•jus 



Plant Tissue Culture 



Fir,. <;:;. A shorl series of scalariforno <-clls forming an incom- 

 plete vascular strand in the interior of ;i Nicotiana callus culture. 

 L000. (From White, P. R. IJKW. Am. .1. Hot. I2t> : (53, fig. 8, 



