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 

 lees 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 

 Bidgway's proportion is apparently the same as ours, when dealing with the 

 same groups. 



III. 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 divi sions 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 palaeontology 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 



