PROCUEING OBJECTS. 103 



should be performed, however, in a little serum or white of an 

 egg; as water, &c., changes its appearance. As soon as the 

 true structure has been well seen, water, ether, &c., may be 

 added, to show how much they change its original appearance. 

 In all examinations of nerve or muscle, the more delicate the 

 structure, the sooner after death should it be dissected. Dr. 

 Stilling recommends to place the spinal cord in weak spirit for 

 twenty-four hours, after which it may be successfully steeped 

 in stronger spirit, before sections are made. He directs the 

 sections to be made with a razor whose surface is moistened 

 with alcohol. 



FIBROUS AND AREOLAR TISSUE. Nearly allied to involun- 

 tary muscular fibre is a fibrous tissue termed the yellow or 

 elastic; this is often found in connexion with another, finer 

 and less elastic, and called, from its color, 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, 

 as 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 in nearly an isolated condition in the ligamen- 

 tum nuchge of the necks of some animals, especially of the 

 ruminating tribe ; it also enters largely into the formation of 

 the intervertebral discs. A portion of the ligament from the 

 neck of a sheep or calf, even after boiling, will exhibit the 

 elastic fibres exceedingly well ; they are of nearly uniform size, 

 generally curled at their extremities, and of a yellowish color. 

 They may be prepared as muscle or nerve, with the needle 

 points. 



CARTILAGE. Consists of cells, contained in cavities which 

 are formed in a solid and hyaline intercellular substance. 

 (Fig. 41). In fibro-cartilage, instead of homogeneous intercel- 

 lular substance we meet with elastic fibres. The structure is 

 easily examined by making thin sections. 



