FIVE FIGURES
The blue staining that occurs in malignant cells (sarcoma, carcinoma and lymphoma) and in the thymus, lymph nodes and testicles of mice receiving diets containing Nile blue dyestuff is characterized by diffuse coloration of the entire cell mther than by staining of concrete granules within the cells as occurs in vital and supravital staining (Lewis, Sloviter and Goland, '46 ; Lewis, Goland and Sloviter, '46 ; and Lewis and Goland, '47). There are, however, a few exceptions to this for certain granules in the adrenal glands, the intestinal imcosa, the kidney tubules, the prostrate gland and in some macropages, do become stained blue, although the granules that become colored following administration of Nile blue are not the same as those that stain with vital dyes such as janus green, neutral red, niethylene blue and trypan blue. F o r example g r a n u l p in cells of the islands of Langerhans become deeply colored with neutral red, but not with Nile blue.
Two types of Nile blue granules appear in the adrenal glands. One (fig. 1) corresponds to the pigment granules of brown degeneration first described in adrenals of mice by Crainer and Horning ( '37), and later by Tobin and Briiibaum ( '-27). The other (fig. 2 ) resembles those described as ascorbic acid granules in chick embryos by Barnett and Bourne ( ?41)? and in the adrenals of rats by Dean and Xorse ( '48).