ROY LANE 



found that the ratio of interchanges to B" remained at between 0-41 and 

 0-52 at all doses tried. This high ratio of 1 -4 is consistent in the two time 

 intervals analysed (31 and 52 hours), but in view of the relatively small 



f 



Figure 3 



sample (200 cells) needs confirmation by further experiment and analysis. 



Another difference in the interchanges induced by diepoxide in Trades- 



cantia roots is that there appears to be no tendency towards interchange 



269 



