Some effects of hydrogen ion concentration, total salt concentration, calcium and citrate on longevity and fecundity of the rotifer

✍ Scribed by Lansing, Albert I.

• Publisher: John Wiley and Sons
• Year: 1942
• Tongue: English
• Weight: 769 KB
• Volume: 91
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1400910206

✦ Synopsis

Prolongation of the life span has been demonstrated to result from low temperatures while high temperatures shorten it. This action of temperature has been demonstrated by several workers, among them Loeb and Northrup ( '17) in the case of Drosophila, and Schwerdtfeger ( '38) with Melolontha. Retardation of the growth rate and starvation have been shown to increase the life span of silkworms by Kellogg and Bell ( '03)' of Drosophila by Northrup ( '17) and Kopec ( '28), of Cladocera by Ingle ( '33) afid Ingle, Wood and Banta ( '37)' of Planaria by Child ( '15) and of the rat by McCay ('35) and

('39). It is quite likely that the effects of starvation and temperature are related to their influence on metabolic activity.

Child's ( '15) extensive regeneration experiments on the Turbellaria led him to believe that regeneration results in rejuvenation. This conclusion stands or falls with the validity of Child's criteria of ageing and rejuvenation. More or less related to this line of investigation are the experiments of Hartmann ('22) on Stentor who found that this organism could be reared without divisions by repeated amputations. Luntz ('37) obtained a similar effect on Stylonychia by means of periodic electrical stimulation to this protozoan.

'Aided by a grant from the Josiah Macy, J r . Foundation.