314 LEO LOEB. 



these conditions that the protoplasm of the epithelium is in very 

 close connection with the solid body, for instance the coag- 

 ulum forming a scab, and if one raises the scab from the wound 

 parts of the epithelium may remain in contact with it and are 

 raised with it. It is not unlikely that similar changes in the con- 

 sistency of the protoplasm of the epithelial cells take place dur- 

 ing regeneration, as take place in the blood cells after they have 

 left the body, and the adhesion may in both cases have to be ex- 

 plained by a change in the consistency of the protoplasm which 

 makes the cell or part of it sticky. 



(f) We have been able to show that under the influence of trac- 

 tion the protoplasm of the cells assumes a fibrillar structure and that 

 these fibrils frequently are continuous through a number of cells. 

 Similar phenomena can be observed in many other cells. Epithe- 

 lial fibrils, for instance, are not limited to one cell and especially 

 under the influence of traction exerted during the regenerative 

 process, the fibrils passing through more than one cell are drawn 

 in the direction of the traction exerted and indicate therefore the 

 movements of the epithelium. In a similar way we find fibrils 

 passing through many cells, for instance in the heart muscle, in 

 the developing white fibrous tissue and neuroglia and probably 

 also in the peripheral nerves and in ganglia cells. The same 

 mechanical factor bringing about fibrillation which can be ob- 

 served experimentally in the protoplasm of blood cells, may be of 

 importance also in these cases. The main factor is of course the 

 specific structure of the different cells determining the specific 

 structure of these fibrils. 



(d) The blood corpuscles which in the body under normal con- 

 ditions do not change their oval form, produce outside the body 

 an agglomeration of cells which may be compared to a tissue. 

 Under certain conditions, e. g. t in gelatine or in adrenalin, or even 

 in distilled water, many cells form through agglutination an 

 epithelial-like tissue ; under ordinary conditions^however the cells 

 soon form intercellular substances and the appearance of connec- 

 tive tissue is produced. The network of spread-out cells closely 

 resembles the reticular tissue. The exoplasm of the spread-out 

 cells under the influence of slight mechanical agitation, takes on a 

 fibrillar character. If we make sections through a coagulum in 



