MORBID CONDITION OF CARTILAGE. 219 



destruction be superficial, the breach may be repaired by the 

 formation of the fibro-nucleated membrane. In such cases the 

 affected part will present a velvety appearance. If the synovial 

 membrane be involved, the fibro-nucleated membrane may be 

 incorporated with an exudation from the synovial surface. 



Dr. Eedfern, in his researches On the Healing of Wounds 

 in Articular Cartilages, has satisfactorily demonstrated that the 

 repair of cartilage is always a very slow process. In one experi- 

 ment, in which he had made three incisions into the cartilage of 

 a patella, and two into that of the trochlear surface of the femur 

 of a dog, he found that no union had taken place in twenty-nine 

 weeks, but a reparative process had just commenced. In another 

 case, similar incisions were firmly united by fibrous tissue in 

 twenty-four weeks and five days. 



The appearance of the parts, upon examination by Dr. Eedfern 

 at the end of this time, I beg to give in his own words : — 



" A slightly increased quantity of synovia exists in the joint ; 

 the patella rests by the external half of its articular surface on 

 the inner side of the internal condyle of the femur, and the part 

 of the fibrous capsule of the joint which lies upon the trochlear 

 surface of the femur, and glides over it, presents a dense wliite 

 and smooth spot, similar in appearance to fibro-cartilage, and of 

 exactly the same size and shape as the trochlea. The edges of 

 the trochlear surface of the femur, and the vertical ridge on the 

 cartilage of the patella, are less prominent than usual, and 

 rounded. The cartilage of the femur appears perfectly healthy, 

 and that of the tibia somewhat softer than natural, and the car- 

 tilage of the patella is more transparent, and has a small perfora- 

 tion in its centre leading down to the bone. The position of the 

 incisions is difficult to see on the patella, and is only marked by 

 the slightest curvilinear depressions^; on the femur, one incision 

 is recognised with the greatest difficulty, and the position of the 

 other cannot be seen with the naked eye. 



" On microscopical examination, the superficial cells over a 

 considerable extent of the surface of the cartilage of the patella, 

 and especially in the neighbourhood of the central depression, 

 have become much enlarged, many measuring xxiVir of an inch 

 in diameter ; they are nearly spherical, and their contents appear 

 to have divided into three or four masses like nuclei ; they are 

 lodged in hyaline substance of greater transparency and much 



