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Charles E. Allen 
of thc energy changes with which it is intimately concerned. Since it is 
thus built up out of other substances present within thc cell, it is quite 
conceivable that it may in turn bc retransformed into something quite 
different from kinoplasm. In view of these considerations, evident in- 
creases or decreases in its total bulk need not affect our conception of the 
kinoplasm as a distinct substance with a definite function. 
So far as I know, no structures closely similar to the kinetosomes 
of Polytrichurn have hitherto been recognized as kinoplasmic in nature; 
and as we have seen, the great majoritv of cell inclusions thus far described 
which superficially resemble the kinetosomes are plainly non -kinoplas- 
mic. Nevertheless, it seems clear that the substance of the bodies now in 
question is to be referred to this category. The bodies are certainly active; 
their position, to all appearances, determines the spindle poles; the spindle 
fibers grow out from them; and while the latter fact does not finally prove 
the fibers to be made from the substance of the kinetosomes, it is suggestive 
that the amount of fibrous material which appears in anv mitosis is roughly 
proportional to the bulk of the kinetosomes present within the cell. These 
bodies, then, have the same claim to being considered kinoplasmic as have, 
for example, central bodies (of whatever form) or blepharoplasts. 
The kinetosomes give no evidcnce of being, in such sense as are the 
blepharoplasts, definite morphological entities. They seem rather to be 
irregulär masses of material destined to be used in the formation of spindle 
fibers and cell plates. They are thus comparable to the nueleoles of the 
higher plants, as conceived by Strasburger — namely, reserve masses 
of kinoplasm which usually take on, to be sure, about the same form, 
but whose size, shape and number in any particular nucleus are offen 
variable and apparently immaterial. It is true that the kinetosomes 
differ from niost nueleoles in that they persist during mitosis and are 
transferred from mother to daughter cell, and it may be that they possess 
a higher degree of individuality than I have ascribed to them; but my 
present inclination is to think of them as rather haphazard, unorganized 
masses. 
The strongest Suggestion of a definite structure is presented when 
the kinoplasm is inassed in the form of a plate, which divides at a certain 
stage into two. If this were always the condition, it would be natural to 
compare this plate with the variously formed central bodies of some of 
the thallophytes; but the facts that thc kinoplasm is not uniformly ar- 
ranged in a single plate, even in the earlier androgones, and that later it 
is always broken up into a variable number of kinetosomes, seem to show 
that its comparatively regulär form in the earlier generations results simply 
