208 THE INDUSTRIES OF ANIMALS. 



looks towards the road ; the reason for this being, no 

 doubt, that the bird keeps a continuous eye on the 

 movements of people near it while building, and 

 so leaves the nest opened and unfinished on that side 

 until the last, and then the entrance is necessarily 

 formed. When the structure has assumed the globular 

 form with only a narrow opening, the wall on one 

 side is curved inwards, reaching from the floor to the 

 dome, and at the inner extremity an aperture is left 

 to admit the bird to the interior or second chamber, 

 in which the eggs are laid. A man's hand fits easily 

 into the first or entrance chamber, but cannot be 

 twisted about so as to reach the eggs in the interior 

 cavity, the entrance being so small and high up. The 

 interior is lined with dry soft grass, and five white 

 pear-shaped eggs are laid. The oven is a foot or 

 more in diameter, and is sometimes very massive, 

 weighing eight or nine pounds, and so strong that, 

 unless loosened by the swaying of the branch, it often 

 remains unharmed for two or three years. A new 

 oven is built every year, and I have more than once 

 seen a second oven built on the top of the first, when 

 this has been placed very advantageously, as on a 

 projection and against a wall." ^ 



Masons working in association. — Ants have already 

 furnished us with numerous proofs of their intelligence 

 and their prodigious industry. So remote from Man 

 from the anatomical point of view, they are of all 

 animals those whose psychic faculties bring them 

 nearest to him. Sociable like him, they have under- 



' P. L. Sclater and W. II. Hudson, Argentine Oinilhology, l8S8, 

 vol. i. pp. 1 68, 1 6g. See also Burmeister, " Ueber die Eier und Nester 

 einiger brasilianischen Vdgel," Cabani's Journal fur Ornith., 1S53, 

 pp. 161-177. 



