150 FOREST CULTURE AND 
lia, Zamia alone haying been noticed in South Austra- 
lia (Zamia Macdonnellii), but there as an exceedingly 
local plant. Neither climate nor geologic considera- 
tions explain this curious fact of phytogeography. 
Over some of the healthy tracts of scrub-country, to- 
ward the south-west coast, poisonous species of Gas- 
trolobium (Gastrol bilobum, G. oxylobioides, G. caly- 
cinum, G. callistachys) are dispersed. These plants 
haye, in some localities, rendered the occupation of 
country for pastoral pursuits impossible, but these 
poison-plants are mostly confined to barren spots, and 
it is not unlikely that, by repeated burnings, and by 
the raising of perennial fodder-plants, they could be 
suppressed, and finally extirpated. Fortunately, in 
no other parts of Australia Gastrolobium occurs, ex- 
cept on the inland tract from Attack Creek to the Sut- 
tor River, where flocks must be guarded against ac- 
cess to the scrub-patches harboring the only tropical 
species (Gastrolobium grandiflorum). The deadly ef- 
fect occasionally produced by Lotus Australis, a herb 
with us of very wide distribution, and extending also 
to New Caledonia, and the cerebral derangements 
manifested by pasture animals, which feed on the Dar- 
ling River pea (Swainsona Greyana), need yet extensive 
investigation, but may find their explanation in the 
fact that the organic poisonous principle is only local- 
ly, under conditions yet obscure, developed ; or in 
the probable circumstance that, like in a few other 
leguminous plants, the deleterious properties are 
strongly concentrated in the seed. The gorgeous des- 
ert-pea (Clianthus Dampierii), which, in its capricious 
distribution, has been traced sparingly from the 
Tachlan River to the north-west coast, offers, still te 
seed-collectors a lucrative gain, 
4 
