376 JULIA ELEANOR MOODY 



(e) The tentacles, extremely slender organs, are of equal 

 thickness throughout their length; the tip, which is slightly 

 rounded, never pointed or knobbed, is quite opaque, owing to 

 the presence of a mass of minute dark granules, the trichocyst 

 material. The tentacles, greatly extended, are sometimes en- 

 tirely detached from the body; this phenomenon, in the three 

 cases observed, was followed by speedy disintegration of the 

 organism. These organs, readily traced into the cortical region, 

 have not been observed in the endoplasm. 



(f) The single terminal vacuole pulsates at intervals of one 

 minute and a half, a one minute interval occurring once in 

 some thirteen or fourteen pulsations. 



(g) The mouth opens into a funnel shaped gullet, the walls 

 of which are strengthened by longitudinal folds of the cortex. 



(h) Great variation is seen in form, length and position of 

 the rod-shaped macronucleus; sometimes it lies, fully extended, 

 parallel to the circumference of the body; again, straight, looselj^ 

 coiled, or tightly twisted in the centre of the cell. The nucleus 

 is covered with a delicate membrane within which, imbedded 

 in an achromatic substance, lie coarse, deeply staining chromatin 

 granules which in division stages are greatly elongated. 



(i) Spherical and comma-shaped bodies composed of deeply 

 staining granules imbedded in an achromatic medium, have been 

 observed in many sections and total preparations, which may 

 possibly be micronuclei, but owing to the fact that they have 

 not been observed in process of division, it seems more probable 

 that they are the nuclei of partially digested Halteriae. 



(j) Actinobolus reproduces by transverse division, the entire 

 process from the first elongation of the cell to the separation 

 of the two individuals, occupying about one hour and a half. 

 The division is unequal, the posterior cell being somewhat smaller 

 than the anterior cell. About half-an-hour after the beginning 

 of division, a new vacuole is formed anterior to the constriction 

 and a little to one side of the median plane of the body. The 

 number of daily divisions shows considerable variation owing 

 to the fact that the organism is extremely sensitive to food and 

 environmental, conditions. Encystment was not observed. 



