292 INTERNAL SECRETION 



melting point, and its elementary analysis, was identified with 

 cholesterinpalmitate C 27 H 45 O (C 10 H 31 O). This substance was 

 present in a comparatively large quantity. .8 grm. was obtained 

 in a state of chemical purity from 2,320 grm. of suprarenal. 



Special interest is further attaching to the discovery of a 

 cholesterinester which crystallized into very fine needles, which 

 became illuminated under crossed Nicol's prism; molecular 

 weight, 740. Elementary analysis showed figures corresponding 

 to the formula C 51 H 92 O 2 ; thus the substance may be described as 

 carnauba-acid-cholesterinester. 



These findings supplied material for a further investigation 

 of the question as to whether or no the suprarenal is the source 

 of the cholesterinester present in the blood. It is well known 

 that Hiirthle found cholesterinoleate, cholesterinpalmitate, and 

 cholesterinstearate in blood serum. The examination of pigs* 

 blood for cholesterinester shows that cholesterincarnaubate is not 

 present in the blood in demonstrable quantities. 



Of the further results of my experiments, I propose to mention 

 here only that the benzine extract contains the monoamidomono- 

 phosphatide cephalin. The diamidomonophosphatide discovered 

 by Rosenheim, namely, sphingomyelin, must be present in the 

 alcoholic fraction, but, up to now, I have failed to isolate it. 



My investigations into the nature of the suprarenal lipoids 

 cannot be regarded as complete, and it is proposed to pursue them 

 further at a future date. They show, however, that Aschoff's 

 view, that the double-refractive substance present in the lipoid 

 granules is represented by the cholesterinesters, receives con- 

 siderable support from the results of chemical analysis. They 

 suggest, moreover, that the cholesterinesters are substances 

 specific to certain organs, and perhaps also to certain species, 

 which are produced in the suprarenal, but which cannot be re- 

 garded as products of secretion, destined to be carried off by the 

 blood-stream. 



THEORY OF THE FUNCTION OF THE INTERRENAL 



SYSTEM. 



At a first glance, the remarkable profusion of the lipoid 

 substances in the suprarenal cortex suggests that this tissue is 

 the locality in which the lipoid substances required by the entire 

 organism are formed. Hence the hypothesis arose that the lipoid 

 substances, the presence of which in each cell was believed to be 

 essential to the acquirement by that cell of its nutritive material, 

 were formed by a process of secretion in the suprarenal cortex, 

 or rather in the suprarenal tissue. The evidence in favour of a 

 secretory process on the part of the cortex was supplied by the 

 different nature of the lipoid contents in different cells ; by the dif- 

 ference between cells in different parts of thecortex, containing little 



