REACTION OF SELACHII TO INJECTIONS 109 



granule. This sample of urine also contained a few blood cor- 

 puscles and hence the carmine probably entered with the blood. 



Microscopical examination, a. Digitiform gland. Carmine 

 is present in the endothelium and leucocytes of the blood-vessels 

 in this gland in all stages, but very Httle in the first (1^ hours), 

 and less in all the sections than in the endothelium of the kid- 

 ney, liver, spleen, and gills. In the 21-, 24-, and 50-hour speci- 

 mens there is an occasional carmine granule seen in the cyto- 

 plasm of the tubules. These few granules may possibly have 

 been dragged into the cells in the cutting of the sections and in 

 any case are too few in number to be of any importance. None 

 was seen in the lumen of the tubules. 



h. Kidney. In the first two stages there is considerable 

 amount of free carmine in the capillaries, much of it in large 

 'clmnps filling the entire vessel, and a few leucocytes and endo- 

 thelial cells contain carmine granules. 



In later stages (21 to 96 hours) there is a gradual decrease in 

 the amount of free carmine in the capillaries and there are no 

 large masses of it present. There is a decreasing amount seen 

 in the leucocytes and endothehum. A few sections have car- 

 mine granules in the connective-tissue cells. In only three 

 tubules of the hundreds of sections examined are carmine gran- 

 ules to be seen in the cytoplasm. These few granules may have 

 been carried in, in the pi-eparation, and as in the digitiform gland 

 are considered to be of no practical significance. Each of two 

 tubules of one section contained a granule in the lumen, but 

 one also finds blood corpuscles occasionally in the tubules and 

 these carmine granules may have entered accidentally. 



c. Liver. Carmine granules are seen in all stages after the 

 first, in the leucocytes and endothelial cells of the sinusoids, in 

 the hepatic cells, and in the normal pigment accumulations, 

 which are very abundant in the liver of the dogfish. 



Carmine was found in the bile in all stages after the first, as 

 free granules, in cells resembling leucocytes and mixed with 

 the normal pigment. 



d. Spleen. Carmine is present in all the sections of spleen 

 examined and in decreasing amounts in later stages (fig. 1). 



