author's abstract op this paper issued by 

 the bibliographic service, november 3 



CONTRIBUTIONS TO THE STUDY OF CELL 

 MECHANICS 



II. MONASTER EGGS AND NARCOTIZED EGGS 1 



THEOPHILUS S. PAINTER 



Osborn Zoological Laboratory, Yale University and the Laboratory of Zoology, 



University of Texas 



TEN TEXT FIGURES AND FIVE PLATES 



CONTENTS 



Introduction 445 



Monaster eggs 



1 . Changes in living egg 449 



2. Internal changes 456 



3. Discussion 461 



Experiments with narcotics 469 



Further discussion 474 



The cent rosome 478 



The aster and cytoplasmic division 480 



Behavior of the chromosomes 481 



'Spinning' or 'filose activities' in the light of monaster eggs 484 



Summary 485 



INTRODUCTION 



The present contribution embodies the results of a micro- 

 scopic study of monaster eggs in sea urchins, together with some 

 experiments made in an attempt to understand the meaning of 

 the behavior of certain cell elements. In making an analysis 

 of the observed facts, we have been brought face to face with 

 so many mooted questions of cell mechanics, which have been 

 left unsolved, that it is best, perhaps, to define the view-point 

 from which the present research was undertaken. Cytologists 



1 The present work was carried on at the Zoological Station at Naples, at the 

 Woods Hole Marine Biological Laboratory, and at the Osborn Zoological Lab- 

 orator}'. Contribution No. 136 from the Zoological Laboratorj', University of 

 Texas. 



445 



THE JOURNAL 07 EXPERIMENTAL ZOOLOGY, VOL. 24, NO. 3 

 JANUARY, 1918 



