213 



II is ol" course not in place here lo go into llie lilcraUire 

 ol" Ihe origin of the connective tissue til)res. hul only lo 

 refer lo some of the most imporlanl {)apers dealing with 

 Ihe problem from the point of view of tissue explantation. 



One would think, that the modern technique of cul- 

 tivating tissue cells in vitro, would he just the method for 

 the solution of the problem. It is to-day still an open 

 question, whether the fibrilhr are intra- or extracellular 

 products. 



Baits ell '^) has shown in his beautiful work, that it 

 is the fibrin network in the plasma clot which is trans- 

 formed into fibrillse under the influence of various me- 

 chanical factors. The main conclusion of Baitsell is that 

 this transformation of the fibrin-network into connective 

 tissue fibres, can take place without the presence of any 

 living or dead tissue cells. 



Harrison 251) has shown that it is absolutely n e- 

 c c s s a r 5' for the tissue cells to have a frame work or 

 supporting apparatus for the growth and movements of 

 the cells. This has already been claimed by L e o Loeb^so) 

 long ago, w^hen he termed the phenomenon stereotro- 

 pismus. Any one who has worked a little with tissue 

 explants will soon have realized that tissue cells die very 

 rapidly when placed in a liquid medium. 



Baitsell "') shows that frequently a definite reaction 

 occurs when a piece of tissue is placed in the plasma. 

 Shortly after the tissue is placed therein, fibrilhe, resembling 

 the connective tissue fibrilliie, are formed, which to begin 

 with are (luite small. By and by the fibres increase in size 

 and number, and branch in all directions. The fibi*es arc 

 most solid near the tissue and from here thej^ branch out 

 into the plasma in all possible directions. Certain tissues 

 give rise to fibrillse much more quickh^ than others; spleen 

 tissue develops fibrillse very rapidly. These experiments 

 seem to prove that the formation of the fibrillse does 

 not take place as an outgrow-th from the tissue itself, but 



