Postelsia aT 
low for the item of error due to the various con- 
ceptions of species and genera. Only in so far 
as they are general can figures in this connection 
be relied on, and only in so far as they can be 
co-ordinated with other explanations do they 
explain. 
Summary and Conclusion. 
In the hght of the above generalization, the 
main facts to be gained from the cited figures 
can be summed up as follows:— 
a. That the pteridophytic flora is poor in 
number of species for a region showing almost 
tropical conditions as regards moisture, yet 
shows great density and profusion. 
b. That the gymnospermous flora forms the 
all important group and constitutes the great 
mass of the island vegetation. 
c. That of the two classes of Angiosperms, 
the Monocotyledons occupy a more important 
position than the Dicotyledons. This relegation 
of the Dicotyledons to a secondary place is not 
without bearing upon other and interesting bio- 
logical phenomena. For there can be little doubt 
that the dearth of insects of almost all kinds 
