410 PROFESSOR DUNSTAN AND DR. HENRY ON CYANOGENESIS IN PLANTS. 
obtained a further insight into the nature of other cyanogenetic glucosides now under 
investigation. So far as Lotus ardbicus and Sorghum vulgare are concerned, it would 
appear that the existence of a cyanogenetic glucoside in the young plant up to the 
period when the seeds ripen at any rate may serve as an important protection to the 
plant from the attacks of animals. It appears that animals, indigenous to the 
countries in which these plants are native, refuse to eat them in the earlier and 
poisonous stages of growth. The part played hy the glucoside in the general 
metabolism of these plants and the origin and fate of the cyanogenetic group still 
remain to he ascertained. The temporary presence in a plant of a considerable 
quantity of a cyanogenetic glucoside, together with an enzyme capable of decomposing 
it, appears to us to be a fact which must have an important biological meaning. 
As so much interest attaches to the subject from several points of view, we are 
engaged in investigating the constituents of other plants which furnish prussic acid. 
Among them we may mention Phaseolus lunatus (seeds), Lotus australis, Manihot 
utilissima , and Linum usitatissmum, as well as a number of little known plants 
derived from the Colonies which have proved to he poisonous to cattle, some of which 
may contain cyanogenetic glucosides. From the chemical point of view it is 
important, in the first instance, to isolate these glucosides and to ascertain their 
properties, composition, and molecular structure. This work we have now accom¬ 
plished with the glucosides of I^otus arabicus and Sorghum vulgare, which are shown 
to he radically different in chemical constitution, whilst each belongs to a type 
chemically distinct from that of amygdalin, the only naturally occurring cyanogenetic 
glucoside hitherto definitely known. 
