92 THE PHYSIOLOGY OF REPRODUCTION 



The Cycle in Insectivoees 



The changes which occur in the internal generative organs 

 during the cycle in Tupaia javanica, and in the aberrant Inseotivore, 

 Gcdeopithecus volans, have received some slight attention. 



Stratz^ has described the existence of a blood-clot and a 

 " menstrual " flow in Tupaia, and records the presence of de- 

 squamated epithelial cells in the blood-clot. Va;n Herwerden,^ 

 however, states that the individuals which Stratz examined were 

 in the puerperal stage, and that, although Twpaia can experience 

 " heat " and become pregnant at this time, trustworthy conclusions 

 regarding the severity of the procestrous changes cannot be drawn 

 from such specimens. That there was considerable bleeding van 

 Herwerden admits. Nothing is known about the periodicity of the 

 changes in Tupaia. 



In Galeopithecus van Herwerden describes uterine hypertemia 

 during the prooestriim. In the superficial mucosa numerous highly 

 congested capillaries were noticed. In the later stages blood was 

 found extravasated in the stroma, some of it being collected in 

 spaces which were probably comparable to the sub-epithelial htemato- 

 mata described by Gebhard in the menstruating human female. In 

 the superficial epithelium spots were detected where a few of the 

 cells had been removed. Bleeding did not appear to be localised 

 to any particular area in the uterus. 



Van Herwerden is certain that the changes observed could not 

 be ascribed to a puerperal condition, as in the case of Tupaia, but 

 must have been the result of a normal proosstrum. The periodicity 

 of the changes is unknown. 



The Cycle in Carnivores 



The histological changes in the non-pregnant uterus have been 

 studied in the dog * and in the ferret.* The periods into which the 

 uterine cycle is divided in the dog are as follows: — 



(1) Period of rest - - Anoestrum. 



(2) Period of growth and congestion ) t. „ ,. 



(3) Period of destruction J 



(4) Period of recuperation - CEstrus. 



Followed by further growth and glandu- Followed by pregnancy or pseudo- 

 , lar development, these changes being pregnancy (or, as sometimes in the 



succeeded by degenerative changes. ferret, by metoestrum^. 



1 Stratz, loo. cit. 



2 Van Herwerden, loc. cit. 



3 Marshall and JoUy, "Contributions to the Physiology of Mammalian 

 Eeproduction : Part I. The CEstrous Cycle in the Dog," P/iil. Trans., B., 

 vol. cxcviii., 1905. Marshall and Hainan, loc. cit. 



* Marshall, "The CEstrous Cycle in the Common Ferret," Qiiar. Jour. Mier. 

 Science, vol. xlviii., 1904. 



