182 



ORVILLE T. BAILEY 



Fig. 10. Longitudinal section of spinal cord, showing herniation of necrotic tissue 

 in an area of damage to the pia. Gallocyanin-van Gieson Xl50. Same monkey as 

 Fig. 9. 



area. The layer next to the surviving spinal cord tissue is composed of colla- 

 genous tissue with its fibers oriented about the central necrotic material, now 

 fragmented and amorphous (Fig. 11). Compound granular corpuscles are 

 found in the meshes of the collagenous tissue and in the necrotic central 

 region, but astrocytes are absent. The lesion at this stage is somewhat more 

 reminiscent of repair of necrosis in tissue outside the central nervous system 

 than within it. 



In monkeys sacrificed at still longer intervals (usually 8 months and 

 longer), proliferation of astrocytes is conspicuous outside the zone described, 

 but the collagenous scar remains unpenetrated by astrocytes in its central 

 dense zone. 



Further opportunities to study the behavior of collagen are aflForded by the 

 monkeys in which Ta^*"" activated wire has been inserted into the corona 

 radiata. It is difficult to evaluate collagen behavior in or near the point of 



