thrown　up　either　in　one　night　or　in　two。　　Where　the　ground　in
  Bengal　is　dry；　as　under　large　trees；　castings　of　a　different　kind
  are　found　in　vast　numbers：　　these　consist　of　little　oval　or　conical
  bodies；　from　about　the　1/20　to　rather　above　1/10　of　an　inch　in
  length。　　They　are　obviously　voided　by　a　distinct　species　of　worms。
  The　period　during　which　worms　near　Calcutta　display　such
  extraordinary　activity　lasts　for　only　a　little　over　two　months；
  namely；　during　the　cool　season　after　the　rains。　　At　this　time　they
  are　generally　found　within　about　10　inches　beneath　the　surface。
  During　the　hot　season　they　burrow　to　a　greater　depth；　and　are　then
  found　coiled　up　and　apparently　hybernating。　　Mr。　Scott　has　never
  seen　them　at　a　greater　depth　than　2。5　feet；　but　has　heard　of　their
  having　been　found　at　4　feet。　　Within　the　forests；　fresh　castings
  may　be　found　even　during　the　hot　season。　　The　worms　in　the　Botanic
  garden；　during　the　cool　and　dry　season；　draw　many　leaves　and　little
  sticks　into　the　mouths　of　their　burrows；　like　our　English　worms；
  but　they　rarely　act　in　this　manner　during　the　rainy　season。
  Mr。　Scott　saw　worm…castings　on　the　lofty　mountains　of　Sikkim　in
  North　India。　　In　South　India　Dr。　King　found　in　one　place；　on　the
  plateau　of　the　Nilgiris；　at　an　elevation　of　7000　feet；　〃a　good　many
  castings；〃　which　are　interesting　for　their　great　size。　　The　worms
  which　eject　them　are　seen　only　during　the　wet　season；　and　are
  reported　to　be　from　12　to　15　inches　in　length；　and　as　thick　as　a
  man's　little　finger。　　These　castings　were　collected　by　Dr。　King
  after　a　period　of　110　days　without　any　rain；　and　they　must　have
  been　ejected　either　during　the　north…east　or　more　probably　during
  the　previous　south…west　monsoon；　for　their　surfaces　had　suffered
  some　disintegration　and　they　were　penetrated　by　many　fine　roots。　　A
  drawing　is　here　given　（Fig。　4）　of　one　which　seems　to　have　best
  retained　its　original　size　and　appearance。　　Notwithstanding　some
  loss　from　disintegration；　five　of　the　largest　of　these　castings
  （after　having　been　well　sun…dried）　weighed　each　on　an　average　89。5
  grammes；　or　above　3　oz。；　and　the　largest　weighed　123。14　grammes；　or
  4。33　oz。；that　is；　above　a　quarter　of　a　pound！　　The　largest
  convolutions　were　rather　more　than　one　inch　in　diameter；　but　it　is
  probable　that　they　had　subsided　a　little　whilst　soft；　and　that
  their　diameters　had　thus　been　increased。　　Some　had　flowed　so　much
  that　they　now　consisted　of　a　pile　of　almost　flat　confluent　cakes。
  All　were　formed　of　fine；　rather　light…coloured　earth；　and　were
  surprisingly　hard　and　compact；　owing　no　doubt　to　the　animal　matter
  by　which　the　particles　of　earth　had　been　cemented　together。　　They
  did　not　disintegrate；　even　when　left　for　some　hours　in　water。
  Although　they　had　been　cast　up　on　the　surface　of　gravelly　soil；
  they　contained　extremely　few　bits　of　rock；　the　largest　of　which　was
  only　0。15　inch　in　diameter。
  Dr。　King　saw　in　Ceylon　a　worm　about　2　feet　in　length　and　0。5　inch
  in　diameter；　and　he　was　told　that　it　was　a　very　common　species
