. A text-book of animal physiology [microform] : with introductory chapters on general biology and a full treatment of reproduction, for students of human and comparative (veterinary) medicine and of general biology. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. ..^«;...»-^..--«: 578 ANIMAL PHYSIOLOGY. I of the Eatiaa.—There is no doubt that the fibers of the optic nerves can not of themselves be directly affected by light. This may be experimentally demonstrated to one's self by a variety of methods, of which the following are readily c
. A text-book of animal physiology [microform] : with introductory chapters on general biology and a full treatment of reproduction, for students of human and comparative (veterinary) medicine and of general biology. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. ..^«;...»-^..--«: 578 ANIMAL PHYSIOLOGY. I of the Eatiaa.—There is no doubt that the fibers of the optic nerves can not of themselves be directly affected by light. This may be experimentally demonstrated to one's self by a variety of methods, of which the following are readily car- ried out: 1. Look at the circle (Fig. 421) on the left hand with the. right eye, the left being dosed, and, with the page about twelve to fifteen inches distant, gradually approximate it to the eye, when suddenly the cross will disappear, its image at that dis- tance having fallen on the bUndspot, or the point of entrance of the optic nerve. 2. Fixing the eye as before on a mark on a sheet of white paper made by a pen, draw the latter outward till its point disi^ypears from view. Mark the location of the pen-point when this occurs, and continue the movement till it again appears. Mark this point also. This process may be continued in other directions bendes the horizontal, and, by joining these pcnmts, an irr^nilar outline is formed, marking off a portion of the " visual field," within which there is really no vision. 8. A small image from a fbune projected on the blind-spot by a mirror is not visible* though readily perceived when it falls OD. the retina Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Mills, Wesley, 1847-1915. New York : D. Appleton; London : Caxton House
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Keywords: ., bookauthormillswes, bookcentury1800, bookdecade1880, bookyear1889