RESEARCH ON THE DIGESTIVE SYSTEM OF THE SCHIZOPODA 47 



stomach; the cell membranes and a few fibrils are left remaining attached 

 to the inner membrane. 



The superficial portion of thèse bodies is formed of a plateau some- 

 what thick; this is covered by a cuticle with vertical striations and very 

 thin. The cuticle is of a chitinous nature, fig. 45, 50. 



The cuticle seems to be of the same nature as that which covers the 

 ordinary secreting cells of the digestive gland, fig. 49. 



The striated plateau, below the cuticle, is composed of protoplasmic 

 fibrils of the superior portions of the cells. 



This différenciation of the protoplasm takes place before the first 

 vacuoles are formed. 



The plateau takes the Congo red stain very well. 



It is to this plateau that the cell membranes are attached when the 

 protoplasm is transformed. 



Beneath the plateau, surrounding the terminal portions of the cell 

 membranes numerous fibrils areseen, fig. 45, 50. 



It wUl be seen in our drawings that the nuclei lie close to the convex 

 surface of the protoplasm which marks the limit of the vacuoles. 



The nuclei become gradually smaller as the vacuoles descend in the 

 cells. When the vacuolisation has been completed there is found a row of 

 nuclei very much reduced in size, lying against the external membrane of 

 the tube, fig. 46. There remains, however, in ail the cells a very small 

 amount of protoplasm at the base attached to the débris of nuclei and to 

 the base of the membranes. The contents of the cells are cast into the lumen 

 of the tube b}^ a splitting of the plateau and cuticle. 



The bursting of the cells is generally seen when the whole of the cell 

 has been transformed in the région nearest to the stomach. 



We are not aware that any formations similar to thèse ridges hâve been 

 seen in other Crustacea. 



