Reginald Crundall Punnett

“ But the majority of workers have taken natural selection for granted and then interested themselves in shewing how the characters studied by them might be of use. Probably there is no structure or habit for which it is impossible to devise some use [2] , and the pursuit has doubtless provided many of its devotees with a pleasurable and often fascinating exercise of the imagination. So it has come about that the facts instead of being used as a test of the credibility of natural selection, serve merely to emphasise the pæan of praise with which such exercises usually conclude. ”

“ It is now more than fifty years since Darwin gave the theory of natural selection to the world, and the conception of a gradual evolution has long ago become part of the currency of thought. Evolution for Darwin was brought about by more than one factor. ”

“ The advent of natural selection threw a new light upon adaptation and the appearance of design in the world. In such books as those on The Fertilization of Orchids and The Forms of Flowers Darwin sought to shew that many curious and elaborate structures which had long puzzled the botanist were of service to the plant, and might therefore have arisen through the agency of natural selection. ”

“ With the lapse of time there has come about a tendency to find in natural selection alone a complete explanation of the process of evolution, and to regard it as the sole factor by which all evolutionary change is brought about. Evolution on this view is a gradual process depending upon the slow accumulation by natural selection of small variations, which are more or less inherited, till at last a well-marked change of type is brought about. ”

“ It was perhaps in connection with adaptation that Darwin obtained the most striking evidence in support of his theory, and it is clear from his writings that it was in this field he laboured with most delight. The marvellous ways in which creatures may be adapted in structure and habit for the life they lead had not escaped the attention of the older naturalists. ”

“ Influenced by the writings of Bateson and de Vries, and by the experimental results that have flowed from Mendel's discovery in heredity, they have come to regard the process of evolution as a discontinuous one. The new character that differentiates one variety from another arises suddenly as a sport or mutation, not by the gradual accretion of a vast number of intermediate forms. ”

“ Though "mimicry" is but a small corner in this vast field of inquiry it is a peculiarly favourable one owing to the great interest which it has excited for many years and the consequently considerable store of facts that has been accumulated. ”