Buller. — Illustrations of Darwinism. 75 



Sphcerococcus elevans, blisters on bark, 

 female in cavity. 

 „ adult female, side view. 



dorsal boss of female, after treatment. 

 Frenchia semiocculta, male and female galls on twig. 



female galls, one with protruding tail. 

 „ male galls. 



early adult female, side view. 

 „ adult female, dorsal view. 



extremity of tail, showing anal ring and 

 setae. 

 „ diagram of larva, showing spinnerets, 



antenna of larva, 

 spinnerets of larva. 

 „ pupal indusium of male, 



antenna of male. 



Art. III. — Illustrations of Darwinisjn ; or, The Avifauna of 

 New Zealand considered in relation to the Fundamental 

 Law of Descent with Modification. 



By Sir Walter L. Buller, K.C.M.G., D.Sc, F.E.S., &c. 



[Read before the Wellington Philosophical Society, 27th June, 1S9±.~\ 



On my retirement from the chair last year I had to apologize 

 for my inability, owing to my hurried departure for England, 

 to prepare the usual presidential address, but I then promised 

 to deliver it later on ; and by the courtesy of Major-General 

 Schaw I am enabled to do so this evening in the form of a 

 paper. 



The Turks have a proverb which says that "the devil 

 tempts the busy man, but the idle man tempts the devil." 

 Bearing this in mind, I employed myself during a portion of 

 my last six weeks' voyage from England in gathering together 

 from my New Zealand notes and recollections, and carefully 

 elaborating, certain facts and inferences tbat appear to me to 

 bear directly on the great doctrine of the evolution of species 

 by a natural process of descent with modification — that is to 

 say, the ever-operating law of natural selection by variation 

 and the survival of the fittest. And, as I must to-night take 

 up some special subject for my address, it seems to me that 

 I cannot perhaps do better than place before you, whilst the 

 matter is fresh in my memory, the facts and considerations 

 that presented themselves to my mind and the conclusions 

 arrived at in the course of this interesting study. I do so the 

 more readily because I find that the distinguished and gallant 

 officer who succeeded me, and who still occupies the presi- 



