174 



ALLUREMENTS OF ANIMALS FOE 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 {cf. fig. 246^). This tissue secretes honey which, 

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



Fig. 246.— Nectaries. 



1 Flower of Cinquefoil (Potentilla micrantha), tlie 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 the Atragene with trough-like filament 

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

 6 Flower of Ranunculus glacialis, the front part cut away. ? A single petal of the same, seen from above, fl The petal cut 

 through longitudinally, seen from the side. 8, «, ', 8 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 (cf. fig. 246 ^ showing MamTnilla/ria). 



In the Thymelacese, Scrophulariacese, Gesneracese, Boraginaceae, and Labiatse 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, Clandestina, Lath- 

 rcea, and Pedicxdaris, there is a cushion which is attached to only one side of the 

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

 honey-secreting lobe. Moreover, in the Cruciferse, 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 



