Chap. II. THEIR INTELLIGENCE. 81 



necessary in plugging up the burrows, the 

 proportion of those drawn in by the tip (130) 

 to those drawn in by the base (48) was 

 rather less than three to one. That these 

 petioles had been dragged into the burrows 

 for plugging them up, and not for food, 

 was manifest, as neither end, as far as I 

 could see, had been gnawed. As several 

 petioles are used to plug up the same burrow, 

 in one case as many as 10, and in another 

 case as many as 15, the worms may perhaps 

 at first draw in a few by the thicker end so 

 as to save labour ; but afterwards a large 

 majority are drawn in by the pointed end, in 

 order to plug up the hole securely. 



The fallen petioles of our native ash-tree 

 were next observed, and the rule with most 

 objects, viz., that a large majority are dragged 

 into the burrows by the more pointed end, had 

 not here been followed ; and this fact much 

 surprised me at first. These petioles vary in 

 length from 5 to 8| inches ; they are thick 

 and fleshy towards the base, whence they 

 taper gently towards the apex, which is a little 

 enlarged and truncated where the terminal 

 leaflet had been originally attached. Under 

 soine ash-trees growing in a grass-field, 229 



