46 SYMBIONTICISM AND THE ORIGIN OF SPECIES 



rather than practical demonstration." In another investi- 

 gation on the sebaceous gland cells, Ludford ('25b) says: 

 ''Mitochoncria do not appear to be directly concerned in 

 the formation of the secretion." 



From an analysis of the literature on secretion, it is 

 evident that the internal mechanism of secretion varies in 

 different glands and in different animals. Investigations 

 have demonstrated that in some glands the mitochondria 

 are concerned in secretion. The recent experimental in- 

 vestigations of Takagi ('25) in which he used various means 

 to stimulate secretory activity in the submaxillary gland 

 of the cat demonstrate conclusively that mitochondria play 

 a role in submaxillary secretion. Cramer and Ludford 

 ('26) demonstrated a relationship of mitochondria to the 

 functional state of the thyroid gland. Horning ('26) found 

 mitochondria in the food vacuoles of paramoecium, indi- 

 cating a digestive function. The manner in which mito- 

 chondria enter into secretory activity appears to vary in 

 different kinds of cells. In some cases the mitochondria 

 appear to transform directly into the secretion; in other 

 instances the secretion appears to be related to the mito- 

 chondria, but not in the nature of a transformation. In 

 still other cases the Golgi apparatus appears to be directly 

 concerned in the secretory process. The question that 

 presses for solution in connection with the mechanism of 

 secretion is : What is the relationship between mitochondria 

 and the Golgi bodies? 



While some investigators maintain that the Golgi bodies 

 are chemically related to mitochondria, others hold that 

 they are distinct and of a different nature. The basis for 

 these opinions rests on the staining reactions of the two 

 structures. It is pertinent to emphasize the fallacy of 

 attributing specificity to staining reactions. It is conceded 

 that shght variations in staining reactions can be detected 

 between mitochondria and the Golgi apparatus; but what 



