PRESIDENTIAL ADDRESS. 63 



Dr. Greslioff draws attention to two constituents of plants 

 which are of especial interest to us in Australia. 



1. The presence of hydrocyanic or prussic acid, which is 



of especial interest to us whose country is pastoral, 

 farming and dairying. 



2. The presence of saponins, which are probably the key 



to the cause of the acrid or even poisonous nature 

 of some of our native plants. 



And here let me say, that while one does not presume to 

 doubt for a moment the facts as to the cyanogenetic 

 properties of some of our grasses, it is not desirable to be 

 careful (I do not say that anything extravagant has been 

 said, but the very mention of hydrocyanic or prussic acid 

 frightens some people), in making unreserved statements 

 as to their poisonous nature, because evidence is abundantly 

 available that under some circumstances, or during certain 

 periods of the year, these grasses are eaten with impunity. 

 We therefore require information as to the interpretation 

 of results. 



In the following Australian plants Greslioff finds hydro- 

 cyanic acid: — 



Drimys aromati ca,F.v.M.; Drosera or "Sun-dew." Some 

 species are already recorded as harmful to cattle. Maca- 

 damiaternifolia,W.v.M., "Queensland Nut," leaves strongly 

 cyanogenetic. Stipa or "Spear grasses." 



The fringe of the subject has been but touched, and I am 

 glad to see that Dr. J. M. Petrie is specialising in regard 

 to this particular work. 



Greshoff finds saponins in the following Australian plants : 

 Arrhenatherus avenaceum, Beauv.; Atriplex "Salt-bush," 

 in the seeds and leaves of certain species; Gleichenia 

 flabellata, R.Br., characterised by a high saponin content. 

 Kochia, various non- Australian species of salt-bush; the 



