178 THE ARTICULATIONS. 



Movements. — The amphiarthroses only permit of a see-saw or swinging 

 movement, the extent of which depends on the thickness of the intermediate 

 fibro-cartilage. 



Classification. — Only one kind of amphiarthrosis is recognized in the Horse, 

 the most, remarkable of which is found in the articulations between the bodies of 

 the vertebrae. 



CHAPTER II. 



ARTICULATIONS OF MAMMALIA IN PARTICULAR. 



In the special study of the articulations, the same order will be followed as for the 

 bones ; the articulations of the spine will be first noticed, then those of the head, 

 thorax, and anterior and posterior limbs. 



Preparation. — The preparation of the bones which have been described, has not been made 

 the subject of any particular recommendation, because it suffices, in order to study them, to 

 remove the soft parts by which they are surrounded, either by boiling, maceration, or scraping. 

 But when we come to examine the soft textures, in order to do so profitably it is necessary to 

 learn beforehand the rules whicli should be followed in their preparation. The following 

 directions are given with regard to the study of the articulations : — 



1. To prepare the articulations, young subjects are cliosen in preference to those advanced 

 in years, because the density of tlie connective tissue in them is not so great, and this tissue is 

 easily removed from around the ligaments. As tiiese are prepared with difficulty when the 

 external surface is in a dry state, care should be taken, before dissecting them, to have them 

 excluded from the air by covering them with damp cloths, or with the skin of the animal. 



2. It is convenient to separate the articulation we wish to dissect, by sawing through the 

 bones at a certain distance from the articular surfaces. The manipulation of the part is then 

 rendered easier, and its dissection can be made under the most favourable conditions. 



3. It is necessary to preserve, as carefully as possible, the muscles surrounding the articula- 

 tions, in order to be able to study their relations with the ligaments which bind these. If it 

 be absolutely requisite to remove them, their insertions corresponding to the articulation 

 should always be retained. 



4. The capsular ligaments should be first studied, as they have soon to be removed, the 

 better to show the funicular ligaments. Tliese, in their turn, must be sacrificed in order to 

 display, by different sections, the interosseous ligaments, when they are present. Lastly, the 

 two articular surfaces should be completely separated, so as to examine their conformation. 



5. The synovial membranes, with their different cuU-de-sac, being a very important study — 

 with reference to the diagnosis and treatment of articular tumours — it is convenient to devote a 

 special piece to the examination of these serous membranes. It is very useful to inject their 

 interior with plaster or tallow coloured black, in order to distend their cavities, and thus aid 

 the study of their relations with ligaments, tendons, or muscles. 



6. When an articulation is completely dissected, it may be left exposed to the air for some 

 time. When the ligaments begin to dry, they are more visible and easier studied. 



For the preparation of each articulation it is not necessary to give any directions ; a glance 

 at the figures accompanying the description will suffice to dispel any embarrassment the 

 student may experience, while he always requires particular indications. 



Article I. — Articulations of the Spine. 

 These articulations comprise all those of the vertebrse with each other. 



Preparation. — In order to properly study the vertebral joints, the spine of one subject 

 should be freed from all tlie muscles surrounding it; this being done, portions consisting of at 

 least two vertebrse from the cervical, dorsal, and lumbar regions, should be detached trum it. 

 In the portions from the cervical regions, the interlamellar ligaments and the capsules of the 



