4l6 MONTGOMERY. [Vol. XV. 



and eosin (Figs. 68 and 69). With the Ehrlich-Biondi method 

 this difference is not quite so clearly demonstrable. The latter 

 stain is peculiar and differs from all other stains used by me 

 for these cells, in that it very often gives to the smaller vacuoles 

 of the nucleolus the appearance of black, refractive granules ; 

 but a careful focusing of these supposed granules shows them 

 without doubt to be vacuoles, their apparent solidarity being 

 probably due to the refraction of light by the enveloping 

 nucleolar substance. 



The chief result derived from the foregoing observations is 

 that the nucleolus takes up some or all of those nutritive 

 globules which lie in the caryolymph, and whose substance had 

 been probably derived from the cytoplasm. Some of these glob- 

 ules then become collected within the nucleolus, representing 

 its fluid vacuoles ; and these globules, increasing in number at 

 the same time, gradually fuse together and thus give rise to 

 a single large excentric vacuole, which is enveloped by the 

 unchanged true nucleolar substance. Since the substance of 

 these small globules is probably nutritive in function, the 

 nucleolus in thus collecting some or all of them would appear 

 to act as a reservoir for nutritive substance, or as a reservoir 

 for that portion of the nutritive substance accumulated in the 

 nucleus, for which the nucleus may have no use. Of course 

 it is not a priori impossible that these globules may represent 

 waste products of a nutritive substance, so that the nucleolus 

 might here fulfill the office of an excretory organ. But the 

 function of these nucleoli can only be decided when the 

 behavior of the nucleolus during the pole-body mitosis is 

 known ; I had no ova showing pole-spindle formations. 



Finally, the true nucleolus appears not to be bounded by a 

 special membrane ; after staining with acid carmine and nigro- 

 sine the nuclear substance appears bluish green and a red 

 membrane seems to envelop it (Fig. 80), but this appearance is 

 probably due to the refraction of light, since nothing of the 

 kind can be found after the use of other staining methods. 



We now come to speak of what I have called the " pseudo- 

 nucleoli," but merely in order to distinguish them from the 

 true nucleolus, and without wishing to express by the use of 



