castings。
  Dr。　King　informs　me　that　the　majority　of　the　before　described
  gigantic　castings；　which　he　found　on　a　fully　exposed；　bare；
  gravelly　knoll　on　the　Nilgiri　Mountains　in　India；　had　been　more　or
  less　weathered　by　the　previous　north…east　monsoon；　and　most　of　them
  presented　a　subsided　appearance。　　The　worms　here　eject　their
  castings　only　during　the　rainy　season；　and　at　the　time　of　Dr。
  King's　visit　no　rain　had　fallen　for　110　days。　　He　carefully
  examined　the　ground　between　the　place　where　these　huge　castings
  lay；　and　a　little　watercourse　at　the　base　of　the　knoll；　and　nowhere
  was　there　any　accumulation　of　fine　earth；　such　as　would　necessarily
  have　been　left　by　the　disintegration　of　the　castings　if　they　had
  not　been　wholly　removed。　　He　therefore　has　no　hesitation　in
  asserting　that　the　whole　of　these　huge　castings　are　annually　washed
  during　the　two　monsoons　（when　about　100　inches　of　rain　fall）　into
  the　little　water…course；　and　thence　into　the　plains　lying　below　at
  a　depth　of　3000　or　4000　feet。
  Castings　ejected　before　or　during　dry　weather　become　hard；
  sometimes　surprisingly　hard；　from　the　particles　of　earth　having
  been　cemented　together　by　the　intestinal　secretions。　　Frost　seems
  to　be　less　effective　in　their　disintegration　than　might　have　been
  expected。　　Nevertheless　they　readily　disintegrate　into　small
  pellets；　after　being　alternately　moistened　with　rain　and　again
  dried。　　Those　which　have　flowed　during　rain　down　a　slope；
  disintegrate　in　the　same　manner。　　Such　pellets　often　roll　a　little
  down　any　sloping　surface；　their　descent　being　sometimes　much　aided
  by　the　wind。　　The　whole　bottom　of　a　broad　dry　ditch　in　my　grounds；
  where　there　were　very　few　fresh　castings；　was　completely　covered
  with　these　pellets　or　disintegrated　castings；　which　had　rolled　down
  the　steep　sides；　inclined　at　an　angle　of　27　degrees。
  Near　Nice；　in　places　where　the　great　cylindrical　castings；
  previously　described；　abound；　the　soil　consists　of　very　fine
  arenaceo…calcareous　loam；　and　Dr。　King　informs　me　that　these
  castings　are　extremely　liable　to　crumble　during　dry　weather　into
  small　fragments；　which　are　soon　acted　on　by　rain；　and　then　sink
  down　so　as　to　be　no　longer　distinguishable　from　the　surrounding
  soil。　　He　sent　me　a　mass　of　such　disintegrated　castings；　collected
  on　the　top　of　a　bank；　where　none　could　have　rolled　down　from　above。
  They　must　have　been　ejected　within　the　previous　five　or　six　months；
  but　they　now　consisted　of　more　or　less　rounded　fragments　of　all
  sizes；　from　0。75　of　an　inch　in　diameter　to　minute　grains　and　mere
  dust。　　Dr。　King　witnessed　the　crumbling　process　whilst　drying　some
  perfect　castings；　which　he　afterwards　sent　me。　　Mr。　Scott　also
  remarks　on　the　crumbling　of　the　castings　near　Calcutta　and　on　the
  mountains　of　Sikkim　during　the　hot　and　dry　season。
  When　the　castings　near　Nice　had　been　ejected　on　an　inclined
  surface；　the　disintegrated　fragments　rolled　downwards；　without
  losing　their　distinctive　shape；　and　in　some　places　could　〃be
  collected　in　basketfuls。〃　　Dr。　King　observed　a　striking　instance　of
  this　fact　on　the　Corniche　road；　where　a　drain；　about　2。5　feet　wide
  and　9　inches　deep；　had　been　made　to　catch　the　surface　drainage　from
  the　adjoining　hill…side。　　The　bottom　of　this　drain　was　covered　for
  a　distance　of　several　hundred　yards；　to　a　depth　of　from　1。5　to　3
  inches；　by　a　layer　of　broken　castings；　still　retaining　their
  characteristic　shape。　　Nearly　all　these　innumerable　fragments　had
  rolled　down　from　above；　for　extremely　few　castings　had　been　ejected
  in　the　drain　itself。　　The　hill…side　was　steep；　but　varied　much　in
  inclination；　which　Dr。　King　estimated　at　from　30　degrees　to　60
  degrees　with　the　horizon。　　He　climbed　up　the　slope；　and　〃found
  every　here　and　there　little　embankments；　formed　by　fragments　of　the
  castings　that　had　been　arrested　in　their　downward　progress　by
  irregularities　of　the　surface；　by　stones；　twigs；　&c。　　One　little
  group　of　plants　of　Anemone　hortensis　had　acted　in　this　manner；　and
  quite　a　small　bank　of　soil　had　collected　round　it。　　Much　of　this
  soil　had　crumbled　down；　but　a　great　deal　of　it　still　retained　the
  form　of　castings。〃　　Dr。　King　dug　up　this　plant；　and　was　struck　with
  the　thickness　of　the　soil　which　must　have　recently　accumulated　over
  the　crown　of　the　rhizoma；　as　shown　by　the　length　of　the　bleached
  petioles；　in　comparison　with　those　of　other　plants　of　the　same
  kind；　where　there　had　been　no　such　accumulation。　　The　earth　thus
  accumulated　had　no　doubt　been　secured　（as　I　have　everywhere　seen）
  by　the　smaller　roots　of　the　plants。　　After　describing　this　and
