Reference for Chullin 88:1

רוב עוביה ואמרי לה

The greater part of the outer circumference [of the windpipe].<span class="x" onmousemove="('comment',' Lit., 'the greater portion of its thickness'. It must be remembered that the trachea or windpipe is a cylindrical membranous tube, stiffened and held open by a series of many cartilaginous rings. These rings of cartilage are incomplete in part of their circumference, being about one third filled in by fibrous tissue. It is evident, therefore, that the greater part of the outer circumference which includes the thickness of the cartilage would not necessarily be also the greater part of the inner circumference.');">¹</span>

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