VARIEGATION. 67 



Among the Papilionace<z> variegation and lines of 

 colour are common in the higher genera, which are 

 more strictly adapted to bees and other specialised 

 honey-suckers, such as Vicia, Lathyrus, Onobrychis, &c. 

 The standard is usually the most highly coloured ; 

 the wings and keel are generally paler, or one degree 

 lower in the scale of progressive colouration. In 

 Lathy rus hirsutus, L. silvestris, Vicia Bithynica, and 

 Astragalus alpinus, this peculiarity is well marked. 

 The cultivated sweet-pea, a Sicilian Lathyrus, illus- 

 trates the general principle even better than any of 

 our native kinds. 



Among regular Corolliflorce, variegation is not very 

 common, though it occurs much oftener than in the 

 polypetalous classes, especially at the throat of the 

 tube, as in the forget-me-nots (Myosotis) ; but in irre- 

 gular Corolliflorce it is exceedingly frequent. The 

 Lentibulacece and 4 other small families afford several 

 examples. In the great order of Labiatcz, the highly 

 modified lower lip is very often spotted, especially 

 where it is most developed. This is the case in 

 S tacky s silvatica, Lamium purpureum, Galeopsis tetra- 

 Jiit, Calamintha acinos^ Nepeta cataria, N. glechoma, 

 Ajuga reptans, Scntellaria galericulata, and many other 

 species. Several exotic kinds show the same tendency 

 in a more marked degree. 



The Scrophularinece, however, form perhaps the 

 best example of any. It was noticed above that 

 comparatively few of these are as blue or as purple 

 as might be expected from their high organisation, 

 The explanation is that they have mostly got beyond 

 the monochromatic stage altogether, and reached the 

 level of intense variegation. They are, in fact, a 



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