404 KING. [Vou. XIX. 
substance in these bodies forms one large rounded mass which 
contains either one large vacuole or a varying number of small 
ones (Fig. 40). Such a structure greatly resembles the large 
vacuolated nucleoli found by Carnoy and Lebrun and also by 
Leydig in the ova of various amphibians, and it is also very 
similar to the “principal nucleolus” described by Maréchal 
(67) in the selachian egg. In many cases the plasmosome 
substance in these bodies is divided, the greater part of it 
forming a large, rounded central mass which usually stains 
rather faintly and appears either homogeneous (Fig. 41, R) 
or vacuolated (Fig. 41, S), the remaining portion being 
broken up into a varying number of small, round, deeply stain- 
ing bodies which are attached, for a time, to the outer surface 
of the larger mass and later separate from it to form small 
plasmosomes. © 
The large plasmosome bodies shown in Figs. 40, 41 and 51, 
disintegrate in various ways and at different times. In some 
cases they persist as rounded, vacuolated bodies until the 
germinal vesicle disintegrates at the beginning of the matur- 
ation period when they are slowly absorbed by the cytoplasm; 
in other cases they break open during the later growth stages 
of the ova (Fig. 51, b), and subsequently divide into several 
rounded portions which are gradually dissolved in the karyo- 
plasm (Fig. 43). It is not uncommon to find these large 
plasmosome bodies budding off portions of their substance 
(Fig. 51, c, d); and it is probable that many of the nucleoli 
found at the stage of Figs. 48-50 have been formed in this 
way. 
The central vacuole of these large plasmosomes frequently 
contains a number of nucleolini which may be separated or 
so joined together that they simulate a granular chromatin © 
thread (Fig. 51, C, D). These nucleolini always stain like 
the plasmosome, and they are evidently granules which have 
broken away from the inner surface of the ground substance 
in a manner similar to that by which the small plasmosomes 
are budded off from the outer surface. It seems probable that 
Carnoy and Lebrun have in mind linear aggregations of 
