THE SUPRARENAL SYSTEM 283 



amounting to 2.08 per cent, of the total weight. According to 

 these authors, lecithin is actively produced by the suprarenals. 

 They found that, during muscular exertion, there was a consider- 

 able increase in the number and size of the labile fat granules in 

 the spongiocytes, but that the ordinary fat remained unchanged. 



Mulon (1903) points out the double refractivity of the cortical 

 granules in the suprarenals of guinea-pigs, though this, as we 

 know, had already been discovered by Kaiserling. Mulon also 

 comments upon the fact that, as early as 1866, Darest described 

 double refractive granules in the ovum, in the suprarenals, and in 

 other tissues ; and that Dastre, in 1877, showed that these granules 

 are composed of lecithin. According to Mulon, oleate of soda and 

 lecithin are the only double refractive granules which are soluble 

 in ether and alcohol. He calls the zona spongiosa the zone 

 lecithinogene. He found that the cortical granules, like those of 

 the medullary sheaths, stain blue by Regaud's modification of 

 Weigert's ha^matoxylin copper method. Bonnamour and 

 Policard proved that the cortical granules of the suprarenals of 

 frogs possess the following characteristics : they stain grey-black 

 with osmium ; they are afterwards soluble in Canada balsam and 

 in xylol ; and they colour blue with Weigert's hasmatoxylin. 

 These authors consider that the cortical granules are composed of 

 a phosphorus fat belonging to the lecithin group. 



These double refractive granules, which were believed to be a 

 specific product of the suprarenal cortex, were also found by 

 Kaiserling in an amyloid kidney with pronounced fatty changes; 

 and Kaiserling and Orgler discovered similar granules in organs 

 which had undergone regressive and fatty degenerative changes, 

 for instance, in regressive changes in the thymus, fatty degener- 

 ation of the intima cells of the vessels, in large white kidney, &c. 

 They believed these double refractive granules to be identical with 

 the myelin globules found by Schmidt and F. Mu'ller in the 

 bronchial mucus, and they described the granules which they had 

 discovered as " myelin " without, however, attaching a chemical 

 significance to the term. Albrecht also described as myelin the 

 globular formations and the figures which appear in the cell-body 

 as the result of nuclear decomposition as seen for instance post 

 mortem in the kidney if kept at the temperature of the body and 

 which, unlike the nucleus, stain red with neutral red. Dietrich and 

 Hegler also described the occurrence of myelin figures which 

 were formed by autolysis in organs kept under aseptic conditions. 

 By rapidly bringing crushed suprarenal cortex to a moderate 

 degree of heat under the microscope, Albrecht produced every 

 possible change in the appearance of the double refractive 

 granules, from slight increase in size to enlargement equal to that 

 of the globules seen in fatty infiltration of the liver, together with 

 pronounced double refraction, and, in many instances, distinct 

 formation of myelin forms. Certain other authors (Orgler, 

 Loehlein, Rosenfeld) believed that the double-refractive substance 



