THE CONNECTIVE TISSUES

have developed to the practical exclusion of the other elements. It is found in the ligamenta subflava, in the vocal cords, in the longitudinal coat of the trachea and bronchi, in the inner coats of-the blood-vessels, especially the larger arteries, a.nd to a very co.nsiderable ex~ent in t~e thyro-hyoid, crico-thyroid, and ~tylo-hy~id ligaments. It IS also found In the ligamentum nuchre of the lower animals (FIg. 614). In some parts, where the fibres are broad and .Iarge and the netwo.rk close, the tissue presents the appearance of a membrane, with gaps or perforatIOns cor­responding to the intervening space. This is to be found in the i~ner coat of the arteries, and to it the name of fenestrated membrane has been given by Henle. The yellow elastic fibres remain unaltered by acetic acid.