﻿(ESTROUS 
  CYCLK 
  IN 
  THE 
  COMMON 
  FERRET. 
  327 
  

  

  two 
  or 
  three 
  individuals 
  I 
  did 
  not 
  observe 
  any 
  external 
  

   bleeding, 
  but 
  it 
  may 
  have 
  occurred 
  and 
  escaped 
  my 
  notice, 
  

   since 
  it 
  was 
  sometimes 
  impracticable 
  to 
  make 
  regular 
  observa- 
  

   tions 
  upon 
  the 
  animals 
  during 
  their 
  prolonged 
  sexual 
  season. 
  

   But 
  bleeding 
  into 
  the 
  uterine 
  cavity, 
  as 
  I 
  shall 
  presently 
  

   show, 
  regularly 
  occurs 
  at 
  the 
  pro-oestrum, 
  and 
  is 
  accompanied 
  

   by 
  a 
  greater 
  or 
  less 
  removal 
  of 
  uterine 
  mucosa. 
  I 
  am 
  in- 
  

   clined 
  to 
  think, 
  however, 
  that 
  the 
  discharge 
  so 
  formed 
  is 
  

   usually 
  disposed 
  of 
  very 
  gi-adually. 
  

  

  During 
  the 
  pro-oestrum, 
  as 
  at 
  all 
  other 
  times 
  during 
  the 
  

   cycle 
  excepting 
  at 
  the 
  oestrous 
  period, 
  the 
  female 
  will 
  not 
  

   permit 
  copulation. 
  

  

  The 
  period 
  of 
  oestrus 
  can 
  be 
  recognised 
  by 
  the 
  behaviour 
  

   of 
  the 
  female 
  ferret 
  towards 
  the 
  male. 
  The 
  vulva 
  remains 
  

   enlarged, 
  and 
  a 
  slight 
  flow 
  of 
  mucus 
  may 
  continue 
  to 
  be 
  

   discharged 
  at 
  the 
  external 
  genital 
  aperture. 
  As 
  before 
  

   remarked, 
  the 
  oestrus 
  may 
  last 
  for 
  several 
  weeks, 
  and 
  is 
  

   associated 
  throughout 
  with 
  the 
  swelling 
  of 
  the 
  vulva. 
  This 
  

   extension, 
  in 
  the 
  absence 
  of 
  pregnancy, 
  of 
  the 
  period 
  of 
  

   desire, 
  is 
  perhaps 
  comparable 
  to 
  what 
  occurs 
  in 
  the 
  case 
  of 
  

   bears 
  in 
  captivity, 
  for 
  with 
  these 
  animals 
  in 
  the 
  Zoological 
  

   Society's 
  Gardens 
  oestrus 
  is 
  said 
  to 
  last 
  continuously 
  for 
  two 
  

   or 
  three 
  months, 
  (Heape, 
  1900.) 
  

  

  The 
  female 
  ferret, 
  as 
  already 
  described, 
  is 
  mon 
  oestrous, 
  

   coming 
  in 
  season 
  about 
  the 
  end 
  of 
  March, 
  but 
  presents 
  a 
  

   transition 
  to 
  the 
  polyoestrous 
  condition 
  in 
  sometimes 
  having 
  

   a 
  second 
  (and 
  occasionally 
  a 
  third) 
  oestrous 
  cycle 
  in 
  the 
  

   summer 
  months. 
  In 
  showing 
  this 
  tendency 
  towards 
  a 
  con- 
  

   centration 
  of 
  sexual 
  seasons 
  the 
  ferret 
  may 
  be 
  reg-arded 
  as 
  

   standing 
  midway 
  between 
  such 
  animals 
  as 
  the 
  dog 
  or 
  cat 
  

   Avhich 
  are 
  monoestrous, 
  with, 
  as 
  a 
  rule, 
  two 
  fairly 
  regularly 
  

   recurring 
  oestrous 
  cycles, 
  and 
  the 
  otter, 
  which, 
  in 
  captivity 
  

   at 
  any 
  rate, 
  is 
  polyoestrous, 
  and 
  has 
  a 
  recurrent 
  dioestrous 
  

   cycle 
  of 
  a 
  month's 
  duration. 
  (Cocks, 
  1881.) 
  

  

  So 
  far 
  as 
  I 
  am 
  aware 
  there 
  is 
  no 
  periodicity 
  of 
  the 
  sexual 
  

   season 
  with 
  the 
  male 
  ferret, 
  which 
  is 
  said 
  to 
  be 
  capable 
  of 
  

   copulation 
  nt 
  any 
  time 
  of 
  the 
  year. 
  

  

  