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rich in nectar, so much so, that the nectar is removed by honey-birds. 
Being peripheral, the secretion of the calyx-nectaries may be 
compared with that of the corollar-nectaries of Manunculaceae. My 
investigations have now shown me, that in the order of Malvaceae 
a central secretion of nectar may also be observed, which in most 
genera gives the impression of being the more important — perhaps 
in all genera except Abutilon. 
As is well known, the stamens in Malvaceae are united to form 
a tube. This staminal cylinder, which extends upwards round the 
ovary, is, at its base, joined to the corolla in such a way that their 
common tissue encloses the ovary and hides it from view. If the 
ovary be now liberated from its little “house”, its wall, in almost 
all Malvaceae, is found to be thickly covered with nectar-secreting 
trichomes of the same structure as those, which constitute the calyx- 
nectary (Sekretionspapillen of Brnrens) and these trichomes conti- 
nually pour a layer of glucose on the ovary. In Hibiscus esculentus 
and in H. Trionum these ovarial trichomes are even larger than 
those of the calyx-nectary, and consist of 28 cells. The ovaries are 
therefore not only enclosed in the staminal tube, but are always 
confined in a space, kept moist by nectar-secretion. 
I hope afterwards to return to a detailed study of this order, 
which is so extremely interesting as regards nectar-production. 
Before closing this communication, I still wish to call attention to 
two important matters. In the first place to the secretion, which takes 
place in many flowers, while they are stil in bud. We are accus- 
tomed to assume, that secretion only begins at or after the opening 
of the flower, but I have found many exceptions to this rule. The 
phenomenon may be observed in Ranunculaceae especially. The ovaries 
of Clematis Viticella, covered with silken hairs, the ovaries of 
Paeonia, Pulsatilla and of Aconitum are bathed in nectar, long before 
the opening of the bud, and it may probably be assumed with safety, 
that the secretion of nectar, which already takes place in the bud, 
serves here to protect the sexual organs, and is therefore comparable 
to the secretion of water in flowers with a water-calyx. In the flowers 
of Aconitum I found that indeed the central, but not the peripheral, 
secretion may be observed before the opening; this suggested to me 
that the latter secretion serves more especially to keep the flower 
moist during the flowering period. Further investigation will be 
required to show, whether this difference can also be traced in other 
plants with a double secretion of nectar. 
Before there is any question of the flower’s opening, a copious 
secretion of nectar may also be observed in other plants, such 
