56 GENERAL REMARKS ON THE 



lope of grasses, it may be observed that tlie view of its 

 structure now given, in reducing its parts to the usunl 

 ternary division of ]\lonocotyledones, affords an additional 

 argument for considering it as the real perianthium. This 

 argument, however, is not conclusive, for a similar conflu- 

 ence takes place between the two inner lateral bracteaB of 

 the greater part of Iridese ; and with these, in the relative 

 insertion of its valves, the proper envelope of grasses may 

 be supposed much better to accord, than with a genuine 

 perianthium. If, therefore, this inner envelope of grasses 

 be regarded as consisting merely of bracteee, the real perian- 

 thium of the order must be looked for in those minute 

 scales, which in the greater part of its genera are found 

 immediately surrounding the sexual organs. 



These scales are in most cases only two in number, and 

 placed collaterally within the inferior valve of the proper 

 envelope. In their real insertion, however, they alternate 

 with the valves of this envelope, as is obviously the case 

 in Ehrharta and certain other genera ; and their collateral 

 approximation may be considered as a tendency to that 

 confluence which uniformly exists in the parts composing 

 the upper valve of the proper envelope, and which takes 

 place also between these two squamae themselves, in some 

 genera, as Glyceria and Melica. In certain other genera, 

 as Bambusa and Stipa, a third squamula exists, which is 

 placed opposite the axis of the upper valve of the proper 

 envelope, or, to speak in conformity with the view ah'cady 

 taken of the structure of this valve, opposite to the junction 

 of its two component parts. With these squamae the sta- 

 mina in triandrous grasses alternate, and they are conse- 

 quently opposite to the parts of the proper envelope ; that 

 is, one stamen is opposed to the axis of its lower or outer 

 valve, and the two others are placed opposite to the two 

 nerves of the upper valve. Hence, if the inner envelope be 

 682] considered as consisting of bracteae and the hypogynous 

 squamae as forming the perianthium, it seems to follow, 

 from the relation these parts have to the axis of inflorescence 

 that the outer series of this perianthium is wanting, while 

 its corresponding stamina exist, and that the whole or part 



