them。
  In　the　beginning；　the　planet　upon　which　we　live　was　（as　far
  as　we　now　know）　a　large　ball　of　flaming　matter；　a　tiny　cloud　of
  smoke　in　the　endless　ocean　of　space。　Gradually；　in　the　course
  of　millions　of　years；　the　surface　burned　itself　out；　and　was　covered
  with　a　thin　layer　of　rocks。　Upon　these　lifeless　rocks　the
  rain　descended　in　endless　torrents；　wearing　out　the　hard
  granite　and　carrying　the　dust　to　the　valleys　that　lay　hidden　between
  the　high　cliffs　of　the　steaming　earth。
  Finally　the　hour　came　when　the　sun　broke　through　the
  clouds　and　saw　how　this　little　planet　was　covered　with　a　few
  small　puddles　which　were　to　develop　into　the　mighty　oceans　of
  the　eastern　and　western　hemispheres。
  Then　one　day　the　great　wonder　happened。　What　had　been
  dead；　gave　birth　to　life。
  The　first　living　cell　floated　upon　the　waters　of　the　sea。
  For　millions　of　years　it　drifted　aimlessly　with　the　currents。
  But　during　all　that　time　it　was　developing　certain　habits　that
  it　might　survive　more　easily　upon　the　inhospitable　earth。　Some
  of　these　cells　were　happiest　in　the　dark　depths　of　the　lakes　and
  the　pools。　They　took　root　in　the　slimy　sediments　which　had
  been　carried　down　from　the　tops　of　the　hills　and　they　became
  plants。　Others　preferred　to　move　about　and　they　grew
  strange　jointed　legs；　like　scorpions　and　began　to　crawl　along
  the　bottom　of　the　sea　amidst　the　plants　and　the　pale　green　things
  that　looked　like　jelly…fishes。　Still　others　（covered　with　scales）
  depended　upon　a　swimming　motion　to　go　from　place　to　place
  in　their　search　for　food；　and　gradually　they　populated　the　ocean
  with　myriads　of　fishes。
  Meanwhile　the　plants　had　increased　in　number　and　they　had
  to　search　for　new　dwelling　places。　There　was　no　more　room
  for　them　at　the　bottom　of　the　sea。　Reluctantly　they　left　the
  water　and　made　a　new　home　in　the　marshes　and　on　the　mud…
  banks　that　lay　at　the　foot　of　the　mountains。　Twice　a　day　the
  tides　of　the　ocean　covered　them　with　their　brine。　For　the　rest
  of　the　time；　the　plants　made　the　best　of　their　uncomfortable
  situation　and　tried　to　survive　in　the　thin　air　which　surrounded
  the　surface　of　the　planet。　After　centuries　of　training；　they
  learned　how　to　live　as　comfortably　in　the　air　as　they　had　done　in
  the　water。　They　increased　in　size　and　became　shrubs　and　trees
  and　at　last　they　learned　how　to　grow　lovely　flowers　which
  attracted　the　attention　of　the　busy　big　bumble…bees　and　the
  birds　who　carried　the　seeds　far　and　wide　until　the　whole　earth
  had　become　covered　with　green　pastures；　or　lay　dark　under　the
  shadow　of　the　big　trees。　But　some　of　the　fishes　too
  had　begun　to　leave　the　sea；　and　they　had　learned　how　to　breathe
  with　lungs　as　well　as　with　gills。　We　call　such　creatures　amphibious；
  which　means　that　they　are　able　to　live　with　equal　ease　on　the　land
  and　in　the　water。　The　first　frog　who　crosses　your　path　can　tell　you
  all　about　the　pleasures　of　the　double　existence　of　the　amphibian。
  Once　outside　of　the　water；　these　animals　gradually　adapted
  themselves　more　and　more　to　life　on　land。　Some　became　reptiles
  （creatures　who　crawl　like　lizards）　and　they　shared　the
  silence　of　the　forests　with　the　insects。　That　they　might　move
  faster　through　the　soft　soil；　they　improved　upon　their　legs
  and　their　size　increased　until　the　world　was　populated　with
  gigantic　forms　（which　the　hand…books　of　biology　list　under
  the　names　of　Ichthyosaurus　and　Megalosaurus　and　Brontosaurus）
  who　grew　to　be　thirty　to　forty　feet　long　and　who　could　have
  played　with　elephants　as　a　full　grown　cat　plays　with　her　kittens。
  Some　of　the　members　of　this　reptilian　family　began　to　live　in
  the　tops　of　the　trees；　which　were　then　often　more　than　a　hundred
  feet　high。　They　no　longer　needed　their　legs　for　the　purpose
  of　walking；　but　it　was　necessary　for　them　to　move　quickly　from
  branch　to　branch。　And　so　they　changed　a　part　of　their　skin
  into　a　sort　of　parachute；　which　stretched　between　the　sides　of
  their　bodies　and　the　small　toes　of　their　fore…feet；　and　gradually
  they　covered　this　skinny　parachute　with　feathers　and　made
  their　tails　into　a　steering　gear　and　flew　from　tree　to　tree　and
  developed　into　true　birds。
  Then　a　strange　thing　happened。　All　the　gigantic　reptiles
  died　within　a　short　time。　We　do　not　know　the　reason。　Perhaps
  it　was　due　to　a　sudden　change　in　climate。　Perhaps　they
  had　grown　so　large　that　they　could　neither　swim　nor　walk　nor
  crawl；　and　they　starved　to　death　within　sight　but　not　within
