PREFACE 



In an introductory course in biology a text-book is helpful 

 because the notes taken by lower class students are usually 

 unsatisfactory, if not useless, and require much time. This 

 volume contains an outline of a course given by the author for 

 more than ten years. It is designed to supplement the practical 

 work in the laboratory and field, and to relieve the student of 

 the greater part of the burden of taking lecture notes. Purely 

 discriptive matter is reduced to a minimum and examples are 

 largely omitted because the teacher is supposed to have suffi- 

 cient command of the subject to supply these, and local and 

 familiar examples are always better for illustration than those 

 less well known. The figures in the book are regarded as an 

 important part in the presentation of the subject and should 

 be carefully studied. Many points omitted or only briefly 

 alluded to in the text are explained by them. 



Part I is designed to acquaint the student with the funda- 

 mentals of plant organization and life processes. Part II 

 does the same for animals but in a different and more thorough 

 method. Part III discusses the most important general biolog- 

 ical phenomena. The difference in treatment of plants and 

 animals rests on well-known pedagogical principles which 

 need not be discussed here. There is little in the book for 

 which originality can be claimed, but justification for publishing 

 rests on the fact that there is at present no text which even 

 approximately covers the field in subject-matter and method 

 of treatment. 



For the classification of plants and animals given in the ap- 

 pendices to Parts I and II, many authorities have been con- 



