1919] Kofoid-Sirrzy: TricJionijniplia caiiipaiiula 57 



food of the trichonymphs, since few specimens were noted which did 

 not contain small particles of wood in the endoplasm. The entire 

 posterior portion of the body is often found densely filled with this 

 material which is light in color in the unstained preparations. Tlie 

 particles seem to be confined exclusively to the posterior region of 

 the endoplasm. 



Longitudinal Myonemes : The longitudinal myonemes are found 

 in the outer layer of endoplasm (fig. B, long, my.), a short distance 

 below the inner layer of ectoplasm containing the transverse myonemes. 

 These extend from the base of the tubular portion of the neuromotor 

 apparatus posteriorly to near the end of the differentiated ectoplasmic 

 region (fig. B, long. my.). They are subparallel for most of their 

 length, spreading apart posteriorly and converging anteriorly until 

 the}' meet in the region of the lobes of the centroblepharoplast. . The 

 connection between these myonemes and this portion of the neuro- 

 motor system is one difficult to determine. The myonemes stain only 

 faintly or not at all in the ordinary smear preparations. In sections 

 they may be seen as dark granular masses near the outer border of 

 endoplasm. It is in the living flagellates that they are best observed. 

 Here they may be seen as slender bands of homogeneous appearance, 

 somewhat refractive, and extending in an anteroposterior direction 

 and vibrating with the movements of the body. In stained material 

 they appear as strands of rather coarse granules which are somewhat 

 denser and slightly darker than the surrounding endoplasm. Their 

 structure seems to be entirely changed by the processes of fixing and 

 staining. 



The longitudinal mj'onemes seem to be the chief organelles con- 

 cerned in flexions of the anterior end of the body. This is extremely 

 mobile, turning easily from side to side (fig. C, 2), sometimes reaching 

 backward upon itself until it touches the posterior portion of the body. 

 With such movements in the living organism somewhat slowed down, 

 these strands may be seen to sway slightly with each movement. 



Nucleus: The nucleus is a rotund ellipsoid lying in the middle 

 third of the body. Its position varies from one-third of the total 

 length of the body from the posterior end (pi. 7, fig. 23) to about 

 the mid-region (pi. 5, fig. 6). In a cross-section of the body at its 

 level it lies near the center of the plane (pi. 5, fig. 4). A thin, dis- 

 tinct nuclear membrane separates it from the surrounding plasma. In 

 its internal structure it presents some unusual features which differ- 

 entiate it from other fiagellate nuclei. 



