INTEODUCTION. 



r 



invent any hypothesis, and if it explains various large and independent masses of facts it rises to 

 the rank of a well-grounded theory. ... If the principle of natural selection does explain 

 these and other large bodies of facts, it ought to be received. On the ordinary view of each 

 species having been independently created we gain no scientific explanation of any one of these 

 facts. We can only say that it has so pleased the Creator to command that the past and present 

 inhabitants of the world should appear in a certain order and in certain areas ; that He has 

 impressed on them the most extraordinary resemblances, and has classed them in groups 

 subordinate to groups. But by such statements we gain no new knowledge ; we do not connect 

 together facts and laws ; we explain nothing."* In his ' Origin of Species ' Mr. Darwin has 

 shown that all organic beings, without exception, tend to increase at a very high ratio, and that 

 the inevitable result is an ever-recurrent struggle for existence, in the natural course of which the 

 strongest ultimately prevail and the weakest fail. By this process those variations, however 

 slight, which are favourable are preserved or selected, and those which are unfavourable are 

 destroyed. This continued production of new forms through natural selection inevitably leads to 

 the extermination of the older and less improved forms, these latter being necessarily intermediate 

 in structure, as well as in descent, between the last-produced forms and their original parent 

 species. The position to which this brings us is thus stated : "Now, if we suppose a species to 

 produce two or more varieties, and these in the course of time to produce other varieties, the 

 principle of good being derived from diversification of structure will generally lead to the 

 preservation of the most divergent varieties ; thus the lesser differences characteristic of varieties 

 come to be augmented into the greater differences characteristic of species, and, by the 

 extermination of the older intermediate forms, new species end by being distinctly defined 

 objects. Thus, also, we shall see how it is that organic beings can be classed by what is 

 called a natural method in distinct groups — species under genera, and genera under families." 

 Following the subject up with consummate skill, and bringing together a marvellous array 

 of facts and observations, Darwin has shown very conclusively that descent with modification 

 has been from time immemorial the means, whether naturally or artificially it matters not, 

 of producing new and distinct forms of animal and vegetable life. The subject is on the face of 

 it a very attractive one, and, when we come to deal with the actual facts, there is room for almost 

 endless speculation in all directions. But what I propose to do now is to single out some well- 

 established features and peculiarities of the New Zealand avifauna, to which, as most of my 

 readers are aware, I have for many years given special attention, and to consider their 

 direct bearing on the theory of evolution, or, putting it the other way about, to endeavour 

 to find in the Darwinian doctrine of natural development their true and rational explanation.! 



* ' The Variations of Animals and Plants under Domestication,' 2nd ed., vol. L, page 9. 



f " The theory of evolution was started as an hypothesis by Buffon, and defended and modified by Lamarck and 

 others, but was regarded by most scientific men as a wild dream, until Darwin and Wallace, after years of patient 

 accumulation of materials, overwhelmed the learned world with such a vast array of facts that with scarcely an 

 exception scientific men acknowledged their defeat, and the hypothesis of evolution was raised to the rank of a theory 



as firmly based on facts as Newton's theory of gravitation, or the undulatory theory of light The great 



charm of Darwin's theory of natural selection is its simplicity. The theory of evolution by descent with modification 

 had a great deal to recommend it ; but the difficulty always presented itself, By what possible machinery could it be 

 worked ? To suppose a special creation of every species was bad enough, and looked weak, as if the clock always 

 wanted mending or altering to make it go right. But to suppose not precisely a special creation, but a special inter- 

 ference, in a given direction, with the law of like producing like, at every generation, was a thousand times worse ; and, 

 consequently, of two evils scientific men chose the least, and the theory of evolution was laid on the shelf until Charles 

 Darwin and Wallace took it down again. The fact of the survival of the fittest in the struggle for existence is such a 

 simple theory that a child can understand it; and not only the scientific world, but almost every educated man, 

 accepted the new theory of evolution as soon as they saw— or thought they saw — the simplicity of the machinery by 

 which it is worked." — Seebohm. 



