The Experimental Modification of the Oestrous Cycle in the Ferret by Different Intensities of Light Irradiation and other Methods

Abstract

ABSTRACT The original discovery by Bissonette (1932) that the recurrence of oestrus in the ferret was greatly accelerated by light was corroborated and extended by Marshall & Bowden (1934, 1936), who found that ultra-violet light had a more long-continued effect than rays from the visible part of the spectrum, but that rays of long wave-lengths caused no acceleration. The experiments described in this paper were upon (1) the effects of different degrees of light intensity as obtained by placing the cages at different distances from the electric lamp, (2) the effect of ultra-violet light on the duration of oestrus, (3) the effect of feeding vitamin D to anoestrous animals, and (4) the effects of copulation as shown by the discontinuance of oestrus and the subsequently observed state of the ovaries and other reproductive organs. Under present circumstances it has not been possible to continue the experiments, but the results, although not so complete as originally hoped for, seem sufficiently conclusive to make their publication desirable.