TMK LACHIiYMAL CLANI) 229 



very iiuportaut role in the formation of granules. I have seen 

 no evidence that mitochondria are diretly concerned in the pro- 

 duction of secretion granules. 



12. Mitochondria are abundantly present in the cells of the 

 larger ducts — intralobular, interlobular, etc. — where they are 

 either arranged as filaments or appear irregularly distributed 

 without any special arrangement whatsoever. In the cells of 

 the intercalary duct and secreting tubules they are much less 

 numerous and are distributed irregularly throughout the cyto- 

 plasm. The number of mitochondria for these cells appear 

 approximately equal — whether the cells are a maximum granular 

 stage or contain the minimum of granules. 



13. I did not find that an abundance of fat globules in the 

 secreting cells is characteristic of the lachrymal gland as claimed 

 by other investigators. While glands were studied in which 

 numerous fat globules were observed, in the vast majority the 

 quantity of fat globules was found to be no more than that 

 observed in the submaxillary gland and the pancreas. 



14. Intercellular secretion capillaries varying in width and 

 length — depending upon the secretion stages of the cells — and 

 bounded by cement substance are prominently seen in the 

 tubules. In the intercalary duct these capillaries may not be 

 seen or they may appear as slight indentations between the 

 cells. Cement substance is found throughout the secretion 

 passages. Pyronin when used intra \'itam selectively stains the 

 secretion capillaries. 



15. The canalicular apparatus is readily seen in the cells of 

 the lachrymal glands. In the cells of the tubules they are only 

 seen when few or no granules are present. 



16. I have failed to observe the constant presence of centro- 

 somes described by Zimmermann and Fleischer. Likewise I 

 have failed to find the constant presence of the paranucleus 

 described by other investigators. 



I am especially indebted to Professoi- R. R. Bensley of the 

 University of Chicago for numerous suggestions. This work 

 was begun in his laboratory under his inspiring direction. Since 



