100 PRESIDENTS ADDRESS—SECTION D. 
disconnected specimens, sometimes even single specimens, with 
the resulting disadvantage that their contributions to literature 
were piecemeal, and too often on the scale of one specimen, 
one species, one paper. The lack of personal knowledge of 
Australia; the indifference to questions of geographical dis- 
tribution and the authenticity of specimens; the want of 
knowledge, or the incorrectness of the information supplied 
on those heads, in conjunction with imperfect knowledge 
of the collections and of the work of naturalists in 
other countries, eventually resulted in the necessity for undoing 
a good deal that had been done; for correcting and for supple- 
menting, which has tended to complicate matters. For the 
collections available, too, the field was occupied by too many 
zeologists. The study of the fauna for too long was synthetical 
when it should have been analytical. Further, as both the 
collecting and the scientific work soon became international on 
a large scale, but without any organisation, it has become 
difficult to reach the revisional stage of knowledge of large 
groups, especially among the invertebrates. The collecting has 
been so sporadic, so independently carried on, and the resulting 
collections are so scattered, without in any case being exhaus- 
tively representative, that the prospect of some of the large 
invertebrate groups ever being completely worked up becomes 
more and more remote. Under these circumstances it becomes 
more and more difficult for any one individual to acquire a 
critical knowledge even of a single group. The Austrahan 
- naturalist may compile a list of the described species of a 
group in which he may be interested, but very rarely can he 
make it a critical list, because types and type collections and 
literature are out of reach; or because species still “live in 
descriptions” only and cannot be identified from descriptions 
drawn up without knowledge of allied species, or from the only 
descriptions which are available. From the way in which the 
knowledge of the fauna has developed, it results that at the end 
of the nineteenth century no man can say precisely what it 
amounts to. No data in a suitable form are available for 
enabling one to arrive at a definite conclusion as to what exactly 
is known of the fauna as a whole, or even of the land fauna as 
a whole. 
The colonisation of Australia not only offered an unexampled 
opportunity of dealing with a continental flora and fauna, but 
also of studying on a large scale the important questions of the 
displacement and replacement of species. In the light of the 
evidence which has already been adduced it is not taking a 
pessimistic view to say that as regards the fauna the first of 
these opportunities was but imperfectly realised. As to the 
second, it is difficult to say anything very definite. The changes 
in the land fauna directly or indirectly traceable to the advent of 
