728 



Colchicine 



in 



B 



J)' 



D 



Fig. 4.7 — Oedogonium cultures, treated and untreated. A. Untreated cell showing the 

 usual ring and cellular striations. B. Enlargement caused by colchicine, indentation of 

 cellular layers a result of treatment. C. Inner cell thickening, and depositions. D. En- 

 largement of the cell from treatment and irregular depositions. (After Gorter) 



An interesting vascularization lollowing recovery from colchicine 

 has been described for the huge cells in Allium roots that form in the 

 differentiated pericycle at points where lateral roots originate. Scalari- 

 form vessels developed and a unique tumor was left buried in the 

 root. 15" Nuclear contents that were estimated to contain over 1000 

 chromosomes as a result of 6 or more c-mitoses disappeared during 

 the differentiation process. A complex series of pretreatmtnt with 

 NAA (0.0002 per cent) and colchicine (0.25 per cent) inters|)crsed 

 with recovery periods preceded this development. No one can doubt 

 that an interesting problem of differentiation is presented by this 

 work. 



Stomatal development regularly proceeds from an embryonic 

 mother cell and eventually forms the guard cells,^'"*' i"*'' ^"^ with as- 



