~~ 
BD ELEMENTARY BOTANY 
at the mouth of the corolla-tube, and in these the stigmas will 
be hanging down quite limp and flabby (Fig. 61). An insect 
coming to a flower in this condition will take the pollen from _ 
the stamens (the stigma has already been pollinated and is 
‘not in a condition to receive more pollen), will carry it to - 
_ other flowers, and when alighting on one with the stigmas at 
the mouth of the corolla-tube will pollinate it. 
(c) Some flowers—e.g., the Primrose and Loosestrife—have 
two or three forms, and in this way cross-pollination is insured. 

Fics. 62 AND 63.—-PRIMROSE. 
62.—LONG-STYLED Form. 63.—SHORT-STYLED Form. 
In one form of primrose (Fig. 62) the style is long and the 
anthers are situated half-way down the corolla-tube ; in the 
other form (Fig. 63) the style is short and the anthers are at 
the mouth of the corolla-tube. Obviously, it is impossible for 
the pollen in the stamens half-way down the tube to fall on 
the stigma, for this latter is above the stamens, so that the 
“long-styled” primrose must receive pollen from another 
flower ; it does receive it from the “short-styled”” primrose. 
In this latter the pollen could fall on the stigma of the same 
flower, and it is conceivable that self-pollination might take 
7 
