BY JAMES M. PETRIE. 625 



With regard to this peculiarity, we may compare the results of 

 the Armstrongs and Horton (Proc. Roy. Soc. Lond., B.86, 1913, 

 265), with Lotus corniculatus growing in different countries. In 

 apparently identical plants, they found that most contained both 

 a cyanophoric glucoside and enzyme, but that in certain countries, 

 the plants were acyanophoric. Of the latter, some were rich in 

 enzyme, others contained only a trace. They state in explanation, 

 that the presence of the two correlated factors mentioned is not 

 sufficient, and that a third factor is necessary, probably one influen- 

 cing concentration. It would appear then, that the conditions of 

 concentration are unsuitable in some instances, such as in our three 

 grasses. 



Table i. 

 Cyanogenetic Grasses Previously Known. 



Bambusa arundinacea Roxb., 1911,* cultivated in N.S.W. 



Briza minor Linn., 1908, naturalised in N.S.W. 



Catabrosia aquatica Beauv., 1908. 



Cortaderia argentea Stapf, 1906, cultivated in N.S.W. C. con- 

 spicua, C. kermesiana, 1906. 



Elymus spp. 



Festuca poa Kunth, 1908. 



Holeus lanatus Linn., 1908, naturalised. 



Lamarckia aurea Mcench., 1908, naturalised. 



Melica altissima, M. ciliata, M. nutans, M. uniflora. 



Panicum maximum, P. muticum, 1903, introduced, P. junceum. 



Poa aquatica Linn., 1884; P. pratensis Linn., 1908, naturalised. 



Sorghum vulgare Pers., 1902, introduced; S. halepense Pers., 

 native ; S. saccharatum, S. tartaricum, 1903, introduced ; S. nigrum. 



Stipa capillata, S. gigantea, S. hystricina, S. leptostachya, 8. 

 Lessingiana, S. tortilis, 1906. 



Zea Mays, 1 903, naturalised. 



We have now to add to the above list of cyanogenetic grasses the 

 names of 17 more species, which are found in New South Wales, 



* The dates refer to record of hydrocyanic acid. 

 46 



