38 Chapters in Modern Botany CHAP. 



caught, a secretion from the rosy glands immediately follows, 

 and the leaf remains closed for a week or two according 

 to the size of the insect. During that time the leaf acts 

 as a temporary stomach, and the insect is digested and 

 absorbed, as far at least as can be expected, and then the 

 leaf reopens, but remains for a time in a torpid state. 

 Sometimes, however, if the insect caught happen to be a 

 very large one, the leaf never opens again, its meal proving 

 too much for it ; and even in a state of nature the most 

 vigorous leaves are rarely able to digest more than twice, 

 or at most thrice, during their life. 



The attractive rosy patches on the leaf, the rapid 

 closure of the blade on its midrib, the interlocking of the 

 teeth around the margin, the specialised sensitiveness of 

 the six jointed hairs, the copious secretion of the digestive 

 glands, combine to make Dionaea a very efficient fly- 

 trap. 



The secretion poured out from the stimulated glands 

 contains formic acid and a digestive ferment. It further 

 resembles gastric juice in having marked antiseptic quali- 

 ties ; thus when Lindsay fed leaves with such quantities of 

 meat as to kill them with indigestion, the meat inside 

 remained fresh while portions hanging outside putrefied. So 

 abundant is the secretion that when Darwin made a small 

 opening at the base of one lobe of a leaf which had closed 

 over a large crushed fly, the secretion continued to run 

 down the footstalk during the whole time nine days 

 during which the plant was kept under observation. That 

 absorption follows digestion is shown by the disappearance 

 of the digestible substances, and Fraustadt was able, by 

 feeding leaves with albumen stained with aniline red, to 

 colour the contents and nuclei of the gland-cells. 



The three pairs of hairs are exquisitely sensitive to the 

 contact of solid bodies, but are indifferent to wind and 



