vi Preface 



The primary object of the text is to meet a definite 

 need felt by botanical students. Such students, in their 

 contact with current botanical literature, frequently 

 encounter papers dealing with the genetics of plants, 

 and through lack of preparation are unable to grasp their 

 significance. Since this literature is far too important 

 to be neglected, it was thought advisable to provide such 

 preparation in the simplest possible manner. In addi- 

 tion to this need, it is felt that the text will be useful 

 to biological students for two important reasons. In the 

 first place, the presentation is simple enough for students 

 with little or no biological background to understand; 

 and in the second place, the subject is brought more 

 nearly "up to date" than in any earlier text. This is 

 especially important in view of the numerous significant 

 investigations that have been made during the last year 

 or two. 



In order to adapt the text to a greater variety of 

 needs and interests, an arrangement of material is made 

 by means of which it may be used either as an elementary 

 text or as one somewhat more advanced. The material 

 presented in large type provides a simple account which 

 may be read coherently without reference to the material 

 in smaller type. The latter material presents a more 

 intensive treatment of certain phases of the subject, and 

 will be of interest and value to those who wish to work 

 out more thoroughly some of the details of investigation 

 or application. 



M. C. C. 



