NATURAL HISTORY 375 



67 brought over. 



68 calved from the 280th to the 290th day. 

 20 on the 300th day. 



5 on the 308 th day. 



l6o 



Consequently there were 6? days between the two extremes. 



II. Mares. 

 One hundred and two mares were observed. 

 3 foaled on the 311th day. 



1 on the 314th day. 



1 on the 325th day. 



1 on the 326lh day. 



2 on the 330th day. that is, exactly at the end of 11 months. 



47 from the 340th to the 350th day. 



25 from the 350th to the 360th day. 



21 from the 360th to the 377th day. 



1 on the 394th day. 



102 



This gives a latitude in the time of gestation, of 83 days ; and the fol- 

 lowing observation may be made respecting cows and mares, namely, that 

 more of the first brought forth before the completion of the 9th months 

 than of the second before that of the eleventh. 



III. Sows. 

 Of these only fifteen were observed. 



1 brought forth young, whichlived, on the 109th day, thatis, 3 months 



and 19 days. 

 10 from the 110th to the 120th day. 



2 — — on the 1 2 1st day. 



1 on the 122d day. 



1 on the 123d day. 



15 



Consequently, the difference between the two extremes was 14 days. 



IV. Rabbits. 

 One hundred and thirty-nine were observed, during the course of three 

 years. 



1 brought forth on the 26th day. 



2 on the 27th day. 



3 on the 28th day. 



53 on the 29th day. 



