PLATE 4 
A. —Cross section of central stele of the root of a good inbred strain of Yellow Dent 
com that was unusually vigorous, had no chlorophyll deficiencies, yielded well, and 
was highly resistant to rootrot and smut. The tracheids are large and the pith cells 
are closely bound together with thickenings at the corners. 
B. —Cross section of central stele of the root of an inbred strain of Yellow Dent com 
that possessed the other desirable qualities mentioned above but was susceptible to 
rootrot and lodged easily. The tracheids are comparatively small and the pith cells 
are very loosely connected so that they are round in cross section, whereas those 
above are angular. The spaces between the cells are open, and there are no special 
thickenings. 
