590 J. M. MACFARLANE ON VEGETABLE AND ANIMAL CELLS. 
would generally possess an irregular periphery. Or, if they originated by 
deposition of layers from without, this lamellar structure would be perceptible 
in large and perfect nucleoli.” 
NAEGELI regarded it functionally as a centre round which protoplasm 
gathered to form the nucleus. Recent botanical authors have either greatly 
neglected it or supposed it to result from a firming or segregation of the 
nucleoplasm. 
The conelusions-expressed in my previous paper have been amply confirmed 
in studying Chara. In every active embryonic cell one nucleolus only is present 
in the resting state. 
In very rare cases, and only where it had attained a large size, have I noticed 
a clear homogeneous liquid-like globule enclosed. Whether this resulted from 
degradation of the endonucleolus, or whether the latter was enclosed in it, I 
cannot definitely say, though, judging from appearances in Spirogyra, Rheum, 
&c., the former view seems most probable.. 
From the action of chemical reagents, and the impression which it gives during 
division of being thick and viscid, it seems to be a vesicle containing richly 
differentiated protoplasm. 
All reagents used, such as carmine, logwood, iodine solution, osmic acid, 
eosin, and the various aniline dyes agree in this, that they invariably, or with 
but few exceptions, stain the nucleolus more deeply than the nucleus. 
During division the nucleolus elongates, becomes constricted rather sharply 
in dumb-bell fashion, but during the whole period retains its dense consistence, 
and then separates into daughter nucleoli. In Spirogyra, even before division, 
I have pointed out that it is the centre of two opposing forces acting along the 
length of the cell. The reason of this seems to be that a large nuclear spindle 
has to-be formed in order to bring the daughter nuclei into the middle of the 
two forming daughter cells. In Chara no such necessity exists, so that even 
if similar forces be acting in it before division, these do not, since they need 
not, exert themselves in the same pronounced way. But that the daughter 
nucleoli are new centres of influence, determining greatly the future division 
of the cell, cannot well be doubted in. view of what has been seen to take 
place. 
JoHow, in regarding the daughter nucleoli of cells as formed from the 
chromatin granules, states that the latter are at first numerous, but gradually 
unite to form the nucleoli. We might expect then to find preparations with 
aggregating masses of four, five, or more. I have never found such in multi- 
plying cells, and further, the idea is opposed to all that we know of cell division 
where an increase and not a decrease in number occurs. 
Nucleus.—I come now to a matter of great importance in view of recent 
