I.] 



FLOWER- LEA VES. 



to the stamen,* so we must carefully examine them under a 

 microscope. Fig. 5 shows them highly magnified. We find 

 that they are distinct globular cells, with minutely granular 

 contents. The fine powder is the pollen^ and each of its 

 globular cells is z. polleii-grain. 



Remove all the stamens, noting that they are, like the 

 leaves of the corolla and calyx, inserted directly upon the 

 floral receptacle, and immediately underneath the central 

 organ of the flower. Such being the case, they are techni- 

 cally described as hypogynoics. 



8. You have now left in the centre of the flower, slightly 

 raised upon a thickened cushion or ring, called the disk, 

 the germ of the future fruit. If the lower part be cut across, 

 you find it to be divided into a number of small cavities, 

 radiating from the centre, each cavity containing the minute 

 rudiments of future seeds. If you take the pains to count 

 the number of cavities (you will probably 

 find them about ten ; they vary from seven 

 to fifteen), you will ascertain the number of 

 leaves which are united to form this central 

 organ of the flower, which we shall speak of 

 as the pistil. But how am I to convince you 

 that the pistil is really composed of united 

 leaves ? It would not be easy to make this 

 clear without reference to some other flower 

 in which the pistil is of much simpler struc- 

 ture than in the orange-flower, so \:hat I must 

 ask you to lay it aside for a short interval 

 while we examine the pistil of some pea- 

 flower. Take the flower of the common Field 

 or Garden-pea itself, or of a Scarlet-runner 

 or Haricot, of Lablab, Chick-pea, Sunn-hemp, 

 or Indigo. Any of them will serve, and one or another 



F:c;. 6. A longi- 

 f.idinai section 

 of the Pistil of 

 Orange, show- 

 ing the interior 

 of the ovary, 

 with ovules, 

 and style thick- 

 ened upwards 

 into the stigma. 



