PATHOLOGIC OVA, ALBINO RAT 131 



decidual crypts are relatively. shallow when compared with those 

 of normal uteri of similar stages with normal ova. The uterine 

 mucosa of the two rats under discussion does not appear to have 

 reacted in a normal manner. In these preparations, attention is 

 especially drawn to the presence of maternal blood with numerous 

 phagocytic leucocytes found in relation with the ova, a condition 

 never observed in normal development of ova and uterine mu- 

 cosa. In A and B, figure 7, the red and white blood cells with 

 granular detritus may be observed as found in relation with the 

 respective vesicles, these presenting essentially the same appear- 

 ances as do the other six ova obtained from these two rats; the 

 one figured having been more favorably cut than any of the 

 others. The appearances presented in these two rats are inter- 

 preted as showing a probable degeneration of the eight ova, and 

 probably complete dissolution and removal. The vesicles appear 

 to have developed normally to the stage at which they were ob- 

 tained. As a result, however, of pathologic condition of the 

 uterine mucosa, maternal blood, especially leucocytes, have 

 entered the lumen of the uterus, the leucocytes being destined 

 to play the role of phagocytes. In normal development of the 

 albino rat, maternal blood does not enter the lumen of the uterus 

 decidual crypts until after the uterine epithelium has become 

 detached from the mucosa of the wall of the decidual crypt, in 

 the region of lodgment of the enclosed ovum. Normally, very 

 few leucocytes are met with in the lumen of the uterus, even in 

 later stages of development, stages in which maternal red blood 

 cells are met with in the decidual crypts. After experience had 

 accumulated, uterine tubes supposed to contain developmental 

 stages aging from the fourth to the sixth day, which on examina- 

 tion revealed blood and especially leucocytes in the lumen of the 

 uterus, were regarded as not favorable specimens for finding ova. 

 In a number of such uteri, cut completely in serial sections, no 

 ova were found. It is possible that, owing to phagocytic action 

 of the leucocytes present, the ova may have been completely 

 removed prior to killing and fixing the tissues. In such condition, 

 it would seem to me as pertinent to speak of faulty implanta- 

 tion, due to abnormal uterine mucosa. It seems to me signifi- 



