144 ESSENTIALS OF BOTANY 



Cut ofi one stamen, and sketch it as seen through the magnifying 

 glass. Notice that it consists of a greenish stalk, the filament, and 

 a broader portion, the anther (Fig. 108). The latter is easily seen 

 to contain a prolongation of the green filament, nearly surrounded 

 by a yellow substance. In the bud it will be found that the anther 

 consists of two long pouches or anther-cells, which are attached by 

 their whole length to the filament and face inward (towards the 

 center of the flower). AVhen the flower is fairly open the anther- 

 cells have already split down their margins and are discharging a 

 yellow, somewhat sticky powder, the pollen. 



Examine one of the anthers with the microscope, using the two- 

 inch objective, and sketch it. 



Cut away all the stamens and sketch the pistil. It consists of a 

 stout lower portion, the ovary, which is six-ridged or angled, and 

 which bears at its summit three slender stigmas. 



In another flower, which has begun to wither (and in which the 

 ovary is larger than in a newly opened flower), cut the ovary across 

 about the middle, and try to make out with the magnifying glass 

 the number of chambers or cells which it contains. Examine the 

 cross-section with the two-inch objective, sketch it, and note partic- 

 ularly the appearance and mode of attachment of the undeveloped 

 seeds or ovules with which it is filled. Wake a vertical section of 

 another rather mature ovary, and examine this in the same way. 



Using a fresh flower, construct a diagram to show the relation of the 

 parts on an imaginary cross-section, as illustrated in Fig. IIG.-' Con- 

 struct a diagram of a longitudinal section of the flower, on the general 

 plan of those in Fig. 114, but showing the contents of the ovary. 



Make a tabular list of the parts of the flower, beginning with 

 the sepals, giving the order of parts and number in each set. 



173. The Flower of the Tulip. ^ — Make a diagram of a side view 

 of the well-opened flower as it appears when standing in sunlight. 



1 It is important to notice that such a diagram is not a picture of tlie section 

 actually produced by cutting thvougli tlie flower crosswise at any one level, 

 but that it is ratlier a projection of the sections through the most typical part 

 of each of the floral organs. 



2 TuUpa Gesni'riana. As the flowers are rather expensive and their parts 

 are large and firm, it is not absolutely necessary to give a flower to each pupil, 

 but some may be kept entire for sketching and others dissected by the class. 

 AU the flowers must be single. 



