THE GOLDEN DOWN AND ITS OBJECT. 1.83 



as to its use might be offered; but it is exceedingly Ccapricious, 

 appearing now on one part of the body, now on another, and 

 seeming to obey no particuhir rule. For example, in Eupczus 

 nigerrimus, the down exists on two pairs of legs and not on 

 the third. In the JNIoluris it occupies the shoulder and dis- 

 appears from the limbs. In the Hercules Beetle a ridge of 

 such hair runs along the under surface of the beak-like thorax, 

 and in a weevil, which we shall presently see, tlie elongated 

 head is surrounded with radiating golden down, so that it looks 

 like a small bottle-brush. 



Now, it is evident that wliatever may be the function which 

 this yellow down exercises, it must be one which belongs equally 



Fig. 85. — Eupezus ni£;eirii]ius Is w species 

 (Black ) 



to aU the parts of the body on which it appears, and that there- 

 fore it cannot be for the purpose of giving the insect a firmer 

 hold, as has been suggested by those who have judged from its 

 presence on the legs ; or for the purpose of absorbing the juices 

 of plants, as has been said by those Avho judged from its pre- 

 sence on the head ; or for the purpose of affording warmth, as 

 has been conjectured by those who judged from its presence on 

 the body. There can be no doubt that it does exercise some 

 function which it can discharge in all these positions, though 

 what that function may be is at present a mystery. 



To return to our present insect. The head and thorax are 

 shiny black, and so are tire elytra, whicli are striated and punc- 



