﻿CONTENTS. 
  

  

  Pag*. 
  

  

  Introduction 
  5 
  

  

  Plan 
  of 
  investigation 
  6 
  

  

  Marking 
  of 
  specimens 
  6 
  

  

  Field 
  records 
  7 
  

  

  Planting 
  sites 
  7 
  

  

  Planting 
  of 
  tagged 
  specimens 
  7 
  

  

  Shoofly 
  Creek 
  7 
  

  

  Chikaskia 
  River 
  8 
  

  

  Growth 
  results 
  9 
  

  

  Table 
  1. 
  A 
  year's 
  growth 
  in 
  young 
  Quadrulse 
  10 
  

  

  Table 
  2. 
  Two 
  periods 
  of 
  growth, 
  of 
  one 
  year 
  and 
  three 
  months, 
  respectively 
  11 
  

  

  Table 
  3. 
  Seasonal 
  growth 
  12 
  

  

  Tables 
  4-7. 
  Rate 
  of 
  growth 
  in 
  different 
  sizes 
  of 
  Quadrula 
  undulata 
  l3 
  

  

  Table 
  8. 
  Rate 
  of 
  growth 
  by 
  species 
  15 
  

  

  Discussion 
  of 
  data 
  15 
  

  

  Arrested 
  -growth 
  rings 
  17 
  

  

  Migration 
  19 
  

  

  Shoofly 
  19 
  

  

  Chikaskia 
  20 
  

  

  Discussion 
  of 
  migration 
  data 
  21 
  

  

  Economic 
  bearing 
  of 
  experiments 
  — 
  Related 
  problems 
  21 
  

  

  Summary 
  22 
  

  

  Literature 
  cited 
  22 
  

  

  Explanation 
  of 
  plates 
  23 
  

  

  3 
  

  

  