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MR.  R.  OWEN  ON  THE  YOUNG  OF 
water ;  and  having  at  the  same  time  prepared  a  little  Coiv's  milk  by  first  coagulating  it 
with  spirit,  and  then  diluting  the  coagulum,  I  compared  the  two  substances  under  a 
high  magnifying  power.  The  ultimate  globules  of  the  Ornithorhynchus's  milk  were 
most  distinctly  perceptible,  detaching  themselves  from  the  small  coherent  masses  to 
form  new  groups  :  the  corresponding  globules  of  the  Cotv's  milk  were  of  larger  size. 
Minute  transparent  globules  of  oil  were  intermixed  with  the  milk  globules  of  the 
Ornithorhynchus.  A  drop  of  water  being  added  to  a  little  mucus,  it  instantly  became 
opake ;  and  was  resolvable  by  minute  division  into  transparent  angular  flakes,  entirely 
different  from  the  regularly  formed  granules  of  the  milk  of  the  Ornithorhynchus. 
In  the  smaller  specimen  the  stomach  was  empty ;  when  distended  with  air  it  ex- 
hibited a  less  disproportionate  development.  It  was  situated  in  the  left  hypochondriac 
and  lumbar  regions.  The  intestines  contained  air,  with  granular  masses  of  a  mucous 
chyme  adhering  to  their  internal  surface.  This  condition  of  the  digestive  canal  would 
seem  to  show  that  no  long  period  had  elapsed  since  the  birth  of  the  specimen,  and  that 
lactation  had  either  not  been  in  full  action,  or  that  the  young  one  had  been  deserted  by 
the  parent  for  some  time  before  it  was  taken. 
In  both  specimens  the  spleen  bore  a  proportionate  size  with  the  stomach ;  and  as 
the  difference  in  the  development  of  the  stomach  was  considerable,  the  correspondence 
of  the  condition  of  the  spleen  with  that  of  the  digestive  cavity  was  made  very  obvious. 
The  difference  in  the  development  of  the  liver  was  not  greater  than  corresponded  w^ith 
the  different  size  and  age  of  the  two  specimens.  But  the  pancreas  in  both  bore  the  same 
ratio  to  the  stomach  as  the  spleen.  This  would  seem,  therefore,  to  afford  some  indica- 
tion of  the  organs  with  which  the  function  of  the  spleen  is  more  immediately  related. 
The  intestinal  canal  in  the  larger  specimen  was  situated  almost  entirely  on  the  right 
side  of  the  abdomen.  The  cacum,  in  both,  was  very  minute  and  filamentary.  I  exa- 
mimed  the  ileum,  and  more  especially  in  the  usual  situation  above  the  cacum,  but  could 
not  perceive  any  trace  of  the  pedicle  of  the  umbilical  or  viteUine  vesicle.  The  other 
vestiges  of  foetal  organization  were  more  obvious  than  in  the  ordinary  Marsupial  or 
ovo viviparous  Mammalia. 
In  both  specimens,  but  more  distinctly  in  the  smaller  one,  the  umbilical  vein  was 
seen  extending  from  a  linear  cicatrix  of  the  peritoneum,  opposite  the  middle  of  the  abdo- 
men, along  the  anterior  margin  of  the  suspensory  ligament,  to  the  liver.  It  was  reduced 
to  a  mere  filamentary  tube,  filled  with  coagulum.  From  the  same  cicatrix  the  remains 
of  the  umbilical  arteries  extended  downwards,  and  near  the  urinary  bladder  were  con- 
tained within  a  duplicature  oi  peritoneum,  having  between  them  a  small  flattened  oval 
vesicle,  the  remains  of  an  allantois,  which  was  attached  by  a  contracted  pedicle  to  the 
fundus  of  the  bladder. 
As  both  the  embryo  of  the  Bird  and  that  of  the  ovoviviparous  Reptile  have  an  allantois 
and  umbilical  vessels  developed,  no  certain  inference  can  be  drawn  from  the  above 
a])pearances  as  to  the  oviparous  or  viviparous  nature  of  the  generation  of  the  Ornitho- 
