THE INTESTINAL PROTOZOA OF FROGS AND 'TOADS. 273 
Fig. 12,—The same creature a few seconds later. The protoplasm, 
after welling in and out rapidly several times, has suddenly been con- 
stricted, completely severing the two daughter-monads. Hach monad 
has an axostyle which is half of the rod-like structure which connected 
the blepharoplasts. 
Fig. 13—Trichomastix which has developed a karyosome in its 
nucleus and is preparing to encyst. 
Fig. 14.—Newly-encysted animal. The flagella have gone and the 
axostyle is degenerating. 
Fig. 15.—Permanent cyst. The axostyle has quite disappeared and 
the nucleus has taken on its characteristic elongate form, with the 
blepharoplast lying upon it. 
Figs. 16-28.—Trichomonas batrachorum. 
Fig. 16.—Ordinary individual, large specimen. 
Figs. 17-24.—Stages in division. 
Fig. 17._First stage in division. The axostyle has gone, and the 
edge of the undulating membrane has split. 
Figs. 18, 19, 20, 22, 23, 24.—Various stages in division, corresponding 
with those shown in Trichomastix. (Cf. figs. 4-10.) The mem- 
brane is seen in various stages. 
Fig. 21—In this organism a very distinct spindle figure is seen 
during the division of the nucleus. Note also the diplosomic blepharo- 
plasts and undulating membranes. 
Fig. 25—Trichomonas about to encyst. Nucleus with karyosome. 
Figs. 26, 27.—T wo successive stages in encystment. Resorption of 
axostyle, undulating membrane, etc. 
Fig. 28.—Permanent cyst, with elongate nucleus and no axostyle or 
locomotory organelle. ! 
PLATE 3. 
[Figs. 31, 39, 42, 43, 44, 45, 47, 48 and 51 are drawn from living 
specimens under Zeiss 2°5 mm. apochromatic water-immersion, comp. 
oc. 12. Remainder from permanent preparations: figs. 46, 49 and 
50 fixed absolute alcohol, stained Giemsa; the others sublimate-alcohol 
and Heidenhain’s iron-hematoxylin. Drawn, unless otherwise stated, 
under Leitz 2 mm. oil-immersion (apochrom.) with comp. oc. 12. } 
Figs. 29-41—Octomitus dujardini. 
Fig. 29.—Ordinary individual to show nuclear apparatus, etc. 
Fig. 30.—Individual with more consolidated nucleus, crossed axo- 
styles, ete. 
