8 Uiiiversify of Califoniia Publications {>i Zoologij [Vol.20 



siderable increase in length to nearly three or even six times the 

 normal seems possible (pi. 1, fig. 3). No evidence of an extension 

 of the protoplasmic pellicle to form a sheath for this remai'kable 

 organ has been found. It may also be so foreshortened that the 

 blepliaroplast and centrosome are brought into close juxtaposition 

 (pl. 1, fig. 2). 



In view of the fact tliat the individuals lie closely packed against 

 the digestive epithelium with the blepharoplast thrust against the 

 epithelial cell of the host, it appears that this protrusible organ serves 

 in some way as a part of a somewhat adjustable holdfast. We have 

 no evidence that it can be or is ever thrust into the body of the cell, 

 though such a mode of attachment seems possible. 



The blepharoplast (fig. A, bl.)is a sphere at the anterior end of 

 the rhizoplast about 0.5/* in diameter. The six flagella spring directly 

 from it. It lies normally in the extreme anterior end of the body and 

 is carried out with the extruded rhizoplast. The possibility of its 

 being drawn out in detaching the parasite from its adhesion to the 

 cells of the host is not precluded, but the numbers of such cases and 

 the retention of normal symmetry of both body and rhizoplast does 

 not support the suggestion of forceable extraction: 



In one instance (pl. 1, fig. 4) a terminal blob of cytoplasm with 

 a deeply staining terminal cap is attached to the side of the blepharo- 

 plast, and in another a considerable mass of protoplasm lies about 

 the extruded blepharoplast. While these may be abnormalities it is 

 possible that under certain conditions the cytoplasm assists locally 

 in the holdfast function of the blepharoplast bj' forming an enlarged 

 mass about it. 



The six flagella are equal, habitually trailed posteriorly and about 

 half as long as the body. They serve to keep up the circulation of 

 the fluid contents of the digestive tract as they lie parallel to the 

 closely packed bodies of the parasites (pl. 1, fig. 8) in the folds of 

 the digestive ej^ithelium. 



The four peripheral spiral threads (fig. A, my.) which terminate 

 at or near the blepharoplast must be regarded as a part of the neuro- 

 motor apparatus. Their relations to the blepharoplast and their 

 stainability as well as the homology suggest this. Their function, 

 if contractile (and their spiral course indicates this), appears to be to 

 force the blepharoplast into intimate contact with the cells of the host. 

 They persist at cytolysis and individuals are often found (pl. 1, 

 fig. 10) in which these myonemes are frayed out as distinct lines. 



