THE FLOWER 



203 



many of each are there, and how do they alternate with one 

 another? Sketch the pistil and stamens as they stand on 





a 



287 



Figs. 285-288. — A flower of the cress family : 285, side view ; 286, view from 

 above ; 287, diagram of parts : p, petals ; s, sepals ; st, stamens ; pi, pistil ; d, claw 

 of petal ; +, +, position of the missing stamens ; 288, pistil and stamens, enlarged. 

 (After Gray.) 



the receptacle ; how many of the latter are there ? Notice 

 that two of the six are outside and a little below the others, 

 alternate with the petals, while the other four stand opposite 

 them, as is natural, if they were alternating with another 

 ring of stamens between themselves and the corolla. Put a 

 dot before two of the sepals in your first drawing to indicate 

 the position of the two outer stamens, and a cross before 

 the other two to show where stamens are wanting to com- 

 plete the symmetry of this set, as in Fig. 287. When parts 

 necessary to complete the plan of a flower are wanting, as 

 in this case, they are said to be obsolete, suppressed, or 

 aborted. Place dots before the petals to represent the other 

 four stamens. Sketch one of the anthers as it appears 

 under a lens, showing the arrow-shaped base, and the 

 mode of attachment to the filament. Is it such that the 

 pollen can reach the stigma without external agency ? In 

 what manner do the anthers open to discharge their pollen ? 

 Are the anthers and stigma mature at the same time? 

 Remove all the stamens from a flower and sketch the pistil, 

 showing the long, slender ovary, the very short style, and the 



