174 



ALLUREMENTS OF ANIMALS FOR THE DISPERSION OF POLLEN. 



whose edge is studded with crescent-shaped, oval, or rounded bodies. These bodies 

 glisten on their upper side with a thin coating of nectar, just like the cushions on 

 the ovaries of Umbelliferous Plants or of the Spindle-tree. 



In the flowers of the Sloe, Almond, and Peach trees, Raspberries and Straw- 

 berries, some Cinquefoils, and numerous other Rosaceae, a fleshy tissue is formed 

 around the ovary or its summit, which, spreading from the base of the flower, lines 

 the calyx-tube like a vestment (c/. fig. 246^). This tissue secretes honey which, 

 however, is not visible from the exterior, because of the very numerous stamens 



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Fig. 246.— Nect.iries. 



> Flower of Cinquefoil (PotentUla micrantha), the front part cut .away. 2 Flower of Mamillaria glochidiata, the front part 

 cut away. " Flower of Atragene alpina, the front part cut away. * Stamen of tlie Atr.ageue with trough-like tllament 

 (anther downwards). ' I'our imbricating trough-like stamens of the same plant held together by a spoon-shaped petal. 

 « Flower of Hanuncuhts glacialis, the front part cut away. 7 A single petal of the same, seen from above. 8 The petal cut 

 through longitudinally, seen from the side. 8, 6, 7^ s natural size; the other figs, somewhat enlarged. 



which surround it and roof it over. In the flowers of Cactuses, also, the lowest 

 cup-shaped or tubular portion is covered inside with a honey-secreting layer of 

 tissue (c/. fig. 246 - showing MamTnillaria). 



In the Thymelacese, Scrophulariaceaa, Gesneraceae, Boi-aginaceae, and Labiatae the 

 honey-tissue forms a wall surrounding the base of the ovary like a ring; while in the 

 closely-allied Rhinanthacese, particularly in the genera Bartsia, Glandestina, Lath- 

 roea, and Pedicularis, there is a cushion which is attached to onlj' one side of the 

 base of the ovary, and in Rhinantkus and Melampyrum at the same point a fleshy, 

 honey-secreting lobe. Moreover, in the Cruciferae, the tissue surrounding the 

 stalk of the ovary is thickened and swollen, while warts and pegs which secrete 

 honey project from it here and there. In the Stocks {Matthiola annua and 



