ALLUREMENTS OF AXIMALS FOB THE DISPEESIOX OF POLLEN. 175 



incana), in Abjssum, Schivej-ekia, and Thla^i such warts are seen right and left 

 of the two short stamens, and in AUiaria and Draba one wart projects from the 

 longer pair of stamens from the outer side facing the corolla. It must remain 

 uncertain whether these structures are to be regarded as part of the stem or as 

 metamorphosed leaves. In many cases — as, for example, in Haberlea, Fcedemta, 

 and Folimoniu/m, where the ring-shaped cushion is divided into five, and in 

 Scrophuiaria, where it is divided into two symmetrically-placed lobes — the appear- 

 ance is in favour of the latter view. In the flowers of the Bindweeds (Ckm- 

 volvulaceii?) the base of the ovary is surrounded by five thick honey-secreting 

 scales of equal size, which together form a small cup reminding one of an egg in 

 an ecST-cup. and in the Crassulace« a Httle knob or a fieshy scale projects from the 

 circular wall of the base of the flower opposite each carpel, sometimes spoon-shaped 

 (Sctfujft annuum), sometimes linear and spht at the free end {Stdwn atratum). 

 and of other varied forms. In these instances the honey-secreting stmcttires are 

 without doubt to be regarded as metamorphosed leaves. 



Instances are comparatively rare where the formation of honey is carried on 

 by the carpels — as, for example, the flowers of several Piimulaceje {AndrC'sace. 

 Atvtia\ in which the slightly arched roof of the ovary secretes minute drops of 

 nectar, and in those of many Gentians {Gentiana acavZis, asclepiadea, Bavarica, 

 Fneamonantki. pi-ostrata, punctata, kc), where the btilb-like. thickened ba^e of 

 the ovary exhibits five cushions which exude abundant honey into the base of 

 the flower-tube. In the flowers of some LLliaceae and Melanthaceae t^e.g. Aloiu-a, 

 Ornithogalum., Tojiddia). the honey is secreted in the lateral grooves of the 

 ovaiy, and in the flowers of Anthericum as well as of Allium. Chamcemoly a small 

 depression is found on each of the three lines of union of the carpels from which a 

 drop of honey is poured. 



Nectaries are found much more frequently on the stamens. They occur there 

 in all sizes and shapes. Sometimes it happens that whole stamens are changed 

 into nectaries, which of course can only be at the expense of the anthers. The 

 stamens of the Whortleberry and Bog-whortleberry (Yacciniuvi Mynillis and 

 ■id'tgincsuni), like those of Tulips {Tulipa^ have a small depre^on which secretes 

 honey on the broad thickened base of the filament opposite the corolla. In thf 

 widely-distributed Meadow Saffixai (Coickicujn autumnal^e) there is an orange- 

 eoloored honey-secreting body on the stamens just above the place of union 

 with the violet leaves of the perianth, and the honey there formed fills a channel 

 which traverses the adjoining perianth-leaf. The same thing occurs in other 

 S^&ons and also in the genus TriUium. In Geraniaceous plants, especially in 

 Srodium and Greranium, a w^art-shaped, sometimes hollow, nectary arises on 

 the base of each of the five inner stamen-filaments on the side direciei towsirds 

 the sepals. The nectaries at the base of the thread-like filaments of many 

 Caiyophyllaceffi exhibit an immense variety of form. S-C'merimes all the stamens 

 of a flower are a little thickened at their root, and secrete honey from a yellow 

 tissue opposite the ovary (e.g. in Telephium. Impni'.i), or a tfir o- Lrrey-secretizig 



