. The anatomy and physiology of the human body. Containing the anatomy of the bones, muscles, and joints; and the heart and arteries . J I •tio-. (1. 7:i> F 32 t /^.^tf ft x^«*v>.;/f \ .A 7 ©F THE IRIS. 31 tracting ;ind relaxing, holds a control over the quantity oilight transmitted to the bottom of the eye. For, by the exten-sion of this membrane, the diameter of the pupil is diminished,and, by contraction of the membrane, it is dilated. This motion,of the iris, and, consequently, the size of the pupil, is con-nected with the sensation of the retina; by which means, indisease o

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. The anatomy and physiology of the human body. Containing the anatomy of the bones, muscles, and joints; and the heart and arteries . J I •tio-. (1. 7:i> F 32 t /^.^tf ft x^«*v>.;/f \ .A 7 ©F THE IRIS. 31 tracting ;ind relaxing, holds a control over the quantity oilight transmitted to the bottom of the eye. For, by the exten-sion of this membrane, the diameter of the pupil is diminished,and, by contraction of the membrane, it is dilated. This motion,of the iris, and, consequently, the size of the pupil, is con-nected with the sensation of the retina; by which means, indisease of internal parts of the eye, it is often an index to usof the state of the nerve, and of the possibility of giving reliefby operation. The iris, and corona ciliaris, or ciliary processes, are, ingeneral, considered as being the Uvo laminse of the choroidcoat, continued forward and split: the internal lamina of thechoroid forming the corona ciliaris, and the outer one formingthe iris. The former I was vvilling to consider as the anteriormargin of the choroid coat, because it has no distinction in itsstructure from that coat;

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Keywords: ., bookcentury1800, bookidanatomyphysiolog, booksubjecthumananatomy