I. MATRIX FOR THE GENERATION OF THE PRIMARY ORGANISMS 227 



Thus, they can accomplish both growth and multiplication, though 

 the fission appears not to occur spontaneously, proper environmental 

 changes, such as those of temperature, or some mechanical effects 

 appearing to be necessary for it. 



From what has been described above, it will be evident that the 

 mass is capable of exhibiting all the properties believed to be essential 

 for living organisms, and therefore it may be said that a living orga- 

 nism is produced in vitro. 



It should be a remarkable fact that such artificial cells can also 

 be prepared from Merck's ricin preparation, in which no virus-like 

 particles are contained. Therefore, it seems improper to regard the 

 formation of the artificial cell as merely an example of reversible 

 decomposition of protoplasm. The Merck's ricin preparation with 

 which the writer carried out the experiment was composed of water 

 soluble protein containing entirely no virus-like particles, but when 

 its water solution was added with ethanol of 1/3 of its volume and 

 left in an ice box for several days after the pH had been adjusted to 

 5.5 by adding acetic acid, the protein would precipitate together with 

 lipids contained in the preparation in forming virus-like particles. 

 These particles after isolated by centrifugation were suspended in 

 water of pH 5.5 and left at the laboratory temperature, thereby the 

 particles were fused into protoplasm-like masses. 



This fact indicates that the globulin-like protein exhibits the pro- 

 perty to polymerize with lipids to form virus-like particles, which 

 in turn can fuse into larger protoplasm-like masses. As stated in 

 Part II, elementary bodies of protoplasm are considered to be a parallel 

 array of thread-like protein molecules among which lipids are inserted, 

 and the protoplasm is assumed to be composed of such elementary 

 bodies associating mutually also in parallel alignment. The virus-like 

 particles prepared from ricin are comparable to the elementary bodies ; 

 the particles can combine with one another in a regular alignment to 

 form larger masses which may in turn be comparable to protoplasm. 

 The association among the particles in the mass, however, is not 

 sufficiently strong to make the mass remain always in the same homo- 

 geneous state, so that upon the addition of a certain stimulus, the mass, 

 like the protoplasm, will be decomposed into the particles, stable poly- 

 merization units of globulin-like proteins. 



It should be considered, therefore, that globulin-like proteins possess 

 in themselves the property to form protoplasm-like masses. Namely, 

 globulin-like proteins possess the property to polymerize to virus-like 

 particles by arranging themselves in parallel alignment in their stre- 

 tched polypeptide chains in inserting lipids among them; these particles 

 tend to combine further with each other in parallel arrangement to 



