104 NATURE'S TEACHINGS. 



longer in proportion to its diameter than either of the preceding 

 traps, but it is formed on the same plan. An eel can easily 

 pass into the basket through the conical tunnel, but it is next 

 to impossible that it should find its way out again. 



So much for Art, and now for Nature. 



On the left hand of the illustration, at Fig. A, is the cocoon 

 of the common Emperor-moth (Saturnia pavonia minor), the 

 cocoon having been stripped of its outer envelope, so as to allow 

 its structure to be better seen. 



The reader will at once perceive that the entrance of the 

 cocoon is guarded by an arrangement exactly like that of the 

 above-mentioned traps, except that the cone is reversed, so as 

 to allow of exit and to debar entrance. Guarded by this 

 conical arrangement of stout bristly appendages, the pupa can 

 remain in quiet during the time of its transformation, for nothing 

 can force its way through such a defence, and yet the moth, 

 when fully developed, can push its way out with perfect ease. 



So admirably is this cocoon formed, that even after the moth 

 has escaped, it is impossible to tell by mere sight whether or 

 not it is within, the elastic wires closing on it after its passage. 



ANOTHER modification of the same principle now comes before 

 us. In the above-mentioned examples the arrangement of the 

 reverted spikes is more or less conical, and they lead into a 

 chamber. In the present instances, however, the mere reversion 

 of the points is all that is needed. 



The upper figure on the right hand represents the " Catch- 

 poll " of the Middle Ages, an allusion to which has already 

 been made. The reverted spikes turn on hinges, and are kept 

 apart by springs. This beautifully formed head was attached 

 to a long shaft, and was used for the purpose of dragging horse- 

 men from the saddle. It was thrust at the neck of the rider, 

 generally from behind. If a successful thrust were made, the 

 spring-points gave way, sprang back again, and thus clasped 

 the neck with a hold that was fatal to the rider. 



BELOW it is the Deer-trup which is used in many parts of India, 

 and to which allusion has already been made. The reader will 

 see at once that if a deer should get its foot through the con- 



