552 THE PHYSIOLOGY OF REPRODUCTION 



the vessels. It is evident, therefore, that the uteri of the second 

 and third groups will resume relatively quickly their non- 

 puerperal appearance. The principal changes that occur are 

 the reduction of the surface epithelium, both by the casting off of 

 superfluous parts and by the changing of larger cells into smaller 

 ones, the advance of new epitheUum to cover places that were 

 bare,* and the reduction and consohdation of the connective 

 tissue. The latter process is effected by the cells becoming 

 more compact, as in the bitch, or by a reduction in the amount 

 of inter-cellular substance, as in the hedgehog.^ The puerperal 

 changes in Tarsius are said to resemble those of Rodents.^ 

 Excepting in those animals which belong to the first group 

 mentioned the lochial discharge is either very sUght or absent 

 altogether. 



The changes which take place in connection with the forma- 

 tion of milk in animals are described in the next chapter. 



' Duval, "De la B^generation de I'Epithelium des Corne uterine aprfes 

 la Parturition," C. R. de la Soc. de Biol., vol. ii., Series 9, 1890. 



' Strahl, "The Uterus of Erinaceus europceus after Parturition," Proc 

 Sect. Sciences, Kon. Akad. Wet. Amsterdam, vol. viii., 1906. 



' For the puerperal changes in Tupaia see von Herwerden, loc. cit. 



