Although no toxic principle has been isolated from the Western Aus- 
tralian species of Macrozamia , the isolation by Cooper (54) of macrozamin 
from the Eastern States species M. spiralis (R. Br.) Miq- may give a lead 
in the solution of the wider problem. Macrozamin does not give hydrocyanic 
acid by hydrolysis with acids, almonds or yeast, but it does so after, hydro- 
lysis with alkali followed by acidification. Malloch (55) has examined the 
outer coat and the endosperm of the seeds of M. Biedlei (Gaud.) C. A. 
Gardn. and has shown that the toxic substance i.s present in the endosperm. 
Malloch obtained no evidence of the presence of a saponin, glycoside or 
alkaloid and suggested that the toxicity might be due to the presence of 
n toxalbumen. 
(ii) Saponins. 
Saponins are probably as widely distributed as the cyanogenetic glyco- 
sides and they are of considerable importance not only on account of their 
toxic properties but also because of their value as emulsifying agents. 
Ewart (56) has isolated a powerfully haemolytic saponin from Atalaya 
Uemiglauca (F. Muell* ) F. Muell. ex Benth., the whitewoocf of our North 
West, which is responsible for walkabout disease in stock. New South Wales 
specimens of this species are much less toxic than material from the vicinity 
of Fitzroy Crossing and Ewart has suggested that possibly two or more 
saponins of varying toxicity may be present in varying proportions in 
material from different localities. The saponin is stable and retains its 
toxicity for months. Dr. H. W. Bennetts (priv. comm.) has commented on 
the similarity between the toxic symptoms caused by A. hemiglauca and by 
Senecio species. This is of interest since the poisonous principles of the 
latter are alkaloids. 
Acacia Cunninghamii (21), in addition to being cyanogenetic, is of 
interest in that its unripe pods contain about 3 per cent, of a highly toxic 
saponin which resembles the mydriatic alkaloids i:i its properties, producing 
local anaesthesia, mydriasis and paralysis of accommodation. Hurst (21) 
also records references to the presence of toxic saponins in Acacia delibrata 
A. Cunn. ex Benth., A. pidchella R.Br. and Do dona ea physocarpa F. Muell. 
The genus Isotropis contains some powerfully toxic species, notably 
7. atropurpurea F. Muell. from which Finnemore has isolated a saponin. 
I. cunei folia (Sm.) Domin. var. parviflora Benth. has been proved toxic to 
sheep and 7. juncea Turcz. to guinea pigs; there is strong field evidence 
against 7. cnneifolia (Sm.) Fomin., while 7. Drummondii Meissn., 7. canes- 
cens F. Muell. and 7. Forrestii F. Muell. are considered toxic. There is no 
indication of the nature of the poisonous principles of these species. 
Albizzia distachya (Vent.) Maebride is recorded by Maiden (22) as con- 
taining about 10 per cent, of saponin in its dried roots, while the blister 
bush, Phebalium argent earn, is considered to be very rich in saponins. 
Anagallis arvensis, the scarlet pimpernel, contains the highly toxic cyclamin 
in its roots and saponins are also recorded to be present in Cardiospermum 
Halicacdbum L. (32), Tetragonia expansa Murr. (21) and Trianthema 
c rys t a lima V a hi . (21). 
The caustic vine, Sarcostemma australe R.Br., is of interest because, al- 
though it has been proved toxic to stock and to laboratory test animals 
(57) in the Eastern States, it is generally regarded as a most useful fodder 
plant in Western Australia. Finnemore has shown the absence of alkaloids 
