364 Scientific Intelligence— Botany. 
Van Diemen’s Land, will readily account for the paucity of species 
found in that island. 
By the term peculiar, I do not mean to convey the idea that the - 
birds are strictly confined to the respective countries, but that as 
yet they have not been found elsewhere. 
Independently of the vast accession of birds attracted by the great 
supply of food, as mentioned above, there are many species which make 
regular migrations, visiting the southern parts of the Continent and 
Van Diemen’s Land during the months of summer, for the purpose 
of breeding and rearing their progeny, and which retire again north- 
wards on the approach of winter, following, in fact, the same law 
which governs the migrations of the species inhabiting similar latitudes 
of the Old World. There are also periods when some species of birds 
appear to entirely forsake the part of the country in which they have 
been accustomed to dwell, and to betake themselves to some distant 
locality, where they remain for five or ten years, or 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 obser- 
vation. The beautiful little warbling Grass Parrakeet (Melopsitta- 
cus undulatus), 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 multitudes on the Liver- 
pool 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 Nymphicus Nove Hollandie 
forms another case in point, and the Harlequin bronze-winged pigeon 
(Peristera histrionica) a third ; this latter bird occurred in such num- 
bers 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 
that they had suddenly arrived, and that they had never before been 
seen in that part of the country. The Aborigines who were with me, 
and of whom I must speak in the highest praise, for the readiness 
with which they rendered me their assistance, affirmed, upon learn- 
ing 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 by the same law. ‘This bird visited the colony of 
Swan River in 18338, and that of South Australia in 1840, in such 
countless myriads, tlat 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. 
BOTANY. 
7. On the Gamboge Tree of Siam. By Dr Christison.—Although 
Gamboge has been known in European commerce for nearly two 
centuries and a half, and its applications in the arts have been ex- 
Ne nara Raat ee 
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