SPINDLE FORMATION IN THE POLLEN- 

 MOTHER- CELLS OF CASSIA 

 TOMENTOSA L. 



BY HENRI T. A. HUS. 



CONTENTS. 

 Plates XXX-XXXII. 



Page 



■ 329 



■ 333 

 - 341 



Introduction 



Description 



Discussion 



The Nature of the Multipolar Spindle 34i 



The Origin of the Cones of the Multipolar Spindle 343 



Summary ^ „ 



Bibliography -^^ 



Explanation of Plates ^^o 



Introduction. 



Cassia tonientosa L. possesses a number of qualities 

 which particularly recommend this plant to the cytologist. 

 Chief among these are the large number of buds produced 

 and the protracted flowering period. The stages of cell- 

 development which are of greatest interest at the present 

 time are passed through very rapidly, and are also the most 

 difficult to fix; hence the collection of an immense amount 

 of material is necessary to ultimate success. At the same 

 time the protracted flowering period affords an opportunity 

 to determine at leisure which is the best fixing-medium and 

 what shall be the duration of the fixing-period. 



The following fixing-fluids were tried : 



[ 329 ] April 6, 1904. 



