9788 Notices of Books. 



other birds that are thus influenced ; but the extent of their journeying 

 has not been clearly ascertained further than that they generally pro- 

 ceed north wlien the sun retires, and return when he approaches : that 

 they do not cross the equator is certain, for we should then find these 

 peculiar species northward of the hne, which we never do. There are 

 also some non-migratory species which appear to perform a kind of 

 exodus, and entirely forsake the part of the country in which they have 

 been accustomed to dwell, and to betake themselves to some distant 

 region, where they remain for five or ten years, and even for a longer 

 period, and whence they as suddenly disappear as they had arrived. 

 Some remarkable instances of this kind came under my own observa- 

 tion j for instance, the beautiful little warbling grass parakeet {Melopsit- 

 tacus undnlalus), which prior to 1838 was so rare in the southern parts 

 of Australia that only a single example had been sent to Europe, ai-rived 

 in that year in such countless nuiltiludes 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 Novae Hollandiae forms another case in 

 point, and the beautiful harlequin bronze-winged pigeon a third : this 

 latter bird occurred in such inimbers 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 Tribonyx 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 countless 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. Simi- 

 larly 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 beau- 

 tiful 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 

 humeralis, which inhabits the Angophora-flals of New Sonth Wales, is, 

 in like manner, represented by the P. trachypterus in Western Aus- 

 tralia, which presents a similar character of country, and so it is with 



