CAPSELLA BURSA-PASTORIS. 165 



stamens and number in each cycle. Are they alternate 

 or opposite the petals? 



4. Carpels or pistils. 



a. Parts of pistil; ovary, style, and stigma. 



b. Number of chambers or cells in the ovary, as determined 

 by a cross-section of it. 



5. Whether flowers are hypogynous, perigynous, or epigynous. 



III. THE SEED-POD. Observe: 



1. The general form. 



2. The midrib dividing it into two parts. 

 By dissecting it, observe: 



3. The seeds (ovules), their number and how they are placed 

 in the pod. 



4. By use of manuals, beginning with the analytical key, de- 

 termine the family, genus, and species of this plant. 



ANNOTATIONS. 



This plant has well-marked generic and specific char- 

 acteristics. The leaves are distinctly notched, the basal 

 ones being arranged into a rosette. This rosette persists 

 through rather unfavorable seasons, and shows interest- 

 ing adjustments in form and position to insure adequate 

 exposure to the light. The leaves on the stem are 

 younger and are small, sessile, and constantly smaller as 

 they approach the top of the plant, probably doing but 

 a small part of the plant's chlorophyll work. 



The main root is strong and serves as a storehouse 

 for surplus food, thus enabling the aerial organs to make 

 rapid growth when conditions are favorable. Secondary 

 roots arise from this primary one. 



The flowers are small, the tetradynamous character 



