﻿Samuel 
  Wendell 
  Williston. 
  221 
  

  

  Cretaceous, 
  producing 
  valuable 
  monographic 
  studies 
  on 
  

   both 
  groups. 
  From 
  1897 
  on 
  Williston 
  's 
  paleontological 
  

   papers 
  began 
  to 
  appear 
  in 
  increasing 
  proportion, 
  finally 
  

   almost 
  to 
  the 
  exclusion 
  of 
  those 
  on 
  the 
  Diptera, 
  there 
  

   being, 
  all 
  told, 
  one 
  hundred 
  and 
  twenty-two 
  of 
  the 
  former 
  

   to 
  ninety-two 
  of 
  the 
  latter. 
  

  

  In 
  1902 
  came 
  the 
  call 
  to 
  the 
  chair 
  of 
  paleontology 
  in 
  

   the 
  University 
  of 
  Chicago. 
  Here 
  Williston 
  found 
  the 
  

   nucleus 
  of 
  a 
  collection 
  of 
  Permian 
  vertebrates, 
  and 
  he 
  

   determined 
  to 
  undertake 
  research 
  in 
  that 
  group. 
  Skilled 
  

   assistance, 
  together 
  with 
  his 
  own 
  indefatigable 
  endeavors, 
  

   has 
  brought 
  together 
  at 
  Chicago 
  a 
  collection 
  of 
  Paleozoic 
  

   land 
  vertebrates 
  that 
  is 
  incomparable 
  both 
  for 
  its 
  extent 
  

   and 
  the 
  perfection 
  of 
  the 
  material, 
  for 
  Williston 
  describes 
  

   entire 
  skeletons, 
  whereas 
  his 
  predecessors 
  had 
  to 
  be 
  con- 
  

   tent 
  with 
  individual 
  bones 
  and 
  fragments. 
  Paper 
  after 
  

   paper 
  on 
  these 
  obscurely 
  known 
  forms 
  came 
  from 
  his 
  pro- 
  

   lific 
  pen. 
  The 
  material 
  was 
  prepared 
  under 
  his 
  guidance, 
  

   and 
  drawn 
  and 
  photographed 
  entirely 
  by 
  his 
  own 
  hand, 
  

   a 
  feature 
  that 
  gives 
  a 
  unique 
  value 
  to 
  the 
  product. 
  

  

  Two 
  books 
  appeared 
  during 
  Professor 
  Williston 
  's 
  term 
  

   at 
  Chicago, 
  his 
  American 
  Permian 
  Vertebrates 
  and 
  his 
  

   Water 
  Reptiles 
  of 
  the 
  Past 
  and 
  Present, 
  concerning 
  both 
  

   of 
  which 
  groups 
  he 
  had 
  thought 
  and 
  studied 
  until 
  none 
  

   knew 
  them 
  better 
  than 
  he. 
  A 
  book 
  on 
  the 
  Evolution 
  of 
  

   the 
  Beptiles 
  was 
  in 
  course 
  of 
  preparation 
  at 
  the 
  time 
  of 
  

   his 
  death. 
  

  

  Williston 
  possessed 
  a 
  broad 
  and 
  accurate 
  knowledge 
  of 
  

   human 
  and 
  comparative 
  anatomy, 
  so 
  that 
  his 
  morpho- 
  

   logical 
  results 
  were 
  rarely 
  in 
  error; 
  when 
  such 
  was 
  the 
  

   case, 
  however, 
  no 
  one 
  was 
  more 
  willing 
  to 
  acknowledge 
  

   it 
  than 
  he. 
  His 
  knowledge 
  of 
  the 
  flies 
  was 
  both 
  compre- 
  

   hensive 
  and 
  minute, 
  and 
  it 
  is 
  characteristic 
  of 
  him 
  that 
  

   after 
  years 
  of 
  paleontological 
  study, 
  to 
  the 
  utter 
  exclu- 
  

   sion 
  of 
  entomology, 
  he 
  was 
  able 
  to 
  revise 
  and 
  extend 
  his 
  

   great 
  Manual 
  of 
  the 
  North 
  American 
  Diptera, 
  treating 
  

   the 
  minutia? 
  of 
  description 
  with, 
  a 
  thoroughness 
  of 
  grasp 
  

   which 
  showed 
  that 
  little 
  had 
  escaped 
  his 
  memory 
  in 
  a 
  

   dozen 
  years. 
  

  

  Williston 
  's 
  contributions 
  to 
  science, 
  aside 
  from 
  the 
  

   material 
  value 
  of 
  the 
  collections 
  which 
  he 
  aided 
  in 
  build- 
  

   ing 
  up 
  at 
  Yale, 
  Kansas, 
  and 
  Chicago, 
  are, 
  first, 
  his 
  

   entomological 
  work, 
  mainly 
  with 
  the 
  Diptera, 
  which 
  

   covered 
  the 
  description 
  of 
  hundreds 
  of 
  genera 
  and 
  

  

  