OEIGIN OF SPECIES. 7- 



time. If this is the case with varieties, I think it must follow that the same principle may also 

 act in the formation of species. The difficulty in drawing the distinction between a variety and 

 a species seems a sufficient reason for holdmg that if we find a principle affecting the production 

 of the one, it wUl also apply to the other. At any rate, it -will not be the Darwinians who will 

 object to the same measure being applied to both ; and as to their opponents, I have no fresh 

 argument beyond what may be inferred from the above to bring to bear upon them. 



I need scarcely say that, in other respects, this change in my views brings me no nearer Mr. 

 Darwin. In the alteration which has been made in the European races by transfer to America, 

 I see no indication of the principle of constant change, nor selection, nor yet of the struggle for life, 

 which are essential parts of his theory. 



These are the chief differences between his views and mine. He believes that in all organic 

 beings a certain degree of change is at all times unintermittingly going on ; and that, from that 

 variation and selection, through the struggle for life, new species are being incessantly developed. He 

 believes that the portals of the manufactory of new species are constantly open, and the process 

 always going on. He makes ample provision for instability ; none for stability. I believe that the 

 gates are habituallj- shut, but that they are alwajs ready to be opened to a greater or less width at a 

 touch of the kej', and fhaf that h'lj is change in the conditions under which species live. It does 

 not matter what the change is, nor in what direction it takes place. It has no relation to adap- 

 tation nor teleological purposes, it may be for their comfort or discomfort ; for their benefit or the 

 reverse ; its bearing on theii" organization is a matter of indifference ; all that is wanted is change 

 of some land or other to ruffle the repose of the pool. The only relation in kind, whicli I can 

 conceive between the alteration of condition and the change of species is that the greater and more 

 sudden the change of circumstances the greater and more divergent is the change in the species. 



On the other hand, it is plain to me that there must be some law which arrests variation 

 and confines it within certain bounds. Mr. Bentham has truly said, " Every species has 

 certain determinate limits of variation, which it only exceeds under exceptional circimistances, 

 and the exceptionally abnormal forms thus produced are few in individuals, and are not 

 reproduced." I imagine that the law which secures this stability of species is inertia. So long as 

 they are not meddled with they stand still; but subject them to change, — whether it comes to 

 them, or they go to it, — give them an impulse of any kind, and variation commences. Some receive 

 the impulse more oasUy than others. What may be felt by one may not be felt by another. Con- 

 stitutions differ : hence, the greater range of some species than others ; but whenever the change 

 makes itself felt, then I aj^prehend modification commences ; and as we go along, we shall, I think, 

 find instances, such as the half-completed species of the ciixumpolar regions, hovering between 

 varieties and species, which prove that the degree of modification which takes place in species, 

 bears some relation to the amount of alteration on the conditions of their existence ; and it may be, 

 that change once induced works more vigorouslj- in warm than in cold climates. It is well known 

 to hybridizers that it is not until the second generation of hybrids " tliat those which do not all 

 revert to the specific types give rise to that irregular variation which induces, after some generations, 

 that chaos of undecided forms, in the face of which all the efforts of botanical describers miscarry."* 

 It is not imtil the barrier has been broken down that these irregularities commence ; that once done, 

 there is no end to them. A somewliat parallel case is quoted by Sir Charles LyeU from the 



* Naudin, in " Coujptcs Eendus dc 1' Academic ties Sciences." Nov. 21, IS64. 



