264 Prof. H. E. Armstrong and others. [Jan. 1, 



compared with that found on the East coast near Dundee and St. Andrews on either 

 side of the Tay estuary. L. corniculatus is abundant in these localities on the outer 

 margin of the sand dunes, where it grows in fine blown sand. The growth is chiefly 

 underground and is much less coarse in character than that at Ballantrae ; usually, the 

 leaves alone, which are very small and delicate, appear above ground. Cyanide was 

 found to be present in this plant, though in very much smaller amount than in the 

 coarse growing Ballantrae form. 



Taking the observations made in the field last year and the previous year 

 into account, it appeared to be little short of established that, in addition to 

 the common widely distributed cyanophoric form of L. corniculatus, a 

 botanically indistinguishable form exists, different from L. major, which, 

 like this latter, is acyanophoric. 



Considerable quantities of plant collected in the Cree valley were brought 

 to London for the purpose of determining the enzymic activity. Among these 

 were various samples in which cyanide had not been detected ; when these 

 were incubated at 37°, with a few drops of toluene, the presence of cyanide 

 in the plant became obvious within 24 hours, though the amount detected 

 was very small in all cases. On testing L. major in the same way, no 

 trace of cyanide was detected. 



It may be added that traces of cyanide have been found in plants grown 

 during 1912 from seed gathered the previous year in Norway from plants in 

 which cyanide could not then be detected. 



Whilst therefore it appears that L. major is uniformly acyanophoric and 

 that the common forms of L. corniculatus are more or less strongly 

 cyanophoric, a form of this latter species undoubtedly exists in which the 

 power of producing the cyanophoric glucoside is all but suppressed. 



Enzymic Activity of L. corniculatus from Various Localities. 



The determination of the enzymic activity of plants differing in habit and 

 from various localities is obviously of importance in view of the probability 

 that the cyanophoric glucoside and the enzyme are in close correlation. 



It should be noted that the activity of L. major towards linamarin is so 

 slight as to be negligible (see Part I) and it may almost be assumed that 

 this species is not only acyanophoric but also free from the specific enzyme 

 met with in L. corniculatus. 



The enzymic activity of all the specimens of L. corniculatus examined during 

 1911 in which the cyanophoric glucoside was present was high. Of the four 

 specimens from Norway, in which cyanide was not detected, however, one 

 was moderately active, one but slightly active and two active. 



The results obtained on examining specimens collected last year are as 

 follows : — : 



