File:The natural history of plants, their forms, growth, reproduction, and distribution; (1902) (14578937540).jpg

Identifier: naturalhistoryof02kern (find matches)
Title: The natural history of plants, their forms, growth, reproduction, and distribution, vol. 2;
Year: 1902 (1900s)
Authors: Kerner von Marilaun, Anton, 1831-1898 Oliver, Francis Wall, 1864- Macdonald, Mary Frances Ewart Busk, Marian Balfour, Lady
Subjects: Botany
Publisher: London, Blackie
Contributing Library: NCSU Libraries
Digitizing Sponsor: NCSU Libraries

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
est stamen springs up with such violence that it hurls theloosely-coherent pollen against the insects proboscis at an angle of 50° with thetube of the corolla, and with an initial velocity of about 3 mm. per second; atthe same time it closes the entrance to the tube. The upper and lateral stamensspring at the same time to the sides, the empty anthers of an upper and alateral stamen remaining coherent on either side. About twelve hours afterwardsthe lowest stamen extends itself again and leaves the entrance to the flower openonce more. If a hawk-moth, after exploding a flower in the first stage, comes EXPULSIVE MECHANISM IN ORCHIDS. 269 to one in the stage under consideration, it is repaid for its startling reception iuthe former case by a rich supply of honey; and in thrusting its pollen-dustedproboscis down to the base of the flower it brings it in contact with the stigma,which stands in the middle of the tube. The most noteworthy cases of Orchids furnished with expulsive mechanism1
Text Appearing After Image:
Fig. 275.—Expulsive apparatus in Orchid-flowers: flower of Catasetum tridentatum. Side view. 2 Front view, s Longitudinal section through the same; the band connecting the pollen-masses with the visciddisc is stretched like a bow over the protruding rostelluni. ■! The pollen-masses and viscid disc are liberated and arebeing jerked away by the sudden straightening of the connecting-band; the anther-case which hitheito concealed thepollen-masses tumbles away at the same time (below). « Front view of pollen-masses, viscid disc, and the band connectingthem; the margins of the band somewhat involute. « Side view of the same. ! Column removed from the flower; towardsthe summit is the anther, below it the elastic connecting-band stretched like a bow; next the stigniatic chamber with itsfleshy margins prolonged into two horn-like irritable processes. 8 Flower of Dendrohium fimbriutum. » The same inlongitudinal section, lo Side view of the hood-like anther at the end of the column, n Th

Note About Images