CORPORA AMYLACEA. 319 



example after atrophic processes. In tabes dorsalis, as 

 one used to say, or the atrophy of single columns of the 

 cord, as we now usually interpret the old expression, we 

 find, in proportion as the atrophy progresses, and the 

 nerves in certain directions perish cuneiform segments, 

 in which the substance up to that time white becomes 

 from without inwards grey and translucent there being 

 apparently a production of grey matter. This degene- 

 ration is most frequent in the posterior columns, gene- 

 rally in the immediate vicinity of the posterior fissure, 

 and here it may go on, and generally does go on, in such 

 a manner that the wedge penetrates deeper and deeper 

 and at the same time increases in width. In these parts 



then the whole substance of the medullated fibres gradu- 

 ally disappears, and distinct nerves are no longer disco- 

 verable the whole spot generally consisting of neuro-glia 

 with an enormous accumulation of corpora amylacea. 



Nowhere in the body has there as yet been found any- 

 thing completely analogous to structures of this sort, ex- 

 cepting, as I have said, in those parts which appear to 

 be direct protrusions of the cerebral substance, namely 

 in the higher organs of sense, in the case of which origi- 

 nally a certain quantity of central nervous matter entered 

 into the sensorial capsules (Sinneskapseln) of the embryo. 

 In the cochlea too, and the retina, bodies occur, which 



Fig. 96. Section of the spinal marrow in partial (lobular), grey or gelatinous atro- 

 phy (degeneration), f. Posterior longitudinal fissure, s, s posterior, rn, m anterior 

 nerve-roots, communicating with the grey substance of the horns. In A a slighter, 

 in B a more marked degree of atrophy, which is shown in the posterior columns 

 around the central fissure /, and in the lateral columns at /. Natural size. 



