168 



AMERICAN HONEY PLANTS 



though, for just as animals excrete various organic substances that are 

 by-products, or waste, from some of their functions, so it was thought by 

 some students that the sugar or nectar might really be an excreted waste 

 or surplus rather than a substance secreted because it is to become useful 

 to the plant. 





L-MW' 



^s 



Christian KoNRAD Sprengel, 





Fig. us. Sjirengels title jiage. 



Toward the end of the eighteenth century a German rector, Sprengel. 

 who seems to have found in nature a good deal of inspiration that he 

 failed to "put over," noticed that the petals of the common German wild 

 geranium were fringed with hairs at their bases. That was in the day 

 before men believed in evolution, but when they did l)elieve in a purposeful 



