Be MATHILDE M. LANGE 
number of nuclei is due to amitotic or direct division. This 
opinion was confirmed by the discovery of several nuclei in 
different stages of amitotic division (fig. 26b). Lang (’09, 710) 
found that the epithelium of the Turbellarians also regenerates 
by means of Amitosis. 'Techow, however, claims that the 
increase in epithelial cells of the Gastropoda is due to both 
mitotic and amitotic division. 
At the time when this lively nuclear division of the epithelium 
begins, the latter is already provided with a well-developed 
basal membrane. It is difficult to say where this membrane 
has its origin. It is possible that the subjacent tissue takes an 
active part in its formation. The presence of a basal membrane 
probably prevents any epithelial cells from migrating into the 
subjacent tissue. At any rate, I could not find any such cases 
of migration. In this point the epithelium of the Cephalopoda 
differs greatly from the epithelium of the Gastropoda. Accord- 
ing to Techow, the latter contributes cells to the subjacent 
tissue, this being made possible by the tardy appearance of the 
basal membrane (it took eight days before it was formed). 
b. The muscles. Soon after operation disintegration sets in 
in those muscles immediately adjacent to the wound. This 
is due to a degeneration of muscular tissue, which comes to pass 
in the following manner. The sarcoplasm breaks down, the 
spiral fibers seem to expand or grow thicker, thereby filling the 
gaps left by the decaying sarcoplasm, and crowding out the 
granulated plasm of the core (fig. 27). In spite of this degener- 
ation, the muscle fibers still stain deeply when eosin is employed. 
Later on in the course of further degeneration the colorability 
decreases, the axial tube disappears, and the muscle fiber loses 
its cylindrical shape. In the end all that is left of the muscle 
fiber is a clotty mass, which stains very slightly. 
The nuclei of the muscle fibers do not all degenerate in the 
same way. In some the disintegration becomes noticeable in 
the chromatin, the latter massing together in little lumps, but 
the exterior form of the nucleus is not changed during this process, 
neither were there any visible signs of shrinkage. In other nuclei 
the shrinkage and the concentration of the chromatin seem to 
