THE BIRDS OF AUSTRALIA. 
Colluricincla ? Is Eopsaltria a relation of Pachycephala ? Is Falcunculus any- 
thing else save a peculiarly modified Pachycephalan ? Where does Oreoica 
come in ? 
The recent investigations of Leach and Milligan have enabled the more 
correct appreciation of Strepera and Sphecotheres , and many more similar 
instances are required. 
In the succeeding pages, while generally adhering to the above system, I 
will institute amendments wherever such appear necessary, and hope from co- 
operation with the younger school of Australian ornithologists to advance our 
knowledge of Passeriform birds a little. At the present time our classification 
is based upon an old-world system which has served its turn, and we now need 
to provide a new one based upon the study of Australian birds. Practically, we 
now know all about the subspecies, the exact limits of whose ranges still, however, 
need definition and we have settled all (practically speaking) the nomenclatural 
problems involved ; we have searched most of the literature, so that we can 
now safely ascend to the more complex study of the osteology and anatomy 
at the same time as the field worker compiles his field notes and works out 
the bird’s economy. 
In the Auk, Vol. XXXIX., p. 159, April 1912, Trotter contributed a short 
paper, entitled “ The relation of genera to faunal areas,” and began : “ The relative 
antiquity of a genus is probably indicated by the greater or less departure of 
its several species and their varietal forms from a common ancestral type. The 
degree of departure may be the resultant of two opposing factors — first, the 
influence of conditions favouring segregation, as the character of the vegetation 
and the variety of habitat within the breeding range ; and, secondly, the opposing 
factor that of the inherent quality of resistance in the common ancestral type 
against the disrupting influences of environment and of variational tendencies. . . 
It is a habit of mind to regard a species as very definitely related to its range. 
It is much more definitely related to its habitat.” 
This is much more decidedly shown in Australia than probably in North 
America, as we have the Mallee forms extending unchanged from South to West 
Australia, the desert forms almost inseparable across the whole continent, and 
the Mangrove species ranging through many degrees of latitude as far as the 
Mangroves persist. A few miles of different habitat determine the range of many 
of these species and ofttimes they recur with the variety of habitat. The com- 
plexity of the subject, however, is well shown in connection with Tasmania, 
where birds do not occur though the apparent habitat is present, and birds 
occur whose apparent habitat on the mainland does not show them. In 
these cases the separation of the island does not appear as the cause of the 
presence or absence of the forms, nor does evolution satisfy the case absolutely. 
6 
