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MONTGOMERY. 
[Vol. XV. 
points than at others, there are no visible pores in it, so that 
the nucleolar substance must be squeezed through the nuclear 
membrane itself. When one takes a sponge filled with water 
and presses it in the hand the water is forced out of it in the 
form of jets or columns, which are radial to the surface of the 
sponge; exactly similar seems to be the method of the discharge 
of the nucleoli in the case at issue, except that the nucleus is 
itself actively contracting. Thus we find the greater number 
of the nucleoli which lie in the cell body close to the surface 
of the nucleus to be irregularly columnar or rod like in shape 
(Fig. 198) and radially grouped around the nucleus. Those 
which lie nearer the periphery of the cell, however, and which 
had probably been discharged by a previous contraction of the 
nucleus, are more irregular in form, and their axes have a less 
regular position with regard to that of the nucleus. Further, 
those ends of the rod-like nucleoli in the cell which are directed 
towards the surface of the nucleus are usually more attenuated 
than the opposite ends, i.e., a nucleolus lying in the cell close 
to the nucleus has often the form of a pyramid the apex of 
which is directed towards the surface of the nucleus, and this 
form we would expect to result in the squeezing of a more or 
less viscid substance, like that of the nucleoli, through the 
nuclear membrane. I give only two figures showing the stage 
of the discharge of the nucleoli from the nucleus, simply in 
order to save time in the drawing of the numerous nucleoli ; 
but my preparations show very clearly all the stages of this 
process: one has only to examine sections of the mature leech to 
find them in abundance. The extrusion of the nucleoli continues 
until only about twenty, then a dozen, then four or five, and 
finally only a single nucleolus (Fig. 199) remains in the nucleus ; 
corresponding to these successive states of the discharge of the 
nucleoli we find cells in which only a few nucleoli, and then 
those in which the greater number of the nucleoli, lie in the 
cell body. One nucleolus always remains in the nucleus, though 
this one appears to differ in no wise from those which are dis¬ 
charged. Those nucleoli which lie in the cell body (Figs. 197- 
199) differ from those in the nucleus in their lesser density, 
greater size, and different reactions to certain stains (we shall 
