EUGLENA. VOLVOX. 9 



MASTIGOPHORA. 



EUGLENA. 



Understand its habitat and with what forms it is usually 

 associated. 



1. Observe the free-swimming movements of the organism, 

 and the eiiglenoid changes in the form of the body. 



Make drawings showing the changes in the shape of a single in^ 

 dividual. 



2. Distinguish anterior and posterior ends. Is there any 

 dorso- ventral differentiation? Note the motile organ, the fiagel- 

 lum. Where is it attached? What relation does it bear to the 

 gullet? How is it directed during locomotion of the organism. 

 Does it serve any other purpose besides locomotion? (Minchin, 

 p. 52.) 



3. The green color of Euglena is due to chlorophyl, and this 

 enables it to live in clear water, being nourished like a typical 

 green plant. (Minchin, p. 14.) 



4. Note the absence of color near the anterior and posterior 

 ends of the organism. Near the anterior end also notice the red 

 pigment spot, or stigma. What is its probable function? 



5. Stain a specimen with iodin and look for the nucleus. 

 It is somewhat obscured by the chlorophyl. 



6. Observe specimens in the resting stage. 

 Make a drawing showing all of the points observed. 



Look through the stock cultures for other forms of Masti- 

 gophora, such as Trachelomonas, Peranema, Phacus, etc. 

 It is desii^ahle to make drawings of the different forms. 



Klebs: Ueber die Organisation einiger Flagellatengruppen und ihre Be- 

 ziehungen zu Algen und Infusorien. Unt. Bot, Inst. Tubingen, 1, 1883. 



: Flagellatenstudien. Zeit. f. Wiss. ZooL, 55, 1893. 



Walton: Review of the Order Euglenoidina. Ohio State Univ., 1915. 

 Baker: Studies in the Life History of Euglena. Biol. Bull, 51, 1926. 



VOLVOX. 



Volvox globator is better for study than V. aurens. It may 

 be distinguished from the latter by the larger size of the colony, 

 the greater number of cells that compose it (about 15,000), the 



