VAUCHERIA SESSILIS 103 



holdfasts? If so, describe them, and state their 

 use to the plant. 



6. Can you detect one or more nuclei? Any vacuole 

 or vacuoles? Any individual chromatophores or 

 chloroplasts? If so, what is their position and 

 shape? 



7. Describe the arrangement of the protoplasm within 

 the filament. 



E. Physiology: 



1. Explain whether, or not, photosynthesis and respira- 

 tion are possible with this plant. 



2. Do you find any chromatophores dividing? 



3. Do you find oil globules within the plant? Test 

 dechlorophyllized plants with iodine for starch. 



4. How are mineral matter and carbon taken into this 

 plant? Explain the need or lack of need of special 

 structures for conducting food and food elements 

 from one part of the plant to another. Are such 

 structures present? 



5. Why is the plant not crushed by the weight of the 

 water (when it grows in water), or by the cover- 

 glass? 



6. Can you detect any movement of the protoplasm? 

 Observe carefully on this point. 



7. Make careful drawings showing all features to which 

 attention has been directed under D, and E, 2. 



F. Asexual Reproduction: 



1. Carefully examine the tips of numerous filaments 

 and see if you find any of them slightly enlarged, 

 and cut off from the rest of the filament by a cross- 

 wall. Such a differentiated portion of the thallus 

 of Vaucheria is a sporangium ; its contents a spore. 



2. If you are fortunate enough to have material at a 

 suitable stage of development, you may, by care- 



