The operation of median tracheotomy may require a word. As has been stated, that part of the trachea covered by the isthmus of the thyroid gland is very commonly encroached upon in performing either or both superior and inferior tracheotomy, the isthmus being slightly displaced from its site. Other than this the site here mentioned would rarely be selected as the point for opening the trachea. Certain conditions, it is true, might render it necessary, but they would be rare. The danger lies in the hemorrhage which, theoretically at least, is to be expected when the isthmus of the thyroid gland is either torn or cut through; but opinions vary very greatly as regards this danger. With a thin, narrow isthmus in children I have frequently, in performing superior tracheotomy, cut my way through to a sufficient extent to clear a suitable space upon the trachea through which to introduce a tube without difficulty or danger. I should not recommend the procedure, however, were the isthmus to be seen to be, when reached, thick, wide, and exceedingly vascular, but at the same time believe that the danger even here of cutting into it is much overestimated.[3] Roser's recommendation to apply a ligature to the isthmus on either side of the median line previous to its division is not generally applicable. Hueter has shown that the fibrous capsule of the thyroid gland enclosing it and its blood-vessels is firmly attached to the trachea and sides of the larynx, and that from the isthmus this fascia extends upward over the larynx (fascia laryngo-thyroidea), and thus prevents, in a measure, attempts at displacing the gland downward. Bose[4] recommends that this fascia be divided transversely over the anterior convexity of the cricoid cartilage, when a director can be passed behind the isthmus, to lift it from the trachea and depress it far enough to expose three or four of the {156} rings: the capsule of the gland thus remains unbroken and no hemorrhage occurs. The procedure certainly merits trial; twice it has succeeded well in my hands. [Footnote 3: See Foulis, "Some Points on Tracheotomy," _Glasgow Med. Journ._, vol. xv. No. 2, p. 123.] [Footnote 4: _Archiv für klin. Chirurgie_, vol. xiv. p. 137.] Cricotomy, the division of the cricoid cartilage alone, is an operation which, as far as I am aware, is rarely ever performed. The objection urged against it, however, that in the adult the elasticity of the cricoid cartilage is so great that a wound through its ring cannot be made to gape sufficiently to allow of the introduction and retention of a canula without discomfort and danger of necrosis of the cartilage, is not borne out by experience. In children the objection cannot of course be urged.