TRANSACTIONS OF SECTION D. DEPT. OF ZOOLOGY AND BOTANY. 359 



degree of retrograde metamorphosis may occasionally be brought about. I think 

 then that we have considerable ground for suspecting that degradation has acted 

 much and widely in the field of Biology, and if so, Buffbn is fairly entitled to a 

 certain amount of esteem on account of the views he entertained with regard to it 

 in so early a day and in so undeveloped a condition of zoological science. For it 

 must not be forgotten that migration, the influence of external conditions, and 

 degradation, are connected points : parts of one view. Degradation is most con- 

 spicuous under violent changes of condition (such as parasitism), while migration 

 only acts by bringing organisms under new conditions. 



These reflections lead me to urge upon such of my hearers as may have any 

 unusual facilities for experimental investigation, a course of inquiry which seems 

 to be very desirable. 



What is needed in order to solve as far as possible the question of specific 

 genesis, is a knowledge of the laws of variation, which must, I think, be deemed the 

 true cause and origin of species. 



We may, I think, accept as true two propositions : 



(1) Animals may change in various ways, and amongst them, by degradation. 



(2) Changes in the environment with isolation, induce and favour changes in 

 form. 



I would urge then that inquiries should be pursued in two directions simul- 

 taneously. 



(A) There might be undertaken one set of inquiries to investigate the effects 

 on different species of the same variations of environment. 



(B) Other inquiries might be undertaken with a view to ascertaining the effects 

 of different changes of environment on one and the same species. By series of 

 experiments contrived with these ends in view, and carried on with various 

 selected animals and plants which reproduce with rapidity, we may possibly be able 

 to determine what to attribute to external influences (shown by such influences 

 having the same effects on all), and what to the peculiar nature and innate powers 

 and tendencies of different organisms — shown by the diverging reactions of the 

 latter under the same changes in their environment. 



I next desire to direct your attention to another matter treated of by Buffon — 

 I mean the resemblances and differences which exist between the mind 



OF MAN AND THE HIGHER PSYCHICAL FACULTIES OF ANTMALS. 



This question is eminently a question of our own day, and one which I feel 

 cannot but excite interest in this Section. 



But its accurate investigation is attended with special difficulties, and amongst 

 them are two temptations, which are apt to beset the inquirer : 



(1) The first of these arises from the wide-spread love for the marvellous 

 of whatsoever kind, and the tendency to inverted anthropomorphism. 



(2) The other is the temptation to strain or ignore facts to serve a favourite 

 theory. 



As to the former of these dangers, I may perhaps be permitted to quote some 

 remarks made by Mr. Chambers, approvingly cited by Professor Bain : ' There are 

 two subjects where the love of the marvellous has especially retarded the progress 

 of correct knowledge — the manners of foreign countries, and the instincts of the 

 brute creation .... It is extremely difficult to obtain true observations ' as 

 to the latter ' from the disposition to make them subjects of marvel and astonish- 

 ment.' . . . . ' It is nearly as impossible to acquire a knowledge of animals 

 from anecdotes as it would be to obtain a knowledge of human nature from the 

 narratives of parental fondness and friendly partiality.' This I believe to be most 

 true, and that here the danger of mistaking inference for observation is exception- 

 ally great. The inquirer ought not to accept as facts marvellous tales without 

 criticism and a careful endeavour to ascertain whether the alleged facts are facts 

 and not unconscious fictions. 



As to the second danger, the lamented George Henry Lewes, whom no one can 

 suspect of any hostility to Evolution in its most extreme form, remarks (in his 

 posthumous work * just published) that the researches of various eminent writers 



1 Problems of Life and Mind. Third Series, 1879, p. 122. 



