272 



HARDWICKE'S SCIENCE-GOSSIP. 



beetle {Ocypiis olens) was flung near the centre of a 

 web. The occupant soon wound it round, notwith- 

 standing that the beetle formed tlie back into a 

 most awe-instilling curl, and gnashed the mandibles 

 until the head was bathed in the dark-brown liquid 

 the beetle emits on being handled. 



The formidable LitJiobius forcipatus was perfectly 

 at fault on the web of a spider, its mandibles and 

 clawed feet being of no avail. 



Like newts, spiders will seldom seize a motionless 

 animal. The following fact appeared to prove this : 

 The full-grown larva of a moth {Arcila menthasteri) 

 was thrown on a spider's web ; as the caterpillar 

 remained perfectly immovable, the spider descended, 

 and caused the load to drop below by breaking the 

 threads round it. The caterpillar was replaced, 

 this time it moved, the spider immediately wove a 

 cocoon round it, but the larva was very active, 

 struggled violently, the threads gave way, and it 

 was precipitated below. Spiders, in like manner, 

 free their webs of leaves and other objects that fall 

 or are blown on them. They go systematically 

 rouud the leaf, breaking off thread by thread by 

 means of a falx. In one case a leaf was cut down 

 with the exception of a single thread adhering to 

 the stalk : the spider did not trouble to break this, 

 nor was it necessary to do so, for it shortly fell by 

 its own weight. In another instance a leaf fell on 

 the upper surface of an oblique web, consequently 

 it became more and more involved according as the 

 spider increased her efforts to get rid of it. The 

 upshot of the affair was, the spider gave up, after 

 having demolished half the web. 



E. Halse. 



CARNIVOROUS PLANTS AND TBEIR 

 PREY. 



By PiioFEssoK C V. Riley. 



rpHE insect-catching powers of these curious 

 -*- plants, the Fly-traps {Bionact), the Sundews 

 {Broscrci), and the Trumpet-leaves [Sarrucenici) , 

 have always attracted the attention of the curious, 

 but renewed interest has been awakened in them by 

 virtue of the interesting experiments and observa- 

 tions on their structure, habit, and function, that 

 have lately been recorded, and especially by the 

 summing up of these observations in some charm- 

 ing papers by Professor Asa Gray, which recently 

 appeared under the title of " Insectivorous Plants." 

 Through the courtesy of various friends I am able 

 to submit the following notes of an entomological 

 bearing on the Spotted Trumpet-leaf [Sarracenia 

 variolar in), which must henceforth rank with the 

 plants of the other genera mentioned as a consum- 

 mate insect-catcher and devourer. The leaf of Sar- 

 racenia is, briefly, a trumpet-shaped tube with an 



arched lid, covering, more or less completely, the 

 mouth. The inner surface, from the mouth to about 

 midway down the funnel, is covered with a compact 

 decurved pubescence which is perfectly smooth and 

 velvety to the touch, especially as the finger passes 

 downward. Prom midway it is beset with retrorse 

 bristles, which gradually increase in size till within 

 a short distance of the bottom, where they sud- 

 denly cease, and the surface is smooth. There are 

 also similar bristles under the lid. Running up the 

 front of the trumpet is a broad wing with a hardened 

 emarginate border, parting at the top and extending 



'" v^/ ■ »■ - 



Fig. 179. Pitchers of Sarracenia variolaris. 



around the rim of the pitcher. Along this border, 

 as Dr. Mcllichamp discovered, but especially for a 

 short distance inside the mouth, and less conspicu- 

 ously inside the lid, there exude drops of a sweet- 

 ened, viscid fluid, which, as the leaf matures, is re- 

 placed by a white, papery, tasteless, or but slightly 

 sweetened, sediment or efflorescence; while at the- 

 smooth bottom of the pitcher is secreted a limpid 

 fluid possessing toxic or inebriating qualities. 



The insects which meet their death in this fluid 

 are numerous and of all orders. Ants are the prin- 

 cipal victims, and the acidulous properties which 

 their decomposing bodies give to the liquid doubt- 

 less render it all the more potent as a solvent. 

 Scarcely any other llymcuoptera are found in the 



