Eriksson. — On the vegetative life of some Uredineae . 59 
The inner and outer plasma-portions otherwise show quite the same struc- 
ture, and react in the same way towards staining agents. 
When expelled from the cell the nucleoli of the plasmodium are 
dissolved and their contents are transported into the outer plasma-portions. 
One often finds distinct threads growing from the larger nucleoli towards 
the cell-wall. In this case we have before us a body very like a young 
haustorium, as that is generally described and represented. But there 
is a great difference, in that we have before us here a growth that must be 
considered as coming from within. I will name it an Endohaustorium. 
The contents of the former nucleolus gradually get exhausted, and then 
only the outer light halo remains as a wide vesicle still connected with the 
outer mycelium and transporting nourishment to this from the cell-residues. 
In company with these round-headed bodies we find now and then 
some elongated ones, otherwise of the same structure. Probably they also 
must be considered as endohaustoria. 
It sometimes happens that the production of mycoplasm-nucleoli is 
very reduced or quite absent, and nevertheless the plasmodium is forcing 
itself out. This is probably due to an accidental weakness of the myco- 
plasm. 
At first one observes no distinct nucleoli in the intercellular Proto- 
mycelium, only various small grains of plasma, which take the violet colour 
more deeply than the other parts of the plasma. These grains are to 
be considered as a preliminary stage of nucleoli. 
Very quickly, however, a new stage begins, in which are formed large 
distinct nucleoli, surrounded by a light halo. 
Hitherto there were no partition-walls in the intercellular fungus-body, 
but later on such walls are formed, simultaneously with the dissolving 
of the nucleoli. 
After this we get a true mycelium , and finally a tissue of threads 
winding round the remaining leaf-cells, that is to say a pseudoparenchyma. 
Gradually the tissue of the host-plant is consumed by the Fungus. The 
chlorophyll-corpuscles are agglomerated into an irregular lump, and at last 
all the remaining parts of the cells are devoured by the Fungus. 
Now the Fungus is ready to produce spore-pustules. This seems to be 
initiated by a new appearance of large nucleoli in the pseudoparenchyma. 
The spore-forming threads grow outwards and the spores are produced. 
With the production of spores a new period, the fructificative period, 
of the fungus-life is introduced, the vegetative period being ended. 
So far the investigation has as yet been followed up only to the stage 
of development of the corn-plant, where its tender germ is sprouting out of 
the earth. The question, where the plasmodia in the leaves of the corn- 
plants have come from, must be left for further investigation. 
