304 WALLACE CRAIG 
had laid no eggs previously during the current year. In two of 
these six cases the dove was a virgin aad had never laid. 
3. It is true that the female may, if left without a mate, begin 
to lay late in the season. Hence it might be suspected that the 
sequence of stimulation and egg-laying in the seven cases was mere 
coincidence. But this is precluded, first of course by the fact that 
coincidences are not known to happen seven times in succession, 
and further by the following considerations. 
4. Insome of the trials it was proven that the female when stim- 
ulated by the male laid much earlier in the season than she did 
when not so stimulated. This is shown in the following table. 
Female, no. 20. . 
1908. (Case 4), stimulated by male, laid March 27. 
1909. (Control), without male, began to lay May 138. 
1910. (Case 5), stimulated by male, laid January 29. 
Female, no. 19. 
1909. (Control), without male, began to lay April 26. 
1910. (Case 7), stimulated by male, laid January 26. 
5. The interval between the first stimulation by the male, and 
the laying of the first egg, was as follows: 
Case 1. 6 days. 
Case 2. (Male not used.) 
Case 3. 7 days. 
Case 4. 6 days. 
Case 5. 9 days. 
Case 6. 4 to 10 days, depending on what is regarded as the 
first stimulation in this case. 
Case 7. 6 days. 
The average and the variation of these intervals tally closely 
with the average and the variation of the interval in normal 
breeding, between the first copulation and the laying of the first 
egg. 
6. There were no exceptions. Ovoposition never failed to fol- 
low within nine days after the first contact with the male. (The 
only partial failure was that of the first trial in case 4, which was 
due to faulty experimental conditions. ) 
