Plate III 



No. 6 Phase contrast photomicrograph of tumour cell in prophase of mouse sarcoma 

 'Rb' by LuDFORD and Smiles (J. roj. micr. Soc. 70 (1950) 186) reproduced by kind 

 permission. X 1250 (reduction 3/4). To the left of the nucleus is a central body 

 which the authors describe as a 'juxta-nuclear accumulation of granular material 

 and associated canalicular system'. {Continued on opposite page.) 



