262 Dr F. Buchanan White on the 



whose descriptions are always careful, describes the inner 

 pales of T. violaceiim as acute, and those of T. rcpens as bifid. 

 The Ben Lawers grass had, I found when examining Don's 

 and Melvill's examples, acute inner pales, but had, in 

 addition, the ribs of the pale produced into short lateral 

 awns lying on each side of the acute apex. Numerous 

 examples of T. rcpens showed without exception inner pales 

 constructed as described by Andersson, therefore it seemed 

 probable that the character was a reliable one. A specimen 

 of T. violaceum was then examined, and no trace of the 

 lateral awns could be detected. Under these circumstances, 

 and having occasion to mention the rediscovery of Don's 

 grass, I provisionally named it {Proceedings of the Perthshire 

 Soc. of Nat. Science, vol. i. p. xli.) Agropyrum Bonianum. 

 This name was adopted in preference to Don's manuscript 

 name of Triticum alpinum, since that has been attended 

 with much confusion, and because, moreover, it seemed 

 desirable to associate Don's name with a flowering plant of 

 the Scottish hills. 



As, however, the species of the genus Agropyrum are so 

 variable, it appeared advisable that the specialist on grasses, 

 Professor Hackel, should be consulted. The opinion which 

 he very kindly gave is briefly this : — If the characteristic 

 of the lateral awns of the inner pales is constant, the specific 

 separation of A. Donianum from A. violaccum would be 

 justified ; but if not constant, or at least not obvious (and 

 from the specimens he has seen he is doubtful as to the 

 constancy), it can serve only to separate A. Donianum as a 

 variety. 



This, then, is the history of A. Donianum up to the 

 present time. It remains to be considered whether there 

 are sufficient grounds for believing that the distinction of 

 the lateral awns of the inner pale is to be relied on as a 

 constant character. 



In search of this character I have examined numerous 

 pales in — (1) Don's plant ; (2) Mr Melvill's specimen ; 

 and (3) many spikes from my cultivated Ben Lawers plant. 

 In all of these I have never failed to fiud it. If, however, 

 the pales are examined before the fruit has developed, the 

 awns may easily be overlooked, since at that time they 

 appear to be in a rudimentary condition only. As the fruit 



