FLOWERS AND INSECTS 



135 



will result in rubbing some of the pollen upon the stigma, 

 and in receiving more pollen for another flower. 



\n cases of protandry, as the common figwort, flowers 

 in the two condi- 

 tions will bo visited 

 by tlie pollinating 

 insect, and as the 

 shedding stamens 

 and receptive stig- 

 mas occupy the 

 same I'elative p(jsi- 

 tion, the pollen 

 from one llowcr 



A l)(.-e oljtaining nectar in the pouch of 



will be canned to the stigma of another. It is evident that 

 exactly the same methods prevail in the case of protogyny, 

 as the fire weed (see Fig. 134). 



The iloustonia (see Fig. 135), in which tlierc are sta- 

 mens tiuel styles of different lengths, is visited Ijy insects 



whose liodies fill 

 the tuljc and pro- 

 trude above it. In 

 visiting flijwcrs of 

 both khids, one re- 

 gion of tlie b(jdy 

 r e <; e i v e s p o 11 e n 

 from the sliort sta- 

 mens, and another 

 region from tlie 

 long stamens. In 

 this wav the insect 



Fig. 141. .\ iK-e e«oapin;^ from the pniich of C'ji"''-' 

 pedium, and coming; in contact with tlie gtigma. 

 Advancinij; a little further ttie bee will come in con- 

 tJict \s'ith the anthers and receive ])olleu.— After 

 GinsoN, 



will carry about two bands of pollen, which come in con- 

 tact with the corresponding stigmas. AVhen there tire three 

 forms of flowers, as mentioned in the case of one of the 

 loosestrifes, the insect receives three pollen bands, one for 

 each of the three sets of stigmas. 



93. Warding off" unsuitable insects. — Prominent among 

 W 



