254 THE BIOLOGY OF HYDRA : 1961 



SLAUTTERBACK: In response to Dr. Wood's comment, my 

 suggestion was that the animal be exposed to the colloidal thorium 

 dioxide before it was cut up. In that case there would be no 

 thorium in the ectoderm cells. 



PHILLIPS: True, if the label remains. 



PASSANO: What is the chromosomal integrity in your clones 

 over a period of time? 



PHILLIPS: I don't know. Until I can get rid of these granules 

 and control their formation I do not want to even attempt to ob- 

 serve mitotic figures. 



STREHLER: Does colchicine block their mitosis? 



PHILLIPS: I have not tried it yet. 