  during　the　wet　season。　　These　worms　must　throw　up　castings　at　least
  as　large　as　those　on　the　Nilgiri　Mountains；　but　Dr。　King　saw　none
  during　his　short　visit　to　Ceylon。
  Sufficient　facts　have　now　been　given；　showing　that　worms　do　much
  work　in　bringing　up　fine　earth　to　the　surface　in　most　or　all　parts
  of　the　world；　and　under　the　most　different　climates。
  CHAPTER　IIITHE　AMOUNT　OF　FINE　EARTH　BROUGHT　UP　BY　WORMS　TO　THE
  SURFACE。
  Rate　at　which　various　objects　strewed　on　the　surface　of　grass…
  fields　are　covered　up　by　the　castings　of　wormsThe　burial　of　a
  paved　pathThe　slow　subsidence　of　great　stones　left　on　the
  surfaceThe　number　of　worms　which　live　within　a　given　spaceThe
  weight　of　earth　ejected　from　a　burrow；　and　from　all　the　burrows
  within　a　given　spaceThe　thickness　of　the　layer　of　mould　which　the
  castings　on　a　given　space　would　form　within　a　given　time　if
  uniformly　spread　outThe　slow　rate　at　which　mould　can　increase　to
  a　great　thicknessConclusion。
  We　now　come　to　the　more　immediate　subject　of　this　volume；　namely；
  the　amount　of　earth　which　is　brought　up　by　worms　from　beneath　the
  surface；　and　is　afterwards　spread　out　more　or　less　completely　by
  the　rain　and　wind。　　The　amount　can　be　judged　of　by　two　methods；by
  the　rate　at　which　objects　left　on　the　surface　are　buried；　and　more
  accurately　by　weighing　the　quantity　brought　up　within　a　given　time。
  We　will　begin　with　the　first　method；　as　it　was　first　followed。
  Near　Mael　Hall　in　Staffordshire；　quick…lime　had　been　spread　about
  the　year　1827　thickly　over　a　field　of　good　pasture…land；　which　had
  not　since　been　ploughed。　　Some　square　holes　were　dug　in　this　field
  in　the　beginning　of　October　1837；　and　the　sections　showed　a　layer
  of　turf；　formed　by　the　matted　roots　of　the　grasses；　0。5　inch　in
  thickness；　beneath　which；　at　a　depth　of　2。5　inches　（or　3　inches
  from　the　surface）；　a　layer　of　the　lime　in　powder　or　in　small　lumps
  could　be　distinctly　seen　running　all　round　the　vertical　sides　of
  the　holes。　　The　soil　beneath　the　layer　of　lime　was　either　gravelly
  or　of　a　coarse　sandy　nature；　and　differed　considerably　in
  appearance　from　the　overlying　dark…coloured　fine　mould。　　Coal…
  cinders　had　been　spread　over　a　part　of　this　same　field　either　in
  the　year　1833　or　1834；　and　when　the　above　holes　were　dug；　that　is
  after　an　interval　of　3　or　4　years；　the　cinders　formed　a　line　of
  black　spots　round　the　holes；　at　a　depth　of　1　inch　beneath　the
  surface；　parallel　to　and　above　the　white　layer　of　lime。　　Over
  another　part　of　this　field　cinders　had　been　strewed；　only　about
  half…a…year　before；　and　these　either　still　lay　on　the　surface　or
  were　entangled　among　the　roots　of　the　grasses；　and　I　here　saw　the
  commencement　of　the　burying　process；　for　worm…castings　had　been
  heaped　on　several　of　the　smaller　fragments。　　After　an　interval　of
  4。75　years　this　field　was　re…examined；　and　now　the　two　layers　of
  lime　and　cinders　were　found　almost　everywhere　at　a　greater　depth
  than　before　by　nearly　1　inch；　we　will　say　by　0。75　of　an　inch。
