THE ADRENAL BODIES 239 



referred to from the chemical standpoint (p. 203). They 

 appear to have been first described by Ecker. The earlier 

 observers referred to them definitely as fat droplets and fat 

 granules. Kolliker calls attention to differences in the amount 

 of the cortical fat in different classes of animals. The human 

 being has a moderate amount. 



Rabl investigated the micro -chemical reactions of the cor- 

 tical cells in birds. He showed that the cortical granules are 

 soluble in alcohol, ether, and chloroform, turn black with osmic 

 acid, and red with alkanna. While, however, fat after treat- 

 ment with osmic acid is insoluble in chloroform and oil of ber- 

 gamot, the cortical granules are soluble in these reagents as 

 well as in xylol. For this reason Rabl considers them only as 

 " fat-like " bodies. These observations were found to be true 

 also of the cortical granules of the horse and the dog. Alex- 

 ander, however, noted that the cortical granules do not stain 

 black with osmic acid, but only take on a brownish tinge ; 

 therefore, they must consist of some substance other than fat. 



Kaiserling in 1895 reported that a large part of the granules 

 in question are doubly refracting. Orgler concluded that the 

 particles are not fat, but are related to myelin. 



The granules are present in embryonic life, and, according 

 to Plecnik, are not to be regarded as representing a fatty 

 degeneration. In the medullary cells in the embryo there are 

 granules which blacken with osmic acid, but these are not 

 abundant, and at the fifth year granules are not present in all 

 medullary cells. Now we find more and more cells which 

 stain black with a clear centre, and after puberty these ring- 

 shaped granules are alone present. After this time any 

 solid granules in the cells show that they really belong to 

 the cortex. Adrenal fat is different from other fat. In the 

 external part of the cortex there are hollow spaces which are 

 often lined with a layer of flat cells or ordinary cortical cells ; 

 these are best seen shortly before birth, and are absent in 

 adults. 



According to Bernard and Bigart, the cortex produces 

 lecithin and pigment. It contains cells with compact (dark 

 protoplasm, and cells with less compact (light) protoplasm, 

 In the formation of the lecithin, fat-like droplets arise in the 

 cells, and the process appears to progress from the periphery 

 to the centre of the gland. In the pigment formation vacuoles 



