i8o PRESENT-DAY RATIONALISM 



language, and, unwittingly it may be, is sometimes as teleolo- 

 gical as Paley himself. 



Indeed, if Natural Selection gave the death-blow to teleology, 

 it also revived it ; for it is somewhat astonishing to read the 

 many a priori assumptions of writers who attribute uses to 

 structures without testing them by experiment. Thus one 

 asserts that holly has spinescent leaves up to a certain height to 

 keep off browsing animals, but that it bears non-spinescent 

 leaves at heights they cannot reach. Not only is this by no 

 means a common condition, for trees are often entirely 

 spinescent from twelve to twenty feet in height ; but cows will 

 sometimes destroy a holly bush. Moreover, when the leaves are 

 young the spines are no protection whatever, being as flexible 

 as india-rubber. 



Mr. Poulton in his Colour of Afii/nals writes : " A very 

 beautiful and familiar illustration is given by Mr. Wallace — 

 the white, upturned tail of the rabbit, by which the young and 

 inexperienced or the least wary individuals are shown the way 

 to the burrow. . . . The tail of the rabbit only becomes con- 

 spicuous when it is needed by other individuals of the same 

 species, and when the animal is already alarmed and in full 

 retreat for a place of security ". Upon which Dr. James 

 Iverach observes : ^ " Another interpretation cjuite as plausible, 

 though lacking in the conspicuous element of utility to the 

 rabbit, is that the tail of the rabbit is of great advantage to 

 the dog who pursues it, for it directs his path straight to the 

 mark ; or to the sportsman who knows at once where to shoot. 

 In these instances the possession of the white tail is of disad- 

 vantage to the rabbit." 



I quite agree with Dr. Iverach when alluding to the free 

 use Darwinians make of Natural Selection : " Natural Selection 

 is itself described as a metaphor ; but as soon as we begin 

 to work with it, its metaphorical character disappears and it 

 becomes intensely real, and is quite capable of doing anything".^ 



This is illustrated by Darwin's attempt to account for the 



^Evolution and Christianity, p. 119. ' Up. cit., p. 121. 