  Therefore　mould　to　an　average　thickness　of　0。22　of　an　inch　had　been
  annually　brought　up　by　the　worms；　and　had　been　spread　over　the
  surface　of　this　field。
  Coal…cinders　had　been　strewed　over　another　field；　at　a　date　which
  could　not　be　positively　ascertained；　so　thickly　that　they　formed
  （October；　1837）　a　layer；　1　inch　in　thickness　at　a　depth　of　about　3
  inches　from　the　surface。　　The　layer　was　so　continuous　that　the
  over…lying　dark　vegetable　mould　was　connected　with　the　sub…soil　of
  red　clay　only　by　the　roots　of　the　grasses；　and　when　these　were
  broken；　the　mould　and　the　red　clay　fell　apart。　　In　a　third　field；
  on　which　coal…cinders　and　burnt　marl　had　been　strewed　several　times
  at　unknown　dates；　holes　were　dug　in　1842；　and　a　layer　of　cinders
  could　be　traced　at　a　depth　of　3。5　inches；　beneath　which　at　a　depth
  of　9。5　inches　from　the　surface　there　was　a　line　of　cinders　together
  with　burnt　marl。　　On　the　sides　of　one　hole　there　were　two　layers　of
  cinders；　at　2　and　3。5　inches　beneath　the　surface；　and　below　them　at
  a　depth　in　parts　of　9。5；　and　in　other　parts　of　10。5　inches　there
  were　fragments　of　burnt　marl。　　In　a　fourth　field　two　layers　of
  lime；　one　above　the　other；　could　be　distinctly　traced；　and　beneath
  them　a　layer　of　cinders　and　burnt　marl　at　a　depth　of　from　10　to　12
  inches　below　the　surface。
  A　piece　of　waste；　swampy　land　was　enclosed；　drained；　ploughed；
  harrowed　and　thickly　covered　in　the　year　1822　with　burnt　marl　and
  cinders。　　It　was　sowed　with　grass　seeds；　and　now　supports　a
  tolerably　good　but　coarse　pasture。　　Holes　were　dug　in　this　field　in
  1837；　or　15　years　after　its　reclamation；　and　we　see　in　the
  accompanying　diagram　（Fig。　5）；　reduced　to　half　of　the　natural
  scale；　that　the　turf　was　1　inch　thick；　beneath　which　there　was　a
  layer　of　vegetable　mould　2。5　inches　thick。　　This　layer　did　not
  contain　fragments　of　any　kind；　but　beneath　it　there　was　a　layer　of
  mould；　1。5　inch　in　thickness；　full　of　fragments　of　burnt　marl；
  conspicuous　from　their　red　colour；　one　of　which　near　the　bottom　was
  an　inch　in　length；　and　other　fragments　of　coal…cinders　together
  with　a　few　white　quartz　pebbles。　　Beneath　this　layer　and　at　a　depth
  of　4。5　inches　from　the　surface；　the　original　black；　peaty；　sandy
  soil　with　a　few　quartz　pebbles　was　encountered。　　Here　therefore　the
  fragments　of　burnt　marl　and　cinders　had　been　covered　in　the　course
  of　15　years　by　a　layer　of　fine　vegetable　mould；　only　2。5　inches　in
  thickness；　excluding　the　turf。　　Six　and　a　half　years　subsequently
  this　field　was　re…examined；　and　the　fragments　were　now　found　at
  from　4　to　5　inches　beneath　the　surface。　　So　that　in　this　interval
  of　6。5　years；　about　1。5　inch　of　mould　had　been　added　to　the
  superficial　layer。　　I　am　surprised　that　a　greater　quantity　had　not
  been　brought　up　during　the　whole　21。5　years；　for　in　the　closely
  underlying　black；　peaty　soil　there　were　many　worms。　　It　is；
  however；　probable　that　formerly；　whilst　the　land　remained　poor；
  worms　were　scanty；　and　the　mould　would　then　have　accumulated
  slowly。　　The　average　annual　increase　of　thickness　fo