5 1 3 Wager . — The Nucleus of the Yeast-Plant. 
appears to be surrounded on all sides by a more deeply 
stained membrane in close contact with it (Fig. 4). This 
seems in good preparations to be finely granular in nature, 
but it is not sufficiently definite to allow any positive statements 
to be made concerning it. It may perhaps be only a slightly 
denser portion of the nuclear body. The nuclear body is 
sometimes surrounded by granules which radiate into the 
surrounding protoplasm, giving it a star-shaped appearance 
which is described by Bouin (’ 98 ) as a nucleus. 
On the whole the nuclear body appears to resemble the 
nucleolus of the higher plants more than anything else, and 
should probably be compared to it in function. 
When stained as above described, or with the carmine- 
nigrosin combination, the nuclear bodies of different cells 
generally appear to be fairly uniformly stained and present 
a similar appearance in all ; but in preparations stained with 
gentian-violet (see page 512), a difference in the affinity for 
the stain is observable in the nuclear bodies of various cells. 
In some cells the nuclear body is deeply stained ; in others only 
faintly stained. It is generally clearly defined ; but in badly 
stained or insufficiently washed-out preparations it may 
appear irregular in outline, as already described by Moeller 
and Bouin. This is due to the granular substance often 
found around the nucleus, sometimes in close contact with it, 
but which is not to be regarded as a part of the nuclear body, 
and in well-stained preparations is sharply defined from it. 
The nuclear body can also be fairly easily rendered visible 
by allowing a dilute solution of iodine to run in gently under 
the cover-glass. The protoplasm stains first and the nuclear 
body is then visible as a pale unstained spherical body on 
one side of the vacuole. As the protoplasm becomes more 
deeply stained the nucleus becomes clearer. 
If fresh Yeast be placed in Gram’s solution of iodine for 
twenty-four hours, washed in water and placed in 30 °/ o alcohol, 
and then in 70 °/ o alcohol, the nuclear body can be very easily 
seen as being slightly more refractive than the rest of the 
protoplasm. It can also be very easily seen in specimens 
