The  Physiology  of  Stock-Breeding. 
67 
expense,  the  heavy  cost  of  upkeep,  and.  the  rapid  depreciation, 
make  it  impossible  for  mechanical  traction,  in  the  case  of 
heavy  draught,  to  compete  successfully  with  the  dray  horse. 
In  conclusion,  I wish  to  thank  Mr.  T.  Eaton  Jones, 
M.R.C.V.S.,  and  Messrs.  J.  & A.  Lawson,  M.R.C.V.S.,  of 
Manchester,  for  their  kind  and  valued  assist£(.nce  in  supplying 
me  with  material  for  this  article. 
Stuart  Heaton. 
Worsley,  near  Manchester. 
THE  PHYSIOLOGY  OF  STOCK-BREEDING. 
By  Francis  H.  A.  Marshall,  M.A.  (Cantab.),  D.Sc.  (Edin.), 
Felloiv  of  Christ's  College.  Cambridge,  and  University 
Lecturer  in  Agricultural  Physiology. 
That  the  study  of  chemistry  has  an  important  bearing  on 
agricultural  practice  is  now  universally  admitted.  That  the 
science  of  botany  has  an  equally  close  relation  to  all  kinds  of 
plant  culture  is  regarded  as  too  obvious  to  call  for  comment. 
It  is  a little  remarkable,  therefore,  that  the  claims  of  physiology 
to  be  applied  to  problems  of  stock-raising  receive  comparatively 
little  recognition,  and  that  this  branch  of  biological  study  often 
finds  no  place  in  an  organised  agricultural  curriculum.  It 
cannot  be  contended  that  the  physiology  of  breeding  is  a depart- 
ment of  veterinary  rather  than  of  agricultural  knowledge,  because 
this  subject  in  the  veterinary  text-books  (as  indeed  in  most  other 
works  on  physiology)  is  either  passed  over  entirely,  or  else  is 
relegated  to  a few  final  pages  seldom  free  from  error.  Yet  no 
one  who  has  paid  attention  to  the  phenomena  attending  gener- 
ation in  animals  can  doubt  that  these  ought  to  possess  as  close 
a relation  to  the  methods  of  stock-breeding  as  that  which 
subsists  between  the  facts  of  chemistry  or  botany  and  the 
modern  practice  of  agriculture.  Writers  on  agricultural 
questions  have  laid  little  stress  on  this  point,  yet  Mr.  Walter 
Heape,  who  has  studied  the  subject  closely,  affirms  in  a work 
on  the  national  importance  of  the  breeding  industry,’  that  in 
his  opinion  “ it  is  the  loss  which  is  incurred  in  consequence  of 
ignorance  of  these  matters,  [i.e.,  the  phenomena  attending  the 
function  of  reproduction,]  which  weighs  and  retards  the 
industry,  which  reduces  the  profits,  swallows  up  the  bonus, 
and  prevents  breeding  from  occupying,  as  it  should  occupy, 
a foremost  place  on  the  credit  side  of  the  national  balance 
sheet.” 
Heape  : The  Breeding  Indnsstry.  Cambridge,  1906. 
