Fecundation in Orchidee and Asclepiadee. 737 
closed in the cells of the anthera; this happening 
in A. phytolaccoides in that particular kind of decay 
mentioned in (p. 729 of) the text. 
Tan. 36. 
Fig. 1; Two Pollen masses of Asclepias purpurascens with pro- 
truded tubes; the only instance met with in which 
both cords are introduced into the.same style. 
2. A grain of pollen, of the same species, with a portion 
of its tube; the unusual form probably caused by the 
pressure of other grains and their tubes. | 
3. A grain of pollen of Asclepias purpurascens containing 
numerous minute granules and two larger drops or 
globules of an oily fluid. 
4, 5, & 6. Various combinations of pollen masses of Ascle- 
pias purpurascens. In these it is supposed that the 
insect having removed and applied to the stigma some 
of the masses, has extracted, by means of the arms 
still adhering to it, other masses with their glands 
and arms, | x 
A combination of the same kind, different from and 
more remarkable than any of these, but perhaps not 
very accurately represented, is given, in his Micro- 
scop. Entdeck., tab. 36. fig. 8, by Gleichen, who ap- 
pears (op. cit. p. 81.) to have also met with other 
combinations, without suspecting in any case the real 
cause of such apparently anomalous structures. 
7. A flower-bud of Asclepias curassavica in the earliest 
stage in which I was able to distinguish its parts; the 
unopened corolla in its place with one of the sepala, 
the other four being exhibited separately :—highly 
magnified. 
5522 Fig. 8. 
o 
