REACTION OF SELACHII TO INJECTIONS 113 



thirty hours after the first injection. The urine was examined 

 several times and was free of dye until nearly the time of au- 

 topsy, when a trace of the red portion (Wislocki, '17) was pres- 

 ent. The bile contained a considerable amount of the whole 

 dye. It was also recovered from the serum, but not from the 

 stomach or spiral-valve contents. The liver and spleen were of 

 a slightly darker blue color than the other organs, but all of the 

 organs as well as the skin and peritoneum appeared slightly 

 colored by the dye. 



Microscopical examinations were made of the digitiform 

 gland, kidney, liver, spleen, spiral valve, stomach, skin, and mus- 

 culature. All of these retained their blue color after fixation as 

 seen in gross specimens, but blue granules are found under the 

 microscope, definitely, in only the endothelium of the liver and 

 spleen. The stain in the other organs and tissues is either too 

 diffuse to be seen microscopically or else was all free in the blood- 

 vessels, and hence washed out in preparing the sections. 



2. A young fish (0.25 kg.) was given four daily intravenous 

 injections of 3 cc. each of the above-mentioned trypan blue, 

 and was autopsied five days after the first injection. The dye 

 was found in considerable amount in the bile and serum and 

 was also present in the spiral-valve, but not in the stomach 

 contents. The liver and spleen were very dark blue in color as 

 were the gills at the base of the filaments. The skin was dark 

 blue before fixation, but light blue afterwards. The digitiform 

 gland, spiral valve, post valvular intestine, peritoneum, and 

 fascia of the muscles were light blue in color, the stomach was 

 still fighter, and the kidney, except the peritoneal covering and 

 connective tissue, was practically normal in color. 



All these organs except the first three were of a lighter shade 

 after fixation than before, owing doubtless to loss of blood which 

 contained trypan blue. 



Microscopical examination, a. Digitiform gland. Most of 

 the dye is too diffuse to be located microscopically. A few 

 leucocytes and endothelial cells of the capillaries of the paren- 

 chyma and serosa contain blue granules and one cell of a tubule 

 contains eight such granules in a vacuole, but the amount of 



