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Charles E. Allen 
are often surrounded by astral radiations, and that their function in cilia 
formation is analogous to that of the centrosomes of animal spermatids. 
Ou the other hand, most investigators have not observed the origin of the 
two blepharoplasts in the androcyte mother cell by the division of a single 
body; blepharoplasts have frequently been described as unaccompanied 
at any stage by radiations; tliey play no such part in fertilization as is 
ascribed to the centrosome of the animal spermatozoön; and Webber 
argues that they are not, at least in the Cyc-ads and Ginkgo, located at the 
spindle poles, and that the spindle fibers are at no time attached to them. 
In answer to the latter argument has been cited the description by Meves 
and von Korff (1901) of the central bodies of LithoUus, which, during 
mitosis, are located with reference to the spindle exactly as Webber 
figures the blepharoplasts in the dividing body cell of Zamia. The relative 
transitoriness of the blepharoplast has been urged by those who question 
its centrosomal nature; but this argument, it has been more than once 
pointed out, now avails nothing as indicating a contrast to the centro- 
somes of animal cells. Those who oppose any comparison with centrosomes 
prefer to consider the blepharoplast as an organ developed for the special 
purpose of cilia formation; and its location at or near the pole of the mitotic 
spindle is thought of as merely incidental, bearing in no way upon its essen- 
tial nature. In the same behalf, comparison is made with the cilia-forming 
bodies of epithelial cells and of infusoria, whicli have not been shown to 
be derived from centrosomes. 
In following the history of the blepharoplasts of Polytrichum, so far 
as that history is detailed in the present paper, the observer is impressed 
at every point with their similarity to the central bodies of animal cells. 
No one, I think, observing such a structure, with such behavior, in the 
cells of an animal, would hesitate to apply to it some one of the eommonlv 
accepted designations for central bodies, without considering the question 
of its homology or lack of homology with structures called by a like name 
in other organisms. This being true, it wonld seem that such authors as 
Belajeff, Hirase and Ikeno were fully justified in speaking of the 
bodies which they discovered in androcyte mother cells and androcytes 
as “centrosomes”. However this may be, the term “blepharoplast” has 
become well established, and common consent as well as its obvious ap- 
propriateness make it most convenient for use as applied to cilia-forming 
cell organs. 
In discussions as to a possible homology between the blepharoplast 
and the central bodies of those thallophvtes in which such bodies appear, 
the arguments above cited have been urged also upon the respective 
