312 Geographical Distribution of Plants 
specialisation is the loss of adaptability: It is probable that many 
elements of the southern flora are doomed: there is, for example, 
reason to think that the singular Stapelieae of 8. Africa are a dis- 
appearing group. The tree Lobelias which linger in the mountains 
of Central Africa, in Tropical America and in the Sandwich Islands 
have the aspect of extreme antiquity. I may add a further striking 
illustration from Professor Seward: “The tall, graceful fronds of 
Matonia pectinata, forming miniature forests on the slopes of 
Mount Ophir and other districts in the Malay Peninsula in associa- 
tion with Dipteris conjugata and Dipteris lobbiana, represent a 
phase of Mesozoic life which survives 
‘Like a dim picture of the drowned past®’” 
The Matonineae are ferns with an unusually complex vascular system 
and were abundant “in the northern hemisphere during the earlier 
part of the Mesozoic era.” 
It was fortunate for science that Wallace took up the task which 
his colleague had abandoned. Writing to him on the publication 
of his Geographical Distribution of Animals Darwin said: “I feel 
sure that you have laid a broad and safe foundation for all future 
work on Distribution. How interesting it will be to see hereafter 
plants treated in strict relation to your views*.” This hope was 
fulfilled in Island Life. I may quote a passage from it which 
admirably summarises the contrast between the northern and the 
southern floras. 
“Instead of the enormous northern area, in which highly organised 
and dominant groups of plants have been developed gifted with 
great colonising and aggressive powers, we have in the south three 
comparatively small and detached areas, in which rich floras have 
been developed with special adaptations to soil, climate, and organic 
environment, but comparatively impotent and inferior beyond their 
own domain‘.” 
It will be noticed that in the summary I have attempted to give 
of the history of the subject, efforts have been concentrated on bring- 
ing into relation the temperate floras of the northern and southern 
hemispheres, but no account has been taken of the rich tropical ° 
vegetation which belts the world and little to account for the original 
starting-point of existing vegetation generally. It must be re- 
membered on the one hand that our detailed knowledge of the 
floras of the tropics is still very incomplete and far inferior to that 
1 See Lyell, The Geological Evidences of the Antiquity of Man, London, 1863, p. 446. 
° Report of the 73rd Meeting of the British Assoc. (Southport, 1903), London, 1904, 
p. 844. 
® More Letters, um. p. 12. * Wallace, Island Life, pp. 527, 528. 
eee Gi 
