a 





M 



# 



M 





i 



Figure 2. Photomicrographs of Vicia faba chromosomes in Feulgen squashes of root tip mitoses {all 

 colchicine treated), after treatment with X-rays. All X 3,000. 

 {a) Incomplete interchange between long and short chromosomes. 



(b) Complete intrachange in long chromosome. 



(c) Proposed incomplete intrachange in long chromosome {^: chromatid ' break '). 

 {d) Intrachange at prophase. 



(e) Interchange with isochromatid break in one arm [i^' near triradial'). 

 (/) and (g) Triradial {^chromatid-isochromatid interchange) with diagram of suggested 

 interpretation. 



