Biology and human affairs.
Contributors: Day, Chapin Walker.; Ritchie, Margaret.
Publisher: World book company
Published: 1941
Place of publication: Yonkers-on-Hudson, N.Y
Language: eng
Number of pages: 1026
Subjects: Biology
Other titles: Studies and activities in biology.
Notes: Includes bibliographies.
At head of title: By John W. Ritchie.