87 



is folded over it, and a regular process of digestion commences. 

 That the movement of the hairs is not due to their being pulled 

 together by the struggling prisoner, is proved by the noteworthy fact 

 that they do not begin to bend over towards it until its struggles 

 have ceased. Moreover the same motion follows on placing a piece 

 of meat on the leaf ; whereas not the slightest change is per- 

 ceptible when an atom of wood or worsted is substituted.* 



Similar tales are told of other species of the same family. At the 

 Cape of Good Hope a practical use is made of Roridula, a genus 

 closely allied to Drosera, "the branches being hung up for the pur- 

 pose of catching flies, "t 



Of course all plants furnished, like the S;indew, with viscid gland- 

 ular hairs— even though they may not have the sensitive property 

 with which that vegetable is gifted— are indirectly the cause of death 

 to thousands of insects which come in contact with them, when in 

 search of food or rest. They are veritable traps, though not of so 

 ingenious a character as those just mentioned. 



Sempervkmn glutinosum, a house leek of the Canary Isles, has the 

 stem, (as implied in the second name) daubed from top to bottom 

 with a sticky varnish. Many species of the mouse-ear-chickweed 

 (Cerastium) have flower stalk and calyx clothed with glandular hairs. 

 Another genus of the same Natural Order— Silene, with eight or 

 nine British species — has obtained the common name of ''Catchfly " 

 from the fact of some part of the stem being covered with a viscid 

 matter, to which unvt^ary insects may be seen clinging in death. Of 

 a similar nature are the leaf buds of the horse-chestnut and the 

 Tacamahac poplar (Populus halsamifera), which are painted over 

 with a peculiar varnish of a very adhesive nature. 



But the "viscid" i^rinciple is not the only one employed to 

 beguile simple insects. Nature has other methods equally efficacious 

 for working out her ends. Sometimes the throat of the Corolla is 

 furnished with a ring of stiff hairs, which all point inwards, thus 

 allowing of the entrance of a vagrant insect, but rendering its exit 

 very difficult, and often impossible. Many a poor fly has been in a 

 position to quote— with a depth of feeling which only bitter ex- 

 perience can give — the well-known lines of Virgil : 



Facilis descensus Averni est ; 

 Noctes atque dies patet atri janua Ditis ; 

 Sed revocare gradum. superasque evadere ad auras, 

 Hoc opus, hie labor est. Pauci, (quos sequus amavit 

 Jupiter, aut ardens evexit ad lethera virtus) 

 Dis geniti, potuere. J 



Not the least remarkable of these predatory vegetables is the 

 Californian Pitcher plant, ( DarUngtonia californica), which flourishes 

 in spongy bogs at an elevation of five thousand feet above the sea. 

 It is a vigorous plant, the stout flowering stems reaching three feet 

 in height, and having seeds as large as walnuts. At a short distance 

 the pitchers present the appearance of jargonelle pears, supported 

 with the largest ends uppermost between ten and twenty-four inches 

 above the ground. This results from the pitchers being quite turned 



* A. W. Bennett. (Paper read before the British Association, Septem- 

 ber, 1873.) 

 t Barber. (Transactions Linn. Soc. 1870). 

 t Virgil, (^neid. VI). 



