98 V. E. EMMEL 



with Giesma's stain in contrast to the reddish tone of the rings 

 in pathological blood of the adult, although as already noted 

 blue rings are not entirely lacking even in the latter case. This 

 may be in part due to the different conditions under which they 

 are formed for it is to be observed that in certain regions such 

 as that of the brain wall and nerve ganglia many of the ring 

 bodies stain a reddish rather than a blue tone (figs. 28 and 33e). 

 In the embryo these rings are more frequently found without 

 any surrounding peripheral cytoplasm, that they may, however, 

 also occur within the still intact erythrocyte is well illustrated 

 in figures 34, 35 and 36 (also p. 96). This may be due in part 

 to an earlier disintegration of the cytoplasm in relation to the 

 nucleus in the case of the embryo as contrasted with the adult. 

 Although it is not to be overlooked that Gabriel ('08, p. 604) 

 records the observation even in the adult of ring bodies a par- 

 ently lacking a peripheral rim of cytoplasm. As to the normal 

 or abnormal character of these structures there appears no doubt 

 but that in the embryo just as in the adult (Naegeli) their pro- 

 duction is a phenomena of abnormal nuclear disintegration and 

 not a normal mode of erythrocytic cytomorphosis. Concern- 

 ing the conditions under which the degenerating erythrocytic 

 nucleus will present the form of a ring or that of small compact 

 spherules, the possibility is suggested that this may be asso- 

 ciated in Dart at least with the stage of cytomorphosis at which 

 the degenerative processes are initiated. In the younger eryth- 

 roblasts, as is well known, the nucleus is both relatively larger 

 and the chromatin granules are more loosely distributed through- 

 out the nucleoplasm, whereas in later stages of differentiation 

 the nuclei become not only smaller but also much denser and more 

 compact in chromatin structure. Degenerative changes initi- 

 ated at these different stages may consequently be expected to 

 manifest correlated differences in nuclear disintegration. It is 

 possible that a longer persistence of the thickened reticulum 

 described by Cupp ('15) at the periphery of the erythrocytic 

 nucleus may also be associated in part with the formation of 

 nuclear rings. 



