210 SPENCER MOORE [SEPTEMBER 
“Scandinavian” flora? A considerable portion of it must have been 
in existence then, and it 1s difficult to conceive how the ancestors of so 
large and important an element in the earth’s vegetation could have 
found sufficient room in the few extreme northern lands then suitable 
to them. But during Eocene and Miocene times a large part of 
the antarctic continent must have had a climate suitable to the 
support of “Scandinavian” forms; and if we can suppose, and there 
seems little difficulty in the supposition, warranted as it is by facts of 
distribution, that the antarctic continent was then continuous with 
South America, and had outlying lands permitting of interchange with 
South Africa and Australia, a portion, and no inconsiderable portion, of 
the flora now considered to be of northern origin may well have taken its 
rise in these southern lands. It was probably during the Pliocene 
period that the Scandinavian flora first became important in Northern 
Europe. Phocene times must have been highly favourable to the 
diffusion of herbs which flourish best in colder temperate climates, for 
not only did cold conditions then prevail, but there were ready for 
colonisation large areas raised during the mountain-making Eocene and 
Miocene periods. It is conceivable, therefore, that much interchange 
between northern and southern lands may have taken place during 
this period. 
But it may perhaps be that the Pliocene age is too recent for such 
a relation as has been sketched to have existed between the antarctic 
continent and lands lying to the north of it, though the recent 
discovery in South America of a carnivorous Marsupial allied to 
Thylacinus suggests that such a relation existed during later tertiary 
times. Yet the point to be remembered is that large areas in the 
south have enjoyed a climate eminently suitable to the evolution of 
forms best fitted to flourish in the colder temperate zones, and, 
moreover, that during long periods the larger extent of such areas has 
been in the south. The problem, too, how southern forms could have 
reached the north is no greater than the problem how northern forms 
could have penetrated into antarctic lands. All we know is that a 
genus could have had its origin in but one area, and that, as regards 
temperate forms, there is much generic resemblance between the 
northern flora and the southern; but there is no justification for the 
view that all the genera common to both had their origin in the north 
and none of them in the south. 
It is also necessary to receive with grave doubt any conclusion 
relative to the inherent superiority of certain floras as a whole over 
others, and this although several species of supposed northern origin 
are capable of ready acclimatisation in foreign lands, and can some- 
times flourish at the expense of endemic forms; for in every flora there 
are species more widely diffused and with greater powers of adaptation 
than others. Has anybody ever argued, from the rapid spread of 
Anacharis alsinastrum in our streams a few years back, from the way 
