Elastic tissue.—May also be studied in most sections of skin. If the ligamentum nuchæ of a large quadruped (horse, bullock), &c., is available it yields the best specimens, or the human ligamenta subflava may be examined. Pin a piece out on a piece of wood or wax. Harden in Müller’s fluid. Stain in picrocarmine. Both sections and teased specimens should be prepared.
Tendon.—Readily obtained from an amputated limb. Harden in Müller’s fluid. Make transverse and longitudinal sections. Stain with eosine and hæmatoxyline.
A preparation should also be made by teasing a little of the fresh tendon in normal salt solution, and staining with picrocarmine.
Retiform or lymphadenoid tissue.—Seen in lymphatic glands and in the lymphoid follicles scattered along the sub-mucous coat of the alimentary canal.
Prepare sections in the ordinary way. Stain in eosine and hæmatoxyline or in picrocarmine.
Some sections should also be prepared by pencilling (i.e., dabbing with a camel’s hair brush) or by shaking sections up in a test tube with water or normal salt solution. By this means the leucocytes are removed, and the structure of the adenoid tissue itself becomes more evident.
Fat.—Best studied in sections of skin and subcutaneous tissue, or in the mesentery of the cat. One specimen should be stained with osmic acid and picrocarmine and mounted in Farrant’s medium, and another in eosine and hæmatoxyline and mounted in Canada balsam.
Pigment cells.—Branched cells are best studied in the living foot of the frog, where amœboid movements may be seen in them when the light falling on the retina is made to vary in intensity. Permanent preparations are most conveniently made from the pallium of the common snail. The shell is removed, and the pallium snipped out with the scissors. It is then pinned out flat, hardened for a day in methylated spirit, and mounted unstained in Farrant’s medium. They are also well seen in sections of the choroid coat of the eye.
Hyaline cartilage.—Specimens may be obtained from any joint, from the costal cartilages of young animals, or from the thyroid cartilage and tracheal rings. It may be hardened in spirit. Stain with picrocarmine, eosine and hæmatoxyline, and with methyl violet.