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



are usually found, except in L. major, it is scarcely probable that the power 

 to produce either cyanide or acetone is altogether lacking ; it is more likely 

 that the conditions of concentration may not be suitable and that the factor 

 in question is one influencing concentration. In any case, taking into account 

 the fact that plants possessed of very different characters have been found in 

 close proximity, it is difficult to avoid the conclusion that the differences 

 observed are less the consequence of the operation of special conditions of 

 environment — though these may contribute — than of the presence or absence 

 of definite factors. 



Trifohum repens. 



It was pointed out in the first part of these studies that our special object 

 is the development of methods of appraising the value of the various 

 constituents of the herbage of pasture lands. The study of L. comiculatus is 

 of interest from this point of view-, as the plant affords a striking case of 

 variation under natural conditions and it is to be supposed that any light thrown 

 on the causes of variation will be of assistance in dealing with the general 

 problem of variation. But in other respects, the plant is not well suited to 

 our purpose, as it ranks rather as a weed than as a fodder plant and is an 

 altogether minor constituent of most pastures. 



By far the most important leguminous plant in pastures is white clover, 

 Trifolium repens. We have been the more attracted to this plant by the appear- 

 ance of the account given by Hall and Bussell of their exhaustive study of the 

 remarkable conditions prevailing in Bomney Marsh,* where pastures are 

 found, side by side, one of which is good sheep-fattening land but unsuitable 

 and unsafe for ewes with lambs, whilst the other has no fattening qualities 

 and is used only in rearing lambs, which thrive on it. Trifolium repens is 

 .abundant in these pastures and is an important constituent of the herbage, 

 particularly of the fattening fields and especially throughout the earlier, part 

 of the year. 



Mirande has anticipated us in making known the presence of a cyanophoric 

 glucoside in this plant, f In our experience, the wild plant, wherever tested, 

 always contains cyanide ; the amount is not large — from 0'0036 to 039 

 according to Mirande's determinations — and always below that present in the 

 markedly cyanophoric forms of L. comiculatus. 



It is noteworthy that seedsmen and agriculturists recognise two varieties of 

 Trifolium repens — cultivated and wild white clover ; and that of late years 

 the latter has acquired some popularity as the more lasting variety. An 



* ' Journ. Agric. Sci.,' vol. iv, p. 339. 



t ' Comptes Rendus,' 1912, vol. 155, p. 651. 



