BULLETIN 
OF THE 
WISCONSIN NATURAL HISTORY SOCIETY. 
Vol. 5, New Series. JANUARY, 1907. No. 1. 
PROCEEDINGS. 
Milwaukee, Oct. 25, 1906. 
Eegular monthly meeting of the Society. 
President Teller in the chair and 73 persons present. 
Mr. Teller stated that there had been considerable comment on 
the part of various members of the Society regarding the advisability 
of holding monthly section meetings, and asked for expressions of 
opinion. 
Dr. Earth moved that a section meeting' be held on the second 
Thursdays of the months when regular meetings are held, and 
that these meetings be set aside for scientific discussion and restricted 
to such. Motion seconded and passed. 
The following persons were named for membership: 
Miss Ellen Torelle. 
Mr. George Wetmore Colles. 
Dr. Albert H. Brundage. 
Mrs. A. Bernhardt. 
These names were referred to the Board of Directors, who subse- 
quently passed on them. 
There being no further business, Dr. R. M. Strong, of the University 
of Chicago, spoke on the Colors of Birds. 
The speaker said that in addition to their importance as characters 
in taxonomic work and in studies of evolution and heredity, the colors 
of birds are interesting because of numerous problems in physics that 
they present. T\xo categories of colors are recognized, viz: pigmental 
and structural. To the former belong black, red, orange, yellow, and 
green (occasionally). Structural colors include white, blue (except 
for one case of pigmental blue described by Hacker), and iridescent 
effects. White feathers owe their color tO' the entire absence of pig- 
ment. The whiteness of feathers is produced in the same way as the 
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