Anatomical Changes. 



613 



In one case Joline found scattered small reddish-yellow centers 

 in the cortex and corpus striatum. The roots of the nerves ap- 

 pear to be uninjured. 



Histological investi- 

 gations carried out by 

 Johne and 8chniorl, and 

 by Ostertag yielded nega- 

 tive results ; Dexler in 

 one case, and Wilson and 

 Brinihall in all the eases 

 investigated f o u n d a 

 small-celled infiltration in 

 the meninges and brain. 

 Dexler found this espe- 

 cially at places vphere the 

 arachnoid bridges over fis- 

 sures in the lirain and 

 also in the immediate 

 neighborhood of blood ves- 

 sels in the peripheral 

 parts of the brain and 

 cord (see figs. 84 and 85). 

 Oppenheim found a dif- 

 fuse thickening of the pia 

 mater due to an increase 

 in the amount of connec- 

 tive tissue and also round- 

 celled infiltrations in the 

 pia mater and in the su- 

 perficial layers of the cor- 

 tex. Very occasionally 

 there were cellular infil- 

 trations around the blood 

 vessels in the deeper tis- 

 sues. At places there were 

 small hemorrhages. 



Peculiar "nuclear 

 inclusions" were demon- 

 strated by Joest and 

 Degen in the cells of the 

 ganglia. Applying a modi- 

 fication of Mann's stain 

 for the demonstration of 

 Negri bodies, the large 

 ganglion cells of Am- 

 mon's horn showed small 

 bodies staining intenselj 

 with eosin and containing 

 an unstained part. These 

 bodies were as a rule 

 rounded but sometimes 

 oval and occasionally di- 

 vided into two halves. 

 The nature of these bodies 

 which are apparently char- 

 acteristic of epizootic 

 cerebro-spinal meningitis 

 of the horse is not known. 



Fig. 84. Disseminated infiltration with leucocytes of 



the ventral column of the first cervical segment of the 



cord in a case of Borna disease. Enlarged 30 times. 



(Dexler). 



Fig. 85. Round-celled infiltration and lacuna-forma- 

 tion in the pia mater of the cerebrum in Borna disease 

 (Dexler). 



In the other species the lesions are similar to those found 

 in the horse, or as is sometimes the case in that species, there 

 may be a yellowish-white fibrinous or purulent exudate along 

 the course of the vessels of the membranes covering the base 



