﻿184 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  ralists 
  under 
  the 
  name 
  of 
  cells. 
  Cells 
  are 
  found 
  only 
  in 
  living 
  bodies 
  > 
  

   and 
  it 
  is 
  very 
  probable, 
  though 
  by 
  no 
  means 
  certain, 
  that 
  no 
  life 
  exists 
  

   outside 
  of 
  cells, 
  or 
  in 
  any 
  other 
  bodies. 
  For 
  this 
  reason, 
  to 
  determine 
  

   the 
  essential 
  powers 
  and 
  peculiarities 
  of 
  cells, 
  and 
  to 
  discover 
  the 
  modi- 
  

   fications 
  they 
  undergo, 
  is 
  the 
  fundamental 
  problem 
  of 
  zoology 
  and 
  botany 
  

   at 
  present. 
  Indeed, 
  biology 
  might 
  almost 
  be 
  defined 
  as 
  the 
  science 
  of 
  

  

  Since, 
  however, 
  microscopic 
  anatomy, 
  which 
  is 
  that 
  branch 
  of 
  science 
  

   which 
  deals 
  especially 
  with 
  the 
  forms 
  and 
  appearance 
  of 
  cells, 
  has 
  been 
  

   more 
  actively 
  prosecuted 
  by 
  medical 
  men 
  than 
  by 
  zoologists, 
  our 
  knowl- 
  

   edge 
  of 
  the 
  tissues 
  of 
  the 
  higher 
  vertebrates 
  is 
  much 
  more 
  complete 
  than 
  

   of 
  the 
  lower 
  animals. 
  Of 
  the 
  histological 
  structure 
  of 
  insects 
  singu- 
  

   larly 
  little 
  is 
  known, 
  although 
  they 
  are 
  particularly 
  favorable 
  objects 
  for 
  

   microscopic 
  investigation. 
  The 
  most 
  extensive 
  series 
  of 
  observations 
  

   are 
  those 
  of 
  Leydig, 
  which 
  are 
  summarized 
  in 
  part 
  in 
  his 
  invaluable 
  

   Lehrbuch 
  der 
  Histologic, 
  published 
  in 
  1858, 
  and 
  in 
  part 
  in 
  shorter 
  special 
  

   papers 
  scattered 
  through 
  various 
  scientific 
  journals 
  of 
  the 
  last 
  twenty 
  

   years. 
  Max 
  Schultze 
  has 
  made 
  several 
  important 
  contributions, 
  and 
  

   there 
  are 
  besides 
  a 
  few 
  excellent 
  single 
  papers, 
  by 
  various 
  authors, 
  

   notably 
  Dr. 
  Yon 
  Basch, 
  Landois, 
  Olaparede, 
  Graber, 
  O. 
  Schmidt, 
  &c. 
  

   Several 
  of 
  Professor 
  Rudolph 
  Leuckart's 
  pupils 
  have 
  made 
  very 
  valuable 
  

   additions 
  to 
  our 
  knowledge 
  of 
  insect 
  histology. 
  The 
  writings 
  of 
  earlier 
  

   naturalists 
  contain 
  many 
  observations 
  of 
  importance, 
  but 
  the 
  ground 
  

   covered 
  by 
  them 
  must 
  now 
  be 
  gone 
  over 
  again 
  and 
  viewed 
  from 
  the 
  

   stand-point 
  of 
  modern 
  anatomy. 
  

  

  When 
  I 
  began 
  the 
  work 
  the 
  results 
  of 
  which 
  are 
  here 
  described 
  in 
  

   detail, 
  223 
  1 
  found 
  that 
  very 
  few 
  histological 
  observations 
  had 
  been 
  made 
  

   on 
  the 
  grasshoppers, 
  or, 
  indeed, 
  on 
  other 
  insects. 
  I 
  feel 
  that 
  this 
  is 
  very 
  

   unfortunate, 
  because 
  it 
  prevents 
  my 
  judging 
  of 
  the 
  accuracy 
  of 
  my 
  own 
  

   observations 
  by 
  comparing 
  them 
  with 
  the 
  results 
  obtained 
  by 
  others. 
  I 
  

   must 
  therefore 
  anticipate 
  that 
  some 
  at 
  least 
  of 
  my 
  conclusions 
  will 
  here- 
  

   after 
  require 
  modification. 
  

  

  I 
  regret 
  very 
  much 
  the 
  incompleteness 
  of 
  this 
  report, 
  occasioned 
  in 
  

   large 
  part 
  by 
  my 
  inability 
  to 
  devote 
  myself 
  longer 
  than 
  a 
  little 
  over 
  five 
  

   months 
  to 
  the 
  work. 
  My 
  results 
  are 
  derived 
  chiefly 
  from 
  the 
  study 
  of 
  

   the 
  locust, 
  224 
  to 
  which 
  I 
  have 
  added 
  a 
  limited 
  number 
  of 
  observations 
  on 
  

   Anabrus 
  purpurascens. 
  I 
  have 
  endeavored 
  to 
  increase 
  the 
  value 
  of 
  the 
  

   article 
  by 
  incorporating 
  a 
  considerable 
  number 
  of 
  bibliographical 
  refer- 
  

   ences. 
  I 
  hope 
  that 
  with 
  these 
  additions 
  this 
  report 
  will 
  assist 
  other 
  

   American 
  students 
  in 
  becoming 
  acquainted 
  with 
  the 
  present 
  state 
  of 
  

   our 
  knowledge 
  of 
  the 
  histology 
  of 
  insects 
  without 
  having 
  to 
  search 
  far 
  

   and 
  wide 
  for 
  the 
  authorities. 
  In 
  brief, 
  I 
  attempt 
  to 
  give 
  a 
  bibliographical 
  

   index 
  to 
  the 
  general 
  outline 
  of 
  the 
  subject, 
  and 
  to 
  describe 
  in 
  detail 
  such 
  

  

  223 
  A 
  preliminary 
  report 
  has 
  been 
  published 
  in 
  the 
  First 
  Annual 
  Report 
  of 
  the 
  Commission, 
  pp. 
  273- 
  

   277. 
  

  

  224 
  Tho 
  observations 
  are 
  mostly 
  madoof 
  the 
  Caloptenus 
  femur 
  -rub 
  rum, 
  the 
  common 
  red-legged 
  locust, 
  

   and 
  on 
  (Edipoda 
  sordida. 
  

  

  