358 LOUIS I. DUBLIN. 



occurred, in most cases, long before this. At this point, in the 

 processes of synapsis the several chromosomes of the paternal 

 side very probably individually unite with their correspondents 

 on the maternal side. The position of the thus-formed bivalents 

 " in the equatorial plate of the reducing division is purely a 

 matter of chance, that is, that any chromosome pair may lie with 

 maternal or paternal chromatid indifferently toward either pole 

 irrespective of the position of other pairs and hence, that a large 

 number of combinations of paternal and maternal chromosomes 

 are possible in the matured germ products of an individual ' 

 (W. S. Sutton, "The Chromosomes in Heredity," BIOL. BULL., 

 IV., 5). 



II. 



The nuclei of the several generations of oogonia have already 

 been described ( Fig. 3 ) and need not again be considered except 

 to note that the two nucleoli or the one after the fusion are 

 always homogenous in structure and stain exactly like plastin 



a c 



FIG. 12. 



bodies. These invariably disappear in the ensuing mitosis. In 

 the youngest oocytes, a new nucleolus, more rarely two, makes 

 its appearance (Fig. 12, <?). This body is then quite small and 

 may be situated anywhere within the nucleus ; sometimes near 

 the periphery, sometimes on an arm of a chromosomal V or even 

 in the midst of a number of such intersecting arms. It stains in- 

 tensely at this stage, and shows as yet no trace of vacuolization. 

 In iron-hjematoxylin, carm-alum, Borel's fluid, etc., it stains 

 more deeply than the chromatin itself and might, if superficially 

 considered, be looked upon as a chromatic nucleolus, as several 

 workers have, on such evidence as this, actually considered it. 

 In Auerbach's fluid, however, the true nature of the body is very 

 clearly brought out. It stains invariably a deep red with the 

 acid fuchsin and shows no trace of the methyl green with which 

 the chromosomes are colored. 



