124 Mr. Brown on the Organs and Mode of 
cells. Its membrane is transparent and colourless, made up of 
two united coats, and the cavity is filled with spherical granules of 
nearly uniform size, among which a few oily particles are occa- 
sionally observable*. In this state no appearance or indication of 
the tubes or appendages described by Dr. Ehrenberg is found. 
On the 16th of July, in repeating my examination of Asclepias 
purpurascenst, I observed in several flowers one or more pollen 
masses removed from their usual place, namely the cell of the 
anthera, and no longer fixed by the descending arm to the gland 
of the stigma, but immersed in one of the fissures formed by the 
projecting ale of the anthera:, and in most cases separated from 
the gland, a small portion of the arm or process, generally that 
only below its flexure, remaining attached to the mass]. 
In the cases now described, the mass, which in general is 
entirely concealed by the alz, was so placed in the fissure, that 
its inner or more convex edge was in contact with the outer 
wall of the tube formed by the united filaments, and the gibbous 
part of the edge closely pressed to that point where this tube is 
joined to the base of the corresponding angle of the stigma§. 
These masses, at the point of contact, in most cases adhered 
firmly to the tube or base of the stigma, and on being sepa- 
rated, a white cord or fasciculus of extremely slender threads or 
tubes, issuing from the gibbous part of the edge, which had then 
regularly burst, came into view. 
On laying open the pollen mass,— which in this state was 
easily done, by first dilating the aperture that gave issue to the 
cord,—each of the tubes composing it was found to proceed 
from a grain of pollen. "These grains retained nearly their 
original form, but were become more transparent, and had 
generally lost a great portion of their granules; and these 
* Tab. 34. fig. 6; and Tab. 56. fig. 3, & 13. t Tab. 34. 
t Tab. 35. fig. 9,3, 4, & 7. À S Tab. 34. fig. 7. 
granules 
