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Charles E. Allen 
sistent throughout the life cycle, lias been retained in one or two cell 
generations because of its cilia-forming function, wliile in other genera- 
tions, fellowing a course of development leading toward the conditions 
characteristic of the higher seed plants, the kinoplasmic structures (in- 
cluding particularly the spindle fibers) have acquired a capacity for 
eoördinated action independent of definitely localized centers. This notion 
is strengthened by the study of a case like that of the androcyte mother 
cells of Polytrichum, in which the blepharoplast betrays no perceptible 
difference, in appearance or behavior, from a typical central body. There 
is reason to suspect, as already indicated, that much the same thing will 
be found to be true of the blepharoplasts at least in other bryophytes. 
Even should the event prove otherwise, it may still be argued from a case 
like that of Polytrichum that the blepharoplasts of other plants, while 
morphologieally centrosomes, have lost certain distinguishing charac- 
teristics in the course of phylogeny. It is eonceivable, indeed, that, as 
Strasburger has argued, a body like the cilia-forming organ of Vaucheria 
has taken on some of the properties of another kinoplasmic body — the 
eentrosome — which is morphologieally very different. But it seems 
difficult to imagine such an ineidental acquisition by the blepharoplast 
of Polytrichum of everv visible characteristic of a eentrosome; and in our 
present state of relative ignorance, the doctrine that the blepharoplast 
is the homologue of a eentrosome seems to impose rather less strain upon 
the imagination. 
On the other hand, it is true that thus far no alga which might be 
supposed to stand near the line of descent of the bryophytes and the higher 
plants has been shown to possess a definite cell organ which functions 
as a eentrosome during mitosis. Hence it is among the chlorophyceae 
that we must look particularly for further light on the origin of the blepharo- 
plast. Should it appear that in the members of this group the cilia-forming 
organs described by Strasburger develop from central bodies which 
function in Connection witli nuclear division, the derivation of the blepharo- 
plasts of the higher plants from such central bodies will appear extremely 
probable. If, on the other hand, no central bodies appear in these plants 
in connection with mitosis, Strasburger’s views as to the nature of 
blepharoplasts will be greatly strengthened. Even in the latter case, 
however, it may be argued that the blepharoplasts of these particular 
algae are perhaps developed from the centrosomes of still more primitive 
forms. 
Whatever its liomologies, the blepharoplast of Polytrichum is plainly 
a kinoplasmic body, manufactured out of rnaterials already present in 
