14 ON THE DIFFERENTIAL REACTION TO VITAL DYES EXHIBITED BY 



Fibroblasts contain a scantier number of vacuoles which are, on the whole, similar in size to 

 those in macrophages, are often grouped at one or both poles of the nucleus, show considerable 

 variation in size, and are almost invariably with some linear forms (fig. 25). There is a definite 

 pink color in all the threads. With neutral red, vacuoles often appear strung along threads. Janus 

 green is positive. The threads remain pink. 



Protocol: Rat 47, injected intraperitoneally with 2 per cent aqueous solution of New 

 Bordeaux L (B. A. S. F.). This, which is again a very diffusible compound, has 

 the formula 



Na0 3 S ,N=N-/ V S-N=N SO.Na 



'CO 



H0- 



March 8, March 10 to April 5, inclusive, and April 7, 1 c. c. each day. 



A pril 9: Animal is stained a fairly deep red. Subcutaneous tissue is light red. Under the low- 

 power there is seen to be considerable dye in both types of cell Macrophages are filled with red 

 deposits and are easily distinguished from the paler fibroblasts. 



Under the oil, macrophages contain an abundance of vacuoles which are about the size of mast- 

 cell granules, but are not at all uniform in size, although the variations are slight. Some are more 

 deeply stained than others. Neutral red stains these vacuoles. No definite concretions arc present 

 (fig. 26). Janus green stains normal mitochondria. 



Fibroblasts are closely packed with vacuoles of uniform size. These are about the same size as 

 those most frequent in macrophages and very close to that of mast-cell granules. They are a pale 

 pink in color. In many cells "tails" are present on some of the deposits and a few cells contain 

 numbers of typical thread-forms, but the great majority of the fibroblasts have deposits which are 

 simple round or slightly angular vacuoles (fig. 27). Janus green stains normal mitochondria. 



Protocol: Rat 94, injected intraperitoneally with a 0.5 per cent aqueous solution of dye 230, 

 a red diffusible vital dye, synthesized for the comparative studies of Evans and 

 Schulemann by combining benzidine o-disulphonic acid with 2 molecules of beta 

 naphthylamine 7 monosulphonic acid, and hence with the formula 



- <x> ~co 



N = l 

 NqO.SY' V^> NH , Su~Na" SO Nq H .NY" V ^1 SO.Na 



April 11 to 20, inclusive, 1 c. c. each day. 



April 28: Animal stained a dusky rose. Skin of thigh pink. Under the low-power no difficulty 

 is experienced in distinguishing the cell types on account of the almost complete lack of visibility 

 of the fibroblasts. The deposits in the macrophages are easily seen. They are relatively small for 

 this cell type and intense red. 



Under the oil, the macrophages are characterized by the possession of small vacuoles in which 

 the tendency to deep-red concretions which are punctate or sickle-shaped is almost universal (fig. 28). 

 There are many small deep-red punctate deposits which can be demonstrated to reside in larger 

 vacuoles. It is also true that neutral red fails to show other vacuole deposits about many of the 

 sickles. Neutral red shows some vacuoles about the diameter one would expect from the sickles 

 without a visible amount of dye 230, but these are infrequent. It is evident that this dye resembles 

 vital new red in producing only small vacuoles in the macrophages in which the tendency to con- 

 densation is great, but the form which these condensations take differs from that of vital new red. 

 They are here small, circular concrements and rarely short rods. Janus green 1 : 10,000 (5 minutes) 

 gave a brilliant stain of normal mitochondria. 



