50 THE COLOURS OF FLOWERS. 



occasionally produce purple or white flowers. Hounds- 

 tongue (Cynoglossum officinale) is purple-red, and most 

 of the other species vary between purple and blue ; 

 indeed, throughout the family most flowers are red at 

 first and blue as they mature. The purplish-red of 

 the less advanced species exactly answers to the 

 immature colouring of the more advanced, which are 

 blue in their full-blown stage. Of these, borage at 

 least is habitually fertilised by bees, and the same is 

 partially true of many of the other species. All of 

 them are adapted to a high class of insect visitors. 



Other families of regular Corolliflorce must be 

 glanced at more briefly. Among the Gentianacece, 

 the less advanced types, like the simple Chlora per- 

 foliata and Limnanthemum nymphceoides, are yellow, 

 perhaps by reversion ; but Menyanthes trifoliata, a 

 slightly more developed ally of Limnanthemum, has 

 white blossoms, tinged outside with red ; Erythrcza 

 centaurium, with a divided calyx and the cells of the 

 ovary imperfectly united, is red ; and the true gentians, 

 Gentiana verna, G. campestris, G. nivalis, &c., with a 

 tubular calyx, long throat, and sometimes fringed 

 hairs to the tube, are bright blue. In Apocynacecs, we 

 have the highly developed periwinkles, Vinca major 

 and V. minor, normally blue, though pink and white 

 varieties or species are also cultivated. In Plumbaginecz 

 we have the bluish purple sea-lavender (Statice Li- 

 moniuni] and the pink thrift (A rmeria vulgaris). Other 

 families with special peculiarities will receive notice 

 later on. 



It is necessary, however, here briefly to refer to the 

 great family of Composites, some of whose peculiarities 

 can only properly be considered when we come to 



