in VARIABILITY OF SPECIES IN A STATE OF NATURE 51 
mencing with the outer one. As an example of the irregular 
variation constantly met with, the following occurred among 
twenty-five specimens of Dendraeca coronata. Numbers 
bracketed imply that the corresponding feathers were of 
equal length . 1 
Relative Lengths of Primary Wing Feathers of 
Dendileca coronata. 
Longest. 
Second in 
Length. 
Third in 
Length. 
Fourth in 
Length. 
Fifth in 
Length. 
Sixth in 
Length. 
2 
3 
1 
4 
5 
6 
3 
2 
1 4 
4 
1 
5 
6 
3 
1 
5 
6 
7 
2 1 
3 / 
? 1 
4 
1 
5 
6 
7 
1 f 
4 i 
5 
6 
7 
8 
9 
Here we have five very distinct proportionate lengths of 
the wing feathers, any one of which is often thought sufficient 
to characterise a distinct species of bird; and though this is 
rather an extreme case, Mr. Allen assures us that “ the com¬ 
parison, extended in the table to only a few species, has been 
carried to scores of others with similar results.” 
Along with this variation in size and proportions there occurs 
a large amount of variation in colour and markings. “ The 
difference in intensity of colour between the extremes of a 
series of fifty or one hundred specimens of any species, collected 
at a single locality, and nearly at the same season of the year, 
is often as great as occurs between truly distinct species.” Rut 
there is also a great amount of individual variability in the 
markings of the same species. Birds having the plumage 
varied with streaks and spots differ exceedingly in different 
individuals of the same species in respect to the size, shape, 
and number of these marks, and in the general aspect of the 
plumage resulting from such variations. “ In the common 
1 See Winter Birds of Florida , p. 206, Table F. 
