4 
THE FERN WORLD 
at once, though flowerless, the most graceful and beautiful of 
their lower world. 
God, in His goodness, has, with a liberal hand, scattered 
these beautiful plants nearly over the whole of the earth’s 
surface, only the sterile regions of the frigid poles being 
deprived of them. But their abundance or scarcity in any 
part of the world depends upon the existence, in greater or 
less perfection, of those peculiar conditions of growth which 
these moisture-loving plants require. In Europe, Asia, 
Africa and America, as well as in the islands of the seas, they 
are to be found, and both in tropical and temperate climes. 
Over the whole world, more than three thousand distinct 
species have been discovered ; but the variations from the 
normal forms of these species reach a far larger number than 
three thousand. 
It is curious and interesting to note the proportion borne 
by Ferns, in those great divisions of the world which we call 
‘zones,’ to flowering plants. Within the colder regions of 
the polar circles we have seen that they cease to exist. Just 
outside those regions, but within the boundary of the frigid 
zones they are found in the proportion of one Fern to eight 
flowering plants. In the torrid zone they stand in the pro- 
portion of one to twenty flowering plants, whilst in the 
temperate zones they are in the proportion of one to seventy 
flowering plants. In England and Wales Ferns are doubly 
as numerous in relation to flowering plants as in the tem- 
perate regions generally, and in Scotland the proportionate 
number is even somewhat greater as compared with those 
regions. 
But it is in the tropics that Ferns acquire their greatest 
degree of development, for in the depths of the great tropical 
forests, under the influence of the prevailing heat and 
humidity, they attain the size of trees, giving to those 
forests a strikingly graceful aspect, and even in the open 
