412 ELIZABETH KIXNEY. 



of position in the gland. Several measured 3 micra in diameter 

 and a very few in the more actively secreting region are as large 

 as 5 micra or 6 micra, while in the anterior region, these bodies 

 average about 2 micra in diameter. This size relation is constant 

 regardless of the fixation used. 



Each nucleoloid body contains two or more vacuoles or clear 

 spaces which either do not stain or, if so, only faintly. In a 

 section of a nucleus, usually only one of these bodies is present, 

 rarely two (Figs. 3, 5, 6), and the frequency with which they 

 occur in serial transverse sections 4 micra in thickness leads to 

 the conclusion that not more than two are usually present in a 

 nucleus. This point has been very difficult to determine ac- 

 curately on account of the uncertainty in deciding where one 

 nucleus ends and the next begins. From longitudinal sections, 

 the evidence was more definitely in support of this conclusion. 

 These nucleoloid bodies are either centrally or just eccentrically 

 placed, and are never found in close approximation to the 

 nuclear wall. Their usual shape is spherical, thus distinguishing 

 nucleoloid bodies from nuclear bodies which tend to vary in 

 shape. From careful study, it has appeared that the presence 

 of nucleoloid bodies is usually associated with an increase in 

 the number of nuclear bodies (macrosomes) either in the same 

 section or the next in series. In the immediate vicinity of the 

 nucleoloid body, the nuclear bodies are smaller, increasing in 

 size toward the periphery of the nucleus (Figs. 3, 5, 6). The 

 periphery of the nucleoloid bodies is not always regular, for often 

 protrusions apparently in the process of pinching off may be 

 seen (Fig. 5). 



That the vacuolated nucleolus may give rise to nuclear bodies 

 is not without precedent in observations. Saguchi ('20) in the 

 pancreas cell, describes a very similar process which gives rise 

 to nucleolar corpuscles: p. 355: "As regards the genesis of the 

 nucleolar corpuscles, I am fully convinced that they are derived 

 from the main or side nucleoli." Montgomery ('99) concludes 

 that the nucleolus may act as a nuclear organ either of excretion 

 or storage and that when it has enlarged to a certain extent, it 

 constricts pieces from itself. 



1 lie nucleoloid bodies usually react more specifically to basic 



