298 Canadian Record of Science. 



methods, to make two valid species, while in Lonicera there 

 would be at least three possible species from the same plant. 

 To test the impression likely to be made upon a wholly un- 

 biassed mind, the branches of Lonicera representing four 

 specimens, as in the figures 2-5, were placed upon the table 

 side by side and a student who is a keen observer, was asked 

 to give his opinion as to their specific relations. He unhesi- 

 tatingly answered that certainly three, and probably all four 

 were distinct species, while as a matter of fact they represented 

 only three plants of the same species. It is quite obvious, 

 therefore, that we have here cases which are to some extent 

 the counterparts of what is presented by Liriodendron, re- 

 specting which Berry has observed that " When we look over 

 these leaves, it is with difficulty that we can believe they 

 belong to but one species • were they found as fossils they 

 would undoubtedly be referred to as many different species as 

 there are leaves." (op. cit., 37). It is obvious then, that if 

 we are to continue the identification of species by leaves 

 alone, we must, as already pointed out by Holm (op. cit., 

 312), have recourse to direct comparison with the leaves of ex- 

 isting species if even approximate accuracy is desired. Even 

 under such conditions, however, there will still remain a very 

 large and undesirable margin of error which, however valuable 

 the specific references may be for purposes of identification 

 and comparison, and however important such data may be 

 for stratigraphical purposes, they after all possess but limited 

 value — and in many cases no value at all — for the scientific 

 botanist who sees in plant remains the one means of tracing 

 the phylogeny of existing forms and thus, eventually, of estab- 

 lishing the true geological succession of the innumerable forms 

 which have led to our present flora. If such studies possess 

 any significance, they do serve to emphasize the great im- 

 portance of giving a secondary place to those leaf remains 

 which have heretofore claimed superior notice because of 

 their prominence among fossil forms and their attractive 

 appearance : while on the other hand they bring into strong 

 relief the necessity of concentrating our attention upon the 

 less attractive fragments of stem, the internal structure of 



