132 MALAXED. Chap. V. 



rostellum above, is united on each side behind to a 

 'green membranous expansion, convex exteriorly and 

 concave interiorly, of which the summits on each side 

 are pointed and stand a little above the crest of the 

 rostellum. These two membranes sweep round (see 

 back views, figs. C and D), and are united to the 

 filament or base of the anther ;. they thus form a cup- 

 like clinandrum behind the rostellum. The use of this 

 cup is to protect laterally the pollen-masses. When 

 I have to treat of the homologies of the different parts, 

 it will be shown by the course of the spiral vessels 

 that these two membranes consist of the two upper 

 anthers of the inner whorl, in a rudimentary condition, 

 but utilised for this special purpose. 



In a flower before it expands, a little mass or drop 

 of viscid fluid may be seen on the crest of the ros- 

 tellum, rather overhanging its front surface. After 

 the flower has remained open for a little time, this 

 drop shrinks and becomes more viscid. Its chemical 

 nature is difi'erent from that of the viscid matter in 

 most Orchids, for it remains fluid for many days, 

 though fully exposed to the air. From these facts 

 I concluded that the viscid fluid exuded from ^ the 

 crest of the rostellum; but fortunately I examined 

 a closely-allied Indian form, namely, the Microstijlia 

 rhedii (sent me from Kew by Dr. Hooker), and in 

 this, before the flower opened, there was a similar drop 

 of viscid matter ; but on opening a still younger bud, 

 I found a minute, regular, tongue-shaped projection 

 on the crest of the rostellum, formed of cells, which 

 when slightly disturbed resolved themselves into a 

 drop of viscid matter. At this age, also, the front 

 surface of the whole rostellum, between its crest and 

 the pocket-like stigma, was coated with cells filled 

 with similar brown viscid matter ; so that there can 



