130 G. CARL HUBER 



from rat No. 104, 6 days after insemination. In the uterus of 

 this rat there were found six ova. In both of these rats, the ova 

 present essentially the same stage of development, comparable to 

 that shown in A and B of figure 23, Part I. As may be observed 

 from the text of Part I (page 301) the stages obtained at the 

 end of the sixth day and early hours of the seventh day, were 

 found very difficult to fix. At this stage the ovum consists of a 

 relatively large, thin walled vesicle, very prone to fixation shrink- 

 age. All of the ova or vesicles obtained from rats Nos. 91 and 

 104, are very badly folded in their roof portion. Those shown 



Fig. 7 Two ova of the albino rat partly surrounded by maternal blood with 

 many phagocytic leucocytes. The folding of the roof of the vesicles is due to 

 fixation shrinkage. X 200. A, rat No. 91, 5 days, 16 hours, after the beginning 

 of insemination. B, rat No. 104, 6 days after the beginning of insemination. 



in A and B, figure 7, are representative. This folding, a result 

 of imperfect fixation, is present in all of the vesicles of this stage, 

 even though the respective vesicles present normal structure. 

 The ova here figured may be regarded as having fairly normal 

 structure, both as to rate of development and as to arrange- 

 ment, form, and structure of constituent cells. All of the eight 

 vesicles obtained from these two rats (No. 91, 2 ova; No. 104, 6 

 ova) are in part surrounded by exudated maternal blood, con- 

 taining numerous leucocytes. Small masses of blood with leu- 

 cocytes are found here and there in different parts of the uterine 

 lumen of both rats, lodged in mucosal folds other than the char- 

 acteristic decidual crypts enclosing the respective ova. These 



