8o 



PLANTS 



water. In these the effect of the water on the form of the leaf is 

 clearly shown. Both kinds of leaf, the narrow ones below the sur- 

 face and the broad ones above, may be found on the same plant. 



Fig. 39. — Lactuca as seen from the south. This and the preceding figure 

 show the leaves twisted into the vertical plane and bent toward the plane of 

 the meridian. 



191. Along the border of quiet waters another type of hydro- 

 phyte is to be found. The plants of this type stand in shallow 



