349 
its Applicability to the Ferns , &c. 
The Ferns of New Zealand and Hawaii are also studied. The endemic 
species show a much greater range than the endemic Angiosperms, a result 
to be expected on my hypothesis, but contrary to what one would expect 
if endemics are dying out. The wides only range a trifle farther than the 
wide Angiosperms, which I put down to the probability that new species may 
arrive after the breaking of the land bridges. Cf. especially the numbers 
and rarities in Table V. 
Lastly, it is pointed out that more care must be taken, in view of these 
results, to consider geographical as well as structural relationship in forming 
genera and families, and that this work gives strong evidence in favour 
of mutation. 
Literature cited. 
1 . Baker and Smith: Pines of Australia, Sydney, 1910. 
2 . Bower : Phylogeny of the Filicales. Ann. Bot., vol. xxxi, 1917? P- r. 
3 . Christensen : Index Filicum, Copenhagen, 1906. 
4 . Fawcett and Rendle : Flora of Jamaica, vol, i, London, 1910. 
5 . Hillebrand : Flora of Hawaii, 1888. 
6 . Penzig : Flora of Krakatoa. Ann. Buitenz., 2. iii. 
7 . Ridley : Endemism and the Mutation Theory. Ann. Bot., vol. xxx, 1916, p. 551. 
8. Treub : Flora of Krakatoa. Ann. Buitenz., 1. vii. 
9 . Willis : Distribution of Species in N. Zealand. Ann. Bot., vol. xxx, 1916, p. 437. 
10 . : Endemic Flora of Ceylon. Phil. Trans., B, vol. ccvi, 1915, p. 307. 
11 . : Evolution of Species in Ceylon. Ann. Bot., vol. xxx, 1916, p. 1. 
12 . : Flora of Ritigala. Ann. R. B. G., Perad., vol. iii, 1906, p. 271. 
13 . : Relative Age of Endemic Species. Ann. Bot., vol. xxxi, 1917, p. 189. 
14 . : Studies in . . . Podostemaceae . . . Ann. R. B. G., Perad., vol. i, 1902, p. 267 (especially 
p. 446). 
15 . : The Distribution of the Plants of the Outlying Islands of New Zealand. Ann. Bot., 
vol. xxxi, 1917, p. 327. 
16 . and Gardiner: Flora of the Maldives. Ann. R. B. G., Perad., vol. i, 1902, p. 45. 
B b 2 
