Antiquity of the Angiosperms — SUESSENGUTH 
Australia during the Upper Cretaceous period. 
Many of them may have migrated to Aus- 
tralia in later times, after the separation, and 
may have evolved there into types A 2 , B 2 , 
C 2 , D 2 . . . . But if this is true of some plants, 
it is not likely to be true of the Legumi- 
nosae: It is probable that the primitive 
species of the Mimosoideae, the Papilion- 
ateae, and of some of the other families listed 
above (p. 295) immigrated into Australia 
a long time ago and have survived there un- 
changed, remaining generally identical with 
their ancestors of the Upper Cretaceous 
period, wherever these ancestors may have 
grown. 
For some of the other plant groups, it is 
possible that their species A 2 , B 2 , C 2 , D 2 . . . 
may have risen in different epochs. A 1 , B 1 , 
C 1 , D 1 . . . in Malaysia, and A 2 , B 2 , C 2 , 
D 2 . . . in Australia, continued to live, while 
their common ancestors A, B, C, D. . . died 
out in both territories. Or, if we assume that 
A 3 = A, B 1 = B, C 1 — C, and so on, or if 
we take A 2 = A, B 2 = B, C 2 = C, and so 
on, we might deal, then, with only two lines 
of development instead of three, and only 
one of them need have changed — either 
the one in Australia, since the beginning of 
its isolation, or the line in Malaysia, since 
Australia’s separation. In other words, the 
local ancestors of the line A, B, C, D. . . 
might have died out in one territory and 
might have been preserved in the other for 
a very long time. Yet this is not very prob- 
able a chance inasmuch as most species of 
living things — except for the mussels — gen- 
erally have not been conserved unchanged 
over long periods of geologic time. 
In my opinion this line of approach is 
the most natural way of explaining the 
problem. It does not relegate the appear- 
ance of all the endemic families of the Aus- 
tralian angiosperms to the apocryphal dark- 
ness of antiquity, and yet it does help us to 
understand the rise of the many endemics in 
Australia. If we do not insist that all of 
303 
these developments took place at almost the 
same time (in the Upper Cretaceous period) 
and if we agree that the possibility of sub- 
sequent immigrations into Australia must 
also be taken into account, then we would 
do well to remember that in their manner 
of distribution angiosperms and mammals 
differ markedly in at least this major point: 
Flowering plants are much more able to 
cross the sea — if only by means of driftwood 
— than are mammals. This would seem to be 
an assertion that could hardly be contested. 
And yet it is a strange fact that greater 
numbers of primitive plant types have not 
been preserved. They became extinct, while 
the primitive types of animals — the Mar- 
supialia and Monotremata — continued to live. 
These animals link the mammals with the 
reptiles, but even at the present time no 
plants are known in Australia which link 
the angiosperms with the gymnosperms. The 
botanical systematist will regret this fact, if 
only because such proof of primitiveness 
would be a much more scientific, and there- 
fore a more reliable, basis for the taxonomic 
system. 
My impression of the rise of Australian en- 
demics has been described with reference to 
its relationship to Malaysia, both because the 
endemics of this area are more closely related 
to those of Australia and because of Aus- 
tralia’s former connection with New Guinea 
(see Behrmann, 1937). Perhaps these con- 
clusions will seem quite natural to most 
readers; nevertheless, I think it would be use- 
ful to develop further conclusions based on 
certain concrete suppositions. 
As has been known for a long time, most 
of the species of the plant families charac- 
teristic of Australia grow in the southwestern 
maritime areas (Hooker, I860). Fewer spe- 
cies are found toward the north. According 
to his catalogue, Hooker counted 3,600 spe- 
cies in the southwestern territory, known in 
his day as Swan River and King George 
Sound, but only 3,000 from the eastern area, 
