178 JOHN SUNDWALL 



In cross sections of the intercalary duct the cells are pyramidal 

 in form, the apices being in contact with the lumina which are 

 seen to be very narrow when contrasted with the wide lumina of 

 the intralobular and interlobular ducts. The lumina are formed 

 as a rule by an average of seven triangular shaped cells. (These 

 same cells in longitudinal sections appear cuboidal in form.) 

 The granules are grouped in the apices of the cells and consequently 

 these masses of granules are triangular on outline. A narrow 



L'ig. 12 Secretion gruuules in intercalary duct, Zenlcer's mudiaeniatein. 

 Zeiss, oc. 4, obj. 8. Granules are specifically stained. A, intralolnila duct; B, 

 intercalary duct with granules; C, cross section of intercalary duct; 7X tubules. 



margin of unstained non-granular cell substance is seen between 

 these granular masses and the cell membrane. 



In longitudinal sections these cells appear cuboidal in form and 

 rest on a well defined basal membrane which represents practi- 

 cally all of the supporting tissue. 



Not all of the cells of the intercalary duct are stained by the 

 muchaematein. Many cells are present which i^ossess no granules 

 and consequently are not stained. Occasionally ducts are seen 

 in which in longitudinal sections the majority of cells of one side 

 show no granular stain while the cells of the other side possess the 



