LIFE-CYCLE OP " CYSTOBTA " IRREOULAKIS (mINCH.). 29 



very close and fairly dense, and there are besides numbers 

 of minute highly refractile granules {r.g.) which have stained 

 deeply and give the cytoplasm a granular look. On the other 

 hand, in sections stained with Kleinenberg's hEematoxylin, 

 followed or not by eosin, the spherules have retained the 

 stain and stand out distinctly from the cytoplasmic matrix, 

 whicli is in these cases only faintly stained (fig. 45, PI. 5, and 

 fig. 36, PI. 4). 



Sometimes, however, these paraglycogen grains are very 

 small and not prominent (figs. 38 a and 38 h, PI. 2), but there 

 are besides numerous larger, irregular, more flattened gran- 

 ules (a.g.) ; these apparently correspond to the lenticular 

 plates, which Cuenot (loc. cit.) figures, and which constitute 

 albuminoid reserve material. The}^ are abundant in fig. 38 h, 

 which represents part of the cytoplasm of a sporulating 

 Cystobia, fixed Avith corrosive sublimate and acetic, and 

 stained with thionin and orange. The refringent granules 

 {r.g.) are also very numerous, especially in fig. 38 a, a simi- 

 larly stained section. These granules have a purple tinge 

 owing to their retention of the thionin, the other constituents 

 having only kept the orange. 



In Diplocystis Schneider i the paraglycogen spheres 

 attain a relatively enormous size compared with those of 

 Cystobia (vide fig. 27 &, which shows a portion of the 

 cytoplasm of the former). Between and around the spheres 

 is seen the cytoplasmic matrix. In my sections of this Gre- 

 garine I have not observed any irregular or lenticular grains 

 of any kind. 



The nucleus. — An adequate idea of the nuclei of a 

 Cystobia is best obtained when they have been treated with 

 iron-hfematoxylin. No other stain demonstrates so well the 

 fact that there is a definite chromatic reticulum, although 

 Kleinenberg's hfematoxylin succeeds to a certain extent. 

 Safranin and thionin, however, while staining the karyosomes 

 and also the nuclei of the surrounding tissue well, come out so 

 quickly from the remaining parts of the Cystobia nuclei, 

 that one might imagine there was nothing more in these save 



