The Birds’ Calendar 
ing about seven inches long, and the Bohemian 
about eight), and with a slightly different tinge 
of brown, it is scarcely distinguishable from the 
cedar-bird. 
It is very common for any type of bird to 
have distinct varieties in north and south, and 
often in east and west. ‘Thus among the more 
familiar birds we find a northern and a southern 
variety of the chickadee, the wren, the shrike, 
and the nuthatch, although the range of the two 
nuthatches differs less. East and west also have 
their counterparts in sparrows, bluebirds, robins, 
and many others. ‘The western robin much re- 
sembles the eastern, but has a black band across 
the breast. In these cases the difference seems 
to be more in plumage than in habits. It will 
be one of the most interesting discoveries in re- 
gard to birds when we learn the causes that 
differentiate a genus into its species, causes 
which it is to be presumed are of the same nat- 
ure, though not on so broad a scale, as those 
which from the original type of bird have pro- 
duced classes, orders, families, and genera. 
The vocal powers of the cedar-bird are very 
limited, as it can produce only a faint whistle 
or lisp, much like a note sometimes produced 
by the robin, but not so asthmatic. 
64 
