72 RARER FORMS OF RUBUS LATELY FOUND IN DORSET. 



as " Europe (Arctic), N. Africa, N. and W. Asia, Himalaya." It 

 has, however, long been apparent that the plants grouped together 

 under these two names exhibit an amount of difference among 

 themselves enormously greater than do the majority of plants in 

 other genera. Nothing is easier than to make a selection of 

 extreme forms. If we could rest there the problem would be an 

 easy one ; the extreme forms are abundantly distinct. But they 

 are connected together by so many other forms which pass so 

 gradually into one another that it becomes in many cases almost 

 impossible to assign limits to the forms which so long as we 

 confined our attention to the extremes appeared so distinct. What 

 is to be done ? Men have been working at the problem for many 

 years in Britain, in France, in Germany, in Scandinavia, and we 

 have not yet reached any definite conclusions. But I believe that 

 there are conclusions to be reached, and I believe also that no 

 botanists in the world are in a better position for continuing the 

 investigation than are the botanists of England. Clearly, the first 

 thing to do is to endeavour to differentiate and define our bramble- 

 forms, and to collate them with those of other countries. At 

 present we have, I believe, just 100 such forms in Britain, and 

 this number, large as it is, will probably be considerably increased. 

 In 1869 Genevier described over 200 species from the Valley of 

 the Loire, while Focke gives 72 more or less aggregate species as 

 found in Germany, under which are grouped a considerable number 

 of other less distinct forms. These figures shew considerable 

 differences ; but I suppose that in all these countries the number of 

 separable forms is about the same. I think it is necessary that 

 these forms should be worked out, because, till that is done, the 

 task of re-combining them into groups which shall be more or less 

 equivalent in value to the species met with in other genera can 

 hardly be successfully attempted. Such an attempt has been made 

 by Mr. Baker in the " Student's Flora," but seems to have met 

 with little favour. In the meantime we should, in my opinion, 

 regard the forms of bramble with which we meet as forms rather 

 than species, yet forms with a decided tendency to fix themselves. 



