PREFACE 



Soon after the appearance of "Principles of Breeding" as 

 a college textbook, numerous letters came to both the author 

 and the publishers, suggesting a volume along similar lines, but 

 less technical in treatment and better adapted to the needs of 

 high and normal schools, and appealing more specifically to the 

 general student. 



These suggestions, together with the growing interest in agri- 

 culture both as an occupation and as a subject for instruction 

 in schools of various grades, encouraged the production of the 

 present volume, which runs along the same general lines as 

 M Principles of Breeding," except that more information is 

 afforded as to the origin of domesticated races and the source 

 of the materials out of which they have been formed, and less 

 space is devoted to function and to the more philosophic treat- 

 ment of variation and heredity. 



More attention is given also to the general subjects of natural 

 selection and the survival of the fittest as shown in the way of 

 the wild, — subjects of importance to the high-school student 

 as affording the foundation principles for improvement, and 

 also as contributing to a more rational understanding of the 

 general principles of evolution than commonly exists in the 

 popular mind. 



An incidental purpose has been to insure the student of the 

 secondary school an acquaintance with the essential facts of re- 

 production as illustrated in plant life, and with the foundation 

 principles in heredity, especially in degeneracy and crime, as 

 illustrated in regression tables and the law of ancestral heredity. 

 If the author has been at all successful at this point, the student 

 will derive indirectly and by inference, through this study of 



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