116 F. H. STEWART. 



frequently opposite the epidermal and submedian lines, but 

 also opposite the muscle fields. They are to be found 

 throughout the entire length of the body with the exception 

 of the pharyngeal region. 



(2) Eather flattened cells (PL 7, fig. 10, he") generally 

 crescent-shaped in transverse sections oE the animal, owing to 

 compression between the gut and the body-wall. Maximum 

 diameter, '02152 mm. The protoplasm contains a basophil 

 substance. The nucleus is more or less spherical, has a nuclear 

 membrane, and finely granular acidophil contents. The chro- 

 matin is aggregated into a large spherical pseudo-nucleolus. 



These are the cells referred to above as possibly identical 

 with the third type of cell in the collar. They differ from this 

 type, however, in the fact that the basophil markings in the pro- 

 toplasm are much more extensive and constant, and that the 

 material filling the nucleus is definitely acidophil, not ampliophil. 



They occur most commonly opposite the submedian lines, 

 but also opposite the muscle fields. Commencing at the 

 posterior limit of the collar, they are found as far back as 

 the rectum. As to function, they do not appear to be phago- 

 cytic ; they are possibly nervous. 



The only previous reference to an organised tissue filling 

 the body space in Nematodes is on the part of von Linstow 

 (11 ft), who describes a " plasma cylinder ^^ surrounding the 

 gut in Thoracostoma denticaudatum (Schn.) and Eno- 

 plus edentatus (v. Linst.) 'Won dem dorsal und ventral je 

 zwei Leisten ausstrahlen." His figures, however, show no 

 nuclei in this "cylinder." Jagerskicild (10) for Cylicolaimus 

 magnus writes: "Hie und da findet sich zwischen dem 

 Darme und der Muskulatur eine ganz homogene, bisweilen 

 sich stiirkfarbende Schicht. Ich kann sie nur als eine Art 

 coagulierter Flussigkeit deuton, denn alle Kerne fehlen. 

 Vielleicht ist es sogar nicht allzu gewagt zu vermuten dass 

 diese Flussigkeit, die, wie angedeutet wurde, nicht iiberall 

 oder gar irnmer vorhandeu ist, nur als folge kraftigen Ergrei- 

 fens mit der Pincette oder dergleichen kleinerer Verletzungen 

 exsudiert worden. Denn dass die Thiere norraalerweise 



