. 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. 'the experi- the layer of experiment there seems >f the retina ove requires Is, which, in Actorily: (1) 1 before the nove rapidly idle the sub- moved from id down, the at especially latever plan 9re, in order ixcessive ex- relaxation. 1 LapoliM.— 'pte (rhodop- chemioal ex- 1 animals,
. 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. 'the experi- the layer of experiment there seems >f the retina ove requires Is, which, in Actorily: (1) 1 before the nove rapidly idle the sub- moved from id down, the at especially latever plan 9re, in order ixcessive ex- relaxation. 1 LapoliM.— 'pte (rhodop- chemioal ex- 1 animals, as was renewed t; indeed an be made and leached part limbs of the Lnas of some )urple is also I of man and It is manifest >wn as an ex- ; besides, the I are entirely ion of chem- impulses has such is false, s as yet very 1. and examine VISION. 681 msmiMsiUi. into the facts of comparative anatomy and physiology, there are many of a significance that we can not ignore; the impor- tance of light to most protoplasmic processes, such as the ac- cumulation of pigment in certain regions marking the very beginnings of eyes; the large amoimt of pigment found in the eyes of most groups of animals and of nearly all mammals sug- gesting that this is a provision for the retention of light, which we can scarcely conceive as acting in other than a chemical manner. At the same time, in keeping with the spirit of this work throughout, we suggest caution in believing that explana- tions based on our limited experience are the only ones possible. ^ It is worth while to bear in mind, however, that currents of rest and currents of action similar to those demonstrated to exist in muscle, glands, nerves, etc., may be shown to exist in the retina. In all the other cases these are in intensity parallel to the degree of functional (and chemical) activity of the part, and it makes the probability of there being a chemistry of the retina as a foundation for the impulses therein generated great- er
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Keywords: ., bookauthormillswes, bookcentury1800, bookdecade1880, bookyear1889
