I. MATRIX FOR THE GENERATION OF THE PRIMARY ORGANISMS 225 



globulin was most readily sedimented. 



For the isolation of protoplasm particles, including viruses, by 

 means of the isoelectric point precipitation method we used acetic acid, 

 whereas carbon dioxide has been generally used by many workers for 

 the isolation of substances related to globulin such as serum-euglobulin 

 and the stroma of red-blood cells. The fact that both serum-euglobu- 

 lin and stroma are precipitated at pH about 5.5 in the form of virus- 

 like particles and that both can be regarded as a kind of protoplasm 

 particles was already stated. The application of carbon dioxide is 

 very convenient to adjust a globulin solution to its isoelectric point 

 for the precipitation of the globulin. It may be a relic of this pre- 

 cipitating property of the primeval protoplasm in the ancient oceans 

 that still now the substances related to protoplasm proteins are readily 

 precipitable by carbon dioxide. 



2. The Properties of Artificial Cells 



As above stated, the writer has been able to prepare protoplasm- 

 like masses from certain plant materials ; especially from castor beans 

 most, demonstable, beautiful masses were obtained. The preparing 

 m.ethod was as follows : 



The emulsion of castor beans ground up in a mortar is centrifuged 

 to eliminate precipitable coarse materials together with lipids, which 

 are raised to the surface. The pH of the emulsion from which the 

 lipids and the coarse materials having thus been eliminated, is adju- 

 sted to 5.5 with acetic acid, whereby a precipitate is formed, which is 

 subsequently separated by centrifugation, and washed with distilled 

 water for several times, each time being separated from the water 

 by centrifugation. The substance thus obtained proves to be composed 

 of virus-like particles, which will fuse into protoplasm-like masses if 

 stand in a solution of the weakly acid pH for several days at the 

 laboratory temperature. It appears that peculiar conditions are neces- 

 sary for the production of such masses, for frequently the experiment 

 would fail. Presumably temperature at least is an important factor, 

 and a good result was commonly obtained if the solution was lelt at 

 a temperature near 10°C. 



At any rate, the masses may be called artificial cells or proto- 

 plasm, the properties of which are described in the following. 



As shown in Fig. 22 the masses are globular with sizes of 10 n or 

 more in diameter. Small sized particles similar to red-blood cells are 

 sometimes abundantly produced, and if their size is thus small they 

 are quite homogeneous, but in larger sized particles various granules 



