`` What makes birch leaves shake so much more than the others ? '' asked inquiring Demi , who was always sure of an answer from Dan . `` They are hung differently . Do n't you see the stem where it joins the leaf is sort of pinched one way , and where it joins the twig , it is pinched another . This makes it waggle with the least bit of wind , but the elm leaves hang straight , and keep stiller . '' `` How curious ! will this do so ? '' and Demi held up a sprig of acacia , which he had broken from a little tree on the lawn , because it was so pretty . `` No ; that belongs to the sort that shuts up when you touch it . Draw your finger down the middle of the stem , and see if the leaves do n't curl up , '' said Dan , who was examining a bit of mica . Demi tried it , and presently the little leaves did fold together , till the spray showed a single instead of a double line of leaves . `` I like that ; tell me about the others . What do these do ? '' asked Demi , taking up a new branch . `` Feed silk-worms ; they live on mulberry leaves , till they begin to spin themselves up . I was in a silk-factory once , and there were rooms full of shelves all covered with leaves , and worms eating them so fast that it made a rustle . Sometimes they eat so much they die . Tell that to Stuffy , '' and Dan laughed , as he took up another bit of rock with a lichen on it . `` I know one thing about this mullein leaf : the fairies use them for blankets , '' said Demi , who had not quite given up his faith in the existence of the little folk in green . `` If I had a microscope , I 'd show you something prettier than fairies , '' said Dan , wondering if he should ever own that coveted treasure .
`` I knew an old woman who used XXXXX leaves for a night-cap because she had face-ache .
Dan Demi existence lichen mullein rooms silk-worms stiller twig worms