Columbia subject headings:
Agassiz, Louis, 1807-1873--Correspondence.
Baird, Spencer Fullerton, 1823-1887--Correspondence.
Naturalists--United States--Correspondence.
Science--United States--History.
Zoology--United States.
Harvard subject headings:
Agassiz, Louis, 1807-1873--Correspondence.
Baird, Spencer Fullerton, 1823-1887--Correspondence.
Science--United States--History
Zoology--United States
Princeton subject headings:
Agassiz, Louis, 1807-1873--Correspondence.
Baird, Spencer Fullerton, 1823-1887--Correspondence.
Naturalists--United States--Correspondence.
Science--United States--History.
Zoology--United States.