Chinese Journal of Physiology

32 W. C. MA, H. C. CHANG anp A. C. LIU

than the lipoid in the cell, suggesting that some change occurs on extrusion.

The present observations on pancreas and salivary glands show that the extrusion of a part of the Golgi lipoid is a fairly general phenomenon. It is interesting to note that neutral red passes into all the secretion, and colours them according to the reaction of the secretion fluid, e.g., red in gastric juice and urine, and yellow in saliva and pancreatic juice. In the living cell, however, neutral red is seen only in the Golgi region and pethaps, during active secretion, in the granular zone as well, It is invariably red in the Golgi region, but between the zymogen granules a yellow colour is sometimes seen. That is to say, the neutral red is not distributed elsewhere in the cell but is concentrated in the Golgi material although the dye is freely water soluble. This is to be expected, however, in view of the (selective?) affinity of lipoid substances for neutral red. When the material breaks down, the dye escapes into the secretion fluid and colours it. It would be interesting to know how _ much dye diffuses directly from blood to gland lumen, and how much is conveyed through the Golgi lipoid. :

Evidence indicating that the remainder of the Golgi lipoid may be oxidized or resynthesized, has been obtained by Ni and Lim (33) and Ling, Liu and Lim (22) to whose papers the reader is referred.

DISCUSSION

Neutral red can stain various elements in the living cell, such as intracellular canaliculi in the oxyntic cells of the stomach and Langerhans’ islands of the pancreas (5), granules in the kidney (1), granules in cultures of different tissues (21), (aemoglobinogenous) granules of blood cells (17), vacuoles (3,34) etc.

In identifying the neutral red-Sudan IIT stained material, we feel certain that its behaviour during rest and activity is identical with that of the Golgi lipoid revealed by the osmium technique. While it is probable that not everything which is stained by neutral red intravitally is Golgi material, it would be worth while to check the intravital neutral red stained granules of different tissues as reported by other workers with the standard osmium technique.

The name ‘Golgi apparatus’ or “apparato reticolare interne” implies a network structure as usually obtained by silver or osmium methods. Jn the pancreas, such a structure was described by v. Bergen (6), Kolster (20), Cajal (10), Bowen (8), Saguchi (84), and others, and in the salivary gland by v. Bergen (6), Bowen (8), etc. Using