146 PRACTICAL HISTOLOGY. fvlll. 



Harden the buds in absolute alcohol when they are about i-i| cm. long. 

 Stain in safranin and mount in xylol-balsam. 



(c. ) I have also tried the young growing shoots of an onion bulb placed in 

 water. The tips of the growing rootlets were hardened in Fol's or Rabl's fluid 

 and stained with safranin. Fairly good specimens were thus obtained. 



LESSON VIII. 

 CELLULAR AND HYALINE CARTILAGE. 



Cartilage. The varieties of cartilage are classified as follows : 



1 . Cellular or Parenchymatous occurs in the chorda dorsal is, ear 



of mouse and rat. 



2. Hyaline encrusts the articular ends of bones, occurs in costal, 



trachcal, bronchial, laryngeal (except epiglottis and cornicula 

 laryngis), nasal cartilages, external auditory meatus, and in 

 the " temporary " cartilages of the foetus. 



Fihrmm / ("') White nbro-cartilage. 

 3 ' ' ' 1 (&.) Yellow fibro-cartilage. 



(a.) White fibro-cartilage occurs in the intervertebral discs, 

 interarticular nbro-cartilages, as marginal cartilages on 

 the edge of joints (hip, shoulder), lining tendon 

 grooves, in sesamoid bones, the sacro-iliac synchon- 

 drosis and symphysis pubis. 



(b.) Yellow fibro-cartllaf/e occurs in the epiglottis, cartilages 

 of Wrisberg and Santorini, external ear, and Eustachian 

 tube. 



I. Cellular Cartilage (H). Kill a rat or mouge ; snip off the ear. 

 With a stout pair of forceps remove the skin and the other tissues 

 from the ear until the thin lamella of cartilage 

 which forms the basis of the ear is exposed. 

 Harden the cartilage in absolute alcohol. Mount a 

 thin part of the cartilage in Farrant's solution. 

 1. Cellular Cartilage (H). 



(a.) Observe the clear cdh (fig. 109, c) ; some of 

 them may be spherical, but most are polygonal in 

 FlG CarUiage el from sna P> closely pressed together, and united by a very 

 the Ear of a small amount of matrix or intercellular substance (m). 

 5co'hox 250. By focussing, rows of them in several planes may be 



seen. Usually no nucleus is visible in the cells. 

 If desired, a section can be stained with hsematoxylin and 

 mounted in balsam. 



