PROTOPLASMIC MOVEMENT 1 



1. Mount a few drops of water from a laboratory culture containing an 

 abundant supply of several species of free-swimming Protozoa. Examine 

 microscopically first with the low power and then with the high power. 

 Note the vigorous and rapid movement exhibited by various species 

 present, particularly those bearing cilia, such as Paramecium. Numerous 

 slower moving species bearing one or more vibrating whip-like processes 

 (flagella), such as Euglena which has one flagellum, may usually be 

 found. More difficult to find as a rule are the smaller amoeboid species 

 such as Amoeba, which progress slowly by a flowing movement of the 

 cytoplasm and a consequent formation of irregular pseudopodia. 



2. Place a small piece of the gill of a clam on a slide and with two 

 dissecting needles gently tear the piece of tissue apart in a drop of body 

 fluid. Mount and examine the preparation with high power. Note the 

 currents in the surrounding fluid caused by the rapid vibration of the 

 delicate protoplasmic processes (cilia) which are present on the outer 

 exposed surfaces of the ciliated cells of the gills. 



3. Examine a live Earthworm and note the method of locomotion. Its 

 movements are due to the actions of the muscle tissues in the body wall, 

 coordinated by the nervous system. Slightly irritate various regions of 

 the body and note the response as exhibited by the muscular movements. 



4. Note the rhythmical contraction shown by the muscular tissue in the 

 beating heart of a freshly anaesthetized Frog. Note further that the move- 

 ments still persist when the heart is entirely removed from the body and 

 placed in normal (0.7%) salt solution. 



5. Mount two or three young leaves from near the tip of a stem of the 

 common water-living plant, Elodea. Examine various regions of the 

 leaves with the high power, particularly along the mid-rib and the edges, 

 and find an area in which a flowing movement of the cytoplasm is to be 

 noted in some of the cells. This will be shown by the movements of the 

 green disc-shaped bodies (chloroplastids) as they are carried around the 

 cell, within the cell wall, by the flow of the cytoplasmic current. 



6. To demonstrate the fact that microscopic lifeless particles may also 

 exhibit spontaneous movement, mount a drop of water which contains 

 some powdered carmine in suspension and examine the preparation un- 

 der the high power. Careful observation will show that the suspended 

 particles are constantly exhibiting an oscillating movement which is 

 believed to be due to the impact of the rapidly moving molecules of the 

 liquid. This is known as Brownian movement. 



iB. pp. 13-17. 

 255 



