133 



U is a vci'y ink'rcstint> Iransfonnalioii which can l)c 

 seen It) lake pkicc here. R c n a u I ;m(l Dub r c ii i 1 ^i'»j coii- 

 chidcd thai the various conncclive (issues and also carlihi,t»o 

 originated from the lympliocyles. This seems, ai)parenlly. 

 to have some bearing on my exi)ei-iments with carlihige 

 cells in vitro. Here we are a])le to follow Ihc Iransformalion 

 under certain conditions, from a lymphocyte-like small cell 

 type to an entirely different type of cell. It was also lOuiid 

 in these experiments llnd the amorjjlious subslances are 

 not produced under tlie in viti'o condition. Another interest- 

 ing fact is, that the cartilage cells are unable to grow 

 when embedded in (he plasma clot. As soon as the tissue- 

 is brought to the surface the cells are able to migrate and 

 l)roliferate. 



The main characlerislics ot Ihe cultures of cai'lilage 

 cells are these. The initial grow I h lakes place f)nly on Ihe 

 free siu'face of the coagulated cultui'e medium. Aflei' a 

 good growth has Ijcen obtained here, the tissue is able to 

 grow" embedded in the clot. The cartilage cells form mem- 

 branes as ei)ithelial cells do. as well on the surface as 

 when embedded in the clot. Liquefaction of the cultnre 

 medium occurs to a great extent. The individual cells are 

 spindle-shaped with a rather large spherical nucleus con- 

 taining usually only one nucleolus. The cytoplasm contains 

 often big vacuoles. In stained ])reparations the cells appear 

 with a lighter stained nucleus and a darker stained cytoplasm. 



The segregation ai)paratus of Renaul when vitally 

 stained with neutral red appears to be similar to Ihal of 

 fibroblasts (Fig. 24). 



As a whole, the new growth of cartilage cells in vitro 

 is rather delicate and is often difficult to transfer to new 

 culture media. It lakes often quite some lime before the 

 growth becomes so abundant that the culture can be di- 

 vided (Fig. 25). 



The studies of this tissue are rather interesting because 

 of the definite changes which take place in vitro and can 



