HorNE: ANOMALOUS STRUCTURE ON LEAF OF BEAN 587 
rib, At 4 mm. farther the organ is very nearly free from the 
midrib and shows the same internal structure as where it has be- 
come separated. 
The outer end was sectioned longitudinally. The epidermis 
is contiuous to the tip and set with short hairs The body 
Figure 4. Part of a section such as that shown in figure 3, enlarged. > 200. 
of the structure is parenchyma, the inner cells being larger and 
longer. There is a distinct axial strand composed of much 
narrower cells varying considerably in length and some hav- 
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FIGURE 5, Tip of a section such as that shown in figure 3, enlarged. X 200. 
ing oblique and some square ends. The central strand is much 
broader in the first two millimeters from the end and has devel- 
oped in it numerous lignified vessels with simply reticulated or 
spirally thickened walls. At about 2 millimeters from the end 
