42 ZOOLOGY DIEECTIONS 



III. Structures and Functions. 1. Cilia are delicate 

 protoplasmic projections from the bodies of ciliates. Their de- 

 tection requires a very careful adjustment of the light through 

 the microscope. Are they evenly distributed? Note the arrange- 

 ment of the individual cilia as far as possible. Of uniform size? 

 Do all move? What functions do the cilia perform? Compare 

 Amoeba and Paramecium with reference to locomotion. Notes 

 required. 



2. The body of a Paramecium consists of three distinct 

 parts; (a) a thin, non-living, external covering, or cell wall, the 

 pellicle, (b) a thicker, fixed layer, the ectoplasm, in which the 

 trichocysts are embedded, and (c) the more fluid, granular, in- 

 ner mass, the endoplasm. 



3. To demonstrate the trichocysts get from the preparation 

 table a drop of culture to which red ink has been added. Run 

 a drop of blue ink under the coverglass. This kills the animals 

 upon contact, but in so doing the trichocysts are shot out from 

 the body. Describe the effect the instant the ink reaches an ani- 

 mal. Draw (60 mm. long). Thoroughly wash off your slide 

 and coverglass and get a fresh preparation. Use high power on 

 living specimens and look for unexploded trichocysts in the 

 ectoplasm. Notes required. 



4. To demonstrate the pellicle run a little fifteen percent, 

 alcohol under the coverglass. Notice how the pellicle becomes 

 separated from the ectoplasm. Does the pellicle swell away from 

 the ectoplasm or does the ectoplasm shrink away from the 

 pellicle ? Focus carefully on the surface of the loosened pellicle 

 using the high power. Do you find any cilia? What are the 

 markings that occur in definite arrangements on the surface? 

 Draw (60 mm. long). Notes required. 



5. To observe the endoplasm and its movements get a fresh 

 preparation and before applying the coverglass add a little car- 

 mine suspension to the water containing the Paramecia. The 

 carmine is added here for use in a later part of the work. Car- 

 mine particles, while of no food value, are taken into the body 



