SOUTH AMERICA. 125 



these with your knife, and you will come to a 

 substance more firm than skin, but of not so 

 strong a texture as the horn itself; cut this away 

 also, and behind it is discovered a thin and tender 

 membrane ; yellow, where it has touched the 

 yellow part of the horn ; blue, where it has 

 touched the red part, and black towards the edge 

 and point ; when dried, this thin and tender mem- 

 brane becomes nearly black ; as soon as it is cut 

 away, nothing remains but the outer horn, red 

 and yellow, and now become transparent; the 

 under mandible must undergo the same operation. 

 Great care must be taken, and the knife used very 

 cautiously, when you are cutting through the dif- 

 ferent parts close to where the bill joins on to the 

 head; if you cut away too much, the bill drops 

 off ; if you press too hard, the knife comes through 

 the horn ; if you leave too great a portion of the 

 membrane, it appears through the horn, and by 

 becoming black when dried, makes the horn ap- 

 pear black also, and has a bad effect; judgment, 

 caution, skill, and practice, will ensure success. 



You have now cleared the bill of all those 

 bodies which are the cause of its apparent fading ; 

 for, as has been said before, these bodies dry in 

 death, and become quite discoloured, and appear 

 so through the horn; and reviewing the bill in 

 this state, you conclude that its former bright 

 colours are lost. 



Something still remains to be done. You have 



