12 ] Content* 



feed on fungi that prey on living things precautions against 

 poisonous mushrooms mosses favor moist places the moss as a 

 compass the best-known moss ferns, fronds, and "fiddle heads" 

 ferns for decoration how to make fern prints. 



11. TREES AND HOW TO KNOW THEM . . 339 



Tree rings and what they tell us watching a tree develop buds: 

 new life for the tree how to grow tree buds indoors trees have 

 their own birthday candles how trees are nourished the most 

 famous tree food of all why leaves change color and fall how 

 knots and knotholes are formed trees prune their own branches 

 the underground life of trees-keeping a tree biography how to 

 recognize the trees the white oaks the black oaks oak buds- 

 sugar maples red maples Norway maples sycamores: massive 

 shade trees "the button-ball tree" American elms: graceful and 

 tough poplars: including the quaking aspen the popular cot- 

 tonwood willows: generally found near water the pussy willow: 

 children's favorite beeches: handsome and practical ash trees: 

 pliant but tough the paper birch the gray and yellow birches 

 the cherry birch horse-chestnuts: imported from abroad: 

 ginkgos: admirable for city streets firs for Christmas Canada 

 balsam how to recognize a black spruce the Norway spruce- 

 hemlocks: useful and ornamental pines: majestic trees needles: 

 the key to identification pine cones massive sequoias: thousands 

 of years old the towering redwood how to mount evergreen 

 specimens some spring beauties flowering dogwoods magnolias 

 apple blossoms shrubs witch hazel and its popgun seed- 

 lovely mountain laurel staghorn sumac: brilliant scarlet poison 

 sumac poison ivy and poison oak relief for poison ivy making 

 leaf collections how to make spatter prints how to make prints 

 with printer's ink growing trees at home. 



12. OUR EARTH AND ITS FELLOW PLANETS . 380 



Things are not what they seem looking at the sky galaxies and 

 more galaxies what telescopes tell us telescopes for everyday 

 use choosing a telescope how planets differ from stars how to 

 locate the planets why life is possible on our earth Mars: 

 science-fiction favorite Mars through the telescope the "canals" 

 of Mars life on Mars Mars without a telescope Martian inva- 

 sionMercury: submerged by the sun's brilliance life is impos- 

 sible on Mercury when Mercury is visible Venus: most brilliant 

 of the planets the atmosphere of Venus earth: just another 



