UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 4, No. 6, pp. 345-386, text-figures 33. April 22, 1908 



CONTEIBUTIONS FROM THE LABORATORY 



OP THE 



MARINE BIOLOGICAL ASSOCIATION OF SAN DIEGO. 



XXI. 



EXUVIATION, AUTOTOMY AND REGENER 

 ATION IN CERATIUM. 



BY 



CHARLES ATWOOD KOFOID. 



CONTENTS. PAGE 



Introduction ... 346 



Ecdysis 347 



Occurrence in Dinoflagellata 347 



Relation to schizogony 348 



Exuviation 349 



Statement of the problem 349 



Structure of the cell wall 349 



Transfer of the ancestral theca in schizogony 352 



Assimilative regeneration of the theca in schizogony 353 



Occurrence of senile forms in Ceratium 355 



Removal of the wall by solution 356 



Evidence of exuviation in Ceratium 356 



Significance of exuviation 359 



Normal autotomy in Ceratium 360' 



Its general occurrence 361 



Frequency in collections from deep water 363 



Evidence of autotomy 363 



Formation of section planes 363 



Regulatory character of autotomy 364 



Location of planes of autotomy 373 



Significance of autotomy 374 



Relation to specific gravity 374 



Relation to specific surface 374 



Regeneration in Ceratium 377 



After schizogony 377 



Regeneration after autotomy 377 



Regenerative growth independent of autotomy 379 



Regulatory nature of regeneration of the horns 381 



Significance of regeneration 381 



Summary 383 



Bibliography 385 



