ISO THE INDUSTRIES OP ANIMALS. 



they return to land. The moult takes place in 

 August. At the approach of this dreaded crisis each 

 hollows a hole between two roots, supplies it with 

 green leaves, and carefully stops up the entrance. 

 These labours accomplished, the crab is entirely 

 sheltered ; it undergoes the moult in safety, and does 

 not emerge from its retreat until it is again capable of 

 facing enemies, and of seizing food with its claws, 

 which have become hard again. This seclusion 

 appears to last a month. Here is, then, an example of 

 a temporary dwelling rendered necessary by special 

 conditions of defect for external life. We are here 

 still in the infancy of the art. 



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 Parroquet of New Zealand called the 

 Kakapo {Strigops habroptilus) thus dwells in natural 

 or hollowed excavations. It is only found in a 

 restricted portion of the island and leads a miserable 

 life there, habitually staying in the earth and pursued 

 by numerous enemies, especially half- wild dogs. It 

 tries to hold its own, but its wings and beak do not 

 suffice to protect it, and the race would have com- 

 pletely disappeared if these birds were not able to 

 resist, owing to the prudence with which they stay 

 within their dwellings. They profit by a natural 

 retreat, or one constructed in rocks or beneath roots 

 of trees; they only come out when impelled by 



