233 



and dissolving, leaving the naked nucleus behind. Afterwards the 

 nucleus submits to the same fate. 



The giant-cells have not been able to consume the whole layer 

 of decidual tissue before they disappear. Yet this layer must be 

 removed if the normal situation of tlie uterine-wall is to return. 

 Therefore the giant-cells are supported by another type of cells, 

 apparently amoeboid wandering cells with phagocytal qualities. These 

 cells are of a hitherto unknown kind and in normal egg-chambers 

 they do not occur, not even post partum. Their shapes and sizes 

 are very variable. They have a nucleus which generally lies ex- 

 centrically and sometimes two or more nuclei. Their cytoplasm 

 stains remarkably intenseley with eosin dissoluble in water, 

 whereas eosin dissoluble in alcohol stains them, it is true, 

 but not extraordinarily. I propose to call these cells eosinophiloiis 

 phagocytes. Abont their origin nothing is known to me, but I think 

 that they are maternal cells. The eosinophilous phagocytes were 

 lacking only in one of the twenty empty egg-chambers, and this one 

 obviously had been preserved within a day after the death of the 

 embryo. In the tirst place they appear in small groups between the 

 group of giant-cells and the layer of unattacked decidual tissue. 

 These groups enlarge into constantly thicker layers, which are 

 always situated either between the decidual tissue and the giant-cells 

 or between the former and the uterine cavity. The eosinophilous 

 phagocytes attack only the maternal decidual tissue and not the 

 giant-cells and they continue to do so after the disappearance of the 

 giant-cells. So a fourth group of empty egg-chambers exists where 

 one sees no foetal rests at all, but only eosinophilous phagocytes 

 which remove the layer of decidual tissue, which has in the mean 

 time greatly diminished in size. I could not observe the disappearance 

 of the eosinophilous phagocytes. 



As is known, in egg-chambers of the mouse the uterine cavity 

 disappears at the mesometrical side of the embryo to extend at the 

 antimesometrical side of the embryo starting therewith from the 

 portions of the uterine cavity that are lying between the egg-chambers. 

 Before the parts of the new uterine cavity reach one another in 

 the middle of the egg-chamber, which occurs on the 17'^ day of 

 the pregnancy, a more or less thick partition of decidual tissue in 

 the egg-chamber separates the parts of the new uterine cavity, 

 which approach one another. Now this partition can be found in 

 many empty egg-chambers, but in some it has been ruptured, 

 in others it is attacked by eosinophilous phagocytes, and in still 

 others it has been removed prematurely by eosinophilous phagocytes. 



