188 EXPLANATION OF THE PLATES. 



FIG. IV. Fibrous tumor of the dura-mater. 1, Free 

 fusiform cells ; 2, fasciculi of same cells united at their extremi- 

 ties ; 3, fasciculi of fibres formed by the elongation of the same 

 cells and the disappearance of their nuclei. In this case each 

 row of cells forms but one solitary fibre. 



FIG. V. Fibrous tumor of the uterus in which the for- 

 mation of a fibre by metamorphosis of a nucleus can be traced. 

 1, Finely granular substance ; 2, nuclei. 



FIG. YI. Another portion of same tumor. The nuclei 

 somewhat elongated in shape already show a disposition to 

 assume the form of fibres. 



FIG. VII. Same tumor. The nuclei are still more elon- 

 gated ; at some points they can be seen with their extremities 

 united together so as to form fibres. 



PLATE V. 



CAETILAGE AND BONE. 



FIG. I. Section involving the centre of a costal carti- 

 lage. 1, Fundamental substance, slightly granular and trans- 

 parent ; 2, cartilaginous capsule ; 3, primordial cell, or utricu- 

 lus ; 4, nucleus made up of fatty granules ; 5, capsule contain- 

 ing four cells, two of which have no nuclei. 



FIG. II. Costal cartilage with its perichondrium, taken 

 from a subject eighteen years of age. 1, Perichondrium formed 

 by a dense interlacement of connective and elastic fibres, and 

 studded with plasmatic cells. 2, There is no clear and distinct 

 line of demarcation between the deepest portion of the peri- 

 chondrium and the substance of the cartilage ; it is also almost 

 impossible to make out a distinct difference in the character of 

 the superficial cells of the cartilage and the plasmatic cells of 

 the deepest layer of the perichondrium. 



FIG. III. Fibro-cartilage from the ear. 1, Fibrous fun- 

 damental substance or basis ; 2, capsule inclosing these cells. 



FIG. IV. Transverse section of the ulna. In the midst 



