224 



I'hi ul Tissue Culture 



in,. 69. Transverse section of a Nicotiana callus culture main 

 tamed for two weeks iii the anterior chamber of a rabbit's eve. 

 (Courtesy of Dr. Harry s. X. Greene, Vale University Medical 

 School.) The deep-staining areas are animal cells, largely invasive 

 leucocytes, which have in many cases pushed their way between the 

 less deeply staining plant cells. The very dark, broken, lenticular 



mass at the left is the lens of the eye. The plant tissue contains 

 many gianl cells at the margin and some vascular strands luit no 



meristematic areas, indicating that, while cell division had stopped, 



Cell enlargement and maturation had proceeded for some time after 

 insertion of the culture in the eve. ■ 41'. 



