THE FLOWEB. 79 



and older specimens are prepared in this way, the embryo 

 in various stages of development can be satisfactorily 

 studied. Make a series of sketches showing as many of 

 these stages as. practicable. Compare your own figures 

 "with those of Hanstein.^ Write a brief account of the 

 development of the embryo of this plant as far as you 

 have observed it. 



SPECIAL STUDIES .2 



I. Morphology of stamens. 

 II. Morphology of the pistil. 



III. Protection against unbidden guests. 



IV. Dimorphism. 



V. Mechanical devices favoring cross-fertilization. 

 VI. Changes in the ovule after fertilization. 



REVIEW AND SUMMARY.s 



In the preceding study we have found that a flower is 

 commonly made up of four distinct whorls, or circles, 

 calyx, corolla, stamens, and pistil. The parts parts of the 

 of the calyx are called sepals, those of the cor- *<"*'■ 

 oUa, petals. The stamens are spoken of collectively as the 

 androecium, and the pistil (or pistils) as the gynoecium. 

 While in most flowers all the parts are present, there are 



1 Goebel, Outlines of Glassiflcation and Special Morphology, p. 397. 



2 Gray, Structural Botanij, -pp. 215-2iO,2Ql-2QS ; Kerner, Flowers and 

 their Unbidden Cfuests ; Darwin, Different Forms of Flowers on Plants 

 of the Same Species; Strasturger, Practical Botany, pp. 311-337. 



^ It will probably be better to postpone the review until the flowers of 

 a considerable number of families have been carefully studied. After 

 this has been done the pupil may profitably devote some little time to the 

 resume and references here given. 



