INFLUENCES OF CLIMATE. 
283 
the forests of America, but are they less suited to 
the forests of other countries ? The Nightingale 
certainly finds its peculiar insect food in those 
countries, and counties of England to which it now 
resorts, the climate also being congenial to its 
feelings and habits, yet, though it is found in 
Sweden and Germany, it is absent from Scotland 
and Northumberland, and though it is found in the 
middle and some southern counties of England, 
it is hardly known in Devonshire. The Great 
Bustard is found enjoying a distribution latitu- 
dinally, whereas the same climate, situation, and 
food, could be obtained to the north and south of 
this zone. The Achatina acicula, though found in 
some limstone districts of England has never been 
seen in the south of Devon, where lime abounds. 
The Swallow never migrates to America or China, 
though the food and climate there would suit its 
constitution. The Hedge Warbler is stationary, 
while the Blackcap migrates. Lastly, the Yellow 
Wren which ordinarily migrates, will yet at times 
remain with us through the winter. 
The first of those secondary causes or influences 
ranking as laws of geographic distribution of 
animals which we shall mention, is Climate , a term 
which includes a consideration of temperature, of 
seasons, of winds usually prevalent, of the dryness 
or humidity of the air, of rains, drought, continued 
cold or heat, &c. It deserves notice, that the 
presence of mountains, rivers, seas, barren spots, 
the quality of soil, the degree of cultivation, and 
the clearness or cloudiness of the sky have all some 
influence in forming the climate, and in consequence 
the Fauna of a country. Secondary laws seem to 
act and re-act largely on each other, so that no one 
of them appears to have a separate or unmixed 
influence on animal distribution. The influence 
of climate on the distribution of animals may at 
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