196 FOUNDATIONS OF BOTANY 



the larger bright yellow parts above and within these petals, and 

 the yellow-knobbed parts which occupy a good deal of the interior 

 of the flower stamens. 



Note the difference in the position of the sepals of a newly 

 opened flower and that of the sepals of a flower which has opened as 

 widely as possible. Note the way in which the petals are arranged 

 in relation to the sepals. Jn an opening flower observe the arrange- 

 ment of the edges of the petals, how many entirely outside the 

 others, how many entirely inside, how many with one edge in and 

 the other out. 



Cut off a sepal and a petal, each close to its attachment to the 

 flower ; place both, face down, on a sheet of paper, and sketch about 

 twice the natural size and label it x 2. Describe the difference in 

 appearance between the outer and the inner surface of the sepal and 

 of the petal. Note the little scale at the base of the petal, inside. 



Strip off all the parts from a flower which has lost its petals, 

 until nothing is left but a slender conical object a little more than 

 an eighth of an inch in length. This is the receptacle or summit of 

 the peduncle. 



In a fully opened flower, note the numerous yellow-tipped stamens, 

 each consisting of a short stalk, the filament, and an enlarged yellow 

 knob at the end, the anther. Note the division of the anther into 

 two portions, which appear from the outside as parallel ridges, but 

 which are really closed tubes, the anther-cells. 



Observe in the interior of the flower the somewhat globular mass 

 (in a young flower almost covered by the stamens). This is a group 

 of pistils. Study one of these groups in a flower from which the 

 stamens have mostly fallen off, and make an enlarged sketch of the 

 head of pistils. Remove some of the pistils from a mature head, 

 and sketch a single one as seen with the magnifying glass. Label 

 the little knob or beak at the upper end of the pistil stigma, and the 

 main body of the pistil the ovary. Make a section of one of the 

 pistils, parallel to the flattened surfaces, like that shown in Fig. 150, 

 and note the partially matured seed within. 



