Abstract
Data have been presented, based upon over 4,600 deer-mice of known sex, which were born and reared in captivity, under temperature conditions not far different from those existing in nature. The following results seem to be of most importance.1. In size the broods ranged from 1 to 9, the mean of the 1,567 broods being 3.22.2. The sex ratio for the entire lot was 97.37 ± 1.93. When we include only those broods in which no deaths are known to have occurred (nearly nine tenths of the whole) the figure becomes 98.01 ± 2.07. Broods known to have been incomplete give a ratio of 93.08 ± 5.25. In order to eliminate the effect of seasonal differences, the mean of the monthly means has been computed. This is 95.65. None of these figures can be regarded as differing significantly.3. The probable errors employed throughout this paper are based upon a formula different from that which has been used by various previous writers. As a result, the errors here given are about twice as great as would formerly have been comp...
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
