﻿THE 
  STORY 
  OF 
  A 
  PEARL. 
  55 
  

  

  Tabitian 
  pearl-shells) 
  . 
  The 
  remarkable 
  Fiji 
  Island 
  dresses 
  of 
  

   shells 
  made 
  of 
  sections 
  of 
  a 
  large 
  Pearl-Oyster 
  are 
  still 
  in 
  some 
  

   museums. 
  

  

  The 
  iridescent 
  colours 
  of 
  fossilized 
  shells 
  are 
  retained 
  in 
  the 
  

   ammonites 
  from 
  the 
  Jurassic 
  and 
  cretaceous 
  limestone 
  (Luma- 
  

   chelle 
  marble), 
  which 
  resemble 
  in 
  their 
  lustre 
  the 
  fire-opal 
  from 
  

   Mexico. 
  

  

  From 
  the 
  fresh-water 
  Unios 
  little 
  portmanteaus, 
  satchels, 
  &c, 
  

   are 
  formed, 
  and 
  they 
  are 
  very 
  beautiful 
  when 
  both 
  the 
  exterior 
  

   and 
  interior 
  are 
  perlaceous. 
  

  

  We 
  have 
  thus 
  taken 
  a 
  rapid 
  glance 
  at 
  a 
  comprehensive 
  sub- 
  

   ject 
  — 
  a 
  glance 
  sufficient, 
  however, 
  to 
  show 
  the 
  vast 
  resources 
  of 
  

   nature 
  for 
  scientific 
  investigation 
  and 
  scientific 
  culture. 
  The 
  

   great 
  variety 
  and 
  beauty 
  of 
  pearl-shells 
  and 
  their 
  pearls 
  have 
  for 
  

   ages 
  proved 
  sources 
  of 
  the 
  deepest 
  interest 
  to 
  man, 
  both 
  savage 
  

   and 
  civilized, 
  and 
  the 
  recent 
  discoveries 
  in 
  regard 
  to 
  the 
  forma- 
  

   tion 
  of 
  pearls 
  indicate 
  that 
  that 
  interest 
  is 
  by 
  no 
  means 
  diminished 
  

   as 
  time 
  advances. 
  Here 
  in 
  St. 
  Andrew's 
  we 
  are 
  in 
  the 
  midst 
  

   of 
  a 
  fine 
  field 
  for 
  experimental 
  work 
  in 
  connection 
  with 
  pearl- 
  

   formation, 
  both 
  in 
  the 
  fresh-water 
  Mussels 
  of 
  the 
  Tay 
  and 
  the 
  

   marine 
  forms 
  in 
  the 
  estuary 
  of 
  the 
  Eden. 
  The 
  task 
  would 
  

   involve 
  labour 
  and 
  care, 
  but 
  it 
  would 
  not 
  be 
  more 
  complex 
  than 
  

   those 
  recently 
  carried 
  out 
  in 
  connection 
  with 
  the 
  mosquitoes 
  and 
  

   malaria, 
  or 
  than 
  some 
  of 
  the 
  more 
  intricate 
  bacteriological 
  in- 
  

   vestigations 
  of 
  the 
  day 
  ; 
  whilst 
  a 
  successful 
  result 
  might 
  lead 
  to 
  

   other 
  advantages 
  which 
  do 
  not 
  usually 
  fall 
  to 
  the 
  lot 
  of 
  scientific 
  

   workers. 
  

  

  Note. 
  — 
  Since 
  the 
  foregoing 
  was 
  written, 
  Prof. 
  Herclman's 
  first 
  

   volume 
  of 
  important 
  observations 
  on 
  the 
  Ceylonese 
  Pearl-Oyster 
  

   has 
  been 
  published,* 
  and 
  in 
  this 
  he 
  shows 
  that 
  the 
  most 
  im- 
  

   portant 
  cause 
  of 
  pearl-formation 
  is 
  a 
  larval 
  cestode 
  of 
  the 
  

   Tetrarhynchus 
  form, 
  the 
  free 
  embryos 
  of 
  which 
  become 
  en- 
  

   capsuled 
  in 
  the 
  Pearl-Oyster, 
  the 
  late 
  larval 
  stages 
  being 
  in 
  File- 
  

   fishes 
  which 
  eat 
  the 
  Pearl-Oysters, 
  and, 
  lastly, 
  the 
  adult 
  in 
  a 
  

   large 
  Elasmobranch 
  (Trygon).f 
  Prof. 
  Giardt 
  has 
  also 
  pointed 
  

  

  * 
  "Ceylon 
  Pearl 
  Fisheries," 
  &c. 
  Roy. 
  Soc. 
  1903, 
  pp. 
  11-13. 
  

  

  f 
  ' 
  Nature,' 
  Dec. 
  10th, 
  1903. 
  

  

  X 
  ' 
  Comp. 
  rend. 
  Soc. 
  Biol.' 
  Oct. 
  31st, 
  1903, 
  tome 
  lv. 
  p. 
  1222, 
  with 
  figs. 
  

  

  i 
  

  

  