86 BOVINE OBSTETRICS 



but certaiuly upon its reconstruction, namely, in the shape of 

 fatty degeneration of the newly formed cells. 



Kolliker states in his microscopical anatomy that the 

 muscle cells, which during gestation have become seven to 

 eleven times longer and two to five times wider, are reduced to 

 their original length three weeks later. As a cause of this he 

 mentions atrophy plus fatty infiltration of the contractile 

 elements ; possibly certain fibres are completely resorbed. 

 His observations, confined to man, did not reveal any regener- 

 ation, and he can see no reason why this should not hold 

 good in the uterus of lower animals. 



Balin closely studied the changes iu blood vessels of the 

 uterine muscle during the puerperal state. The arteries 

 showed cell proliferation of the intima both iu the direction of 

 the lumen and intima, this process leading to obliteration and 

 fatty metamorphosis of the media. The thickening of the 

 intima of the larger veins does not result in obliteration, but 

 does so in the amall.er veins ; these undergo fatty degeneration. 



C. W. Broers (Holland), from whom the above is taken, 

 studied the process of involution on the rabbit and came to the 

 following conclusions : 



The decrease in volume of the uterine muscle in the begin- 

 ning of the puerperal state depends on the exit of glycogen 

 from the hypertrophic muscular fibres, where it was present 

 during birth, also on the resorption of the fluid of the oedema- 

 tous inter- muscular connective tissue. The glycogen is prob- 

 ably carried off by the lymph vessels, after undergoing chemical 

 change. The blood vessels lose either entirely or partly the 

 blood, while the entrance of glycogen into the muscularis of 

 the arteries leads to a decrease of this hypertrophied tissue. 



The entrance of glycogen, during the first hours following 

 parturition, is the only cause of the progressive atrophy of the 

 muscular elements, but is joined at the end of the first day by 

 another process. 



At this time some muscle-cells show droplets of fat. In 

 the following days the latter process predominates, the smaller 

 and larger drops of fat become confluent, leave the cells and 



