These  changes  are  most  conspicuous  in  the
Lepidoptera,  where  we  may  observe  the  suc-
cessive contractions  which  take  place  in  the  im-
mensely voluminous  stomach  of  the  caterpillar,
while  passing  into  the  state  of  chrysalis,  and
thence  into  that  of  the  perfect  insect,  in  which
its  form  is  so  changed  that  it  can  hardly  be
recognised  as  the  same  organ.     I  have  given  re-


LOTsof  these  three  diflferent   states  of
the  entire  alimentary  canal  of  the  Sphinx  ligmlri.
.   218  THE  VITAL  INUNCTIONS.
or  Privet  Hawk-moth,  in  Figures  326»  327,  and
328"^ ;  the  first  of  which  is  that  of  the  ciiter-
pillar ;  the  second,  that  of  the  chrysalis ;  Mid  the
third,  that  of  the  moth.  The  whole  canal  and
its  appendages  hare  been  sepaibted  irom  their
attachments,  and  spread  out,  so  as  to  i^spliiy  all
their  parts;  and  they  are  delineated  of  the
natural  liize,  in  each  case,  so  as  to  Show  tbfcir
comparative  dimensions  in  these  three  states.
'^  In  all  the  figures,  a  is  the  oesophiigUs^  b,  th^
stomach;  c,  the  small  intestine;  d,  the  caecal
portion  of  the  canal ;  and  e,  the  colon,  or  large
intestine.  The  hepatic  vessels  are  shown  at  p  ;
and  the  gizzard,  which  is  developed  only  in  the
moth,  at  o.  Fig.  328.
It  will  be  seen  that  in  the  caterpillar,  (Fig.
