8o 



SAGA CITY AND MORALITY OF PLANTS. 



numbers of our wild 

 flowers, and is there- 

 fore well known among 

 botanists. 



A smaller number 

 of flowers have pro- 

 ceeded a stage further, 

 and developed three 

 lengths and sizes both 

 of stamens and pistils, 

 as in the Purple Loose- 

 strife {Ly thrum salica- 

 ria), — famous for Dar- 

 win's lucid examina- 

 tion and lucubration 

 thereon. This addi- 

 tional specialisation of 

 the floral organs for 

 crossing purposes is 

 called Triinorphism. 

 Singularly enough, in 

 trimorphic flowers the 

 differentiation is carried 

 to such a degree that 

 the different -sized 

 stamens produce differ- 

 ent-sized and coloured 

 pollen-grains. 

 The great variety in the colours possessed by 



Fig. 29. — Purple Loosestrife {Lythriitn 

 salicaria). 



