116 THE MITOCHONDRIAL CONSTITUENTS OF PROTOPLASM. 



employed, colors the hemoglobin intensely and may mask or hide the mitochondria 

 (plastosomes) ; but Ciaccio ignores the fact that the iron-hematoxylin stain, which 

 he himself used, acts in m.uch the same way. 



It is quite evident that our information is not sufficiently clear-cut. The 

 technique upon which the above-mentioned observations are based is inadequate. 

 There has been no attempt made to estimate quantitatively either the mitochondria 

 or the hemoglobin, and in spite of this the old i?resence-and-absence argument is 

 made use of. Fixed preparations were alone studied. Now that it is not only 

 possible, but easy, to stain the mitochondria specificall}^ with janus green in these 

 living blood-cells, and to count them, it ought not to be difficult to devise some 

 quantitative colorimetric way of estimating the hemoglobin and to obtain decisive 

 results. The information at hand does not show that the mitochondria exercise 

 even an indirect influence upon the formation of hemoglobin. There is no topo- 

 graphical correspondence between the mitochondria and the deposition of chloro- 

 phyll. The formation of hemoglobin from mitochondria alone involves chemical 

 impossibilities. It involves a change from a phospholipin into an entirely differ- 

 ent material. Ninety-four per cent of the hemoglobin consists of the protein 

 globin, but it also contains the coloring matter hematin. It is accordingly very 

 much like a nucleoprotein in nature, and nothing could be further removed from 

 the mitochondria. We ask ourselves where can the iron come from? Certainly 

 not from a phosphohpin. Pathology may help us. In chlorosis the characteristic 

 thing is a diminution in the amount of hemoglobin in proportion to the number of 

 red blood-corpuscles. There is either a deficiency in the formation of hemoglobin 

 or an increase in its destruction. At any rate, the red blood-corpuscles contain 

 less than the normal amount, and it would be interesting to find out whether 

 there is a corresponding fluctuation in the number of mitochondria in the precur- 

 sors of these erythrocytes; for if a relation exists between the mitochondria and the 

 hemoglobin production it might be possible to detect it in this little-known condi- 

 tion. The mitochondria should also be studied in hemochromatosis and in other 

 disturbances of a similar character. It is interesting to note that PoUcard (19126, 

 p. 230) has discovered that mitochondria form the matrix in which hemoglobin 

 crystals are deposited in the liver of animals defibrinated by the process of Magendie. 

 Mitochondria, however, are not associated with the deposit of other crystalloids 

 (d'Athias, 1915, p. 68), except perhaps in plants. 



SECRETIONS. 

 THVROID-GLAND SECRETION. 



Grynfeltt (1912c, p. 147) was the first to suggest the formation of the colloid 

 substance through either a direct or an indirect transformation of mitochondria. 

 He thinks that this is quite probable in view of our general knowledge of the role 

 of mitochondria in gland-cells and in consideration of some observations which 

 he has made upon the new-born dog. He found appearances which seemed to 

 him to indicate that the mitochondria near the surface of the apical zone of the 

 thyroid cells undergo certain modifications and transform into clear spherules, 



