36 



S. SAGUCHI 



of them return, I think, after a relatively long duration, to the 

 acinus tissue through the stage of the c cell; this seems particu- 

 larly to be the case in the peripheral part of the pancreas, where 

 large islets usually are not found. Some of them, however, es- 

 pecially those which are situated in the center of the pancreas, 



y^y 



j-^-z^-f-^J 



c a 



Figs, a, b, c, d Schematic figures representing the development of islet cells 

 and the change of their arrangement for the formation of the typical islet. Islet 

 cells are shaded; 6c, blood-capillary. 



may enlarge at the expense of the whole acinus, even of the sev- 

 eral neighboring acini. At the beginning of this transformation 

 the initial islet cells maintain the same arrangement as is seen 

 in an acinus; at one end, they are in contact with the basal 

 membrane; at the other, with the cells of the opposite side so 

 that the contact line is in continuity with that of the neighboring 



