go THE INDUSTRIES OF ANIMALS. 



the tube. The animal first pierces the wall towards 

 the base of the stalk; through this hole he introduces 

 acorns until he has filled the lower part of the cavity. 

 This done, he makes a new hole rather above the 

 first, and fills the interval between the two, continuing 

 this process until he has arrived at the top of the 

 stalk and filled the whole interior. (Figs. lo and ii.) 

 The bird seems at first to take unnecessary trouble 

 by boring so many holes. He would reach his end as 

 well, it would seem, by making a single hole at the 

 top to fill his storehouse, and another at the bottom 

 to empty it. But we must not thus accuse him of 

 lack of judgment The interior of the tube is just 

 large enough for the passage of an acorn ; but at 

 certain points the sap is not entirely absorbed, and 

 there might easily be an impediment which would 

 leave a large part of the cavity empty. Hence the 

 necessity for a number of openings. When the sun 

 has scorched up plants, and provisions are rare, he 

 turns to his barns of abundance. Now and every 

 time that he has need he can utilise the method that 

 has been employed by his cousin the Melanerpes. 

 In order to feed on each acorn without too much 

 trouble, or allowing it to slip from his beak, the bird 

 places it in a vice. He hollows a hole in the trunk of 

 a tree, introduces the fruit there forcibly, and eats it 

 at his ease.i 



The provisions collected by these two birds reveal 

 a remarkable fact. They possess indeed two distinct 

 diets ; they do not preserve for the period of famine 

 the overplus of the foods which they consume in the 

 period of abundance. They chase insects and feed on 



• Henri de Saussure, "Observations sur les moeurs de divers oiseaux 

 du Mexique," Arch. Sci. phys. et nalur., 1859, pp. 21-41. 



