NATURAL SELECTION 109 



the opportunity for each development seems to occur but once 

 in the history of evolution. Primitive mammals appeared when 

 there was a chance for them in the age of mere reptiles and very 

 primitive birds. If birds had been what they are now, the first 

 small mammals would hardly have held their own. To go back 

 to the first beginnings of life, the simplest one-celled creatures, 

 compared with which even an amoeba is highly specialised, 

 competed with one another. They developed a contractile 

 vacuole, an imperfect one, or added a cell or two, clumsily 

 attached perhaps, and were in the vanguard of progress. But 

 such old world progressives would have no chance now. In 

 any aquarium there would be twenty animal forms, low yet 

 specialised, ready to assert their superiority. It may be that 

 even now live protoplasm is constantly arising from dead matter. 

 But if so, these new arrivals have no great future before 

 them, for all the good places are occupied, and long established 

 occupants will not tolerate an upstart species that has not even 

 mounted the first rung of the ladder. 



With some evolutionists, I believe, it is an article of faith that Extreme 

 any species, should it not be crushed out of existence by others ^"ifeTkT 

 more richly endowed, has an unlimited vista of possibilities before evolution 

 it, a view that seems to me very difficult to uphold. In the 

 Natural History Museum at South Kensington is a section of a 

 mighty Sequoia from California. At the base it measured 90 

 feet in girth, and 1 8 feet from the ground its girth was 50 

 feet. When cut down in 1892 it was one thousand three hundred 

 and thirty-five years of age, and there is no sign of decay re- 

 vealed in the section every ring is perfect. If the monster tree 

 had been allowed to die a natural death, it is difficult to say 

 when its hour would have come. Its extraordinary longevity 

 we must attribute to the struggle for existence and Natural 

 Selection. The species whose members, when once they had 

 found a good site, could hold it for centuries, was in an almost 

 unassailable position. Year after year more gifted rivals might 

 scatter their superior seeds and try for openings for their 

 offspring. No modern contrivances for scattering, for rapid 

 germination and growth, would be of avail against an old- 



