TISSUE CULTURE 



75 



what might have been expected of any product of blood mechan- 

 ically separated — that plasma is nutrient in itself though not 

 sufficient for very active growth. 



Fig. 59. — Part of living culture of fibroblasts (dark-field). 



The manner of growth of tissues in culture is strikingly differ- 

 ent from that in the body. After a short recovery period of 

 several hours, cells in culture begin to wander out from the 

 explant (Figs. 58, 59). It is interesting that cells which in the 

 animal body cling together to form tissues should in culture 

 separate and wander away from each other, maintaining only a 



2^®' 



Fig. 60. — Fibroblasts in culture showing intercellular connections (stained 



preparation). 



slight contact, just as if they were independent organisms, 

 which indeed in a sense they do become. The cells crawl by a 

 process comparable to amoeboid movement. At first, there is 

 merely a migration of cells. Later, multiplication by cell 



