133 



may in this way be readily distinguished from the cytoplasm of 

 the niaternal cells; in the cytoplasm are found, enclosed in va- 

 cuoles, niaternal blood corpuscles and epithelial and other cellular 

 débris, showing, I think beyond a doubt, that these cells are 

 phagocytic (Figs. 21, 22); further, as the cells eularge fat-gra- 

 nules, which may be stained in the fresh condition with Daddi's 

 stain, or detected in sectious of material preserved in osmic mix- 

 tures, may be seen; and in addition very numerous granules of 

 variable size which are not soluble in any of the ordinary sol- 

 vents of fat, and which appear in material fixed by any and all 

 reagents. (Fig. 23). It may perhaps be considered an adequate 

 explanation to dismiss these structures with the name of Altmann's 

 granules; personally, I prefer to suggest the comparisou of them 

 with those opaque granules which we know to occur in the 

 endosarc of every well-fed protozoon. 



Lastly, although I must speak here with considerable reserve, 

 I believe that the cytoplasm of these cells contains an iron- 

 compound. 



If sections of material preserved in absolute alcohol be treated 

 (by Macallum's method) with warm nitric-acid alcohol for twenty 

 four hours or more, and then placed in acid ferrocyanide, a 

 diffuse pale blue coloration is obtained ; and in certain abnormal 

 cases, to which I shall have to refer again later on, brown gra- 

 nules, precisely similar to those which have already been described 

 as occurring in maternal cells, have been found. 



The nuclei of these cells undergo a still more remarkable meta- 

 morphosis. After a time mitosis ceases, and the nuclei then eularge. 

 At first they resemble in structure the nuclei of other embryonic 

 tissues (Fig. 23). They have one or two rather large, generally 

 elongated nucleoli (plasmosomes) around which the greater part 

 of the chromatin granules are closely aggregated, the remainder 

 being distributed over the delicate achromatic reticulum. The 

 nucleus as a whole thus appears rather pale, and may, with care, 

 be distinguished by this character from the nuclei of certain sub- 

 epithelial cells which often attain a similar size. 



