"Behold the Birds of the Air" 71 



pair of tail feathers next to the outer ones have each a 

 narrow white outer margin and a triangular white patch 

 on the inner web. Many other variations of colour 

 would need to be described to give a complete picture, 

 but these items will serve to show how intricate and 

 seemingly arbitrary is the pattern according to which 

 an array so multitudinous is yet uniformly clad. Surely 

 never was a garb so complicated designed for a human 

 battalion, not even that which Michael Angelo devised 

 for the Pope's Swiss Guard; and never assuredly did 

 human skill more accurately reproduce the simplest of 

 designs. It makes the matter not less, but more astonish- 

 ing, that the bird exhibits unmistakable tendencies to 

 vary. A tinge of yellow is often, but not always, found 

 on the greater wing-coverts, while instances of downright 

 "sports," piebald and buff-coloured varieties, are not 

 unfrequent. What is it that holds such tendencies in 

 check, and instead of motley confusion, produces such 

 practically persistent unity of type, that the next Chaffinch 

 we chance to catch will be sure to agree with it down to 

 the last particular? 



How much labour it requires to keep any race up to 

 a model of our own making, we know by experience ; 

 how much of the vis humana is required if we are not 

 to see our carefully-produced varieties of animals or plants 

 in pejus mere, ac retro sublapsa referri. And yet with 

 all our conscious efforts we cannot obtain such absolute 

 unity of type as nature offers. The short-horns of two 

 herds, the cinerarias from two nurseries, are never pre- 

 cisely the same, whereas not only from John O'Groat's 

 house to Land's End, but from Greenland to Beloochis- 

 tan, and from Siberia to Algiers, we shall find our friend 

 the Chaffinch, undistinguishable in his dress, unaltered 

 in his manner, and everywhere of the same sprightly 

 carriage which has suggested to our friends across the 

 Channel the happy phrase, gai comme pinson. 



Can it be seriously maintained that all this is the work 

 of chance, in the sense that it has been wrought out by 

 mechanical forces apart from a plan ? I think not : for 



