Chap. Vn. CATASETUM SACCATUM. 181 



the parts are a little separated from eacli otiier, in 

 order that the mechanism may be intelligiUe. In 

 the middle of the roof of the stigmatic chamber, far 

 back (d, in A, fig. 28), the upturned anterior edge of 

 the viscid disc can just be seen. The upper mem- 

 branous surface of the disc, before it is ruptured, is 

 continuous with the fringed bases of the two antenna; 

 between which it lies. The rostellum projects over 

 the disc and stigmatic chamber (see section C, fig. 29), 

 and is prolonged on each side so as to form the two 

 antennae ; the middle part is covered by the ribbon- 

 like pedicel (ped.) of the poUinium. The lower end of 

 the pedicel is attached to the disc, and the upper end 

 to the two pollen-masses (p) within the anther-cell. 

 The pedicel in its natural position is held much 

 bowed round the protuberant rostellum ; when freed 

 it forcibly straightens itself, and at the same time its 

 lateral edges curl inwards. At an early period of 

 growth, it is continuous with the rostellum, but sub- 

 sequently becomes separated from it by the solution 

 of a layer of cells. 



The poUinium when set free and after it has 

 straightened itself, is represented at D, fig. 29. Its 

 under surface, which lies in contact with the rostellum, 

 is shown at E, with the lateral edges of the pedicel 

 now curled inwards. In this latter view, the clefts in 

 the under sides of the two pollen-masses are shown. 

 Within these clefts, near their bases, a layer of strong 

 extensible tissue is attached, forming the caudicles, by 

 which the pollen-masses are united to the pedicel. 

 The lower end of the pedicel is joined to the disc by a 

 flexible hinge, which occurs in no other genus, so that 

 the pedicel can play backwards and forwards, as far as 

 the upturned end (fig. D) of the disc permits. The 

 disc is large and thick ; it consists of a strong upper 