  reach　of　the　big　ferns　and　trees。　Whatever　the　cause；　the
  million　year　old　world…empire　of　the　big　reptiles　was　over。
  The　world　now　began　to　be　occupied　by　very　different
  creatures。　They　were　the　descendants　of　the　reptiles　but　they
  were　quite　unlike　these　because　they　fed　their　young　from　the
  ‘‘mammae''　or　the　breasts　of　the　mother。　Wherefore　modern
  science　calls　these　animals　‘‘mammals。''　They　had　shed　the
  scales　of　the　fish。　They　did　not　adopt　the　feathers　of　the　bird；
  but　they　covered　their　bodies　with　hair。　The　mammals　however
  developed　other　habits　which　gave　their　race　a　great　advantage
  over　the　other　animals。　The　female　of　the　species
  carried　the　eggs　of　the　young　inside　her　body　until　they　were
  hatched　and　while　all　other　living　beings；　up　to　that　time；　had
  left　their　children　exposed　to　the　dangers　of　cold　and　heat；
  and　the　attacks　of　wild　beasts；　the　mammals　kept　their　young
  with　them　for　a　long　time　and　sheltered　them　while　they　were
  still　too　weak　to　fight　their　enemies。　In　this　way　the　young
  mammals　were　given　a　much　better　chance　to　survive；　because
  they　learned　many　things　from　their　mothers；　as　you　will　know
  if　you　have　ever　watched　a　cat　teaching　her　kittens　to　take
  care　of　themselves　and　how　to　wash　their　faces　and　how　to
  catch　mice。
  But　of　these　mammals　I　need　not　tell　you　much　for　you
  know　them　well。　They　surround　you　on　all　sides。　They　are
  your　daily　companions　in　the　streets　and　in　your　home；　and　you
  can　see　your　less　familiar　cousins　behind　the　bars　of　the　zoological
  garden。
  And　now　we　come　to　the　parting　of　the　ways　when　man
  suddenly　leaves　the　endless　procession　of　dumbly　living　and
  dying　creatures　and　begins　to　use　his　reason　to　shape　the
  destiny　of　his　race。
  One　mammal　in　particular　seemed　to　surpass　all　others　in
  its　ability　to　find　food　and　shelter。　It　had　learned　to　use　its
  fore…feet　for　the　purpose　of　holding　its　prey；　and　by　dint　of
  practice　it　had　developed　a　hand…like　claw。　After　innumerable
  attempts　it　had　learned　how　to　balance　the　whole　of　the
  body　upon　the　hind　legs。　（This　is　a　difficult　act；　which　every
  child　has　to　learn　anew　although　the　human　race　has　been
  doing　it　for　over　a　million　years。）
  This　creature；　half　ape　and　half　monkey　but　superior　to
  both；　became　the　most　successful　hunter　and　could　make　a
  living　in　every　clime。　For　greater　safety；　it　usually　moved
  about　in　groups。　It　learned　how　to　make　strange　grunts　to
  warn　its　young　of　approaching　danger　and　after　many　hundreds
  of　thousands　of　years　it　began　to　use　these　throaty　noises
  for　the　purpose　of　talking。
  This　creature；　though　you　may　hardly　believe　it；　was　your
  first　‘‘man…like''　ancestor。
  OUR　EARLIEST　ANCESTORS
  WE　know　very　little　about　the　first　‘‘true''　men。　We　have
  never　seen　their　pictures。　In　the　deepest　layer　of　clay　of　an
  ancient　soil　we　have　sometimes　found　pieces　of　their　bones。
  These　lay　buried　amidst　the　broken　skeletons　of　other　animals
  that　have　long　since　disappeared　from　the　face　of　the　earth。
  Anthropologists　（learned　scientists　who　devote　their　lives　to
  the　study　of　man　as　a　member　of　the　animal　kingdom）　have
  taken　these　bones　and　they　have　been　able　to　reconstruct　our
  earliest　ancestors　with　a　fair　degree　of　accuracy。
  The　great…great…grandfather　of　the　human　race　was　a　very
  ugly　and　unattractive　mammal。　He　was　quite　small；　much
  smaller　than　the　people　of　today。　The　heat　of　the　sun　and　the
  biting　wind　of　the　cold　winter　had　coloured　his　skin　a　dark
  brown。　His　head　and　most　of　his　body；　his　arms　and　legs　too；
  were　covered　with　long；　coarse　hair。　He　had　very　thin　but
  strong　fingers　which　made　his　hands　look　like　those　of　a　monkey。
  His　forehead　was　low　and　his　jaw　was　like　the　jaw　of　a
  wild　animal　which　uses　its　teeth　both　as　fork　and　knife。　He
  wore　no　clothes。　He　had　seen　no　fire　except　the　flames　of　the
  rumbling　volcanoes　which　filled　the　earth　with　their　smoke
  and　their　lava。
  He　lived　in　the　damp　blackness　of　vast　forests；　as　the
  pygmies　of　Africa　do　to　this　very　day。　When　he　felt　the
  pangs　of　hunger　he　ate　raw　leaves　and　the　roots　of　plants　or
  he　took　the　eggs　away　from　an　angry　bird　and　fed　them　to　his
  own　young。　Once　in　a　while；　after　a　long　and　patient　chase；
  he　would　catch　a　sparrow　or　a　small　wild　dog　or　perhaps　a
  rabbit。　These　he　would　eat　raw　for　he　had　never　discovered
  that　food　tasted　better　when　it　was　cooked。
  During　the　hours　of　day；　this　primitive　human　being