﻿90 
  

  

  and 
  exit 
  of 
  currents 
  of 
  water. 
  The 
  reproduction 
  took 
  place 
  sexually 
  

   with 
  ova 
  and 
  sperm, 
  resulting 
  in 
  free-swimming 
  young, 
  which 
  

   young, 
  after 
  settling 
  upon 
  a 
  base 
  grow 
  into 
  a 
  more 
  or 
  less 
  large 
  

   colony 
  by 
  budding. 
  The 
  evolution 
  of 
  the 
  skeleton 
  was 
  next 
  de- 
  

   scribed, 
  the 
  substance 
  of 
  which 
  was 
  called 
  " 
  spongin." 
  From 
  the 
  

   hypothetical 
  origin 
  there 
  were 
  two 
  main 
  lines 
  of 
  descent, 
  in 
  one 
  of 
  

   which 
  the 
  spicules 
  which 
  coated 
  the 
  outer 
  surface 
  were 
  composed 
  of 
  

   carbonate 
  of 
  lime, 
  while 
  in 
  the 
  other 
  they 
  were 
  non-calcareous 
  and 
  

   termed 
  "jelly 
  sponges." 
  Of 
  this 
  latter 
  class 
  there 
  were 
  three 
  

   divergent 
  sub-classes, 
  (a) 
  the 
  horny 
  sponges, 
  of 
  which 
  the 
  familiar 
  

   " 
  bath-sponge 
  " 
  was 
  a 
  member; 
  (b) 
  the 
  sponges 
  with 
  three- 
  or 
  six- 
  

   rayed 
  spicules 
  of 
  siliceous 
  matter 
  ; 
  and 
  (c) 
  those 
  with 
  four-rayed 
  

   siliceous 
  spicules. 
  

  

  The 
  slides 
  exhibited 
  illustrated 
  these 
  various 
  sections 
  of 
  the 
  

   group, 
  and 
  also 
  the 
  theory 
  of 
  the 
  formation 
  and 
  development 
  of 
  the 
  

   spicules,' 
  supported 
  by 
  mechanical 
  and 
  mathematical 
  expressions 
  of 
  

   the 
  formation 
  of 
  their 
  "nodes." 
  

  

  OCTOBER 
  2 
  \th, 
  1918. 
  

  

  Mr. 
  Edwards 
  exhibited 
  the 
  Fungus 
  Buhjaria 
  (Peziza) 
  poli/motpha 
  

   {inquinans), 
  found 
  on 
  dead 
  trunks 
  of 
  trees, 
  especially 
  beech. 
  The 
  

   fungus 
  bursts 
  through 
  the 
  bark 
  under 
  the 
  form 
  of 
  small 
  rusty 
  brown, 
  

   scurfy 
  knobs, 
  which 
  gradually 
  expand 
  at 
  the 
  apex 
  until 
  a 
  plain 
  black 
  

   shining 
  disc 
  is 
  formed. 
  The 
  substance 
  is 
  soft 
  and 
  tough, 
  cutting 
  

   almost 
  lilie 
  india-rubber. 
  

  

  Mr. 
  R. 
  Bowman 
  exhibited 
  an 
  example 
  of 
  Cyinatophora 
  ocularis 
  

   with 
  ground 
  colour 
  nearly 
  jet 
  black, 
  taken 
  at 
  Chingford 
  in 
  June 
  

   last. 
  

  

  Mr. 
  W. 
  J. 
  Ashdown 
  exhibited 
  a 
  short 
  series 
  of 
  Geotriipes 
  pyrenaus 
  

   (Col.), 
  from 
  Surrey, 
  including 
  a 
  fine 
  bronze 
  tinted 
  specimen. 
  

  

  Mr. 
  Wheeler 
  exhibited 
  the 
  various 
  phases 
  of 
  variation 
  shown 
  in 
  

   the 
  species 
  Kiiine}>hele 
  titiwniifi, 
  and 
  read 
  a 
  paper 
  "The 
  Variation 
  in 
  

   Kpuiepliele 
  tithoniis, 
  L." 
  (See 
  p. 
  29 
  ante.) 
  

  

  The 
  Rev. 
  A. 
  T. 
  Stiff 
  exhibited 
  a 
  large 
  number 
  of 
  examples 
  of 
  the 
  

   species, 
  especially 
  illustrating 
  the 
  local 
  races 
  in 
  the 
  S. 
  West 
  of 
  Eng- 
  

   land, 
  near 
  Tavistock. 
  He 
  was 
  of 
  opinion 
  that 
  the 
  cause 
  of 
  variation 
  

   in 
  that 
  area 
  was 
  partly 
  due 
  to 
  a 
  combination 
  of 
  heat 
  and 
  moisture. 
  

   Although 
  the 
  species 
  was 
  abundant 
  near 
  Leigh, 
  in 
  Essex, 
  this 
  

   season 
  there 
  was 
  not 
  a 
  single 
  variation 
  worthy 
  of 
  note, 
  while 
  near 
  

   the 
  former 
  place 
  one 
  in 
  six 
  was 
  an 
  aberration 
  more 
  or 
  less 
  notice- 
  

  

  