THE INTESTINAL PROTOZOA OF FROGS AND TOADS. 217 
had previously described it (46) as a “der Bauchseite 
angehdrige Reihe von spitzzackigen, undulirenden Fortsitzen, 
welche gewohnlich fiir Wimpern angesehen wurden.” ‘This 
investigator also saw the axostyle and nucleus. Seligo (44) 
inclined to Stein’s interpretation of the structure, but Bloch- 
mann (1) and others clearly recognised its true nature. 
The method of division, excepting as regards the mem- 
brane, is almost identical with that of Trichomastix (see 
figs. 17—24). I will therefore merely note the few points of 
difference. 
The undulating membrane appears to be multiplied by 
splitting. In this the chromatic border takes part, but not 
the chromatic basis (figs. 17,23). The latter never seems to 
split, but seems to be absorbed and reformed in each daughter- 
membrane. But it is not easy to see what happens to it 
exactly. The two membranes may become completely sepa- 
rated at quite an early stage (figs. 18, 20), or may remain 
attached posteriorly till quite late (fig. 23). 
The blepharoplast and axostyle behave in exactly the same 
way asin Trichomastix (cf. figs.5—10). The stage figured 
in fig. 21 is specially instructive. There is a very distinct 
spindle figure, much more clearly marked than anything I 
have ever found in T'richomastix. Moreover, the resem- 
blance of the blepharoplasts to centrosomes is particularly 
striking (see discussion of this matter, p. 220 et. seq.). In 
the animal here figured the double nature of the blepharo- 
plasts was also particularly clearly shown. 
I have not found so many division stages in Trichomonas 
as in Trichomastix, but the likeness between them is so 
ereat that I have little doubt that they correspond almost 
identically. 
Kneystment takes place precisely as in Trichomastix. 
Before encysting the animal develops a karyosome in its 
nucleus (fig. 25). The axostyle, undulating membrane and 
flagella are then gradually lost as the cyst is formed (figs. 
26, 27). Finally the nucleus becomes drawn out in the cyst, 
and it is almost an impossibility to tell whether any given 
