2 The Problems 



It is in the hope of inducing others to follow these 

 lines of investigation that I take the problems of heredity 

 as the subject of this lecture to the Royal Horticultural 

 Society. 



No one has better opportunities of pursuing such 

 work than horticulturists and stock breeders. They are 

 daily witnesses of the phenomena of heredity. Their 

 success also depends largely on a knowledge of its laws, 

 and obviously every increase in that knowledge is of 

 direct and special importance to them. 



The want of systematic study of heredity is due 

 chiefly to misapprehension. It is supposed that such 

 work requires a lifetime. But though for adequate study 

 of the complex phenomena of inheritance long periods 

 of time must be necessary, yet in our present state of 

 deep ignorance almost of the outline of the facts, obser- 

 vations carefully planned and faithfully carried out for 

 even a few years may produce results of great value. In 

 fact, by far the most appreciable and definite additions 

 to our knowledge of these matters have been thus 

 obtained. 



There is besides some misapprehension as to the 

 kind of knowledge which is especially wanted at this 

 time, and as to the modes by which we may expect to 

 obtain it. The present paper is written in the hope that 

 it may in some degree help to clear the ground of these 

 difficulties by a preliminary consideration of the question, 

 How far have we got towards an exact knowledge of 

 heredity, and how can we get further? 



Now this is pre-eminently a subject in which we 

 must distinguish what we can do from what we want 

 to do. We want to know the whole truth of the matter ; 

 we want to know the physical basis, the inward and 



