ASPECTS OF THE KINETOSO:\IE 29 



1, we are prepared to admit A. L. Cohen's conclusion (1942) 

 regarding the organization of protoplasm: ''We must realize 

 that a surface on the microscale is not a mathematical plane, 

 but a layer of more or less oriented molecules or atoms 

 with fields of forces which in some instances may be quite 

 powerful." 



Now it is obvious that, in Gymnodinioides, there are vari- 

 ations of properties from the anterior to the posterior pole, 

 and from one meridian to another. The notion of morpho- 

 genetic field takes its full value and expresses itself in a 

 spectacular way. Sinnott's (1939) definition of the mor- 

 phogenetic field is here adequate because it is very general : 

 "A field is the sum of the reactions which an entire proto- 

 plasmic system makes with its external and internal en- 

 vironment, reactions which are determined by the specific 

 physiological activities of the living material of which the 

 organism is composed." 



It is obvious that the life history of kinetosomes is de- 

 termined by specific changes of the environment. And this 

 is true not only if we consider the maintenance and mul- 

 tiplication of kinetosomes, but also their specific metabo- 

 lism. 



The main and most characteristic product of the metabo- 

 lism of kinetosomes is the cilium. Generally, all the kineto- 

 somes of a ciliate are cilia-bearing kinetosomes. But many 

 ciliates, either holotrichous ciliates like the Sphenophryidae, 

 Sphenophrya, Pelecyophrya, or Gargarius, or suctorians, 

 are devoid of cilia. Cilia appear only in the ''embryo." 

 This question will be examined later on. All that is neces- 

 sary to know at this point is that the embryo loses its cilia, 

 but that the kinetosomes persist. It is therefore obvious 

 from these examples that the maintenance of a cilium, like 

 its synthesis by the kinetosome, is controlled by the en- 

 vironment. 



In Gyvinodinioides, the kinetosomes of the fields a, h, c, 

 while actively dividing, are devoid of cilia. This absence 



