﻿2 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL. 
  MUSEUM 
  vol.67 
  

  

  indebted. 
  J. 
  Eugene 
  Law, 
  Altadena, 
  Calif., 
  provided 
  me 
  with 
  

   much 
  valuable 
  fresh 
  material, 
  as 
  did 
  also 
  George 
  Willett, 
  Los 
  An- 
  

   geles, 
  Calif., 
  to 
  both 
  of 
  whom 
  I 
  wish 
  to 
  express 
  my 
  thanks. 
  

  

  Finally 
  I 
  am 
  much 
  indebted 
  to 
  Prof. 
  Charles 
  F. 
  Baker, 
  Los 
  Banos, 
  

   Philippine 
  Islands, 
  for 
  his 
  assistance, 
  and 
  to 
  my 
  wife 
  for 
  her 
  aid 
  in 
  

   the 
  preparation 
  of 
  the 
  illustrations. 
  

  

  Before 
  reviewing 
  the 
  variations 
  undergone 
  by 
  the 
  tongue 
  a 
  brief 
  

   consideration 
  of 
  the 
  histology 
  may 
  be 
  of 
  interest 
  to 
  throw 
  some 
  light 
  

   on 
  the 
  function. 
  

  

  ANAS 
  PLATYRHYNCHOS 
  

  

  A 
  cross 
  section 
  through 
  the 
  anterior 
  one-third 
  of 
  the 
  tongue 
  re- 
  

   veals 
  the 
  following: 
  The 
  section 
  is 
  very 
  irregular 
  in 
  shape, 
  with 
  a 
  

   deep 
  groove 
  dorsally. 
  In 
  the 
  center 
  of 
  the 
  tongue 
  is 
  the 
  single 
  car- 
  

   tilaginous 
  and 
  bony 
  mass 
  of 
  the 
  fused 
  ceratohyals. 
  Surrounding 
  

   this 
  is 
  a 
  complex 
  interlacing 
  of 
  adipose 
  and 
  connective 
  tissue, 
  strati- 
  

   fied 
  skeletal 
  muscle, 
  blood 
  vessels, 
  and 
  nerve 
  trunks. 
  Embedded 
  

   deeply 
  in 
  tissue 
  are 
  found 
  groups 
  of 
  mucous 
  glands, 
  ducts 
  of 
  which 
  

   here 
  and 
  there 
  can 
  be 
  traced 
  to 
  the 
  dorsal 
  surface 
  of 
  the 
  tongue. 
  

   Dorsolaterally 
  is 
  seen 
  a 
  double 
  row 
  of 
  cornified 
  spines 
  or 
  hairs, 
  

   from 
  the 
  base 
  of 
  which 
  strands 
  of 
  cells 
  are 
  scattered 
  deeper 
  into 
  the 
  

   tongue. 
  Small 
  nerve 
  corpuscles 
  are 
  seen 
  grouped 
  chiefly 
  about 
  the 
  

   cornified 
  spines. 
  Finally 
  the 
  surface 
  of 
  the 
  tongue 
  is 
  composed 
  of 
  

   stratified 
  epithelium 
  through 
  which 
  ducts 
  of 
  mucous 
  glands 
  pass. 
  

  

  TYTO 
  PRATINCOLA 
  

  

  The 
  extreme 
  tip 
  of 
  the 
  tongue 
  is 
  composed 
  almost 
  entirely 
  of 
  corni- 
  

   fied 
  epithelium. 
  Posterior 
  to 
  this 
  on 
  section 
  the 
  tongue 
  is 
  concave 
  

   dorsally, 
  the 
  epithelium 
  covering 
  this 
  surface 
  being 
  a 
  relatively 
  thin 
  

   layer. 
  The 
  center 
  of 
  the 
  tongue 
  is 
  occupied 
  by 
  the 
  bony 
  mass 
  of 
  the 
  

   ceratohyals 
  surrounded 
  by 
  connective 
  tissue 
  with 
  interlacing 
  fibers 
  

   of 
  striated 
  muscle. 
  At 
  the 
  mid 
  point 
  between 
  the 
  tip 
  and 
  posterior 
  

   margin 
  of 
  the 
  tongue 
  mucous 
  glands 
  make 
  their 
  appearance, 
  and 
  

   from 
  this 
  point 
  posteriorly 
  become 
  abundant. 
  

  

  The 
  glands 
  in 
  this 
  species 
  are 
  quite 
  superficial, 
  being 
  embedded 
  

   in 
  the 
  layer 
  of 
  stratified 
  epithelium 
  itself 
  and 
  opening 
  to 
  the 
  sur- 
  

   face 
  through 
  pores 
  which 
  are 
  visible, 
  with 
  the 
  unaided 
  eye 
  or 
  a 
  

   small 
  lens, 
  on 
  gross 
  inspection. 
  Nerve 
  corpuscles 
  are 
  either 
  absent 
  

   in 
  this 
  species 
  or 
  very 
  infrequent. 
  

  

  PICA 
  NUTTALLI 
  

  

  On 
  section 
  the 
  tongue 
  is 
  concavo-convex, 
  with 
  the 
  concavity 
  rep- 
  

   resenting 
  the 
  dorsal 
  surface. 
  The 
  ventral 
  surface 
  is 
  composed 
  of 
  

   cornified 
  epithelium. 
  The 
  dorsal 
  surface 
  is 
  covered 
  with 
  a 
  deep 
  

   layer 
  of 
  noncornified 
  stratified 
  epithelium. 
  Glands 
  in 
  this 
  species 
  

   do 
  not 
  appear 
  except 
  at 
  the 
  extreme 
  posterior 
  portion 
  of 
  the 
  tongue. 
  

   Nerve 
  corpuscles 
  are 
  infrequent. 
  

  

  