252 NATURE'S TEACHINGS 



A terrible example of the force which is exercised by this 

 principle among the vegetables is shown in some parts of 

 the world where the Aloe flourishes in a wild state. In our 

 colder clime the Aloe, though it does live in the open air, is a 

 slow-growing plant. But, in its own land, it shoots up with 

 a surprising vigour, and its sharply pointed and saw-edged 

 leaves are said to grow to tiie extent of six inches in a single 

 night. 



Taking advantage of this rapid, and, at the same time, powerful 

 growth, the natives, when they want to punish a man with 

 more than ordinary severity, tie him hand and foot, and bind him 

 to the earth just over a sprouting aloe plant, and leave him 

 there. In twenty-four hours the man is nearly certain to be 

 dead, the aloe-leaf having forced itself completely through his 

 body. Or, if he be not actually dead, he lives in frightful 

 tortures, which are continually increased by the flinty point 

 and notches forcing themselves slowly, but surely, through the 

 body. 



FOR an example of the Gimlet we may take the ovipositor of 

 the Sirex, an insect which I believe has no popular name. It 

 is coloured much after the same manner as the hornet, and is 

 often mistaken for that insect by those who are not versed in 

 entomology. And, as its long and straight ovipositor is gene- 

 rally taken for a hornet's sting, the insect assumes a double 

 terror to the ignorant. 



Now, the real fact is, that in its larval stage of existence the 

 Sirex feeds upon the wood of the fir-tree a diet which, to 

 our ideas, is about as unsatisfactory as can well be imagined. 

 In order that the young Sirex may be within reach of food, the 

 egg must be introduced deeply into the body of the tree, and, 

 for the egg to be so received, a channel must be cut for it. 



This is done by means of the marvellously formed ovipositor. 

 Many admirable descriptions have been given of the head of 

 this instrument and its boring powers, but I am not aware that 

 any one has noticed the secondary cutting bla les that are set 

 along the shaft of the principal borer, and which answer exactly 

 the same purpose as the spiral cutting edge of the gimlet or 

 auger. 



Not being desirous of repeating my own observations in dif- 



