the part of the plant cell that is homologous/with the outer living 

 ^ lyiembrane in the amoeba? Determine the/osmotic pressure of a 

 lant cell by rinding a concentration of(KNOj)which just fails to 

 lasmolyse the cell in half an hour. Determine the osmotic pres- 

 ure of the red corpuscles of the frog by finding the solution of 

 NaCl which will neither cause the cells to shrink nor to swell. 

 Does all protoplasm have the same osmotic pressure? How would 

 you expect the osmotic pressure of fresh and salt water plants to 

 compare? (Bayliss, Prin. of Gen. Phys., pp. 162-165). 



E. What is the effect of the electric current on living protoplasm? 

 Use plant cells showing streaming movements, Paramecia and 

 Amoebae. Note particularly the effect on the cilia of the Para- 

 mecia. To which pole do the Paramecia move? Can you explain 

 the movements of the Paramecia in an electric current in non- 

 anthropomorphic terms? (Jennings, Behavior of the Lower 

 Organisms, Chap. V.). 



F. Study the locomotion of the Amoeba. How are pseudopodia 

 formed? Does the animal move in any one direction, or are its 

 movements at random? Touch the amoeba with a fine glass rod at 

 what may be considered for the moment the anterior edge. Where 

 does the next pseudopodium appear? Are the pseudopodia ever 

 wrinkled? (Jennings, Behavior of the Lower Organisms, Chap. I). 

 Construct a trough by fastening a coverslip on each side of a glass 

 slide with Canada balsam. Observe in this trough with the micro- 

 scope stage vertical the movements of the Amoeba in profile. 

 Notice the shape of the Amoeba as it falls freely through the water. 

 (Dellinger, Jour. Expt. Zool., 1906). 



Have you discovered in these examples of protoplasm any 

 evidences (1) of irritability, i.e., the capability of receiving im- 

 pressions from the outside world shown so markedly in our sense 

 organs; (2) of conduction, i.e., the capability of transmitting effects 

 of stimuli to parts remote from the point of stimulation shown in 

 our nerves; (3) of contractibility, as in our muscles, etc.? In other 

 words, can it be said that there are inherent in protoplasm itself 

 as a physico-chemical complex the possibilities for all the specialized 

 functions we find in living beings, such as the eye and brain of 

 man, or the swiftly moving wing of the bee? And is the explanation 

 of these characteristics of protoplasm beyond the realm of physical 

 and chemical laws? (Bayliss, Prin. of Gen. Phys., p. 3-4). 



