THE INNER LIFE OF PLANTS. 329 



cut open ; but none of the above substances exhibited the least 

 signs of digestion or dissolution, the angles of the cubes being as 

 sharp as ever." As the result of this experiment, Mr. Darwin adds, 

 " We may therefore conclude that Utricularia cannot digest the 

 animals which it habitually captures." It was further noted that in 

 most of the bladders examined, the imprisoned victims existed in 

 the form of a pulpy, decayed mass, although whether the process of 

 decay is simply a natural one, or whether, as some botanists suspect, 

 it is hastened by the influence of a special secretion from the bladder 

 itself, appears as yet to be undetermined. 



Beyond the stage of the bladderworts, however, the inner life of 

 the plant- world discloses a still more wonderful modification of plant- 

 habit. There exists a goodly collection of plants which not merely 

 capture living insect-prey, and that in a manner far more elaborate 

 than is witnessed in the bladderworts, but which also literally digest 

 and absorb their insect-food as perfectly as does the spider or other of 

 its animal and insect- eating neighbours. The list of true carnivorous 

 plants is long and varied. It includes the Venus' fly-trap or Dioncea 

 (Figs. 35 and 36); the sundews (Drostra); the butterworts(/y^?/zV#/#), 

 and other species of plants ; and it further contains within its limits 

 the most varied contrivances for effecting the capture of the prey. 

 Perhaps the most convenient starting-point for the brief examination 

 of the effects of plant-habit on the life of the organisms may be found 

 in the case of the butterwort itself. Here we discover a plant, found 

 as a rule in mountainous and marshy districts, and possessing short- 

 stalked leaves of oblong shape. The edges of the leaves are curved 

 inwards, and on their upper surfaces they bear numerous hairs, which 

 are named " glandular hairs," for the reason that "glands," or bodies, 

 adapted to secrete a fluid are associated with and included within their 

 structure. These hairs, it should be noted, are mere modifications 

 of the hairs so familiar on the leaves of most plants. The edges of 

 the leaves are destitute of these hairs. Upon these leaves captured 

 insects are commonly discovered ; but, as Mr. Darwin aptly remarks, 

 the mere fact of a leaf being capable in one fashion or another of 

 arresting insects, is itself no proof of the carnivorous nature of a 

 plant. At the same time, on the principle that it is le premier pas qui 

 coute in the modification of plant-life as in the course of human affairs 

 themselves, it may be well to note that the beginning of the insect- 

 eating habit may have lain in the mere accidental capture of the 

 prey. We shall note that the simplest insect-eating plants lead us 

 towards the more complex forms ; and it is probable that in their 

 turn such simple insect-eaters as Pingwcula represent mere develop- 

 ments of extremely common conditions in plants. Thus in a plant 

 (Mtrabilis] sticky hairs occur both on the leaves and stem. Further- 

 more, this plant continually captures insects by means of these 



