264 The Structure of Protoplasm 



whether of tissue or Protista, pulsate rhythmically. Dr. Warren H. 

 Lewis-'' has observed the pulsation of a single cell from chick heart 

 muscle in culture. The pulsation of a heart is the expression of the 

 many pulsations of its cells which may not be in perfect synchronism 

 with each other, the heart rhythm being merely the resultant. 



Rhythmic movements are common in lower organisms. Kamiya-^ 

 gives an interesting case of it in Euglena. When this Protozoan is 

 treated with certain reagents, notably acids, it undergoes rhythmic 

 peristaltic movements. The pulsation is induced, but the capacity 

 to undergo contractile motions and the rhymicity are innate qualities. 



All nature is rhythmic. In animate nature the visible instances 

 of it are but outward signs of the basic rhythm in protoplasm. The 

 rhythmic contractility of slime mold protoplasm is then but one 

 instance of a very wide-spread phenomenon. In my belief, all proto- 

 plasm is capable of rhythmic contraction, but ordinarily exhibits it 

 only in those tissues where it is functional. 



Some modern workers are inclined to strip protoplasm of the 

 properties of multicellular organisms, forgetting that the attributes 

 of higher forms of life exist because they are properties of proto- 

 plasm. The protoplasm of primitive organisms is not less intricate, 

 less responsive, nor less organized, than that of higher forms of life. 

 It is fallacious to hold that primitive protoplasm is devoid of nervous 

 response because it lacks a nervous system. Protoplasm is itself a 

 nervous system; the nerves of higher organisms are but protoplasm. 

 The properties of tissues are the properties of the protoplasm of 

 which they are made. The rhythmic pulsations of contractile tissues 

 in higher organisms are but grosser manifestations of the innate 

 rhythmic contractility of protoplasm wherever found. 



ACKNOWLEDGMENT 



I wish to express my gratitude to Mr. William Donner and his 

 daughter, Mrs. Curtin Winsor, and to the National Research Council, 

 for their kindness in supplying funds which have made much of 

 this work possible. 



" Carnegie Inst. Pub. 363. 1926. 



-' Ber. Deut. Bot. Ges., 57, 231. 1939. 



