1608 THE STORY OF THE UNIVERSE 



form result from the division of material of any kind; 

 then, as a complication, of materials bound together; 

 then, as a last refinement, of delicate materials, such 

 as blades of grass or threads of wool woven together; 

 such are the nests of certain birds and the tents of 

 nomads; (3) those which are built of moist earth 

 which becomes hard on drying; the perfection of this 

 method consists of piling up hard fragments, pieces 

 of wood or ashlar, the moist earth being only a mor- 

 tar which unites the hard parts together. Animals 

 exercise with varying success these different methods, 

 all of which man still practices. 



We will first occupy ourselves with the. dwelling 

 hollowed in the earth. It is the least complicated 

 form. The number of creatures who purely and 

 simply bury themselves thus to obtain shelter is in- 

 calculable; I will only mention a few examples, and 

 pass on from simple combinations to the more per- 

 fected industries, of which they present the first 

 sketch. 



Speaking generally, birds are accomplished archi- 

 tects. Certain of them are, however, content with a 

 rudimentary cavern. There is no question here of 

 those who retire to clefts in the rock or in trunks of 

 trees, for in these cases the cavity is only the support 

 of the true house, and it is in the construction of this 

 that the artist reveals his talent. I wish to speak of 

 animals which remain in a burrow without making a 

 nest there. A paroquet of New Zealand called the 

 kakapo (Strigops habroptilus) thus dwells in natu- 

 ral or hollowed excavations. It is only found in a 

 restricted portion of the island and leads a miserable 



