THE LACHRYMAL GLAND 207 



mitochondria are affected by these hitter stains but in the differ- 

 entiation do not hold them so tenaciously as do the secretion 

 granules. The presence of demonstrable mitochondria in tissues 

 fixed in alcohol sublimate bichromate solution is interesting in 

 view of the observations of others that mercuric chloride and 

 alcohol fixatives do not preserve them. 



The mitochondria were also stained by the intra vitam method 

 of Michaehs ('00) (Technique VI, 1, 2). Here they appear as 

 deep blue structures being the only stained constituents of the 

 cell. In size, form and distribution they appear as already 

 described. 



Function of mitochondria in gland cells. Regarding the nature 

 and function of mitochondria in general many hypotheses have 

 been advanced which may be briefly summarized as follows: 1) 

 the mitochondrial theory — that these elements are specific ele- 

 ments of the cytoplasm just as the chromosomes are fixed ele- 

 ments of the nucleus and like the latter arise from preformed 

 elements in sex cells and are carried over in all mitosis — this 

 view was championed by Benda and Meves. It has many sup- 

 porters and is gaining ground. 2) Others do not accept the 

 mitochondrial theory but claim that mitochondria arise from 

 nuclear material, from ferment products of the centriole, or 

 that they represent other phases in the metabolic activity of the 

 cell. Many of those who accept the mitochondrial theory hold 

 that these structures later develop into the fixed specific struc- 

 tures of cells; i.e., neurofibrils (Meves and Hoven '10), muscle 

 fibrils, etc. Cowdry ('14 a) has demonstrated that in the case of 

 nerve cells this is not true. 



Cowdry (14 b) assumes that they have to do with the metab- 

 olism of the cell since they are almost coexistent with all active 

 protoplasm. The fact that they do not occur in red blood cells 

 (Cowdry), in superficial layers of epithelial cells (Firket),and 

 in the terminal stages of the cycles of development of certain 

 grains and legumes (Guillermond), according to Cowdry, partially 

 substantiates this view because these cells are in the terminal 

 stages of metamorphosis. Mitochondria, according to him. 



