It is known that the nearest point at which an object can be seen distinctly gradually recedes with advance in age and that this recession in the near point of distinct vision varies so regularly as one grows older that it may be used in determining the age of a person. Figures such as the following are reported in the literature: At 10 years of age the near point of distinct vision is 7 cm. ; at 20 years, 10 cm. ; at 30 years, 14 cm.; at 40 years, 22 cm.; at 50 years, 40 cm.; at 60 years, 100 cm., and at 70 years of age all power of accommodation has been lost. At 40 or 50 years of age this lengthening of the near point of distinct vision obtrudes itself on one in the use of the eyes for near objects, reading, for example, and it becomes necessary

ArticleTHE INFLUENCE OF COPPER ON THE RATE OF DISINTEGRATION OF MAMMALIAN ERYTHROCYTESG. C. Wickwire, W. E. Burge, and Ruth KrouseG. C. WickwireFrom the Department of Physiology, University of Illinois, Urbana, Illinois, W. E. BurgeFrom the Department of Physiology, University of Illinois, Urbana, Illinois, and Ruth KrouseFrom the Department of Physiology, University of Illinois, Urbana, IllinoisPublished Online:31 Jul 1936https://doi.org/10.1152/ajplegacy.1936.116.3.638MoreSectionsPDF (457 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation More from this issue > Volume 116Issue 3July 1936Pages 638-640 Copyright & PermissionsCopyright © 1936 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1936.116.3.638History Received 17 May 1936 Published online 31 July 1936 Published in print 31 July 1936 Metrics

1. The irritability of Mimosa pudica rises rapidly during the first part of the morning, remains high throughout the daylight hours, and falls gradually during the night to a minimum around daybreak. 2. If plants are kept under continuous illumination for 24 hours, irritability does not fall during the night period as normally occurs but remains at the high daytime level. 3. If plants are kept in the dark for 24 hours, irritability does not rise during the daytime period as normally occurs but remains at the low nighttime level. 4. It is concluded that the increase in irritability during the day is due primarily to the effect of light. 5. Other investigators have found contrary to our observations that the irritability of Mimosa is lowest in the daytime and highest in the night. This contradiction in results is attributed to the use by other observers of an improper criterion and method for determining irritability.

ArticleTHE EFFECT OF MOVING LIQUID UPON THE ELECTRICAL STIMULATION OF MUSCLEW. E. Burge, G. C. Wickwire, and O. S. OrthW. E. BurgeFrom the Department of Physiology, University of Illinois, Urbana, Illinois, G. C. WickwireFrom the Department of Physiology, University of Illinois, Urbana, Illinois, and O. S. OrthFrom the Department of Physiology, University of Illinois, Urbana, IllinoisPublished Online:30 Apr 1933https://doi.org/10.1152/ajplegacy.1933.104.2.480MoreSectionsPDF (730 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation More from this issue > Volume 104Issue 2April 1933Pages 480-483 Copyright & PermissionsCopyright © 1933 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1933.104.2.480History Received 19 February 1933 Published online 30 April 1933 Published in print 30 April 1933 Metrics

Previous articleNext article No AccessIncrease of Sugar Utilization in Spirogyra by Means of Commercial FertilizersE. Williams, L. Kneer, G. C. Wickwire, D. J. Verda, and W. E. BurgeE. Williams Search for more articles by this author , L. Kneer Search for more articles by this author , G. C. Wickwire Search for more articles by this author , D. J. Verda Search for more articles by this author , and W. E. Burge Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 92, Number 3Nov., 1931 Article DOIhttps://doi.org/10.1086/334200 Views: 1Total views on this site Journal History This article was published in the Botanical Gazette (1876-1991), which is continued by International Journal of Plant Sciences (1992-present). PDF download Crossref reports no articles citing this article.

1. Raising and lowering the temperature produced an increase and decrease in sugar utilization by the plant Spirogyra, and by a cold blooded animal, the ordinary gold fish, just as it does in pure chemical reactions. 2. Lowering the temperature produced a greater decrease in sugar utilization by Spirogyra than by the gold fish. 3. The effect of temperature on the rate of sugar utilization by Spirogyra and the gold fish followed very closely van't Hoff's law for pure chemical reactions, except at very low temperatures. The explanation that suggests itself for this deviation from the law is that the normal physiological mechanism for sugar utilization in the living cells of the plant and animal is impaired by very low temperatures.

1. The optically active amino acids stimulate sugar metabolism in the plant cell, spirogyra, and the animal cell, paramecium, while the optically inactive ones do not. 2. Paramecium uses sugar much more rapidly than spirogyra, in keeping with the more intense metabolism in animals than in plants. 3. Spirogyra and paramecium use dextrose and levulose more rapidly than galactose, just as is the case with higher animals and man. 4. Insulin increases the rate of utilization of the sugars in paramecium and spirogyra, similar to its action in the higher animals and man.

According to most investigators (1) adrenalin increases heat production and raises the respiratory quotient, thus indicating an increase in sugar metabolism. The object of this investigation was to determine directly the effect of adrenalin on sugar metabolism. Practically all the work that has been carried out with adrenalin has been done on the mammal with its various organs and glands of internal secretion where the situation is very complex. In this investigation we have attempted to simplify matters by using single celled animals and adding the adrenalin directly to the sugar solutions containing these animal cells and studying the effect on the rate of sugar utilization. The animal cell used was Paramecium caudatum. The paramecia were raised in great numbers on an infusion of alfalfa, pond lily leaves, and lake water. They were collected and washed free of debris by the use of a small centrifugalizing machine. The mitrifugalizing tubes were graduated in cubic centimeters, so the paramecia were measured as they were collected. Sugar determinations were made according to the method of Benedict. Air was kept bubbling through the liquid containing the paramecia to insure an adequate supply of oxygen.