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9 
ultimately of continental origin), the greater aggregate fern wealth 
of Malaya as compared ^vith the Philippines, the affinity of the Malayan 
fern flora with that of Polynesia, Australia, India, and even Africa 
(showing its great age), the scarcity of mammals in the Philippines 
and the geological evidence that Mindanao is younger than the highlands 
of Borneo. However, Mindanao is, for its area, richer in ferns than any 
other large island in the world and it can not be doubted that, in its 
measure, emigration southward has occurred and is occurring. 
The comparative share of Borneo and Celebes in the composition of 
the Mindanao flora is a most interesting question, but one the present 
discussion of which may furnish the future with little of more final 
value than the evidence of present ignorance of the flora of all three 
islands. This much, at least, we can establish, that the connection with 
Celebes and presumably through it with other lands to the south and 
east, has been much more intimate than most writers in this field liave 
imagined. San Ramon is at the extreme southwest of Mindanao, from 
wliich a chain of islands dots the sea at intervals of at most a few miles, 
quite across to Borneo. Several of these islands are sufficiently elevated 
to hear an abundance of tree-ferns. Migration to or from Borneo looks 
exceedingly easy. 
Of the San Ramon ferns, Vittaria minor and Polypodium pedicu- 
latum are already known only froni Borneo, or Borneo and the Philip- 
pines. From their further range, Nephroduirn intermedium, Lindsaya 
scandens, Syngramma alismcefolia, Monogramma trichoidea and Polypo- 
dium Beddomei may be regarded as added evidence of connection with 
Borneo. Not one of the genera notable for its occurrence or develop- 
ment in Borneo, such as Matonia, Syngramma, Dipteris and Taeniiis, is 
at all notable at San Ramon. 
Valid evidence of floristic affinity with Celebes is furnished by Nepliro- 
dium diversilohum (even if it is not specifically distinct from N. canes- 
cens), Nephrolepis laurifolia, Dennstaedtia erytJiroracliis, Pterls opaca 
and Polypodium Schneiden, known only from Celebes and the Philip- 
pines. In a few cases, as in that of the conspicuous Polypodium hern- 
cleum, Ailiyrium silvatkum, and Loxogramme iridifolia, Celebes con- 
nects Mindanao with Java. A relationship to the flora of the remote 
east and south is shown by Lindsaya pulchella and Odontosoria retusa. 
More significant than mere community of species is the sharing of 
larger or more isolated groups. Lomogramma is probably a good in- 
stance in this connection, though its confusion with a Leptochilus lias 
made its actual range dubious. Thayeria is found in Luzon, Mindanao 
and Xew Guinea. 
Judging, then, from our present knowledge of the distribution of 
Malayan ferns, there is a closer affinity between the fern flora of San 
Ramon and that of Celebes than between the former and that of Borneo, 
in spite of the fact that the geographical connection with Borneo is 
t 
