DWELLINGS. I49 



HoUoivcd dwellings — Rudimentary burroivs. — 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 incalculable ; I 

 will only mention a few examples, and pass on from 

 simple combinations to the more perfected industries, 

 of which they present the first sketch. 



It is known that at a certain epoch of the year 

 Crabs abandon their hard carapaces. This pheno- 

 menon is known by the name of the moult ; they 

 remain in this condition for some time ; it is the 

 period during which they grow ; then their integu- 

 ments are encrusted anew with lime and again become 

 resistant. While they are thus deprived of their 

 ordinary protection they are exposed to a crowd of 

 dangers, and they are so well aware of this that they 

 remain hidden beneath rocks and pebbles. A crab 

 of Guadeloupe, called Gecarinus ruricola, escapes the 

 perils of this situation, thanks to its kind of life and 

 its habit of hollowing out a burrow to live in while it 

 is deprived of its habitual defence. This Crustacean 

 lives on the earth, at a distance of about ten or twelve 

 kilometres from the sea-shore, and nourishes itself on 

 animal and vegetable remains. It approaches the 

 water only at the period of laying eggs, turning 

 towards the coast in the months of February and 

 March. This migration does not take place, like some 

 others, in compact bands ; each follows the road in 

 independence, and preserves a certain amount of 

 liberty with regard to the path and the epoch of the 

 journey. They lead an aquatic life till May or June; 

 then the female abandons her little ones, who had 

 begun their development attached to her claws, and 



