240 C. CLIFFORD DOBELL. 
In a slowly moving animal all the details of structure—save 
the most minute points in connection with the nuclear 
apparatus—can be made out, with patience, with almost as 
much certainty as in a stained specimen. 
The body is characterised by extreme flexibility, which 
enables the animal to double and twist itself in all directions. 
Movement always occurs in a forward direction—that is, with 
the nuclear end in advance. 
During progression it is only the anterior flagella which 
are lashed about. The caudal pair are usually trailed. Not 
uncommonly they become attached to some object, and thus 
serve to anchor the organism, which may then rotate about 
the fixed point. Saville Kent and others have already noticed 
this. 
Multiplication.—In spite of having examined countless 
thousands of individuals, both alive and in fixed and stained 
preparations, I am still uncertain of the method of repro- 
duction. J have many times found stained specimens which 
are identical with those described as division-stages by Foa 
and Wenyon in the Octomitus in rats. But from observa- 
tions on the living animals I am now satisfied that these 
stages are merely degenerate and fused forms, which have 
nothing whatever to do with division.  Biitschli states that 
“Theilung”’ occurs in Hexamitus inflatus, but beyond 
figuring an animal with two spherical nuclei and four caudal 
flagella he gives no details of the process. According to 
Prowazek, in Octomitus intestinalis “bei der Teilung 
scheint die Achsenréhre' ganz nach Art des Achsenstabes 
der Trichomonaden und -mastiginen zu funktionieren. Sie 
nimmt eine etwas spindelformige Gestalt an, die vornehmlich 
durch eine Anschwellung des aiisseren Belages hervorgerufen 
wird.” Nothing further is said or pictured of the division. 
I have on several occasions found stained specimens which 
appear to me to represent genuine stages in division. ‘These 
are unfortunately extremely rare, and have all been at approxi- 
' The axostyles were thus interpreted. 
