312 KOFOID AND SWEZY. 



cytoplasm is a fixed one in the pellicle. The protruding tip, which in 

 some cases is quite elongated (PI. 1, Fig. 8) is also independently 

 active at times waving back and forth in an arc of 180° or describing 

 the surface of a cone of rotation of varying angle. In all of this 

 activity it is strikingly suggestive of a flagellum constrained in its 

 movements by the enveloping cytoplasm, especially at the point of 

 emergence, and by the mass of its own substance but nevertheless 

 independently and vigorously motile. Some progression over the 

 substrate may occur, by reason of the rotation of the body, but the 

 whole surface is evidently more or less adhesive. Under these condi- 

 tions the axostyle is anything but an organ of fixation. 



From a functional standpoint the axostyle is thus a stout, largely 

 intracytoplasmic flagellum for locomotion in a \'iscid medium. 

 Structurally it has the same connections with the blepharoplast that 

 other flagella have. It does not stain as they do, especially within 

 the cytoplasm.^ Both the chromatic margin and the chromatic 

 basal rod stain an intense black, but the axostyle is hyaline and the 

 least stained of all parts of the organism. It may be, however, that 

 the axostylar chromidia within it ha\e segregated in themselves the 

 stainable substance which is continuous in the other structures named. 

 It should be remembered in this connection that the chromatic basal 

 rod also may be at times made up of chromidial blocks, as noted by 

 Martin and Robertson (1911) for Trichomastix (jallinarum. The 

 tendency for the chromidia to assume an axial position in the axostyle 

 (PI. 1, Figs. 5, S) is also significant in this connection as is also the ten- 

 dency for the distal part of the axostyle just within the cytoplasm 

 to have regularly grouped chromidial granules. When tlie axostyle 

 protrudes a considerable distance, as it sometimes does, these gran- 

 ules may be seen adhering to it. Additional structural confirmation 

 of the flagellar homology of the axostyle in the trichomonads is to be 

 seen in the fact that the projecting parts of these structures in Hex- 

 amitus (= Octomitus) and Lamblia are posterior flagella comparable 

 in appearance to that projecting from the undulating membrane in 

 Trichomonas. We may conclude then that the axostyle of Trichomo- 

 nas is an intracytoplasmic flagellum highly specialized for motor 

 activity on the viscous mucous surface of the intestine. 



The blepharoplast (hi., Fig. B) is a spheroidal body lying very 

 close to the surface near the anterior end of the body dorsal to the 

 cytostome and at its Aery margin. It also abuts against and may 

 even appear to be indented into the head of the axostyle. It is usually 

 about 0.5 jjL in diameter, varying possibly with the degree of extraction 



