THE INTESTINAL PROTOZOA OF FROGS AND TOADS. 225 
the study of the division of the trichomonads recorded in 
preceding pages. ‘To conclude my remarks, I will now sum 
up the views which I have attempted to express as briefly as 
possible in the foregoing pages, in the following words: The 
blepharoplast of the antherozooid, the blepharo- 
plast of the trypanosome and trichomonad, and the 
end-knob of the axial filament of the metazoan 
sperm are all homologous structures, whose func- 
tion is to provide for the locomotory activities of 
the cell. They are further homologous with—in 
some cases (e.g. in sperms) directly derived from 
—the centrosome of the resting cell. 
‘D- 
The Axostyle.—This organ may suitably be considered 
here, as it is very closely connected with the blepharoplast. 
Regarding the function of this organella in the adult 
individual there is some diversity of opinion. I believe 
that its real function is entirely skeletal. It is merely an 
axial support. 
From Prowazek’s work (73) it would appear to be a kind 
of division-centre in addition. But, as I have already said, I 
believe this conception rests upon an incorrect interpretation 
of the appearances observed. Nor can I agree with Wenyon 
(87) that the axostyle is an organ for attachment. One has 
only to observe the living animal to see that it is never used 
for this purpose. 
What I am particularly concerned with here is the origin 
of the axostyle. As I have already shown, it is absorbed 
before division and reformed by the division of the blepharo- 
plast. If the blepharoplast itself is the homologue of the 
centrosome, then the homology of the axostyle with the 
central spindle! at once suggests itself. The homology is 
* Tuse the term in its original sense (Hermann, ‘ Arch. mikr. Anat.,’ 
1891), that is, for the spindle uniting the centrosomes, and around 
which the mantle-fibres of the achromatic spindle are arranged. 
