5 68 
Progress in Science , 
[Oftober, 
to in the Salt Lake district— has a significance which should not be overlooked. 
If it, as can scarcely be denied, reduces the temperature of the soil and in- 
creases the amount of rainfall, it must certainly have a generally pernicious 
effedt in a country like England, where the temperature of the soil in average 
seasons might be advantageously increased, and where the rainfall is already 
so sufficient, in proportion to the evaporation, that any increase would ensure 
us a succession of wet summers and ruined harvests. It is, however, we 
think, demonstrated — even to superfluity — that the destruction of the forests 
has already reduced many regions in Europe, Asia, and Africa, to comparative 
sterility, and is evidently exercising an injurious effect in many others, as at 
the Cape. We have ourselves observed drizzling rain falling in a wood, whilst 
none could be perceived in the open country on all sides. Now if the destruc- 
tion of vegetation can effect a decrease of the volume of water in the rivers, 
and, if not, reduce the total amount of rainfall during long periods of time, 
can still convert it from a regular and useful supply to an alternation of violent 
storms and long periods of drought, it does seem highly probable that planting 
should have an inverse result. 
The ninth volume of Mr. F. V. Hayden’s “ Report of the United States 
Geological Survey of the Territories ” is exclusively devoted to the inverte- 
brate palaeontology of the cretaceous and tertiary formation of the Upper 
Missouri country, and represents the result of a wonderful amount of labour 
and research. This will be at once understood when we say that 130 genera 
of fossil Mollusca have been examined and characterised, and a typical species 
of each described. The synonyms of the genera and species have been col- 
lated, and as far as possible determined. The illustrations consist of forty-five 
quarto plates, some of them containing more than thirty figures each and 
admirably illustrated. The whole work must be pronounced in the highest 
degree creditable to the geological staff of the United States Government, 
and as a most valuable contribution to palaeontological science. 
