506 



Prof. S. Vincent. 



[Apr. 6, 



slightly irregular border (Plate 13, fig. 3, chrom. c). The cells are about 

 15 in diameter, and the protoplasm is very finely granular. The brown tint 

 A'aries in intensity in different cells and in different parts of the same cell. 



The nuclei are large in proportion to the dimensions of the cells, and are 

 on an average 7 /x in diameter (see fig. 3, n). The majority are stained 

 brown by tlie bichromate, and the outlines are distinct and dai'k brown, 

 while the interior is usually clearer. There is sometimes a distinct nucleolus, 

 and the outer portion of the nucleus is studded with small dark brown 

 granules (fig. 3, n). 



Nuclei belonging to nerve-fibres are also to be seen within the area of the 

 group of chromaphil cells (fig. 3). 



IV. The Abdominal Chromaphil Body and other Accumulations of Chromaphil 



Cells. 



a. Macroscopic. 



In the dog, the extra-adrenal cliromaphil tissues are specially abundant, 

 and the abdominal chromaphil body is easily and beautifully shown by 

 the method above described. A few minutes after the mop of absorbent 

 cotton soaked in bichromate has been placed over the aortic region, a long 



Text-fio. 1. — Aluloininal Clu'oiii;i|)hil Body 

 of fin Adult Dog. 



A = Aorta ; Ad. = Adrenal ; = Abdo- 

 minal chromaphil body ; c = Smaller 

 chrDrnaphil bodie.s. 



Text-fig. 2. — Chromai)hil ]5ody of Adidt 

 Dog. Same lettering as text-fig. 1. 



brown streak of rapidly deepening tint may })e seen lying over the aorta, or 

 slightly to one oi- tlio other side. In from Iialf an hour to an hour its deep 



