36 PHYSIOLOGICAL SERIES. 



A. 148. A similar preparation. 0. ( *. 140. Hitnterian. 



A. 149. Another section, to show further progress of the ossifi- 

 cation. 0. C. 141. Hunterian. 



& 150. A section of the epiphysis of the shank-hone of a Calf, 

 in which ossification is chiefly advancing from the centre. 

 0. C. 142. Hunterian. 



A. 151. A section of the epiphysis of a metacarpal bone of the 

 same animal, injected : with a more distinct centre of 

 ossification. 0. C. 143. Hunterian. 



A. 152. Another section, with the ossification more advanced. 

 0. C. 144. Hitnterian. 



A. 153. The cartilage of an epiphysis, with the central ossification 

 well-injected, showing that it is much more vascular than 

 the surrounding cartilage. O. C. 145. Hunterian. 



A. 154. A similar preparation. 0. C. 146. Hunterian. 



A. 155. A similar preparation, with the ossification in its centre 

 more advanced. 0. ('. 147. Hunterian. 



A. 156. A section of temporary cartilage. The large vessel 

 which traverses the preparation probably lies in the inter- 

 space of two adjoining epiphyses. 0. C. 148. Hunterian. 



The following preparations have been injected, steeped in an 

 acid, dried, and preserved in oil of turpentine, to show the 

 vascularity of growing bone. 



" Parts whose use in the machine may be said to be passive, as 

 tendon, cellular membrane, ligaments, investing membrane, bone, 

 and cartilage, which last is probably the most passive, have all 

 small vessels, and of course but few that are visible. As bone, 

 how?ver, is composed of two parts, viz. animal substance and 

 earth, it is probable that there may be more action required to 

 form the latter than either tendon or cartilage, and therefore there 

 will be more vessels. 



" As a further proof that this is a general principle, we find that 



