62 KEV. G. HENSLOW — HOMOLOGY AND 



tlien assume the attractive functions characteristic of a corolla. 

 Several, such as Hanuticulaeea, as well as Labiatce, have coloured 

 calyces; as also Hydrangea, Rhodochilon, Calluna, Fuchsia, etc. 



4. The sepals may be at first attractive, and subsequently green 

 and assimilative, as in Hellehorus niger, and Poh/gala vnlgaris. Or, 

 conversely, they may be at first nourishing and protecting, as in the 

 qreeyi buds of Anemone and Caltha, subsequently attractive when 

 the flower expands ; or once more assimilative in fruit, as in the 

 Poh/gala and Hellehonix just mentioned. 



5. Dispersive. If they be " winged," as in Bipterocarpus, or 

 represented by a " pappus," as in Compositce and Vahrianacece, 

 the fruit is wind-supported ; but if provided with barbs, as the 

 fruit of Bidens, it may be conveyed by animals. 



6. Iloneij -collecting, as the saccate sepals of Cheirantlim and 

 Mdianthus. 



7. Honey-secreting, as the glandular sepals of Malpighia. 



8. Fruit-protecting, dry and marcescent. Tliis state occurs in 

 Bychiis and Silene, Physnlis, etc. It has been noticed that the 

 withered calyx protects the young ovary of the cherry, and those 

 ovaries so protected often escape being frost-bitten. 



9. Protecting by spines in warding off unwelcome guests. This 

 mav be the use of the spreading spiny sepals of the Bahiat(e, several 

 calyces together thus forming a sort of barricade, effectively de- 

 barring crawling insects from reaching the nectaries. 



10. Attractive asfood, in the fleshy perianth oi Mortis, Flaagnus, etc. 



11. Uudimentary or obsolete, as in Asperula, Galium, Sison, and 

 other members of the Umhelliferce and Composite^. 



Progressive cliavges in the Calyx. — Pelaloid sepals are not at all 

 nnfrequent. In RanunculacecB the following genera may be men- 

 tioned in addition to those given as normally possessing a coloured 

 calyx : — Clematis, Acomtuin, Aquilegia, and Trollius. 



in Mussmida, Cah/copliyllum, Ustnia, etc., only one or more of 

 the calyx-lobes is normally enlarged and coloured. 



Normally-coloured sepals are most frequent in polysepalous 

 genera, though Fuchsia and Hh ■docliiton are gamosepalous. 



Abnormal colorisation. with or without a metamorphosis of the 

 form of the sepals, is most fre(]uent in gamosepalous flowers, as 

 in hose-in-hose varieties of I'rimnla, Mimnlus, and Azalea. The 

 calyx may be petaloid either wholly or in part only. In the 

 former case the nerve remains green the longest.*' 



In partial colorisation one oi- moi-e of the calyx-lobes may thus 

 abnormally resemble Mussmnda, etc., as described in Sgringa 

 persica] and in Mimnlus quinqne-rulnera.X In Primula officinalis, 

 var. Smaragdina, obtained by excising the corolla and essential 

 organs early, the colouring matter is dev(doped in a remarkable 

 manner upon a more vigorously produced calyx. 



* In the colorisation of foliage the nerves are often coloured, while the 

 pareuch\Tna remains green, as in Chilian beet-root, 

 t 'Linuica,' t. x, p 738. 

 X C. Morren, ' Bulletins de I'Acad. Royale de Belgique,' t. xix, part 3, p. 85. 



