24 OPHREiE. Chap. L 



game ; and the trap so complex and perfect, with its 

 symmetrical lines of rnptnre forming the saddle- 

 shaped disc above, and the lip of the pouch below ; 

 and, lastly, this lip so easily depressed that the pro- 

 boscis of a moth can hardly fail to uncover the viscid 

 disc and adhere to it. But if this fails to occur, the 

 elastic lip rises and covers again the viscid surface, 

 so as to keep it damp. The viscid matter within the 

 rostellum is attached to the saddle-shaped disc alone, 

 and is surrounded by fluid, so that it does not set hard 

 till the disc is withdrawn. The upper surface of the 

 saddle, with the attached caudicles, is also kept 

 damp by the bases of the anther-cells, until it is 

 withdrawn, and then the curious clasping movement 

 instantly commences, causing the pollinia to diverge, 

 followed by the movement of depression, which move- 

 ments together are exactly fitted to cause the ends 

 of the two pollen-masses to strike the two stigmatic 

 surfaces. These stigmatic surfaces are not so sticky 

 as to tear off the whole poUinium from the proboscis 

 of the moth, but by rupturing the elastic threads to 

 secure a few packets of pollen, leaving plenty for other 

 flowers.* 



But let it be observed that, although the moth pro- 

 bably takes a considerable time to suck the nectar of 

 a flower, yet the movement of depression in the pol- 

 linia does not commence (as I know by trial) until 

 they are fully withdrawn ; nor will the movement be 

 completed, and the pollinia properly placed for strik- 

 ing the stigmatic surfaces, until about half a minute 

 has elapsed, which will give ample time for the moth to 



* The late Prof. Treviranus has bnt points out two unimportant 

 confirmed (' Botanische Zeitung,' inaccuracies in the drawing which 

 1863, p. 241) all my observations, I have given. 



