CHAPTER XXXV 

 BONE, TEETH, AND SKELETONS OF EMBRYOS *t 



910. Bone, Non-decalcified. Ranvier [Traite, p. 297) has the 

 following : 



Bones should be plunged into water, without being allowed 

 to dry, as soon as the surrounding soft parts have been removed, 

 and should be divided into lengths with a saw whilst wet. The 

 medulla should then be driven out from the central canal by 

 means of a jet of water ; spongy bones should be treated as 

 follows : 



An epiphysis having been removed, together with a small 

 portion of the diaphysis, a piece of caoutchouc tubing is fixed 

 by a ligature on to the cut end of the diaphysis, and the free end 

 of the piece of tubing adapted to a tap through which water 

 flows under pressure ; they are then put to macerate for several 

 months, the liquid being changed from time to time. As soon 

 as all the soft parts are perfectly destroyed, the bones may be 

 left to dry. 



Thin sections may then be cut with a saw and prepared by 

 rubbing down with pumice-stone. Compact pumice-stone should 

 be taken and cut in the direction of its fibres. The surface should 

 be moistened with water and the section of bone rubbed down on 

 it with the fingers. When both sides of the sections have been 

 rubbed smooth in this way, another pumice-stone may be taken, 

 the section placed between the two, and the rubbing continued. 

 As soon as the section is thin enough to be almost transparent it 

 is polished by rubbing with water (with the fingers) on a Turkey 

 hone or lithographic stone. Spongy bone should be soaked in 

 gum and dried before rubbing down (but see Von Koch's copal 

 process and Ehrenbaum's colophonium process). 



ScHAFFER {Zeit. wiss. Mik. x, 1893, p. 171) grinds and polishes on 

 stones of graduated fineness. 



Rose (Anal. Anz., vii, 1892, pp. 512-519) follows Koch's process. He 

 penetrates first with a mixture of cedar oil and xylol, then with pure 

 xylol, and imbeds in solution of Damar in chloroform or xylol. The 

 method can be combined with Golgi's impregnation. 



* For a detailed review of the whole subject see the paper of 

 ScHAFFER in Zeit. iviss. Mik., x, 1893, p. 167, or the article " Knochen 

 und Zahne " in Enzyk. mik. Technik. 



t J. T. C. and J. B. G. 



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