(10/48. A large number of
cases are given by Delpino in the 'Bulletino Entomologico' Anno 6 1874.
To these may be added those given in my text, as well as the excretion
of saccharine matter from the calyx of two species of Iris, and from the
bracteae of certain Orchideae: see Kurr 'Bedeutung der Nektarien' 1833
pages 25, 28. Belt 'Nicaragua' page 224, also refers to a similar
excretion by many epiphytal orchids and passion-flowers. Mr. Rodgers has
seen much nectar secreted from the bases of the flower-peduncles of
Vanilla. Link says that the only example of a hypopetalous nectary known
to him is externally at the base of the flowers of Chironia decussata:
see 'Reports on Botany, Ray Society' 1846 page 355. An important memoir
bearing on this subject has lately appeared by Reinke 'Gottingen
Nachrichten' 1873 page 825, who shows that in many plants the tips of
the serrations on the leaves in the bud bear glands which secrete only
at a very early age, and which have the same morphological structure as
true nectar-secreting glands. He further shows that the nectar-secreting
glands on the petioles of Prunus avium are not developed at a very early
age, yet wither away on the old leaves. They are homologous with those
on the serrations of the blades of the same leaves, as shown by their
structure and by transition-forms; for the lowest serrations on the
blades of most of the leaves secrete nectar instead of resin (harz).
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