176 ALLUREMENTS OF ANIMALS FOE THE DISPERSION OF POLLEN. 



warts are found at the base of each filament {e.g. in Alsine mucronata and vema). 

 Sometimes again only the stamens opposite the calyx have swollen bases which 

 secrete honey on the grooved side opposite the ovary (e.g. Cherleria sedoides). 

 In the flowers of Sagina Linncei each of the thread-like stamen-filaments opposite 

 the calyx is surrounded at the base by a cup-shaped nectary. Very often the 

 nectaries of adjacent stamens, in the flowers of the above-mentioned plants, fuse 

 together into a ring, the fusion being only just indicated in the Geraniacese, but 

 more decidedly in many Caryophyllacese {e.g. in Spergula), and still more amongst 

 Linaceous and Caryophyllaceous plants {Linum, Gypsophila, JDianthus, Lychnis). 

 In the flowers of most Papilionaceffi the stamens form the nectar. Nine stamens 

 are fused into a tube in which the ovary is inclosed. This ovary is at the base 



of the flower narrowed into a stalk, while the tube, on 

 the other hand, is somewhat widened. Thus is formed 

 a cavity into which honey is poured from the adjacent 

 part of the staminal tube. The space is covered over by 

 the tenth stamen, which, however, yields no honey. In 

 Atragene alpina, belonging to the Ranunculacese, the 

 abundant honey so eagerly sought by humble-bees is 

 formed in the deeply-grooved inner side of the stamens 

 (c/. figs. 246 3' *> 5). 



Very often nectar is secreted by the floral-leaves, 

 both in flowers where they form a perianth and also 

 Fig. 247.-Fiower of the Snowdrop j^ tt^^gg ^^ere they may be divided into calyx and 



corolla (c/. vol. i. p. 641). In the Snowdrop {Galanthus 

 nivalis, see fig. 247), the honey is formed in parallel longitudinal grooves on the 

 inner side of the three outspread perianth-leaves; in Lilies, especially those with 

 hanging flowers and curled perianth-leaves, e.g. Lilium ChalcedonicuTn and Gwrni- 

 olicum and the well-known Martagon Lily {Lilium Martagon), each perianth-leaf 

 is traversed by a channel studded with bands or ramifying swellings, and filled to 

 overflowing with the abundant nectar secreted in it. Several Orchids, especially 

 species of Twayblade {Listera), also exhibit such a channel swollen with sweet sap, 

 but only on one of the perianth-leaves, the lip, which is at the same time the 

 resting-place for the honey-seeking insects while they clear out the channel. In 

 the perianth of the Helleborine {Epipactis) the lip is deeply grooved, and resembles 

 a boat filled with honey. In Epipogium, the perianth-leaf corresponding to the 

 lip is arched like a helmet or cap, and covers the abundant honey there produced- 

 In many other Orchids the lower lip of the perianth is produced backwards, and in 

 the expansion (called the spur in descriptive Botany) a quantity of honey is usually 

 hidden. The perianth of Tricyrtes pilosa {of. fig. 251 *) is composed of six leaves, 

 of which the three outer are expanded near their base and secrete abundant nectar. 

 In the flowers of the Narcissus (fig. 248), Gladiolus, and Iris, also in those of 

 Sisyrinohium and Thesium, the inner side of the tubular perianth is transformed 

 either wholly, or, at any rate, in the lower third into a honey-secreting tissue 



