-FLOWER OF BUTTERCUP 67 



F. Cut away all the stamens and note the two portions of the pistil, — 

 the ovule case, or ovary, below, and above three roughened, scroll-like 

 lobes of the stigma. Make a sketch of these parts about twice natural 

 size, and label them x 2. Touch a small camel's-hair brush to one of 

 the anthers and then transfer the pollen thus removed to the stigma. 

 This operation is merely an imitation of the work done by insects which 

 visit the flowers out of doors. Does the pollen cling readily to the 

 rough stigmatic surface ? Examine this adhering pollen under l.p. and 

 sketch a few grains of it, together with the bit of the stigma to which 

 it clings. Make a cross section of the ovary about midway of its 

 length, and sketch the section as seen through the lens. Label the 

 three chambers shown locules, and the white, egg-shaped objects within 

 ovules.''- 



Make a longitudinal section of another ovary, taking pains to secure 

 a good view of the ovules, and sketch as seen through the lens. 



G. Making use of the information already gained and the cross section of 

 the ovary as sketched, construct a diagram of a cross section of the 

 entire flower, showing the contents of the ovary. 



H. Split a flower lengthwise and construct a longitudinal section of the 

 entire flower. 



46. The flower of the buttercup.* * 



A. Sketch the mature flower as seen in a side view, looking a 

 little down into it. Label the pale greenish-yellow, hairy 

 outermost parts, sepals; the larger, bright yellow parts above 

 and within these, petals; and the yellow-knobbed organs which 

 occupy a good deal of the interior of the flower, stamens. 



B. 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. In an opening 

 flower observe the arrangement 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. 



C. 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 



1 The section will be more satisfactory if made from an older flower, grown out 

 of doors, from which the perianth has fallen. In this case label the contained 

 objects developing seeds. 



