The dreamer--if you want an exact definition--is not a human being, but a creature of an intermediate sort. For the most part he settles in some inaccessible corner, as though hiding from the light of day; once he slips into his corner, he grows to it like a snail, or, anyway, he is in that respect very much like that remarkable creature, which is an animal and a house both at once, and is called a tortoise.