344 THE HIGHER DICOTYLEDONS. 



platform, in the latter the insect enters the drooping flower 

 from below. Why is the top of the corolla narrow and cup- 

 like in Cowslip, instead of being broad and flat as in Primrose ? 

 Why do Primroses usually grow in woods or on slopes and 

 banks, while Cowslips grow mostly in open and level meadows, 

 often among long grasses? Does the possession of a long 

 flowering-axis in Cowslip, carrying up the flowers in a tuft, 

 as compared with the arrangement in Primrose, seem to be 

 connected with the different situations in which the two plants 

 grow? 



349. The Primrose Family (Primulaceae) 



nised by the regular flowers with stamens opposite to the 

 corolla-lobes and the one-chambered ovary with free central 

 placenta. 



350. Flower Mechanisms in Primulaceae. The polli- 

 nation of Primrose and Cowslip has been dealt with. The 

 flowers are usually homogamous and honeyed. Heterostyled 

 dimorphic flowers occur in many species of Primula (though 

 in P. scotica and various garden Auriculas, etc., stamens and 

 style are of same length), also in Hottonia (Water Violet), 

 Yellow Loosestrife (Lysimachia vulgar is), and Glaux (Sea 

 Milkwort, which also has cleistogamic flowers). In many 

 cases, especially when the flower-tube is shallow or open, the 

 flowers droop so that pollen and honey are protected. 



The flowers of Scarlet Pimpernel open on bright days, usually 

 from about 9 to 3, closing at night and in bad weather ; if 

 not cross-pollinated (by flies, etc.) during the warm hours of 

 the day, the flower is self-pollinated at evening when it closes 

 and the stigma is rubbed against the stamens. The long- 

 tubed forms are largely visited by bees and butterflies ; the 

 honey is secreted by a ring round the base of the ovary. 



351. Scorpion-grass or Forget-me-not 



though not a good " typical " genus of the Borage Order, is 

 the most abundant and familiar to all. Any of the species 

 found wild, or cultivated in gardens, will serve as an example 

 for study, but in order to make our description definite we 

 shall take 



