184.S.] 119 



intercellular matrix. Hence, in the deeper pait of Ihe articular cartilage, tlie 

 rows of cells aregeneraliy vertical to the surface, and parallel to the same in its 

 more superficial portion. 



In some of the articular cartilages sonietimesthere are peculiarities of struc- 

 ture which I think have never been pointed out, and are worthy of notice. 



In the articular cartilage of the condyles of the os femori«, I have occa- 

 sionally noticed numerous minute lacunn? ] found in greatest abundance near 

 the surface of attachment, and graihially decreasing in number until they entirely 

 disappear in the superficial third of the cartilage. They are elongated, compressetl, 

 and th^-ir long diameter is invariably situated transversely, at right angles to the 

 filamentous matrix, or parallel with the surface of the caitilase. The longest mea- 

 sure transverely i,_ of an inch, the shortest _i _ of an inch, in the vertical 



1 2 ') 3 12 5 



direction i of an inch. When well defined, they appear more transparent 



than the cartilaginous matrix in which they are situated, when viewed a little 

 within the focus they appear deep black. 



Fibres of bone are not unfrequently met with in the articular cartilages, 

 especially in that of the head of the os femoris. They are generally found near 

 the surface of attachment, but are not the continuation of the bony structure 

 upon which the cartilage is placed, for they are always arranged in a direction 

 parallel to the surface. They are compresseil cylindrical in form, and in trans- 

 verse section present an elliptical figure, tlie long diameter of which is placed at 

 right angles to the filaments of the cartilage matrix. They present a concen- 

 trically laminated and a radiated structure, resembling somewhat that of the 

 Haversian ossicle, but they neither present the canal nor the Purkinjean cor- 

 puscles. 



The foregoing observations on articular cartilage will be more detailed and 

 illustrated by figures hereafter, in one of our medical journals. 



3. On the arrangement nf iJic areolar sheath of muscular fasciculi and its rela- 

 tion to the tendon. — Well known is it that the fasciculi of fibres of the muscles 

 are surrounded by sheaths of areolar tissue, but the arrangement of the filaments 

 of fibrous tissue forming the sheaths, and their relation with the tendon, I think 

 has not been properly pointed out. From repeated observation, I have found that 

 the filaments of fibrous tissue cross each other diagonally around the muscular 

 fasciculi, forming a doubly spiral extensible sheath. None of the filaments run 

 in the direction of the length of the fasciculi, and but few are transverse. Many 

 of the filaments of a sheath form an interlacement in the same diagonal manner 

 with the filaments of the sheaths of neighbouring fasciculi. This arrangement 

 is readily distinguished, if several fasciculi be drawn slightly from each other 

 upon a plate of glass, and the intervening areolar tissue be viewed beneath the 

 microscope. When the filaments reach the rounded extremities of the fasciculi, 

 they become straight, and in this manner conjoin with the tendinous filaments 

 originating at the extremities of the muscular fibres. The importance of this 

 arrangement can be readily understood ; from the diagonally crossing course of 

 the areolar filaments, comparatively inelastic in themselves, the sheath is ren- 

 dered elastic, thus permitting the muscular fibres freely to move without their 

 action being interfered with, while at the point of attachment of the fasciculi, 

 where any elasticity would be worse than useless, from the fact that part of the 



