SCIENCE-GOSSIP. 



235 



sub-acid fluid. These peculiar developments are 

 fly-traps. The lip of the cup all round secretes 

 a honey-like fluid which attracts flies, and hither 

 these guileless creatures come in vast numbers ; 

 but scarcely have they commenced to enjoy the 

 ambrosia, than they slip into the cup and are 

 drowned. This is an instance of deception in the 

 plant world of consummate cunning and ingenuity. 

 Experiment confirms the digestive property of the 

 liquid, and any one in possession of one of these 

 plants may perform the experiment for his own 

 satisfaction. It is simple and interesting and 

 worthy the labour. Immerse a small piece of the 

 white of a hard-boiled egg in the fluid, and in 

 about fifteen minutes the edges will have a ruptured 

 and gnawed-like appearance, while the surface will 

 be found converted into gelatine. Vary the experi- 

 ment by substituting a small piece of raw flesh, 

 and the whole will gradually dissolve. A piece of 

 cartilage is soon transformed into gelatine. 



Leaf of Venus Fly-tkap. 



The only legitimate inference from these experi- 

 ments is, that there are several groups of plants 

 deriving a part of their nourishment from the 

 animal kingdom. 



The Dionaea, or Venus fly-traps, seize insects 

 which alight on their leaves. The extremity of 

 the leaf is divided into two parts, and round the 

 edges of these divisions is developed a ray of very 

 sensitive tentacles, while upon the upper surface of 

 the leaf, on each division, are three others — long 

 and sharp, and of extreme irritability. A hinge 

 unites the two sections, enabling them to fold 

 together and form a miniature prison ; and woe to 

 the incautious insect that touches them ! his doom 

 is at once sealed. It is seized and suffocated 

 between the two parts of the leaf. The leaf when 

 touched closes instantly, and the poor insect vainly 

 struggles for freedom. It is retained until its fluid 

 parts are completely exhausted, and then the lobes 

 of the leaf open and resume their normal positions. 

 The little victim may be spared the agony of a 

 cruel and prolonged death, if the observer be 

 humane enough to forcibly open the lobes and set 

 him free. The captive is not killed and crushed at 

 once. Its dissolution is gradual, and the exquisite 

 refinement of its torture surpasses the ingenuity of 

 the Inquisition. We may, in passing, note the 

 exceedingly amusing antics of a spider after his 

 delivery. For a moment he appears bewildered, 



then he surveys his surroundings and promptly 

 takes his departure with the utmost celerity ; on 

 no account can he be induced to return, not even 

 for the most tempting of struggling flies introduced 

 into his neighbourhood. 



The Dionaea consumes the insect. After his 

 capture the glands secrete a viscid liquid which 

 has the property of dissolving living animal tissues. 

 This liquid closely resembles that of the peptic 

 glands of animals, and is only efficient when asso- 

 ciated with an acid. The solution is, therefore, a 

 true digestive process, resembling in every particular 

 the corresponding process in the intestinal canal of 

 animals. The insect serves as food for the plant. 



In Scotland we have three species of Drosera or 

 sundews, a genus of fly-trap allied to the Dionaea. 

 The surfaces of their leaves are frequently veritable 

 fly cemeteries. Insects may be found on them in 

 all stages of decomposition. The upper part of the 

 leaf, and particularly round the edge, is furnished 

 with long, reddish hairs, from the extremities of 

 which exudes a tiny drop of a sticky liquid. This 

 liquid is neutral at first, but becomes acid on the 

 application of a nitrogenous substance. These 

 irritable feelers, for such they are in effect, are 

 responsive to the merest touch of a foreign body ; 

 and the insect that commits the mistake of alighting 

 on them is instantly seized and glued down. All 

 the tentacles bend inwards and carry their prey 

 to the centre of the leaf, where, when digested, it 

 is absorbed. Here is a double trap, the tentacles 

 and the glue ; a more dangerous and cunningly- 

 devised apparatus for the destruction of the poor 

 fly than even the spider's web. 



I cannot omit mention of Pinguicula vulgaris, or 



BUTTERWOKT. 



common butterwort, so called from being used 

 by old-fashioned people to curdle milk. The but- 

 terworts are a group of plants belonging to the 



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