251 



lime as two days develoj) a cullurc which can be subcul- 

 tured. This I have done in the following way. II is often 

 observed, that single sarcoma cells migrate relatively long 

 distances from the mother fragmenl. lender the microscope 

 it can be seen, how such cells have migrated far out in the 

 plasma and it is very easy lo cut out thai paiM of the 

 plasma, containing that single cell. The plasma is then 

 brought in contact with a fresh piece of muscle in another 



Fig. 59. 

 Represents a section through a culture of the Rous sarcome after a couple of 

 month's cultivation. An infiltration of the muscle fragment can be seen. 



culture and it will be seen that the cells multiph' xevy 

 rapidly and grow into the muscle. This phenomenon will 

 be discussed in the next chapter. It can be seen here, that 

 it is rather simple to get pure cultures of the sarcoma cells 

 from one single individual. 



The histological examination of the cultures shows, that 

 the muscular tissue added to the sarcomatous tissue is com- 

 pletely invaded by the sarcoma cells in the way typical for 

 this tumoi in vivo. 



