PHYSIOLOGICAL PROCESSES IN PLANTS 113 



Observations. 1. Find tiny bodies on stalks (spore cases or spo- 

 rangia). (Use low power of microscope.) 



2. Some of these sporangia may be broken open by pressing on the 

 cover glass. Can you 

 find small spherical bodies 

 (spores') therein ? 



Conclusions. 1. 

 What method of repro- 

 duction is here repre- 

 sented, the asexual (veg- 

 etative), or the sexual? 

 Explain. 



2. Do you judge these 

 spores were formed by 

 cell union or cell divi- 

 sion f Explain. 



Observations. 1. 

 (Dem.) Search deep in FlG " 32. -Conjugation of mold, a, 6, c, d, suc- 

 cessive stages in the formation of the zygo- 

 spore, zs. 



zs 



the mold for large dark 

 bodies (zygospores) , 

 formed where the tubes from mold filaments meet. 



2. Study Figure 32. What resemblance shown to reproduction in 

 Spirogyra ? 



Conclusions. 1. What method of reproduction is here illustrated ? 



2. What must evidently be the purpose of the zygospores here ? 

 (See Spirogyra.) 



c. A Moss 



Observations. 1. Examine specimens of any kind of moss prefera- 

 bly pigeon wheat moss. Do you find root, stem, and leaves ? 



2. Is there chlorophyll present ? 



Conclusion. Is this plant able to manufacture its own food (independ- 

 ent) or does it use food already made (dependent) ? 



Observations. 1. Find tiny capsules at the tips of slender stalks. 

 How are they covered ? 



2. Crush one on a slide and examine it with low power. What do 

 the capsules contain ? 



Conclusion. What method of reproduction is here evidently shown ? 

 Note. The capsule is on a stalk, which is rooted in the tip of the leafy 

 plant. It is in reality a separate plant, but with no leaves of its own. 

 Where, then, must it get its food ? Is it a parasite ? 



Observation. Refer to charts, models, or slides. What results from 

 the sprouting of a moss spore? Note. The asexual spore grows 

 SHARPE'S LAB. MAN. 8 



