1898 - 99 .] Prof. Duns on Early Post- Pliocene Mammals. 693 
literature, sometimes as being in the university and sometimes as 
in the National Museum. 
The subjects now referred to are of some interest both to the 
naturalist and the antiquary, especially when dealt with from 
wider than mere zoological points of view. Much of the informa- 
tion we have at present of recently extinct forms consists of details 
of structure couched in a terminology which only experts readily 
appreciate. No doubt, progress in palseo-zoology would be impos- 
sible without such details, but it would be greatly helped were 
they associated with other than specific features — with, for ex- 
ample, what might suggest habits and habitats, physical and vital 
surroundings, gradational relations, geographical and geological 
distribution. Extinct animals might thus come to have a place in 
recent history. Thus regarded, the following questions of general 
interest are raised : — Do the remains of extinct forms, looked at in 
the light of their environments, point to local climatal changes, or 
to alterations of surface in the areas in which they occur, or to 
links dropped out of gradational rank, or to the realisation of new 
conditions of life by the disappearance of an old or by the intro- 
duction of a new species ? And suppose we assume the ever-present 
influence in species of an innate, ever-active element of structural 
variation, in what direction does it work? Is it towards new 
species, or is it only towards increase of variation in species ? These 
questions are put in the belief that we have materials to warrant 
them. In Scottish literature, reaching back three or four hundred 
years, we have references to mammals and birds now extinct by 
men who manifestly had cultivated the habit of the eye — men who 
saw the forms around them and who could describe what they 
saw. 
In the literature to which I refer we have information (1) on 
the physical and vital environments of mammals and birds ; (2) on 
the physical features of the districts in which they had been, or in 
which they were, at the time of the observer’s first record ; (3) on 
climatal conditions ; (4) on the prevalent fauna and flora of their 
time ; (5) occasionally , on the nature of superficial deposits ; (6) on 
important phenomena connected with migration ; (7) on the limits, 
if not on the laws of variation; and (8) on outstanding facts in the 
ancestral history of several extinct forms. That the men to whom 
