144 W. H. LONG LEY 



HaA'iiifi; been obtained, the eggs may be examined either with 

 or without a cover glass. Some tube eggs showed many spermat- 

 ozoa which had reached the zona, or were lying between the coronal 

 cells surrounding the egg. The same condition is noted by 0. 

 Van der Stricht ('09) in the bat and by other observers in various 

 animals. 



Sexual season 



The domestic cat may have from two to four sexual seasons 

 during a single year, but only one if the animal become wild, 

 (Heape '00). One of the chief periods of sexual activity occurs 

 during the early spring, after the winter rest, and in the region 

 of New Haven is at its height during, the latter half of February 

 and March. R. Van der Stricht ('08) records it as a fact that 

 for animals in captivity the period of oestrus is delayed several 

 weeks. 



In the absence of the male oestrus will continue nine or ten 

 days, (Hamilton '96). R. Van der Stricht ('08) states that it 

 will last two or three days, presumably after the first copulation. 

 Upon the different lengths of the period of heat in the absence of 

 the male, or with the male present and allowed to inseminate the 

 female, or present and not allowed to pair, no conclusive evidence 

 is here offered, the maximum period of heat having been attained 

 under none of these conditions. No cat studied has shown any 

 unwillingness to be covered within fifty hours after the first 

 pairing. Cats which had not been inipregnated, but which had 

 been approached by the male, gave heat reactions up to six full 

 days, but the only animal in heat so long was inseminated at the 

 end of that time. Since the repeated presentation of the male 

 without the occurrence of copulation serves to keep the female 

 longer than she would otherwise be in oestrus (Van Beneden),i 

 no data obtained after this fashion would fall in the same categor}^ 

 with those of Hamilton. 



1 This statement was never published by Van Beneden himself, but with his 

 consent it was made by Winiwarter and Saintmont. Archives de Biologie, T. 24, 

 p. 129. 



