NATURE'S GEOMETRICIANS 229 



themselves are through with it. Certain it is that 

 our ruby-throated hummingbird robs many webs 

 to fasten together the plant down, wood pulp, 

 and lichens which compose her dainty nest. 



Search the pond and you will find another mem- 

 ber of the spider family swimming about at ease 

 beneath the surface, thoroughly aquatic in habits, 

 but breathing a bubble of air which he carries 

 about with him. When his supply is low he swims 

 to a submarine castle of silk, so air-tight that he 

 can keep it filled with a large bubble of air, upon 

 which he draws from time to time. 



And so we might go on enumerating almost end- 

 less uses for the web which is Nature's gift to 

 these little waifs, who ages ago left the sea and 

 have won a place for themselves in the sunshine 

 among the butterflies and flowers. 



In the balsam-perfumed shade of our northern 

 forests we may sometimes find growing in abund- 

 ance the tiny white dwarf cornel, or bunch-berry, 

 as its later cluster of scarlet fruit makes the more 

 appropriate name. These miniature dogwood 

 blossoms (or imitation blossoms, as the white di- 

 visions are not real petals) are very conspicuous 

 against the dark moss, and many insects seem to 

 seek them out and to find it worth while to visit 

 them. If we look very carefully we may find that 



