65 



ductus of Phillip Island, and probably, at an earlier date, 

 occasioned the similar fate of the singular Dodo. 



But while we may regret the premature extinction of a 

 harmless and useful species of animal by the destructiveness 

 of another one, there can be no doubt that the Creator has 

 imposed a natural limit to the duration of every species on 

 the surface of this globe. Just as individuals are born into 

 the world, live, and, after an appointed period, die ; so we 

 are taught by geology, that the time of the natural 

 existence of every species is also limited. "We observe the first 

 appearance of a species of animal in one stratum, we view it 

 flourishing, as it were, in another, then we trace it 

 languishing, and its numbers rapidly decreasing in a later 

 stratum, until, at last, it appears utterly extinct. We see 

 other limited durations appointed for the existence of 

 genera, families, and orders, so that analogy would make us 

 infer that it must be the same — for all groups of which in 

 geological strata we have, in a manner, witnessed the 

 commencement. It thus may be that classes, nay, the two 

 kingdoms of animal and vegetable nature themselves, — for 

 these, after all, are but groups of greater dimensions — as they 

 have had in geological strata a visible beginning, so must 

 they also in process of time have their due end. 



Nor need speculation cease here ; since it would surely be 

 the height of presumption to suppose that when all that 

 organization of matter which is dependent for existence on 

 atmospheric air, shall, with that gas, have passed away, other 

 kinds of organic beings may not remain, where atmospheric 

 air has never existed, or even where it may have ceased to 

 exist. Nevertheless, it is true that there is no vestige of 

 material life having ever existed^ on this terrestrial globe, 

 except in connexion in some way with the atmosphere, and 

 dependent on it. Nay, it would appear from observation, 

 that the order of the creation of species — aye, and perhaps 

 the order of their extinction too — has been carried on in 

 point of time, with reference to the successive conditions of 

 the circumambient air. Thus, aquatic beings have preceded 



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