CARNOY’S CELL RESEARCHES. 493 
spindle as lies within the area of the new nucleus. The rest 
of the spindle is cut off by the forming membrane and dis- 
charged into the cytoplasm, of which it becomes a constituent 
part. It does not dissolve, but is utilised in the formation of 
the cell-plate (where a cell-plate is formed) and in the recon- 
stitution of the cytoplasmic reticulum. 
Plasmodieresis.—The plasmodieresis of cells whose nucleus 
has divided by karyokinesis takes place in various ways, any 
one of which, however, is a faithful copy of one or other of the 
ways in which it takes place in cells whose nucleus has divided 
akinetically. All the modes of akinetic plasmodieresis are 
represented, and that very frequently, in karyokinetic plasmo- 
dieresis. 
The simplest mode is that of simple constriction. This is 
found in all groups of Arthropods, and in some of them is the 
only mode that is found. But on the whole, if I understand 
the author rightly, it is by no means the commonest mode. 
The commoner case is, that a cell-plate is formed. The 
plate may be ‘‘ complete” or “incomplete.” When it is com- 
plete it has the structure of a vegetal cell-plate; that is to say, 
it may be considered as being made up of two portions, an in- 
ternal one formed by the spindle, and an external one formed 
by the cytoplasm. The former is the spindle-plate, ‘‘ plaque 
fusoriale,” the latter is the cytoplasmic plate, or “plaque com- 
pletive.” I pass over the details of the formation of such a 
plate; they are essentially identical with those of the formation 
of a vegetal cell-plate. 
Complete cell-plates are by no means infrequent in Arth- 
ropods. But incomplete plates are of still more common 
occurrence. By incomplete plates is here meant, as in vegetal 
cytology, spindle-plates which do not give rise to complete cell- 
plates by the addition of the cytoplasmic plate. 
A plate, complete or incomplete, having been formed, the 
separation of the daughter-cells may take place in very various 
ways. There may be cleavage of the plate, and transformation 
of its layers into new membrane, as in vegetal cells; and this 
appears to be very generally the case when the plate is com- 
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