136 Mr. Brown on the Organs and Mode of 
Fig. 4. A longitudinal section of one half of the Stigma and the 
corresponding. style transversely cut near the base, 
showing more distinctly the position of the pollen 
mass with the protrusion and course of the tubes. 
5. The. Style of fig. 4. laid open lengthways, exhibiting 
within its cavity and beyond it the pollen tubes reach- 
ing the apex of the placenta, a reflected portion of 
which, with three of its ovula, is also shown. 
6. An impregnated Pistillum, of which the style is laid 
open longitudinally, and the placenta, thickly covered 
with ovula, exposed, to show the descent and course 
of the pollen tubes. 
7. A Pollen mass, to the apex of which the base of the arm 
adheres, with pollen tubes protruding from the point 
of dehiscence :—more highly magnified. 
8. A transverse section of a Pollen mass, showing an ar- 
rangement of the cells somewhat different from that 
of A. purpurascens, there being here a middle irre- 
gular series, the cells of which in some cases appear 
to separate and cover the grains after the production 
of the tubes. 
9. 'Two grains of pollen with portions of their tubes, very 
highly magnified, the grain to the left having its outer 
. covering or membrane, which is removed from the 
grain to the right, and shown separately further to 
the left. 
10. A Pollen mass which ns burst and protruded its tubes, 
exhibited as entering the cavity of the style, which 
is laid open to show the commencement of their de- 
scent. 
11. Two Pollen masses (with their arms and gland,) which 
have burst and protruded their tubes while still in- 
closed 
