PARAMECIUM, SPIROSTOMUM 27 



8. Place a drop of culture containing a number of animals 

 on a slide and put a drop of Waterman's fountain pen fluid 

 on a coverglass. Invert the coverglass and place it with its 

 hanging drop of ink on the slide. What happens to the 



trichocysts? 



Make a drawing showing the structures revealed by the 



treatment in these two cases. 



9. Observe, if possible, animals dividing and conjugating. 



10. Study demonstrations of permanently stained speci- 

 mens for finer structure. 



Calkins and Cull: Conjugation of P. caudatum. Arch. f. Protistenk., 



10, 1907. 

 Jennings: Effect of Conjugation in Paramecium. Jour. Exp. Zool., 14, 



1913. 

 Metalinkow : Contributions a l'etude de la digestion. Arch. d. Zool. 



Exp. et Gen., 9, 1912. 

 Wenrich: Eight Well Defined Species of Paramecium. Trans. Amer. 



Micr. Soc, 47, 1928. 

 Woodruff: Paramecium aurelia and Paramecium caudatum. Jour. 



Morph., 22, 1911. 

 Woodruff and Erdmann: A Normal, Periodic Reorganization Process 



(Endomixis) Without Cell Fusion in Paramecium. Jour. Exp. 



Zool., 17, 1914. 

 Woodruff: The Structure, Life History, and Intrageneric Relationships 



of Paramecium Calkinsi, sp. nov. Biol. Bull., voi. 41, 1921. 



SPIROSTOMUM 



1. Compare Spirostomum with Paramecium, noting the 

 method of locomotion, the shape of the body, the ciliation, 

 the buccal groove and mouth, and the large excretory reser- 

 voir, filling the posterior end of the body and in communica- 

 tion with the anterior end of the body by a canal. 



2. Note the highly refractive, long, bandlike (monili- 

 form) macronucleus. In a less common species of Spiro- 

 stomum the macronucleus is similar to that of Paramecium. 



3. Note the sudden contractions of the body. When these 

 occur spiral lines appear on the surface. Can you distinguish 

 these lines when the animal is extended? These are primi- 

 tive structures {myonemes) functioning as muscles. 



