736 Mr. Brown o/j 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. 



30. A Pollen mass which has 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 



