x A MANUAL OF THE BIRDS OF AUSTRALIA, 
groups with their plumage changes and growth stages we may suggest genus 
lumping, and we prophesy now that our efforts in that direction will receive 
less encouragement than our present work. We have been accused of 
dogmatism, but never has any work shown so little of that vice ; as a matter 
of fact, many complaints have been made against our changeableness. Conse- 
quently we feel at liberty to allow our successors with better facilities and 
more material to judge our conclusions. 
An American reviewer has complained of our neglect of subgenera “so 
commonly used now,” but we would point out that in the American Ornitho- 
logists’ Union Checklist, out of the first 180 genera (nearly), covering the 
same ground as this volume, only “ 13” are subdivided into subgenera, while 
Ridgway’s proportion is apparently the same as ours, when dealing with the 
same groups. 
IlI.—ZOOGEOGRAPHICAL DISTRIBUTION. 
It is unfortunate for the study of zoology that political boundaries are 
adhered to in the nomination of localities and areas inhabited by animals. 
As a general rule such limits are never coincident with those imposed by 
nature, and nowhere is this fact seen so clearly as in Australia. Having 
studied the avifauna from the viewpoint of the zoogeographer, we here give 
a slight sketch of the peculiarities of the bird life as an incentive to further 
study. When the limits of the zoological divisions are understood the arrange- 
ment of subspecies is a comparatively easy task and their non-admittance 
in certain cases is worthy of attention. The primary constituents appear 
to be complex, as there can be seen two early sources of endemic forms, with 
two later immigrations from the north. Confusion may arise through the 
earlier immigrants being mistaken for the later, and vice versa, while it is 
possible that the two early sources cannot be definitely differentiated. At 
the present time the study of paleontology in Australia cannot give us much 
help, though later it may be of service. It is probable, moreover, that when 
the study of ecological ornithology is well established, facts may be derived 
from that source, which, in conjunction with geological data, may assist us 
to valid conclusions. With the above limitations we may separate the facts 
into groups and use them conservatively in considering the existing avifauna 
with the following results. The Tasmanian fauna shows a little peculiarity 
in the fact that the majority of the birds are separable from the mainland 
ones, but generally only with subspecific rank ; a few are specifically distinct, 
while two have been commonly accepted as showing generic differences. 
It is remarkable that these two are purely island degradation forms, whereas 
some of the restricted genera we utilise are more valuable phylogenetically as 
showing ancestral forms, the mainland representative being more specialised. 
A more peculiar feature is the absence from Tasmania of certain old forms 
which still persist on the almost adjacent mainland. These, moreover, 
inhabit the southern portion of Victoria which is so closely allied as to be 
almost, zoologically, part of Tasmania. It must be here confirmed that the 
