HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by BARNETT, S. A. Articles by COLEMAN, E. M. Search for Related Content PubMed PubMed Citation Articles by BARNETT, S. A. Articles by COLEMAN, E. M.

Breeding stocks of mice of strain A2G have been studied at environmental temperatures of –3° and 21° C. The mean age of opening of the vagina was 33 days at –3° C, 26 days at 21° C. The mean body weight at opening was 13 g in both temperatures. The vaginal smear of typical oestrus appeared at a mean age of 61 days at –3° C, 38 days at 21° C; it was preceded by variable numbers of anomalous smears containing squamous cells. The mean length of the oestrous cycle was 8·5 days at –3° C, 4·8 days at 21° C. Females transferred from 21° to –3° C had longer cycles at first, but tended to return to normal after some months. The interval between parturitions had two modes, at about 3 and 6 weeks respectively: most intervals were around 6 weeks at –3° C, 3 weeks at 21° C. There was evidence of a negative correlation between the numbers weaned in successive parturitions, when the interval between parturitions was near the minimum. The slowing of the reproductive cycle at –3° C may be attributed to the prior demands of catabolism; but this does not account for the recovery of the mice transferred from warm to cold.