718 Mr. Brown on the Organs and Mode of 
and Schreber, respecting the structure of the stamina and stigma. 
With this view I appealed to the remarkable fact, that in the 
early state of the flower-bud the pollen masses are absolutely 
distinct from the glands and processes of the stigma, to which 
they in a more advanced stage become attached. This proof of 
the real origin of parts I then believed to be entirely new. It 
has however been already seen that the fact was noticed by 
Gleichen, and it will presently appear that it was also well 
known to another original observer. | 
In the essay referred to, I had not very minutely examined 
the texture of the pollen mass, and in true Asclepiadez I had 
failed in ascertaining its real internal structure; not having 
been then aware of the existence of the included grains of 
pollen, but believing, until very lately, that the mass in its 
most advanced state consisted of one undivided cavity, filled 
with minute granular matter mixed with an oily fluid; and 
hence concluded that the fecundating matter was conveyed 
from the mass through the arm and gland to the stigma. 
In the month of April last I saw, for the first time, draw- 
ings of several Asclepiadeze made between 1805 and 1813 by 
Mr. Bauer, who, aware of the interest I took in this subject, 
with his accustomed liberality and kindness, offered me any 
part of them for publication. 
Among these drawings, exceeding perhaps in beauty and 
in the completeness of the details all the other productions 
with which I am acquainted even of this incomparable artist, 
an extensive series, exhibiting the gradual development of the 
parts of the flower in Asclepias curassavica, were the most 
important. 
In this series, made in 1805, and commencing when the 
pollen is just separable in a pulpy mass from its cell, the 
glands of the undivided stigma being still invisible, the fact 
of 
