SOUTHEAST EXPEDITION. 
139 
^HEIR first trip was out on the plains to the 
southeast of Boulder, in the neighborhood 
and along the banks of the Platte. After secur- 
ing a number of varieties of petrified wood, shells, 
Indian curiosities, etc., etc., they reached a 
point where some cotton-wood trees shaded the 
river’s bank. Upon the trunk of one a pair of 
agitated flickers was discovered. Flickers, per- 
mit me to explain, are birds of the woodpecker 
family. Their coats are of a yellowish brown, 
profusely adorned with round black spots. They 
wear crescent bibs of velvety black, and in the 
Eastern and Middle States ornament the under 
side of their wings and tails with bright yellow, 
and wear black-check patches. In the far West- 
ern States they change these colors for red. They 
are of especial interest to ornithologists, because 
there is a large region of country in which a 
variety occurs having some of the characteristics 
of both the eastern and western forms ; and the 
question whether in it may not be discovered one 
of the “ missing links ” about which there is so 
much agitation, the change being due to climatic 
influences which terminate in yellow-shafted 
flickers at the East and red-shafted ones at the 
West, is one which a whole, school of modern 
philosophers would give no little to have decided 
