The Interstitial Grannies of Striated Muscle etc. 303 



which stain sometimes red, sometimes blackish by Altmann's granule 

 method. The liposomes may be readily demonstrated by treating the 

 fresh tissues with 5 per cent potassium hydroxid. After a few hours in this 

 alkali, the liposomes show myelin figures. If muscle be removed asep- 

 tically and kept in sterile normal salt solution 24 hours at body tem- 

 perature, the interstitial granules may now be stained with neutral 

 red and they show myelin figures. The term "myelin" is used by Al- 

 brecht in a morphological sense, as it was used by Virchow. It is under- 

 stood that it is not a definite chemical compound. Myelin swells mar- 

 kedly in water to form peculiar characteristic figures — Myelin figures. 

 It is readily soluble in alcohol, ether, benzene, etc. Myelin figures are 

 usually readily stained by neutral red, and are colored a dark grey by 

 osmic acid. It is not stated to what extent myehn figures are doubly- 

 refractive, but apparently substances are identified as myelin whether 

 this property is present or not^). 



Albrecht's reasons for believing that the interstitial granules are 

 composed of fat-like substances seem tobe: 1. They are insoluble in potas- 

 sium hydroxid. 2. They may be readily converted into a substance 

 (myelin) that is readily soluble in ether, alcohol, benzene, etc., and 

 may be stained a dark grey by osmic acid. He seems not to have tested 

 the solubility of the interstitial granules in the fresh tissue; and he 

 evidently regarded Altmann's fuchsinophile granules as liposomes. 

 No mention is made of insect muscle. 



Albrecht distinguishes "postmortem" myelin (substances in dead 

 tissue yielding myelin figures) from "intravital" myelin (substances 

 in living tissue yielding myelin figures). He seems certain that the 

 changing of the liposomes into myelin is a process of saponification. He 

 suggests that the postmortem myelin may be identical with lecithin. The 

 liposomes consist of fat-like substances. , - 



') Adami (Principles of Pathology, Vol. I) seems to identify myelin mainly by 

 its property of forming doubly-refractive droplets. Adami and Aschoff have shown 

 that certain compounds of oleic acid (cholesteryl oleate, cholin oleate, etc.) exhibit 

 the properties of the so-called myelins. Droplets of these substances show the 

 characteristic cross when examined in polarized light. But, as stated above, 

 Albrecht does not make it clear to what extent his myelin is doubly-refractive, 

 and he may have been dealing with substances considerably different from those . 

 studied by Adami and Aschoff. 



