereux gives the following summary of his views de- 
duced from the study of our Tertiary and Cretaceous flora. 
“ist. The Tertiary flora of North America is, by its types, in- 
timately related to the Cretaceous flora of the same country. 
` 2d. All the essential types of our present arborescent flora are 
already marked in the Cretaceous of our continent, and become 
