24 THE CELL 



demonstrate a still more minute structure of protoplasm (granula 

 theory). By means of a special method of treatment, this in- 

 vestigator has succeeded in rendering minute particles visible in 

 the body of the cell ; these he calls granula. He preserves the 

 organ in a mixture of 5 per cent, solution of potassium bichromate 

 with 2 per cent, solution of perosmic acid; he then prepares thin 

 sections of the organ and stains them with acid fuchsine, 

 finally treating them with alcoholic solution of picric acid, by 

 means of which the differentiation is rendered more distinct. The 

 result of these staining reactions is to render visible a large num- 

 ber of very minute dark-red granules. Sometimes they are seen 

 to be isolated, sometimes more densely packed; sometimes they 

 are near together, sometimes further apart ; or they may be united 

 in rows to form threads. 



In consequence of these observations, Altmann has propounded a 

 very important and far-reaching hypothesis. He considers these 

 granules to be still more minute elementary organisms, of which 

 the cell itself is composed ; he calls them bioblasts, attributes to 

 them the structure of organised crystals, and looks upon them 

 as equivalent to the micro-organisms which, as individuals, 

 arrange themselves in masses to form a zooglea, or in rows to form 

 threads. "As in a zooglea the single individuals are connected 

 together by means of a gelatinous substance secreted by them- 

 selves, and at the same time are separated from one another by it, 

 so in the cell the same might occur with the granula ; in this 

 case also we must not consider that there is merely water and salt 

 solution surrounding the granula, but similarly that a more 

 gelatinous substance (intergranula substance) is present ; this is 

 sometimes liquid, and sometimes fairly viscid in consistency. The 

 great mobility, peculiar to most protoplasm, renders the former 

 probable. If this intergranula substance becomes collected with- 

 out granula at any point in the cell, a true hyaloplasm may be 

 formed, which, being free from living elements, does not really 

 deserve the name of protoplasm." 



Thus Altmann defines protoplasm as " a colony of bioblasts, the 

 individual elements of which are grouped together either in a 

 zooglea condition or in the form of threads, and which are con- 

 nected by an indifferent substance." " Hence the bioblast is the 

 much-sought-after, morphological unit of all organic substances, 

 with which all biological investigation must finally deal." How- 

 ever, the bioblast is not able to live alone, but dies with the cell 



