PROGRESS OF MICROSCOPICAL SCIENCE. f 101 



and of colloid, are often to be seen in the same sections with the 

 supposed amyloid bodies. Tlie chromic acid, or other means employed 

 to harden the nerve substance, so far alters its condition that the 

 reactions of iodine or other tests for cellulose are controlled or 

 obscured. 



Dr. Clarke notes a dilated condition of the vessels, and in some 

 parts a disintegration of these to the extent of causing their entire 

 disappearance, with a consequent production of large, empty, and 

 smooth-walled tubular sjiaces, which, according as they were cut 

 transversely or obliquely, presented an appearance of round or oval 

 vacuities. This appearance was first described by the author in a case 

 of general paralysis of the insane,* and has since been noticed also by 

 other observers. It formed the most prominent feature of the lesions 

 described by Dr. Dickinson in the medulla oblongata from several 

 cases of diabetes. Dr. Clarke also refers to the dilated condition of 

 the vessels, in connection with those spaces around them which have 

 been spoken of as " lymphatic spaces," or " perivascular sheaths "; but 

 which, the reporter has endeavoured to show, are the results of patho- 

 logical, or even of merely post mortem changes. 



The cells of the cerebral grey substances in this case were not 

 altogether healthy. Some of them had lost their natural sharj)uess of 

 outline ; others contained rather more pigment than usual, or were 

 somewhat granular at their surfaces. The pigmentation of cells was 

 still more observable in the medulla oblongata. This change is con- 

 sidered by Dr. Clarke to constitute the first stage in the degeneration 

 and subsequent disintegration of nerve cells. The medulla oblongata 

 was one-fifth below the average size, and the diameter of the sj)inal 

 cord was reduced by at least one-fourth ; so much was it reduced that 

 when first seen by Dr. Clarke, without any explanation, he thought it 

 was the cord of a child of fourteen years of age. 



The grey matter of the cord presented a variety of lesions. Con- 

 gestion of the white columns was present. Hypertrophy of the con- 

 nective tissue, with proliferation of its corpuscles, and aggregation of 

 these in masses at the angles of junction in the network, are described 

 by the author, and illustrated in an engraving. Several j)atches of 

 disintegration were observed. One of large size consisted of small 

 remnants of partly disintegrated grey substance, irregularly connected 

 with each other, and forming together a kind of reticular or honey- 

 comb structure. Several large areas of disintegration and hfemorrhagic 

 clots existed, involving large portions of the cord in destruction. In 

 all regions of the cord, the nerve cells had imdergone degeneration 

 and disintegration. Some were completely, others only partially, 

 filled with dark-brown pigment granules, which in many instances 

 enveloped and concealed their nuclei. All the remaining cells were 

 reduced in size ; many seemed to have been lost by gradual atrophy, 

 and numbers had wholly disappeared by complete disintegration, or 

 fallen into granules. The several stages of the process could be 

 followed. 



We have very imperfectly followed Dr. Clarke in the details of 

 * ' Journal of Mental Science,' January, 1870. 



