Vlll 



CONTENTS 



(a) 

 (b) 

 (c) 

 (d) 

 (e) 



VI Reorganization . . . . . . . . . . . . 91 



1 . The course of reorganization . . . . . . 91 



2. Analysis of the reorganization process . . 94 



3. Stimulus to reorganization and the significance of this 

 process . . . . . . . . . . . . 98 



To replace defective mouthparts? . . 98 



Response to change in the medium? . . . . 99 



Need for nuclear reorganization? . . . . loi 



For growth of the adoral band? . . . . . . loi 



Need for adjustment of nuclear dimensions? . . 102 



VII Regeneration . . . . . . . . . . . . 105 



1 . The course of regeneration . . . . . . . . 105 



(a) Oral regeneration and its requirements . . 105 



(b) Regeneration of the holdfast . . . . no 



(c) Reconstitution of the normal shape . . . . in 



2. Nuclear behavior during regeneration . . .. .. 113 



3. Effective stimulus to regeneration .. .. .. 115 



4. Time for regeneration .. .. .. .. .. 117 



5. Minimum size of regenerating fragments .. .. 120 



6. Adjustments to proportionality of parts .. .. 123 



7. Can mouthparts and membranelles be formed in situ? 127 



8. Repeated oral regeneration . . . . . . . . 130 



9. Blockage of regeneration .. .. .. .. 131 



VIII Activation and Inhibition of the Oral Primordium 135 



1. The course and spectrum of cell interactions . . . . 136 



2. Timing the period of activation . . . . . . 142 



3. Relation of the macronucleus to activation and 



inhibition , . . . . . . . . . . . 143 



4. Relation of intact feeding organelles to activation and 



inhibition . . . . . . . . . . 144 



5. Synchronization of developing primordia . . . . 149 



6. Activation in reorganizers and dividers . . . . 152 



7. Rerouting the oral primordium . . . . 152 



IX Primordium Development . . . . . . 159 



1. Normal location and development of the primordium 159 



2. Primordium development under abnormal conditions 164 



3. Determination, or the progressive specification of the 



oral anlage . . . . . . . . . . . . 170 



4. Induction of mouthparts formation .. .. .. 174 



5. Repair, mending, and joining of primordia .. .. 176 



X The Primordium in Relation to the Stripe Pattern 179 



1. Nature of the normal primordium site . . .. 179 



2. Production of supernumerary primordia 180 



3. Abnormal primordia correlated with abnormal striping 184 



4. Primordium formation in loci of minor stripe contrast 188 



