358 



R. R. BENSLEY 



111 formalin Zenker the canals of Holmgren's system show 

 best, though they may also be observed well in preparations fixed 

 in Orth's or Kopsch's formalin bichromate solutions. 



To make clear the structure of the acinus cell, I have made 

 drawings to illustrate these components separately, as well as 

 together. Fig. 10 shows a preparation fixed in chrome sublimate 



^JZr-tJ^'"" ■''' 



Fig. 10 Pancreatic acinus of guinea pig showing the homogeneous basophils 

 substance, in which the light spots represent unstained mitochondria. In the 

 central portions the zymogen-holding spaces. X 1555. 



and stained in toluidin blue alone. In this preparation it will 

 be seen that the inner zone of the cell is occupied by a very regu- 

 lar network, the spaces of which are those which contain the z3^mo- 

 gen granules. This is, however, not a true network, but simply 

 the optical section of the continuous cytoplasmic partitions which 

 separate the granule-holding spaces from one another. The basal 

 substance of the cell stains strongly in toluidin blue, and exhibits 

 an indistinct longitudinal striation. The reason for this stria- 



