CHAPTER I 



THE STRUCTURE AND FUNCTION 

 OF PROTOPLASM 



1. The Structure of Protoplasm. 



Life phenomena are always associated with the protoplasm; indeed, 

 where there is no protoplasm there is no life. The protoplasm is the 

 principal unit of life. As discussed in the former Part the protoplasm 

 is likewise indispensable for virus multiplication. Accordingly, in order 

 to solve the riddle of life as well as to study the nature of viruses, 

 detailed knowledges regarding the structure of protoplasm are of the 

 utmost importance. 



Bensley (1) proposed the opinion that the basic constituents of pro- 

 toplasm are of a fibrous structure, and at present this view is generally 

 held by the majority of workers. Thus, the predominant opinion held 

 by authors in this field seems essentially as follows : The protoplasm 

 is composed of parallel alignment of fibrillar elements made of bundles 

 of thread-like molecules, and the parallel fibres are joined by lateral 

 bonds. Wyckoff has actually observed such fibrillar structures in proto- 

 plasm by electron micrographs, and suggested that fibrillar macromole- 

 cules may be the essential components of protoplasm (2). 



The writer has reached a similar conclusion as to the protoplasm 

 structure through detailed studies on the nature of viruses and on vari- 

 ous fundamental phenomena of life as will be descrided later. So far 

 as our studies have reached, minute particles produced by the disinte- 

 gration of protoplasm are composed of proteins and lipids without 

 reference to the association or non-association of virus activity ; the 

 proteins are demonstrated to have the characters of euglobulin. In the 

 writer's opinion, in the protoplasm the molecules of these proteins are 

 made into parallel fibres in their stretched thread-like form with lipids 

 interposed among them. 



It is an established fact that the protoplasm mainly consists of 

 proteins and lipids, which the latter usually constitute about one third 

 of the total cell mass. The lipid contents of mitochondria and micro- 

 somes, both of which are the important granular elements of proto- 

 plasm, have been reported to be about 24 and 40 per cent, respectively. 

 It has been found that the lipids in these cell inclusions occur in a 

 firm chemical association with the rest of the structure, since they 



