Plate VIII. Methods of applying colchicine. A — Portulaca plants showing method 

 of treating stems by immersing their tips in solutions of colchicine. Such treatment has 

 induced doubling of chromosomes. B — A successful method of inducing chromosome 

 doubling by covering the tip of a Datura plant with an agar solution of colchicine. 

 C— Capillary string method of treating buds with solutions of colchicine. One end of 

 str.ng is immersed in a bottle of solution and the other end is wrapped around buds to 

 be treated. D — Method of applying spray of colchicine solutions by means of an atom- 

 izer With air pressure furnished by a spray tank. The air pressure valve manipulated 

 with the left hand was obtained from a dental supply house. E — Drop method of treat- 

 ment. On right a drop of solution is being applied to a seedling Datura. On left a 

 seedling w.th roughened leaves resulting from similar treatment four weeks previously. 

 (From Journal of Heredity, vol. 28, p. 398.) 



