CYCLES OF REPRODUCTION I9 



In female mammals with prolonged breeding seasons 

 it is common for an unmated individual to experience a 

 series of lesser cycles, known as oestrous cycles. Similar 

 cycles may also be seen in some of the lower vertebrates. 

 It is only during oestrus, or heat, that the eggs are shed 

 from the ovary, and usually too it is only at this time that 

 the female is willing to receive the male. Female primates 

 experience a form of oestrous cycle that is distinguished 

 by the name of menstrual cycle. 



