TABLE OF CONTENTS 
PAGE 
I. List of Illustrations_ 6 
II. Introduction _ 9 
III. Hybrids represented in this discussion_ 9 
IV. Description of hybrids _11 
V. A general survey of the characters in the and subsequent gen¬ 
erations _ 37 
VI. So-called “false hybrids”_ 39 
VII. Summary _47 
VIII. Literature cited_51 
