EXPLANATION OF THE ILLUSTRATION 
Prats V. Projection tracing of cross-sectional view 
of the pulvinus and associated branch from the tas- 
sel of Purdue 39 sweet corn. Note that the tissues 
of this mature pulvinus suggest the primordium of 
an organ (such as the prophyll) in that the swelling 
results from a proliferation of many small cells,rather 
than an expansion in individual cell size. About forty 
five times natural size. 
Drawn by Warton C, GALinaT 
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