438 MANIPULATION. 



its colour, the white fibrous tissue ; a mixture of the two is 

 known to anatomists as the areolar tissue, and is largely used 

 in the animal economy ; it forms a support for all the vessels, 

 nerves, and muscles, from either of which it may be easily 

 procured; the yellow tissue is found nearly in an isolated 

 condition in the ligamentum nuchas of the necks of some 

 animals, especially those of the ruminating tribe ; it also enters 

 largely into the formation of the intervertebral discs; a 

 portion of the ligament from the neck of the sheep or calf, 

 even after boiling, wiU exhibit the elastic fibres exceedingly 

 well; they are of nearly uniform size, generally curled at 

 their extremities, and of a yellowish colour. The following 

 animals will show both these tissues to the best advantage : — 



The elastic coat of arteries is composed of a tissue very 

 like the yellow fibrous above described ; it may be very easily 

 procured if an artery be cut across transversely, and the cen- 

 tral or thickest part selected and separated into as fine fibres 

 as possible by means of the needle-points. If any of the above 

 tissues are required to be kept, they should be mounted in 

 fluid; the spirit and water, or the creosote Uquid, will be found 

 to be the most useful for the purpose. 



Mucous Membrane. — ^Continuous with the skin, or outer 

 tegument of the body, is the membrane termed mucous, which 

 forms the investment of all the internal parts, as the skin 

 does of all the external, and is even continued through the 

 ducts of aU glands, however complicated, that open upon any 

 part of the surface. This membrane has two surfaces, one 

 free and superficial, the other attached or parenchymal ; the 

 former is covered with a layer of particles or cells termed 

 epithelium, which, according to their situation, and to the 

 office they perform, are divided into three varieties, the scaly, 



