XII 



PHYLUM CHORDATA 



515 



parts have become fully formed, except that the eyelids are 

 closed, and the hairy covering is not yet completed. As 

 many as eight or ten young are produced at a birth, and the 

 period of gestation, i.e., the time elapsing between the 

 fertilisation of the ovum and the birth of the young animal, 

 is thirty days. Fresh broods may be born once a month 

 throughout a considerable part of the year, and, as the 



Lut' 



va 



r.ut 



FIG. 288. Lepus cuniCUlUS. The anterior end of the vagina, with the right uterus, 

 Fallopian tube and ovary (nat. size). Part of the ventral wall of the vagina is 

 removed, and the proximal end of the left uterus is shown in longitudinal section. 

 fl. t. Fallopian tube ; fl. t '. its peritoneal aperture ; /. /. left uterus ; /. nt' '. left 

 os uteri ; ov. right ovary ; r. nt. right uterus ; r. ut ' . right os uteri ; s. vaginal 

 septum ; va. vagina. (From Parker's Zootomy.) 



young Rabbit may begin breeding at the age of three 

 months, the rate of increase is very rapid. 



During intra-uterine life the young Rabbit is nourished 

 by an organ called the placenta, formed by an intimate 

 union between the allantois (p. 431) and a specially modified 

 part of the wall of the uterus. By means of the placenta 

 a close connection is established between the blood-system 



L L 2 



