64 



E. RuTisHAusER, W. Taillard, B. Friedli 



vascular buds and showed, at some distance from these buds, a chondrocytic multi- 

 plication and fuso-cellular metaplasia. The cortical bone showed a few foci of 



Fig. la. Series I. Rabbit no. 033; 23 days. Van Gieson. X57.5. Internal border of the articular margin of the 

 femoral head. Epiphyseal congestion; the modification of the osseous plate is very marked. A pannus slides 



over the cartilage, at the same time as the latter is partially destroyed by the medullary pannus 



Fig. lb. Series I. Rabbit no. 033; 23 days. Van Gieson. X47.5. Cellular hyperplasia; congestion and edema of 



cruciate ligament. Erosion of the cartilage 



Fig. 2a. Series II. Rabbit no. 103; 5 days. Hem.-Eosin. X12S. Knee, femoral epiphysis. The articular plate 

 (near the cruciate ligament) presents a focus of modification from which departs a growth of fusocellular meta- 

 plasia of the cartilage without capillary contact 

 Fig. 2b. Series III. Rabbit no. 11; 56 days. Van Gieson. X20. Articular pannus in activity, splitting the car- 

 tilaginous plate 



resorption by fibrovascular sprouts from its medullary side. These transformations 

 were greatest after about 3 or 4 weeks and then regressed. 



