62 



and it seems impossible to doubt that the training of the 

 moral faculty necessarily undergone by the philosopher must 

 react upon the man." 



This preface as it were is, however, little to do directly 

 with the subject on which I had determined to address you ; 

 but it will perhaps suggest an answer to many of you who 

 may be assailed by some carping critic as to why we waste 

 our time on what he considers trifles, or when one is sud- 

 denly asked as to what is the value of a society like ours, or 

 what advantage is to be obtained from the study of natural 

 history. 



The subject to which I wish to direct your attention is 

 the all-absorbing one of the variation and the natural con- 

 sequence of variation, the nature of species. Little by little 

 the old " shibboleths" that collected round the definition of 

 species are being swept away ; one by one the arguments that 

 species, as we have pleased to term them, have existed 

 through all time in their present forms as separately created 

 entities falls into disuse ; one by one facts are added to our 

 knowledge of the organic beings by which we are sur- 

 rounded, that give us a truer insight and more correct 

 appreciation of the organisms themselves, and their actual 

 relation to the environment that surrounds them. The old 

 query, Show us some species that have been formed in 

 comparatively recent times ? no longer comes as a thunder- 

 clap to upset the equanimity of the evolutionist. The 

 student has amassed material, he has made observations, 

 and the general conclusions he is able to draw make for the 

 strengthening of the theory that the species now in exist- 

 ence have been evolved from pre-existent forms, modified in 

 response to a changed environment, each rising as it were 

 on the ashes of its predecessor, which becomes extinct in 

 giving birth to its offspring, the environment which requires 

 the development of a new form sounding the death-knell of 

 the old form, which no longer responds sufficiently to it. 

 We see species in this sense as a continuous series of 

 modifications of previous forms, each in turn becoming 

 extinct, though never really dying or creating a break in 

 continuity, each modification brought about as a change in 

 the external conditions of the life of the species, each modi- 

 fication being developed because of its use to the species, 

 and for this purpose only. 



Long before the publication of "The Origin of Species," 

 many scientific men had stated their belief in the instability 

 of specific forms, both of animal and vegetable life. Buffon 



