Miscellaneous. 381 



ginal and direct created adaptation of species to climate and other 

 conditions, why were these types not reproduced, when, after the 

 colder intervening era, those regions became again eminently adapted 

 to such animals ? Why, but because, by their complete extinction 

 in South America, the line of descent was here utterly broken? 

 Upon the ordinary hypothesis, there is no scientific explanation pos- 

 sible of this series of facts, and of many others like them. Upon the 

 new hypothesis, " the succession of the same types of structure within 

 the same areas during the later geological periods ceases to be mys- 

 terious, and is simply explained by inheritance." Their cessation is 

 failure of issue. 



Along with these considerations, the fact should be remembered, 

 that, as a general thing, related species of the present age are geo- 

 graphically associated. The larger part of the plants, and still more 

 of the animals, of each separate country are peculiar to it ; and, as 

 most species now flourish over the graves of their by-gone relatives 

 of former ages, so they now dwell among or accessibly near their 

 kindred species. 



Here also comes in that general "parallelism between the order of 

 succession of animals and plants in geological times, and the grada- 

 tion among their living representatives" from low to highly organized, 

 from simple and general to complex and specialized forms ; also 

 " the parallelism between the order of succession of animals in geo- 

 logical times, and the changes their living representatives undergo 

 during their embryological growth," — as if the world were one pro- 

 longed gestation. Modern science has much insisted on this paral- 

 lelism, and to a certain extent is considered to have made it out. All 

 these things, which conspire to prove that the ancient and the recent 

 forms of life "are somehow intimately connected together in one 

 grand system," equally conspire to suggest that the connexion is one 

 similar or analogous to generation. Surely no naturalist can be . 

 blamed for entering somewhat confidently upon a field of speculative 

 inquiry which here opens so invitingly ; nor need former premature 

 endeavours and failures utterly dishearten him. 



All these things, it may naturally be said, go to explain the order, 

 not the mode, of the incoming of species. But they all do tend to 

 bring out the generalization expressed by Mr.Wallace in the formula 

 that " every species has come into existence coincident both in time 

 and space with pre-existing closely allied species." Not, however, 

 that this is proved, even of existing species, as a matter of general 

 fact : it is obviously impossible to prove anything of the kind. But 

 we must concede that the known facts strongly suggest such an in- 

 ference. And since species are only congeries of individuals, and 

 every individual came into existence in consequence of pre-existing 

 individuals of the same sort, so leading up to the individuals with 

 which the species began, and since the only material sequence we 

 know of among plants and animals is that from parent to progeny, 

 the presumption becomes exceedingly strong that the connexion of 

 the incoming with the pre-existing species is a genealogical one. 

 Here, however, all depends upon the probability that Mr. Wallace's 



