1602 THE STORY OF THE UNIVERSE 



inhabit these refuges permanently; others only re- 

 main there during the winter; others, again, who live 

 during the rest of the year in the open air, set up 

 dwellings to bring forth their young, or to lay their 

 eggs and rear the offspring. 



We shall find every stage, from that of beings pro- 

 vided for by nature, and endowed with a special or- 

 gan which secretes for them a shelter, up to those 

 who are constrained by necessity to seek in their own 

 intelligence an expedient to repair the forgetfulness 

 of nature. 



Nearly all the Mollusca are enveloped by a very 

 hard calcareous case, secreted by their mantle: this 

 shell, which is a movable house, they bear about 

 with them and retire into at the slightest warning. 



Caterpillars which are about to be transformed 

 into chrysalides weave a cocoon, a very close dwell- 

 ing in which they can go through their metamor- 

 phosis far from exterior troubles. It is an organic 

 form of dwelling, or produced by an organ. It is 

 not necessary to multiply examples of this kind; 

 they are extremely numerous. In the same category 

 must be ranged the cells issuing from the wax-glands 

 which supply bees with materials for their combs in 

 which they inclose the eggs of the queen with a pro- 

 vision- of honey. 



I do not wish to insist on creations of this kind 

 which are independent of the animal's will and re- 

 flection. Near these facts must be placed those in 

 which animals, still using a natural secretion, yet 

 endeavor to obtain ingenious advantages from it 

 unknown by related species. 



