

INSECTS OF THE PRIMEVAL WORLD. 339 



numerous difficulties which must have beset all the 

 earliest forms of life, in earth's primeval days; some 

 of these can survive exposure to salt water for con- 

 siderable periods of time; others can exist in an 

 undeveloped condition for indefinite periods and under 

 every degree of heat and cold. All sorts of peculiar 

 combinations of organization are to be found among 

 the insect creation ; for this among other reasons, it 

 seems probable that these minute creatures are, some 

 of them, perhaps among the oldest existing examples 

 of living organisms. Still, the plant must have preceded 

 the insect. 



The vast variety which the range of plant life exhibits, 

 must be evident to everybody. However poor the 

 flora of a country may be, the number of its plants 

 will foot up to a long list; while the interminable 

 catalogues of the known varieties probably bear but 

 a moderate proportion, compared with the whole number 

 of plants in existence. Yet all these countless forms 

 of vegetable life were themselves evolved, step by step, 

 from an infinite series of ancestry, during enormous 

 periods of time. How long, therefore, shall we suppose 

 it has taken to originate one single new species of 

 plant ? All that can be said on this head is, that as a 

 matter of fact it is exceedingly doubtful, whether within 

 the whole range of historic time, any instance what- 

 ever can be given of a single new species which has 

 been evolved, by the fertility of Nature, during that 

 epoch, that is capable of perpetuating its own existence 

 in the wild state. * Professor Sir A. Geikie, for in- 



* It is desirable to note the fact that plants artificially improved, 

 or apparently newly produced under culture, such as cereal grains, garden 

 fruits, flowers, etc., are mere ephemera, incapable of perpetuating their 





