Cultivated Plcmts of the Future. 
601 
But after all proper exclusions and additions have been made, 
the total number of species of flowering plants utilised to any con- 
siderable extent by man in his civilised state does not exceed, in fact 
it does not quite reach, one per cent. 
The disproportion between the plants which are known and 
those which are used becomes much greater when we take into 
account the species of flowerless plants also. Of the five hundred 
ferns and their allies we employ for other than decorative purposes 
only five ; the mosses and liverworts, roughly estimated at five 
hundred species, have only four which are directly used by man. 
There are comparatively few alga*, fungi, or lichens which have 
extended use. 
Therefore, when we take the flowering and flowerless together, 
the percentage of utilised plants falls far below the estimate made 
for the flowering plants alone. 
Such a ratio between the number of species known and the 
number used justifies the inquiry. Can the short list of useful 
plants be increased to advantage ? If so, how ? 
This is a practical question ; it is likewise a very old one. In 
one form or another, by one people or another, it has been asked 
from early times. In the dawn of civilisation, mankind inherited 
from savage ancestors certain plants which had been found amen- 
able to simple cultivation, and the products of these plants supple- 
mented the spoils of the chase and of the sea. The question which 
we ask now was asked then. Wild plants were examined for new 
uses ; primitive agriculture and horticulture extended their bounds 
in answer to this inquiry. Age after age has added slowly and 
cautiously to the list of cultivable and utilisable plants, but the aggre- 
gate additions have been, as we have seen, comparatively slight. 
The question has thus no charm of novelty, but it is as practical 
to-day as in eai'ly ages. In fact, at the present time, in view of all 
the appliances at the command of modern science and under the 
strong light cast by recent biological and technological research, the 
inquiry assumes great importance. One phase of it is being atten- 
tively and systematically regarded in the great experiment stations, 
another phase is being studied in the laboratories of chemistry and 
pharmacy, while still another presents itself in the museums of 
economic botany. 
The question may be put in other words, which are even more 
practical. What present likelihood is there that our tables may, 
one of these days, have other vegetables, fruits, and cereals, than 
those which we use now ? What chance is there that new fibres 
may supplement or even replace those which we spin and weave, 
that woven fabrics may take on new vegetable colours, that 
flowers and leaves may yield new perfumes and flavours 1 What 
probability is there that new remedial agents may be found among 
plants now neglected or wholly unknown ? The answer which will be 
attempted is not in the nature of a prophecy ; it can claim no rank 
higher than that of a reasonable conjecture. 
At the outset it must be said that synthetic chemistry has made 
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