REPRODUCTION 441 



the membranes or in the deciduata free of the membranes. 

 In the deciduata, the uterus is usually quiescent for a short 

 time, and then contractions supervene, and the placenta and 

 lining of the uterus are expelled as the after-birth. These 

 uterine contractions are presided over by a nerve-centre in 

 the lumbar enlargement of the cord, and in all probability the 

 nervi erigentes play an important part in their production. 