  other　analogous　cases；　Dr。　King　concludes：　　〃I　can　have　no　doubt
  that　worms　help　greatly　in　the　process　of　denudation。〃
  Ledges　of　earth　on　steep　hill…sides。Little　horizontal　ledges；　one
  above　another；　have　been　observed　on　steep　grassy　slopes　in　many
  parts　of　the　world。　　The　formation　has　been　attributed　to　animals
  travelling　repeatedly　along　the　slope　in　the　same　horizontal　lines
  while　grazing；　and　that　they　do　thus　move　and　use　the　ledges　is
  certain；　but　Professor　Henslow　（a　most　careful　observer）　told　Sir
  J。　Hooker　that　he　was　convinced　that　this　was　not　the　sole　cause　of
  their　formation。　　Sir　J。　Hooker　saw　such　ledges　on　the　Himalayan
  and　Atlas　ranges；　where　there　were　no　domesticated　animals　and　not
  many　wild　ones；　but　these　latter　would；　it　is　probable；　use　the
  ledges　at　night　while　grazing　like　our　domesticated　animals。　　A
  friend　observed　for　me　the　ledges　on　the　Alps　of　Switzerland；　and
  states　that　they　ran　at　3　or　4　ft。　one　above　the　other；　and　were
  about　a　foot　in　breadth。　　They　had　been　deeply　pitted　by　the　feet
  of　grazing　cows。　　Similar　ledges　were　observed　by　the　same　friend
  on　our　Chalk　downs；　and　on　an　old　talus　of　chalk…fragments　（thrown
  out　of　a　quarry）　which　had　become　clothed　with　turf。
  My　son　Francis　examined　a　Chalk　escarpment　near　Lewes；　and　here　on
  a　part　which　was　very　steep；　sloping　at　40　degrees　with　the
  horizon；　about　30　flat　ledges　extended　horizontally　for　more　than
  100　yards；　at　an　average　distance　of　about　20　inches；　one　beneath
  the　other。　　They　were　from　9　to　10　inches　in　breadth。　　When　viewed
  from　a　distance　they　presented　a　striking　appearance；　owing　to
  their　parallelism；　but　when　examined　closely；　they　were　seen　to　be
  somewhat　sinuous；　and　one　often　ran　into　another；　giving　the
  appearance　of　the　ledge　having　forked　into　two。　　They　are　formed　of
  light…coloured　earth；　which　on　the　outside；　where　thickest；　was　in
  one　case　9　inches；　and　in　another　case　between　6　and　7　inches　in
  thickness。　　Above　the　ledges；　the　thickness　of　the　earth　over　the
  chalk　was　in　the　former　case　4　and　in　the　latter　only　3　inches。
  The　grass　grew　more　vigorously　on　the　outer　edges　of　the　ledges
  than　on　any　other　part　of　the　slope；　and　here　formed　a　tufted
  fringe。　　Their　middle　part　was　bare；　but　whether　this　had　been
  caused　by　the　trampling　of　sheep；　which　sometimes　frequent　the
  ledges；　my　son　could　not　ascertain。　　Nor　could　he　feel　sure　how
  much　of　the　earth　on　the　middle　and　bare　parts；　consisted　of
  disintegrated　worm…castings　which　had　rolled　down　from　above；　but
  he　felt　convinced　that　some　had　thus　originated；　and　it　was
  manifest　that　the　ledges　with　their　grass…fringed　edges　would
  arrest　any　small　object　rolling　down　from　above。
  At　one　end　or　side　of　the　bank　bearing　these　ledges；　the　surface
  consisted　in　parts　of　bare　chalk；　and　here　the　ledges　were　very
  irregular。　　At　the　other　end　of　the　bank；　the　slope　suddenly　became
  less　steep；　and　here　the　ledges　ceased　rather　abruptly；　but　little
  embankments　only　a　foot　or　two　in　length　were　still　present。　　The
  slope　became　steeper　lower　down　the　hill；　and　the　regular　ledges
  then　reappeared。　　Another　of　my　sons　observed；　on　the　inland　side
  of　Beachy　Head；　where　the　surface　sloped　at　about　25　degrees；　many
  short　little　embankments　like　those　just　mentioned。　　They　extended
  horizontally　and　were　from　a　few　inches　to　two　or　three　feet　in
  length。　　They　supported　tufts　of　grass　growing　vigorously。　　The
  average　thickness　of　the　mould　of　which　they　were　formed；　taken
  from　nine　measurements；　was　4。5　inches；　while　that　of　the　mould
  above　and　beneath　them　was　on　an　average　only　3。2　inches；　and　on
  each　side；　on　the　same　level；　3。1　inches。　　On　the　upper　parts　of
  the　slope；　these　embankments　showed　no　signs　of　having　been
  trampled　on　by　sheep；　but　in　the　lower　parts　such　signs　were　fairly
  plain。　　No　long　continuous　ledges　had　here　been　formed。
  If　the　little　embankments　above　the　Corniche　road；　which　Dr。　King
  saw　in　the　act　of　formation　by　the　accumulation　of　disintegrated
  and　rolled　worm…castings；　were　to　become　confluent　along　horizontal
  lines；　ledges　would　be　formed。　　Each　embankment　would　tend　to
  extend　laterally　by　the　lateral　extension　of　the　arrested　castings；
  and　animals　grazing　on　a　steep　slope　would　almost　certainly　make
  use　of　every　prominence　at　nearly　the　same　level；　and　would　indent
  the　turf　between　them；　and　such　intermediate　indentations　would
  again　arrest　the　castings。　　An　irregular　ledge　when　once　formed
  would　also　tend　to　become　more　regular　and