Hunter, _Laboratory Problems in Civic Biology_. American
Book Company.
Andrews, _A Practical Course in Botany_, pages 160-177.
American Book Company.
Coulter, _A Textbook of Botany_, pages 5-40. D. Appleton and
Company.
Coulter, _Plant Life and Plant Uses_. American Book Company.
Dana, _Plants and their Children_, pages 135-185. American
Book Company.
Sharpe, _A Laboratory Manual in Biology_, pages 90-102.
American Book Company.
Stevens, _Introduction to Botany_, pages 81-99. D. C. Heath
and Company.