1906.] 



On the Myelins, etc., of the Organism. 



367 



myelin figures, more extraordinary even than those of ammonium oleate, 

 long processes being rapidly thrown out, which coil themselves into most 

 complicated knots. These processes are doubly refracting. By slightly 

 altering the conditions of the experiment abundant spherocrystals are 

 formed. 



Here, then, we have a nitrogenous base, a product of proteid dissociation, 

 uniting with oleic acid to form a soap. We reserve a fuller description of 

 the properties of this body for another occasion. We would only point 

 out that cholin is a constituent of both protagon and lecithin : that neither 

 of these, it would seem, afford myelin formation in the pure state : both 

 are unstable and that largely because of the chemically weak fatty acids 

 which enter into their composition. When, therefore, these bodies are 

 found associated with myelin formation it would seem most probable that 

 the dissociation of the combined cholin permits it to act upon the oleic acid 

 also present and that this is the essential cause of the myelin formation in 

 this group of cases. 



There is still, we believe, some debate as to whether the neurin of 

 Liebreich is identical with cholin or no. Employing a solution of " neurin " 

 (Merck), it may be noted that we gained like results. 



Lastly it has to be noted that there exist solid, doubly refractive crystalline 

 bodies (or spheroliths) as well as these fluid spherocrystals. They are of 

 two forms, that of solid spheres and that of spherical masses of closely packed, 

 radiating, fine acicular needles. The appearance under the ordinary microscope 

 serves to distinguish these from the fluid crystals ; they lack the oily 

 appearance of the latter, aud even the most spherical of the first class are 

 apt to be nodose on the surface, or to occur in pairs, as with some of the 

 calcium salts, or to be distinctly irregular in shape. Both forms may occur in 

 the organism and both between the Nicol's prisms give double refraction. 

 With the radiate form there is little chance of confusion ; of the more globular 

 form the most frequent example is encountered in the uratic deposits in the 

 renal collecting tubules forming the uratic " infarcts " of the new born. In 

 our own observations we have obtained exquisite and abundant radiate 

 spheroliths by the action of weak formaline upon cholin oleate (after several 

 hours) : of the small globular forms calcium oleate affords excellent 

 examples. 



2 F 2 



