56 University of California Publications in Zoology [Vol. 20 



fibers, being granular in appearance as are the longitudinal ones. 

 They are circular, passing around the body in nearly transverse 

 planes, and may be found throughout the entire region of thickened 

 ectoplasm. Each myoueme is a slender, granular band, not more than 

 one or two microns in thickness. These lie in parallel rows which give 

 a finely striate appearance to the innermost borders of the ectoplasm. 

 These transverse myonemes are only faintly outlined in the stained 

 specimens and are usually obscured by the wealth of oblique fibers 

 which overlie them. 



ENDOPLASMIC STEUCTUBES 



In the living organism the body is marked off into three distinct 

 regions, the outer clear ectoplasmic zone, the anterior endoplasmic 

 region of rather dense homogeneous appearance, and the posterior 

 endoplasm filled with coarse alveoli and food particles. The two endo- 

 plasmic regions are alwaj^s more or less clearlj^ differentiated, but 

 without the granular layer which separates these two portions of the 

 body in Trichonympha agilis (Porter, 1897). The transition from 

 one region to the other is distinguished by a change of structure rather 

 than by a delimiting layer of differentiated ectoplasm. 



The anterior region extends from the anterior end backward for 

 about two-thirds or slightly more of the total length of the body 

 (pi. 5, fig. 6). Proximally a slender plug or core of endoplasm 

 extends out through the narrow neck formed by the centroblepharo- 

 plast to the periphery of the bodj'. This region of endoplasm is 

 coarsely granular without distinct alveoli. The distal portion, extend- 

 ing up to and around the nucleus, is usually more dense, often taking 

 a darker stain with iron haematoxylin, showing greater metabolic 

 activity than in the anterior portion. It is also frequently filled with 

 minute flecks of a dark color (pi. 5, fig. 6; pi. 7, fig. 23). These are 

 often present in the posterior region of endoplasm and are possibly 

 remnants of bacteria which have been ingested with other food particles. 

 The possibility of their being chromidia is not excluded, however. 



The posterior portion of endoplasm is filled with large alveolar 

 spaces with the interstices occupied by coarsely granular plasma 

 (pi. 5, fig. 6; pi. 7, fig. 23). This part of the body usually contains 

 an abundance of food particles. As most of the termites examined 

 were obtained from decayed wood, this was the only foreign material 

 found in the intestine. It also seems to form at least a part of the 



