36 



THE AMERICAN MONTHLY 



[Feb 



of very thick-walled parenchymatous cells, fig. b, 2. The 

 infoldings of the walls vary in shape. Some are narrow 

 prolongations of the walls with a knob-like end. Others 



lack the rounded end, and some are merely short, blunt 

 thickenings of the walls. In no case are the infoldings 

 branched. The cells are very irregular both in shape and 



