n8 LABORATORY PRACTICE CHAP, xxvm 



and using a pin or needle, gently pry off the outer parts. 

 Notice : 



1. That the splitting is longitudinal. 



2. That the splitting is directly along the line of the par- 



titions. 



3. That the three partitions {septa} are left standing (by 



the complete falling away of the valves) . 



4. Make a diagram to show this method of dehiscence and 



contrast it with each of the methods just studied. 



VII. Circumscissile Dehiscence. Take plants of the 

 Common Pimpernel (Anagallis), the Portulaca of the gar- 

 dens, or the Purslane, which have ripe, dry capsules and 

 examine the method of splitting. 



1. The splitting is horizontal (at the equator, so to speak, 



of the capsule) . 



2. The upper part falls off, leaving 



3. The lower portion as a sort of cup still holding most of 



the seeds. 



4. Make sketches to show this method of dehiscence. 



VIII. Dehiscence by Pores. Examine dry capsules of 

 some Poppy and notice : 



1. The general shape. 



2. The swollen portion. 



3. The terminal discoid portion with scalloped edges (the 



remains of the stigmatic portion) . 



4. The row of small holes or pores at the top of the swollen 



portion and just under the edge of the disk. 



5. Make sketches. 



6. How do the pores arise ? (For determining this, examine, 



if possible, ripe capsules just forming pores.) 



