The Morphology and Physiology of the Nucleolus. 121 
into albuminous granules {55 ) ; while in the silk-gland cells “ as 
the nucleoli migrate from the nucleus they seem to give off 
phosphorus to form themselves one of the lowest members of the 
nuclein series ” {55). He concludes that “ this statement on the 
chemical change may hold true for the migrating nucleoli in 
different other cells/’ 
According to Adami ( 1 ) nucleolar extrusions are quite common 
in pathological conditions of cells. In “ cloudy swelling,” a con- 
dition of cell intoxication accompanying acute fevers, the extrusion 
of nucleolar matter into the cytoplasm is followed by the appearance 
of albuminous granules in the cytoplasm. This condition is well 
seen in the liver cells with phosphorus poisoning. Adami states 
that “ the indications are that the higher syntheses, those associated 
with growth and those governing the specific enzyme actions of the 
different forms of cells, are determined and initiated by the 
nuclear matter.” He suggests that this process is carried out 
through the intermediation of nucleolar extrusions. 
4. Cytomyxis . — A phenomenon in some ways similar to that 
described as occurring in the nerve cells of Mammals, is that to 
which Buggies Gates {15) has given the name cytomyxis. During 
pollen formation in certain plants “ a portion of the chromatin of 
one pollen mother-cell passes through an opening in the cell- wall 
into the cytoplasm of an adjacent mother-cell.” This occurrence 
has been said to be pathological or an artifact due to fixation, but 
Buggies Gates observes that “ in some cases it is followed by a 
return of the nucleus (from which the extrusion has taken place) to 
a central position in the pollen mother-cell, and absorption of the 
extruded chromatin in the cytoplasm of the invaded cell.” 
The extruded nuclear substance forms what Gates calls a 
“ pseudo-nucleus ” ; it persists for a time in the invaded cell, and 
eventually breaks down and disintegrates. 
5. Experimental Researches on the Nucleolus . — Very little ex- 
perimental work has been carried out on the nucleolus, but the 
few papers which have appeared on this aspect of the subject show 
that we have here a very fruitful field for further research. 
Wace Carlier {65) investigated the behaviour of the nucleolus 
in the oxyntic cells of certain mammals during the secretion of the 
gastric juice. He found that after the application of a stimulus — 
iir this case the smell of food — both the nucleus and nucleolus 
increase in size. With continued activity the nucleus as a whole 
shrinks considerably, but the nucleolar matter increases in amount, 
and fragments of it are expelled into the cytoplasm, where they 
remain for a time, then disintegrate. As the cell begins to recover 
from the ‘'exhausted condition,” the nucleus grows larger again, as 
does the nucleolus, and when the nucleolar matter becomes exces- 
sive, extrusion occurs once more either by the expulsion of the 
entire nucleolus or fragments of it. 
