INTRODUCTION. 



instance, the beautiful little warbling Grass Parrakeet {Melo- 

 psittacus undidatus), which prior to 1838 was so rare in the 

 southern parts of Australia that only a single example had been 

 sent to Europe, arrived in that year in such countless multi- 

 tudes on the Liverpool Plains, that I could have procured any 

 number of specimens, and more than once their delicate bodies 

 formed an excellent article of food for myself and party. The 

 Calopsitta Novcb HolkmdicB forms another case in point, and 

 the beautiful Harlequin Bronze-winged Pigeon {Phaps histri- 

 o?iica) a third ; this latter bird occurred in such numbers on 

 the plains near the Namoi in 1839, that eight fell to a single 

 discharge of my gun ; both the settlers and natives assured 

 me they had suddenly arrived, and had never before been 

 observed in that part of the country. The aborigines who 

 were with me, and of whom I must speak in the highest 

 praise, from the readiness with which they rendered me their 

 assistance, affirmed, upon learning the nature; of my pursuits, 

 that they had come to meet me ! The Trihonyx ventralis may 

 be cited as another species whose movements are influenced 

 in the same way. This bird visited the colony of Swan River 

 in 1833, and that of South Australia in 1840, in such count- 

 less myriads, that whole fields of corn were trodden down and 

 destroyed in a single night ; and even the streets and gardens 

 of Adelaide were, according to Captain Sturt, alive with them. 

 Similarly to what occurs in America and on other great masses 

 of land, we find in Australia the law of representation markedly 

 carried out, as it mostly is where the same conditions exist. For 

 instance, the beautiful frill-necked Bower-bird of the scrubby 

 plains of New South Wales is represented in north-western 

 Australia by a nearly allied species, which makes its elegant 

 bower in similar situations. The Podargus humercdis, which 

 inhabits the An(/op1iora-^^i% of New South Wales, is in like 

 manner represented by the P. bracJii/pterus in Western 

 Australia, which presents a similar character of country ; and 

 so it is with many other species, both of mammals and birds. 



