STEMS 119 



of fruit trees the sleeping buds are often called 

 into action. 



165. Winter buds of aquatic plants. — In one 

 class of land plants the upper branches of the stem 

 have been seen to die down, leaving only the basal 

 portion of the stem with its buds to live through the 

 winter. Exactly the reverse action takes place in 

 some aquatic plants which root in the bottom of 

 streams or lakes, or which float on the surface. If 

 a visit is made to a lake or pond about the time that 

 the trees have lost all their leaves, this curious bud 

 formation may be found. The stems of the pond- 

 weeds, stonewort, bladderwort, and others will be 

 seen to have taken on a brownish color except at 

 the tips. Here the stem is still alive, and a large 

 number of leaves of a dark green color overlap each 

 other closely, forming an egg-shaped mucilaginous 

 mass. Break off some of these buds and find if 

 they win float alone. These buds are sometimes 

 termed hibernacula. Preserve your notes upon the 

 subject and visit the same pond in the following 

 spring as soon as the ice has melted. A great num- 

 ber of the winter buds may be seen floating near 

 the surface of the water. Examine, and note their 



