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It was I who resolved the singular problem of rotation in the cells and hairs of plants into ciliary attraction, in spite of the assertions of Mr. Wenham and others, that my explanation was the result of an optical illusion. But notwithstanding these discoveries, laboriously and painfully made as they were, I felt horribly dissatisfied.
Of what parts are the outer, middle, and inner coats of the eyeball made up? What portions of the eyeball reflect light? What absorb light? What transmit light? What refract light? Show how the iris, the crystalline lens, the retina, the ciliary muscle, and the cornea aid in seeing. Trace a wave of light from a visible object to the retina.
As the retrograde motions of the particles of blood in the optic arteries, by spasm, or by fear, as is seen in the tails of tadpoles, and membranes between the fingers of frogs. Another cause he thinks may be from the librations to one side, and to the other, of the crystalline lens in the eye, by means of involuntary actions of the muscles, which constitute the ciliary process.
The long diameter of the pupil apparently lies in the direction of the terminal vessels of the two principal branches of each long ciliary artery which form the circulus iridis major, where the vasomotor spasm would have the greatest effect in lessening the blood supply.
The small end, however, is not produced into one long cilium, but the general surface of the body is covered with small actively vibrating ciliary organs, which are only longest at the small end.
This fibrous envelope takes the form of a closed round vesicle, surrounding the whole of the ball and pushing between the lens and the horny plate at its outer side. The round wall of the capsule soon divides into two different membranes by surface-cleavage. The inner membrane becomes the choroid or vascular coat, and in front the ciliary corona and iris.
This insures establishing our fistula in the most anterior position possible, and, therefore, as far away as possible from the ciliary body and the angle of the chamber. Third: The difficulties of the operation. Far too much stress has been laid on these. Trephining is an operation which can be performed by any surgeon who is used to ophthalmic manipulations, and who has good sight.
Aside from the dangers incident to a wide incision in the neighborhood of the ciliary body and the possibility of accident to the lens or vitreous body, or of intra-ocular hemorrhage, there is for the average operator the added difficulty and danger in removing a piece of sclera of the exact size required.
It is supposed that the ovum is grasped by the fringe-like extremity of the Fallopian tube and is carried through it by the movements of the ciliary epithelium to the uterus. The formation of new follicles continues only for a short time after birth, when the Graafian follicles are the most numerous; the entire number contained within the ovaries of the child being estimated at over 70,000.
Rider speaks of the lodgment of a fragment of a copper percussion cap in the left eye, back of the inner ciliary margin of the iris, for thirty-five years; and Bartholinus mentions a thorn in the canthus for thirty years. Jacob reports a case in which a chip of iron remained in the eyeball twenty-eight years without giving indications for removal.
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