166 



ELEMENTS OP BOTANY. 



205. Protection of Pollen from Unwelcome Visitors. — It is 

 usually desirable for the flower to prevent the entrance of 

 small creeping insects, such as ants, which carry little pollen 

 and eat a relatively large amount of it. The means adopted 



to secure this result are 

 many and curious. In 

 some plants, as the com- 

 mon catchfly, there is a 

 sticky ring about the 

 peduncle, some distance 

 below the flowers, and 

 this forms an effectual bar- 

 rier against ants and like 

 insects. Very frequently 

 the calyx-tube is covered 

 with hairs, which are 

 sometimes sticky, as in 

 Fig. 148, I, II, and VII. 

 How these thickets of 

 hairs may appear to a 

 very small insect can per- 

 haps be more easily real- 

 ized by looking at the 

 considerably magnified 



Fig. 148. — Flowers protected from trnwelcome view of the hairS from 



Visitors. ii i, n c 



. ^ , . . ^ , , .« J ^ ». the outer surface of 



I, enchanter's nightshade, magnified nve times; 



II, gooseberry, natural size ; III, tellima, mullein petals, shown in 



magnified two times ; IV, speedwell, magni- "p:™ ij.Ql 

 fled four times ; V, bearberry, magnified six o' 



times; VI, hound's-tongue, magnified four SometilTieS the reCUrved 

 times ; VII nodding campion, natural size, ^.^^^^ ^^ divisions of the 



at midnight. ^ 



, corolla stand in the way 



of creeping insects, as in III and VII. In other cases the 

 throat of the corolla is much narrowed, as in V, or closed 



• On protection of pollen see Kerner and Oliver, vol. IX, pp. 95-109. 



