144 Darwin and Romanes dealt witli. 



The time that elapsed between the date (1787) of 

 Jenner's observation and those of Messrs. Seebohm 

 and Elwes, who conclusively demonstrated the fact 

 of cuckoos laying blue eggs was, as already said, 

 about a century — a century on which English ornith- 

 ologists would pique themselves, regarding it as one 

 of the greatest activity and definite result, with evo- 

 lution, natural selection, etc., etc. — and the very fact 

 that cuckoos' blue eggs for so long escaped all notice 

 whatever, is a kind of justification for our saying that 

 points of almost equal importance about this mys- 

 terious bird may be overlooked even now. One of 

 them, the very frequency of parasitic deposition, in 

 opposition to Mr. Romanes' easy, very easy assump- 

 tion that it is so " comparatively an exceedingly 

 rare event " that it wasn't worth while for mother 

 nature to arm the hosts of little birds by counter-in- 

 stinct to prevent and defeat it ; and so with a full 

 appearance of philosophy get quit of that difficulty 

 by a most monster assumption — the most pretentious 

 petitio principii that I, in the language of the delight- 

 ful Artemus, " have ever experiunced." Besides, just 

 realise where these fellows go. Instead of patiently 

 looking and pointing us to new facts, they are keen 

 to speak ex cathedra for mother nature in what she 

 might, may, would, could, or should do. Mother 

 nature, you may rely on it, will not come and make 

 her bosom bare in this sort of way, even to them. 

 She doesn't come : indeed, she mostly goes ; and she 

 has no back hair or odd fal-als about her, on which 

 you can lay hold to hinder her, either, or pull her 

 back. All you can do is very laboriously and humbly 

 to follow after — often even with sighs, and groans, 



