THE EVIDENCE FROM MISSING LINKS. 149 



surface always existed. Changes of land, and the separation of even 

 our great continents into detached portions of territory, are not theo- 

 ries, but facts of geology. And, admitting the existence of separate 

 islands or disconnected portions of land-surface, the distinction <^f 

 species by such separation, and the absence of intermediate forms, 

 would be fully accounted for. Nor must it be lost sight of that the 

 neutral territory or " No Man's Land " common to two species, is 

 usually small and ill-defined as compared with the wider territory or 

 area of the distribution of each group. And again, the range and 

 extension of a species, and its power of commingling with other 

 species, will be materially affected by the range of distribution of 

 other and already well-defined groups. The species will be preyed 

 upon by these latter groups, and the tendency to mix and unite with 

 its nearest allies is thus lessened and limited ; whilst the fact has been 

 already noted that the narrow and limited character of the common 

 area is by no means favourable to a blending of the characters of 

 the nearly related groups. Conversely, in a larger area, with less 

 risk of destructive competition from other species, we find the repre- 

 sentative group attaining the maximum of its development, and, even 

 in point of greater numbers alone, attaining a marked and charac- 

 teristic personality, as do the representative species alluded to in the 

 north and south of a large land-surface. Each species thus " fighting 

 for its own hand," and either aided, or on the other hand weakened, 

 by surrounding conditions, improves or decays, without mixing with 

 neighbouring groups. 



Summing up these preliminary observations on the theory that 

 " missing links " are by no means so necessary on a fair showing of 

 Nature's ways and polity as might be supposed, we may submit, 

 firstly, that the favourable variation of a species is a slow process, 

 depending not merely on changes in the constitution of the included 

 animals or plants, but on many other external causes, such as changes 

 of climate, and the like. Secondly, in connection with this first 

 discouragement to the mixing of specific characters, we must re- 

 member that detachment of land-surfaces will account for the 

 absence of intermediate forms; and in cases where such forms have 

 existed, they would be developed, as we have seen, in fewer numbers 

 than the species they would tend to connect ; lesser numbers imply- 

 ing few chances of either actual or geological preservation. 



But we may not forget that up to the present stage we have been 

 merely contending for the relevancy of the indictment. Supposing 

 our objections to the invariable necessity for " missing links " have 

 been maintained, there yet remain very many instances wherein, as 

 the evolutionist would freely admit, such connections require to be 

 supplied, theoretically or actually, for the support of his case. The 

 connected chain of life which the evolutionist postulates, implies the 



