IN THE VEGETABLE KINGDOM. 19 



pect to derive some advantage from their guarded use, 

 especially in methodizing the more intricate departments ; 

 and none, surely, stands more in need of being systematized 

 than that involving the consideration of all those diversified 

 and seemingly anomalous phenomena, which have of late 

 been so abundantly accumulated in connection with the 

 function of reproduction. Only we must see that no 

 hypothesis be admitted which is not in consistency with 

 known facts, and jealously resist all attempts to bend facts 

 into conformity with hypothesis. 



It is with this view that I now propose, before proceed- 

 ing to theorize on the nature and relations of the reproduc- 

 tive function, to give a summary of what I believe to be the 

 main facts of the process in the principal groups of both 

 kingdoms of nature. But I may observe at the same time 

 that the conclusions which were indicated at the close of 

 the last chapter are only partly of the nature of hypotheses 

 partly I consider them as matters of fact. Thus I believe 

 it to be a matter of fact that there is a very essential dis- 

 crepancy in the so-called cases of alternation of generations, 

 and that of a kind to divide them naturally into groups as 

 above indicated. It is, on the other hand, a matter of 

 theory and it may be of mere conjecture that one class 

 is represented by the process of embryogeny, and the other 

 by that of the maturation of the sexual organs in the higher 

 species. It is at least a question that requires to be argued, 

 and this cannot be done till the facts have been brought 

 forward ; but that the difference referred to does exist in 

 cases of alternation, is only, I think, what will appear in 

 the course of the summary from the very facts of the 

 case. 



It is no part of my intention to discuss here the whole 

 history of Reproduction. I propose to confine myself to 

 such points as have some distinct bearing on alternation, 

 but these I will endeavour to state, as distinctly as I can, 



