34 Nature of the Formative Stimulus 
almost without exception tangentially disposed, that is 
perpendicularly to the radius of the wound, and the 
protoplasmic filaments within the cells ran parallel with 
their axes. In correspondence with this interior cellular 
arrangement, the intercellular bridges into which the 
protoplasmic filaments were prolonged ran for the most 
part from tip to tip of the fusiform cells and parallel to 
their long axes. 
Outside this annular zone, (from 2 to 2.5 mm. outside 
the inner epithelial border,) were found large cells in 
which the filaments and protoplasmic bridges were 
remarkably well developed and there also were found 
mitoses. It is therefore in this area that new cells are 
formed. In this zone the intercellular spaces are larger 
than elsewhere, from 3 to 6 » wide, whereas 1.8 to 3 2 
represents the mean normal figure for the epidermis. 
This considerable enlargement of the intercellular spaces 
makes it possible for these cells to store up the larger 
quantity of nutritive fluid which is necessary for their 
more intense activity.” 
If one admits for the moment that the intercellular 
bridges are traversed by a continuous nervous flux this 
result will find in this hypothesis its immediate 
explanation. 
In order to make our idea clearer let us consider the 
concrete case of a.stream of flowing water, which at a 
certain point divides up into several branches. Sooner 
or later a dynamic equilibrium is established and the 
quantity of water flowing during each unit of time into 
each of the branches respectively will be constant. If 
“Siegfried Garten: Die Interzellularbriicken der Epithelien und 
ihre Funktion. Archiv fir Anatomie und Physiologie. Leipzig. 
1895. P. 407—4009. 
