1 62 



On Plants and Insects. 



fig- 57- AMPHIBIOUS POLYGONUM (Polygonum amphibium}. 



II. 



I. The same consideration throws light on the 

 large number of plants which are more or less 

 glutinous, a condition generally produced as, for 

 instance, in the flowers of the Gooseberry and 

 of Linnaea borealis (fig. 58) by the presence of 

 glandular hairs. Kerner has called attention to a 

 very interesting illustration afforded by a kind of 

 Polygonum (fig. 57). In this species the stigma, 

 or top of the pistil, projects about one-fifth of an 

 inch above the flower, so that if ants could obtain 

 access, they would steal the honey without ferti- 

 lising the flower ; a flying insect, on the contrary, 



