274 ABBEY, ON ORGANIC STRUCTURE, 
If my interpretation of microscopical appearances is correct, 
it seems impossible to avoid the conclusion, that the deep and 
uniform colour of the nucleolus is so far from indicating the 
maximum of nutritional activity, that it is actually the sign 
of its minimum, if not, indeed, of its absence. 
As I have illustrated the nucleus, with its nucleolus, by 
reference to a higher grade of life, so may I illustrate the 
individual nucleolus. 
We find its analogue in the resting spores of alge, with 
their dark, condensed mass of inactive endochrome contained in 
a self-secreted coat; also in one of the older cells of a Conferva 
(Cladophora glomerata), whose crowded contents become ever 
paler and less dense with the progress of renewed growth. 
The phenomena of cell-growth are so conveniently epito- 
mised in the short career of the annual stems of herbaceous 
plants, that we may advantageously take a transverse section 
of such a stem for the purposes of illustration. 
Such a section, by-the-bye, dyed with magenta and blue 
or with orange and blue, and viewed with a l-inch objective 
and C Kelner eye-piece, is, from its intrinsic beauty, a striking 
object for the unphysiological eye. 
The common dock (Rumex) sufficiently serves the purpose. 
In the cambium-layer, where growth is actively progressing, 
we observe that the young cells, as yet very small, are quite 
full of darkly stamed nuclear matter, usually, if not always, 
in the form of a hollow nucleolated nucleus. 
In the older tissue, as represented by the central paren- 
chyma, we find, if the plant be young, that the nuclei are 
very distinct, the germinal molecules being so thickly grouped 
as to need the use of a +!” object-glass for their satisfactory 
optical separation. The seemingly homogeneous nucleolus 
has, in this case, little or no areola. In the corresponding 
parenchyma of an older plant the nuclei are often more 
numerous ; they are absolutely larger, but smaller in pro- 
portion to the containing-cell; the germinal molecules are 
distinctly isolated, and there is a very apparent areola round 
the nucleolus. 
Not unfrequently may be noticed a series of three nuclei 
with their nucleoli, each smaller and more deeply coloured 
than its predecessor, the presumptive common parent being 
but the ghost of its former self. Many nuclei have two 
areolated nucleoli. Here and there may be seen, clinging, as 
it were, to the nucleus, a smaller mass, consisting solely of 
large molecules separated by plasma, which seems to be the 
result of fission of the nucleolus, followed by assumption of 
