HEMOGLOBIN IN THYONK 1!RI. \KI-.rS LKSUKUR. 97 



The question arose as to what the nature of the red pigment in 

 the corpuscles of the Polian vesicle was. 



The following evidence will serve to show that true hemoglobin 

 is present in these corpuscles : 



1. A small quantity of the fluid was dried on a slide, heated a 

 few times under cover-glass with acetic acid till bubbles appeared, 

 then cooled. Blue-black prismatic crystals could be seen, which 

 though not absolutely congruent with the figures of text-books of 

 biochemistry, doubtlessly were hemin crystals. 



2. Centrifuged and " laked " "blood" showed the typical ab- 

 sorption spectrum of oxyhemoglobin one broad band in concen- 

 trated solution, two on dilution, one of which can be easily identi- 

 fied by means of the D sodium line. 



3. On reduction with Stokes's reagent the single band of hemo- 

 globin could be seen. After continued vigorous shaking, the 

 double band of oxyhemoglobin could again be produced. 



4. Material treated with KCN and kept in the thirty-seven- 

 degree incubator for some time, became orange-yellow and showed 

 the absorption band in the green which characterises cyanhemo- 

 globin. 



5. A small quantity of the material gave a positive Prussian 

 blue test for iron. 



6. To a solution of one or two drops of I per cent, benzidine in 

 a large quantity of hydrogen peroxide a few drops of the " blood " 

 were added. A dark blue color developed at once and a vigorous 

 foaming of oxygen could be seen (peroxidase action). 



From this evidence the writer concluded that hemoglobin is 

 present in these corpuscles. This is very interesting in connection 

 with the fact that Thyone is a mud-dweller, living in a medium 

 in which oxygen is scarce. Though the controversy between 

 Krogh and other investigators, e.g., Jordan, as to whether hemo- 

 globin actually functions as an oxygen store, has not yet been 

 settled, it is beyond doubt, that the presence of a respiratory pig- 

 ment is a great help in the struggle for o-xygen. 



In how far the Polian vesicle acts as "mover" of the cor- 

 puscles, as a kind of primitive heart, could not be investigated 

 more closely. It is strongly contractile however and is generally 



