Antiquity of the Angiosperms — SUESSENGUTH 
On the other hand, if we hold the opinion, 
as many botanists do, that the Polycarpicae 
are the most primitive of the Angiospermae, 
we should find that only two very small fami- 
lies of Polycarpicae are endemic in Australia: 
the Eupomatiaceae and the Himantandraceae, 
which are related to the Eupomatiaceae, but 
which possess neither calyx nor corolla 
(Diels, 1919: 126 et seq . ) . The other fami- 
lies of Polycarpicae are not well represented 
in Australia: the Magnoliaceae afford only 
4 species, the Annonaceae 18, the Nymphaea- 
ceae 5 , the Ranunculaceae 17, and the Myris- 
ticaceae 1. In view of these facts, it cannot 
be claimed that the Polycarpicae are the most 
primitive of angiosperms in Australia and 
that a comparison with the preservation of 
the earliest mammals could be made. 
This brief appraisal is enough to show that 
the angiosperms which most botanists con- 
sider to be the oldest of flowering plants 
(Polycarpicae) do not exist exclusively or pre- 
eminently in Australia. But in the informa- 
tion we have learned about the Casuarinaceae 
and the Proteaceae we may have found cer- 
tain clues which will be of value later when 
we investigate their degree of primitiveness. 
WHICH SPECIES OF ANGIOSPERMS 
PERSISTING IN AUSTRALIA ARE 
THE MOST PRIMITIVE? 
Now we can set about answering the sec- 
ond question, inquiring into the conclusions 
which can be drawn from a study of the his- 
tory of the Australian flora. At first it may 
seem questionable in itself to compare the 
early histories of flowering plants with those 
of mammals, particularly when it is realized 
that the conditions governing their migra- 
tions were quite different. We assume that 
those mammals living in Australia during 
the Upper Cretaceous period have been iso- 
lated since that time because of the conti- 
nent’s isolation, and that only rarely have 
they been joined by later immigrants. Can 
the same assumption be made for the flower- 
289 
ing plants? Or may those various plant spe- 
cies now found in Australia have migrated 
to the continent since its separation because 
they — or rather, their seeds — could cross the 
ocean gap while the animals were not able 
to do so? 
To obtain a general view of the whole 
flora of Australia, let us consider the cata- 
logue of F. von Mueller, his Census of Aus- 
tralian Plants (1889). Because of the recent 
advances in our knowledge, Mueller’s list is 
neither complete nor infallible, yet it is not 
likely that the proportions of the numbers 
of species within large groups and of the 
endemic species have changed significantly 
since that time. Therefore we may use the 
Census without hesitation, all the more neces- 
sarily because there does not exist a later cat- 
alogue for the whole Australian territory 
(including Tasmania but not New Zealand). 
Mueller’s catalogue lists 8,842 species, 
and, because it does not mention those spe- 
cies introduced in recent times (since about 
1800), it is well fitted for our purpose. Of 
these 8,842 species, 7,734 (that is, 87.5 per 
cent) are endemic in the larger sense of the 
word — that is to say, they are found in Aus- 
tralia itself but may also extend to New 
Zealand and to parts of Polynesia as well. 
The percentage of endemism is extremely 
high. 
Table 1 may serve for comparison of the 
percentage of endemic plants found in Aus- 
tralia with those found in other parts of the 
world. 
As a matter of fact, it is probable that 
among the 8,842 species listed in Mueller’s 
Census of Australian Plants there may be a 
great many species which were introduced by 
man, although this hypothesis cannot be 
substantiated in its details. If this is true, 
however, the percentage of endenism in Aus- 
tralia would be even higher than it is here 
calculated. 
There is no doubt but that the longer a 
country has been isolated the more endemics 
