May 1904] 
Elementary Mycology 
147 
water and mineral constituents. The chemical elements in the 
cellulose are Carbon, Hydrogen and Oxygen. The important 
elements in protoplasm are these three — Carbon, Hydrogen and 
Oxygen — and in addition also Nitrogen. The presence of the 
latter is very significant; all nitrogenous bodies are, potentially 
at least, active. The non nitrogenous on the contrary are passive. 
The nervous tissue, the glands, the muscles, contain nitrogen — 
as does also powder and dynamite; the bones and the ligaments 
are non-nitrogenous. Protoplasm is a highly nitrogenous sub¬ 
stance ; it does all the work involved in manufacturing food and 
carrying on the various processes in nutrition, growth and repro¬ 
duction. In a unicellular plant, with or without a cell wall, there 
is but one mass of protoplasm. But those plants in which the 
cells divide into two, these dividing again and so on, have pres¬ 
ently a multitude of protoplasmic masses — each cell cavity being 
filled with the active living substance. It is interesting to note 
that in a few groups of the lower plants, the nucleus divides, and 
this is repeated, so that finally many nuclei may be present in the 
cytoplasm, yet no cellulose walls are developed separating these 
as is the case in the higher plants. It would seem that the essen¬ 
tial process of cell-division had taken place and that such plants 
( coen 3 -o-cytes they have been called) might be said to be multi¬ 
cellular — though not in exactly the same sense in which the 
term is used in reference to the higher plants. In the uni-nucleate 
or the multinucleate mass of protoplasm there could well be a 
more or less free play of the resident energy — the whole as one 
individual. Can such a conception be retained when the higher 
multicellular plants are considered? Without doubt, because it 
has been found that notwithstanding the existence of isolating or 
surrounding walls, the individual masses of protoplasm, the 
“cells,’’ are in the closest sympathy; at least they maintain actual 
connections with each other. Minute protoplasmic threads pene¬ 
trate these walls and it is this fact that is alluded to in the phrase 
“continuity of protoplasm.” We can readily understand then 
that the entire plant — whether tiny herb, spreading shrub, or 
giant tree — is in a real sense an indivdual, these several 
anatomical elements which are called cells being — not isolated 
like so many cemented bricks or stones in a wall, but as inti¬ 
mately bound together as is the case in a perfect machine; we can 
also with equal propriety suggest the likeness to the sympa¬ 
thetic organs of the human body. Work then can be co-ordinated 
in the highest plant — those in which the tissues are differentiated 
to a marked degree. Some of the tissues — composed of specially 
differentiated cells — do one kind of work, others perform other 
functions. Thus the varied processes of absorption of food ma¬ 
terials the decomposition of carbonic dioxide and water, the for¬ 
mation of carbohydrates and other organic substances, digestion, 
assimilation and respiration are carried on, each by tissues spe- 
