EXPLANATION OF THE PLATES. 



PLATE XXXI. 



STRUCTURE OF CARTILAGE. 



Fig. 1. A thin transverse section of the cartilage of the 

 concha of the ear : magnified 350 diameters. 



Fig. 2. The cells of the centre of an intervertebral car- 

 tilage in the different stages of their develop- 

 ment. 



Fig. 3. A longitudinal section of the cartilage and bone of 

 the rib of an adult, showing the mode of union 

 between the two: magnified 130 diameters. 



Fig. 4. A transverse section of one of the rings of the 

 trachea ; in these the cells are so closely aggre- 

 gated that but little room is left between them for 

 intercellular substance : 350 diameters. 



Fig. 5. A transverse section of the thyroid cartilage of a 

 young man eighteen years of age, in which fibres 

 analogous to those of the fibro-cartilages have 

 made their appearance : 130 diameters. 



