CHAP. X11I. SECRETION AND ABSORPTION. 295 



shall presently see, if nitrogenous organic bodies which 

 are at all damp, are left on the lobes ; for these then 

 close by a slow and gradual movement, very different 

 from that caused by touching one of the sensitive fila- 

 ments. The footstalk is not in the least sensitive ; 

 a pin may be driven through it, or it may be cut off, 

 and no movement follows. 



The upper surface of the lobes, as already stated, 

 is thickly covered with small purplish, almost sessile 

 glands. These have the power both of secretion 

 and absorption ; but unlike those of Drosera, they 

 do not secrete until excited by the absorption of 

 nitrogenous matter. No other excitement, as far as I 

 have seen, produces this effect. Objects, such as bits 

 of wood, cork, moss, paper, stone, or glass, may be left 

 for a length of time on the surface of a leaf, and it 

 remains quite dry. Nor does it make any difference if 

 the lobes close over such objects. For instance, some 

 little balls of blotting paper were placed on a leaf, 

 and a filament was touched ; and when after 24 hrs. 

 the lobes began to re-open, the balls were removed by 

 the aid of thin pincers, and were found perfectly dry. 

 On the other hand, if a bit of damp meat or a crushed 

 Hy is placed on the surface of an expanded leaf, the 

 glands after a time secrete freely. In one such case 

 there was a little secretion directly beneath the meat 

 in 4 hrs. ; and after an additional 3 hrs. there was a 

 considerable quantity both under and close round it. 

 In another case, after 3 hrs. 40 m., the bit of meat was 

 quite wet. But none of the glands secreted, except- 

 ing those which actually touched the meat or the 

 secretion containing dissolved animal matter. 



If, however, the lobes are made to close over a bit of 

 meat or an insect, the result is different, for the glands 

 over the whole surface of the leaf now secrete copiously, 

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