﻿Geology 
  and 
  Natural 
  History. 
  81 
  

  

  careous 
  algae; 
  while 
  a 
  list 
  of 
  the 
  diatoms 
  is 
  contributed 
  by 
  

   Albert 
  Mann. 
  

  

  Daily 
  determinations 
  of 
  the 
  salinity 
  of 
  the 
  ocean 
  water 
  at 
  

   Fowey 
  Rocks, 
  Florida, 
  are 
  tabulated 
  by 
  Richard 
  B. 
  Dole 
  and 
  

   Alfred 
  A. 
  Chambers. 
  Roger 
  C. 
  Wells 
  describes 
  the 
  solubility 
  

   of 
  calcite 
  in 
  sea-water. 
  

  

  The 
  final 
  paper, 
  by 
  L. 
  R. 
  Casey, 
  discusses 
  the 
  Gorgonaceae 
  as 
  

   a 
  factor 
  in 
  the 
  formation 
  of 
  coral 
  reefs 
  and 
  shows 
  that 
  over 
  large 
  

   areas 
  in 
  the 
  region 
  of 
  the 
  Tortugas 
  Islands 
  this 
  group 
  of 
  corals 
  

   is 
  far 
  the 
  most 
  important 
  element 
  in 
  the 
  formation 
  of 
  reef 
  lime- 
  

   stones. 
  He 
  estimates 
  that 
  each 
  acre 
  of 
  the 
  reef 
  is 
  covered 
  by 
  

   an 
  average 
  of 
  over 
  five 
  tons 
  of 
  living 
  gorgonians, 
  about 
  one- 
  

   fifth 
  of 
  which 
  are 
  killed 
  annually. 
  This 
  means 
  a 
  yearly 
  con- 
  

   tribution 
  of 
  about 
  one 
  ton 
  of 
  limestone, 
  as 
  spicules, 
  per 
  acre. 
  

  

  The 
  entire 
  volume 
  constitutes 
  a 
  most 
  important 
  contribution 
  

   to 
  our 
  knowledge 
  of 
  coral 
  islands 
  and 
  reefs 
  and 
  the 
  organic 
  and 
  

   physical 
  agencies 
  concerned 
  in 
  their 
  formation. 
  w. 
  r. 
  c. 
  

  

  10. 
  Forced 
  Movements, 
  Tropisms, 
  and 
  Animal 
  Conduct; 
  by 
  

   Jacques 
  Loeb. 
  Pp. 
  209, 
  42 
  figs. 
  Philadelphia 
  and 
  London, 
  

   1918 
  (J. 
  B. 
  Lippincott 
  Co.). 
  — 
  In 
  this 
  first 
  volume 
  of 
  a 
  series 
  

   of 
  Monographs 
  on 
  Experimental 
  Biology 
  to 
  be 
  written 
  by 
  

   American 
  investigators 
  the 
  author 
  elaborates 
  a 
  theory 
  which 
  he 
  

   proposed 
  many 
  years 
  ago 
  to 
  account 
  for 
  the 
  movements 
  of 
  

   animals 
  on 
  a 
  purely 
  chemico-physical 
  basis. 
  He 
  aims 
  to 
  show 
  

   that 
  the 
  conduct 
  of 
  animals 
  and 
  plants 
  depends 
  upon 
  movements 
  

   forced 
  upon 
  them 
  as 
  a 
  result 
  of 
  reactions 
  to 
  stimuli 
  of 
  the 
  var- 
  

   ious 
  forms 
  of 
  energy 
  and 
  that 
  by 
  the 
  quantitative 
  methods 
  of 
  

   the 
  physicist 
  the 
  nature 
  of 
  the 
  response 
  to 
  these 
  stimuli 
  is 
  often 
  

   mathematically 
  predictable. 
  The 
  symmetry 
  of 
  the 
  animal 
  body, 
  

   with 
  its 
  paired 
  sense 
  organs 
  in 
  the 
  higher 
  forms, 
  causes 
  the 
  

   animal 
  to 
  respond 
  to 
  stimuli 
  in 
  a 
  purely 
  mechanical 
  way 
  regard- 
  

   less 
  of 
  whether 
  or 
  not 
  such 
  actions 
  are 
  purposeful. 
  The 
  effects 
  

   of 
  each 
  of 
  the 
  forms 
  of 
  energy 
  which 
  may 
  act 
  on 
  the 
  organism 
  

   are 
  explained, 
  with 
  a 
  brief 
  discussion 
  of 
  instincts, 
  memory 
  images 
  

   and 
  tropisms, 
  leading 
  to 
  the 
  conclusion 
  that 
  the 
  direction 
  of 
  

   motion 
  is 
  forced 
  upon 
  the 
  organism, 
  and 
  that 
  what 
  passes 
  for 
  

   free 
  will 
  is 
  essentially 
  a 
  combination 
  of 
  tropistic 
  reactions 
  and 
  

   memory 
  images. 
  

  

  The 
  book 
  provides 
  many 
  interesting 
  examples 
  of 
  animal 
  

   behavior 
  which 
  can 
  be 
  explained 
  without 
  the 
  aid 
  of 
  vitalism, 
  and 
  

   while 
  the 
  reader 
  may 
  not 
  accept 
  the 
  author's 
  extreme 
  mechan- 
  

   istic 
  theory 
  he 
  cannot 
  fail 
  to 
  derive 
  a 
  stimulus 
  for 
  further 
  

   inquiries 
  concerning 
  the 
  nature 
  of 
  the 
  vital 
  energy, 
  w. 
  r. 
  c. 
  

  

  11. 
  The 
  Human 
  Skeleton; 
  An 
  Interpretation; 
  by 
  Herbert 
  

   Eugene 
  Walter. 
  Pp. 
  xv, 
  214, 
  with 
  175 
  illustrations. 
  New 
  

   York, 
  1918 
  (The 
  Macmillan 
  Co.).— 
  The 
  evidence 
  of 
  man's 
  

   lowly 
  ancestry 
  as 
  indicated 
  by 
  his 
  framework 
  is 
  cleverly 
  sum- 
  

   marized 
  in 
  this 
  entertaining 
  book 
  for 
  the 
  general 
  reader. 
  In 
  

  

  Am. 
  Jour. 
  Sci.— 
  Fourth 
  Series, 
  Vol. 
  XLVII, 
  No. 
  277.— 
  January, 
  1919. 
  

   6 
  

  

  