Additional Floristic Results. 
355 
Europe ” gives us many themes for thought, not only from an 
ecological but from a systematic standpoint. 
My own notes (pp. 306—328, 1911) were published so soon after 
the excursion, that in some cases the names given were only provi¬ 
sional, and many more had to be submitted to the fire of criticism, 
but in no case was any dogmatic statement made. One is too 
conversant with the variability of nature, and too cognisant of one’s 
own imperfect knowledge to give hard and fast definitions or to 
refuse to recognise that a plant may be looked at from more than 
one point of view—the characters on which one authority relies for 
definition are not always those which another chooses—so that when 
one is dealing with some of the plastic species, it is quite evident 
that discordant opinions may result. It is sufficiently obvious that 
a number of botanists drawn from a wide area in Europe would 
have different systems of nomenclature, and would take divergent 
views as to the limitations of species and the lower grades into 
which plants have been divided. Yet on the whole it was rather the 
general agreement, than the instances of difference which impressed 
me. One fact, however, stood out as a prominent feature, namely 
that whereas many leading British systematists have been extremely 
reluctant to acknowledge that the British Isles contained endemic 
species—for instance Sir J. D. Hooker in the preface to Wallace’s 
Island Life , where the suggested endemic species were almost 
entirely rejected, either as not being endemic or as not being species. 
Yet, as one would expect, a more minute and critical study of plant 
forms, especially by observers working in the field, rather than in 
herbaria— since in the latter one only sees a specimen or two and 
not the group, sees it only in part and not as a living entity, so that 
the field student is ahle to notice many points of difference, some 
so minute as to elude our power to adequately define, and yet 
other variations which can not only be seen but described—has led to 
well-marked differences being established between many of our 
island species and their homologues on the mainland of Europe. 
Drude (l.c. 237) well says “very many common species constantly 
polymorphic in their German stations appear to me to look very 
different in England, to represent in fact slightly differentiated 
examples of local endemism. How otherwise can we interpret the 
Birches for instance ? .... I may say that I gained the impression 
of numerous slightly differentiated local forms, endemic in England.” 
For an example of this local endemism attention may be directed 
to so well known a plant as our Golden Stonecrop, which in Britain 
