660 president's address. 



at first sight seems a not very large census; and no doubt in time 

 and under very favourable circumstances it will be to some extent 

 increased. Every naturalist who resides for some time even in a 

 good collecting district knows how long a time it takes to arrive 

 at a complete census of the groups of its fauna in which he is 

 especially interested; and how his experiences vary from year to 

 year and from season to season. Still less is it likely that the 

 zoological resources of an enormous area like Central Australia 

 should be exhausted at a single attempt by visiting naturalists 

 almost constantly on the move, however enthusiastic and assiduous 

 they might be. From the experiences of Prof. Spencer we gather 

 that if a zoological collector in Central Australia is to be success- 

 ful in getting together a collection — not merely of skins of beasts 

 and birds — but one at all rejDresentative of the general fauna, 

 questions of time and patience must be of quite secondary import- 

 ance. First of all he has to catch his animals— but in some 

 seasons, and in the case of some of the most interesting members 

 of the fauna, this is an unusually difficult task, and may entail 

 long and patient waiting upon the rains, as well as securing the 

 cooperation of the Aborigines. Should he arrive in a dry season 

 he might without previous experience even wonder whether, 

 except ants, there were any animals to be caught. The visit of 

 the Horn Expedition was made during the winter months (Ma}^- 

 Aug.) after good rains. But during the course of the expedition 

 the rain kept off, the result being that a number of forms were 

 overlooked, and many experiences were missed, and would have 

 been missed altogether, had not Professor Spencer on his own 

 account subsequently made a rapid supplementary journey to 

 Charlotte Waters in time to see some of the more important but 

 transient aspects of the transformation scene which the advent of 

 good rains brings about. 



Looking at the Larapintine fauna as a whole, we find it 

 characterised by both negative and positive features. The 

 negative characteristics are shown by the absence of many widely 

 distributed Australian forms, or among the higher groups by the 

 limited number of species of the types which do occur, or by the 



