214 WHAT IS LIFE 



for the manifest variety and the observed specificity. 



As everyone now recognizes it to be, the problem 

 of the origin of species primarily is the problem of 

 heredity, which involves the problems of specificity 

 and of variation. Until recent years, the theory of 

 organic evolution was only a quasi-scientific one; 

 certainly, there was little inquiry into the actual 

 life-process. But the problem of the origin of species 

 undoubtedly is first of all a problem of life, a part of 

 the general problem of life. Without being able to 

 account for the fundamental life-process, to try to 

 account for the ascent of life, for the observed speci- 

 ficity and for variety, necessarily is a pitifully futile 

 and hopeless effort. 



It would seem obvious that a knowledge of the 

 process of the reproduction of life-forms is essential 

 to an intelligent inquiry into the causes and factors 

 of heredity. A brief review of the general facts about 

 reproduction, therefore, may not be omitted. 



Though there still is much to learn, today science 

 can at least boast that it has a fair knowledge of the 

 process of reproduction. 



The study of the reproduction of life-forms is an 

 elaborate study. Reproduction takes place in many 

 different ways. The vegetable kingdom possesses a 

 variety of methods for reproducing forms. In the 

 animal kingdom the methods of reproduction range 



