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Herbage Studies. I. — Lotus corniculatus, a Cyanophoric Plant. 

 By Henry E. Armstrong, F.E.S., E. Frankland Armstrong and 

 Edward Horton. 



(Received and read November 23, 1911.) 



Hitherto little attention has been paid to the individual plants which 

 constitute the herbage of pasture lands and no serious attempt has been 

 made to appraise their quality ; this is the more surprising, as it is well 

 known that certain pastures are of special value as grazing lands and that 

 the food value of herbage often differs to an extraordinary extent in 

 different districts and even in neighbouring fields — so much so that it is 

 impossible to fatten cattle on many, if not on the majority, of pastures ; 

 moreover, there are marked differences depending on seasonal conditions. 

 It is clear that such differences may be due both to variation in the 

 botanical composition of the herbage and to variation in the composition of 

 individual plants induced by variation in soil and in climatic conditions ; 

 at present, however, it is impossible even to hazard an opinion as to the 

 manner in which these and doubtless other factors are operative. 



Our present difficulty arises from the lack of methods of appraising 

 quality : we are no longer satisfied with determinations of dry matter, 

 digestible matter and albuminoid nitrogen, now that we realise that quality 

 as much as quantity is of importance — that in the case of cattle, as in our 

 own ease, a mixed and varied diet is required and that what may be termed 

 the condimental constituents of food are, perhaps, at least equal in importance 

 to those which serve exclusively as building materials or as a source of energy. 

 An increasing weight of evidence appears to be in favour of the view that the 

 vital processes in plants as well as in animals are controlled in greater or less 

 degree by substances of the class we have proposed to designate collectively 

 as Hormones. There can be little doubt, in fact, that it will be necessary to 

 take many factors into account in appraising the value of foods — far more, 

 indeed, than it has been customary to consider hitherto. 



It is not at all improbable that the glucosides present in plants in small 

 quantity are in some cases of definite condimental value. A case in point 

 is that of linseed. Owing to the presence of the glucoside linamarin 

 (pliaseolunatin) in the unripe seed, a small quantity of hydrogen cyanide 

 is usually to be found in linseed cake. It is well known that this cake has 

 qualities which make it superior to all other seed cakes as a food in 

 bringing cattle into condition ; it may well be that it owes its superiority 

 to this small amount of hydrogen cyanide and perhaps also to the acetone 



