CH. XI.] TWO OBJECTIONS CONSIDERED. 33 



allege certain objections as being quite obvious to all intelli- 

 gent people, save to the one-sided speculator who is supposed 

 to have ignored them. In INIr. Darwin's case, this mode of 

 treatment is peculiarly impertinent, since even the less ob- 

 vious objections to the theory of natural selection were for 

 the most part foreseen and answered in the first edition of 

 the " Origin of Species," — a book to which, as to an arsenal 

 of scientific facts, one must still resort who would deal intel- 

 ligently with the latest criticisms directed against the theory. 



The most obvious objection to the Darwinian theory is the 

 paucity, or, as it is often incorrectly alleged, the absence, of 

 transitional forms in the various sedimentary strata. This is 

 at first sight a weighty objection against the doctrine of natural 

 selection, according to which the progress has been effected 

 by infinitesimal increments ; although it is of no force against 

 the doctrine of derivation, as held by Mr. Mivart, who 

 rejects the maxim Natura non facit saltum, and maintains 

 that progress has been effected by sudden jumps, occurring 

 at rhythmical intervals. Mr. Mivart's suggestion, however, 

 cannot be entertained as a scientific hypothesis so long as it 

 alleges no physical agencies competent to effect the sudden 

 jumps from one specific form to another ; nor does the com- 

 parative paucity of transitional forms in a fossil state afford 

 any reason for our adopting it. A brief consideration will 

 show us that the fact is entirely consistent with the theory 

 of progress by minute variations. 



In the first place, let us note that in general intermediate 

 transitional forms must be the soonest killed off in the 

 struggle for existence; and that, especially, where two 

 strains or varieties become further differentiated into true 

 species, it is the extreme forms which multiply at the 

 expense of those which are intercalated betweeii them. 

 Here, as on a former occasion, cur comprehension of the 

 argument will be facilitated by a reference to the analogous 

 set of phenomena which occur during the process of lin- 



VOL. II. D 



