120 THE MITOCHONDRIAL CONSTITUENTS OF PROTOPLASM. 



simply saw lipoid droplets in the epithelial cells, and I am inclined to share his 

 opinion on the basis of my own prostate preparations. 



SECRETION IN THE VENOM CELLS OF MUREX TRUNCULUS. 



Grynfeltt (1913, p. 11) found that the venom cells in the hypobranchial gland 

 of Murex contain large granules of secretion antecedent (which stain intensely with 

 picric acid and are therefore called "Boules picrophiles ") as well as large and con- 

 spicuous mitochondria. He claims to have traced a genetic relationship between 

 the mitochondria and the secretion granulations. He found large mitochondria 

 which stain more faintly than the rest with the crystal violet in Benda's stain, and 

 large mitochondria with a central core of material staining orange with alizarin 

 just as the secretion granulations do. He also found that the masses with more . 

 of the central yellow-staining material possessed less peripheral coating of mito- 

 chondrial substance, and vice versa. He interprets these observations as follows: 

 In the process of secretion certain mitochondria, arising through the fragmenta- 

 tion of chondriocontes, increase in size. Their central part undergoes a chemical 

 transformation by which it loses its coloration with crystal violet and takes the 

 orange color of the alizarin. This tint, at first very pale, increases more and more 

 in intensity until finally it is identical with that of the secretion granules. He con- 

 cludes that the mitochondria play the part of plasts and he regards the product 

 as chemically a transformed mucus and the cells as goblet cells. His interpreta- 

 tion does not necessarily follow from his observations. On page 113 I have dis- 

 cussed in detail the theory that the mitochondria are plast-formers. Suffice it 

 here to say that he has presented no evidence that the mitochondrial substance 

 itself changes chemically into the material of the secretion antecedents. It may 

 be, as I say, that the secretion is formed in the surrounding cytoplasm and is accu- 

 mulated in the mitochondria on account of its solubility in them or for some other 

 reason. The mitochondria may be entirely passive in the process. Neither are 

 we justified in sajdng that the disapi)earance of the mitochondrial substance indi- 

 cates that it is transformed into the secretion, for it may well be that it goes back 

 into solution as in the parotid and submaxillary glands. Furthermore, we would 

 like to know something about what the steps are in the chemical transformation 

 of a phospholipin into a mucin, and it is just this that makes one so skeptical. We 

 have not the right to say, in any of this work on mitochondria, that a substance 

 of totally different character is formed by a chemical transformation of their sub- 

 stance, because it is altogether impossible to dissociate the mitochondria from their 

 surroundings. These attempts to make definite statements are futile. We can 

 hope only to make approximations to the truth and should bear in mind that the 

 apparently homogeneous ground-substance of the cytoplasm probably plays the 

 most important part in secretion as well as in all other cytoplasmic activities. 



PANCREATIC ZYMOGEN. 



Hoven (1910f>, p. 349) has furnished detailed evidence in favor of the par- 

 ticipation of mitochondria in the formation of secretion granulations in the pancreas. 

 He records the presence of little swellings in the course of the mitochondrial fila- 



