Ophthalmic and otic memoranda / By D.B.St. John Roosa ... and Edward T. Ely.

  • Ely, Edward T. (Edward Talbot), 1850-1885
Date:
[1885]
Catalogue details

Licence: Public Domain Mark

Credit: Ophthalmic and otic memoranda / By D.B.St. John Roosa ... and Edward T. Ely. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    r.ective-tissue fibres ; not continuous, but per* forated by numerous foramina. (9) Is perceptive layer. Rods and cones packed together like palisades forming external nervous layer; probably termini of optic-nerve fibres ; have striated appearance from fine lines of connective tissue surrounding them ; divided into external and internal segments connected together by sheath and filled with highly refractive molecular matter; delicate fibres, rod and cone fibres, run inward from rods and cones and appear to arise by club-shaped and finely-fibrillated expansions in ext. mole- cular layer: ext. granules are connected with them. Existence of axial fibres in rods and cones doubtful. Rods are cylindrical, 500 in. long, Woo in. thick. Cones flask-shaped, about -giro in. long, -50V0 thick. Layer about 5710 in. thick. (10) Hexagonal cells pressed closely together containing brownish-black pigment and held together by homogeneous connective tissue ; send processes inward which surround rods and cones—pigment-sheaths: closely connect- ed externally to choroid. Pigment almost ab- sent in albinos, small amount in blondes, most in negroes. (See p 245.) Supporting connective tissice consists of radial fibres stretched between limitans ex- terna and interna, and spongy tissue, forming- networks and sheaths for nervous elements. Yellow spot of Soemmering [1804], or mac-