14 



DR. HJALMAR BROCH 



[1918 



intestine through two narrow åpenings or short ducts; the glands 

 have an almost globular shape, and show no indication of bran- 

 ching or division. 



The o e s o p h a g u <s (textfig. IV) is lined with a rather thick, 

 honiogeneous, and chitinogene cuticle, the direct continuation of 

 the external thoracic cuticle; the oesophagal cuticle accordingly 

 exhibits an intense affinity to bleu de Lyon (pl. V, fig. 25). The 

 cuticle is supported by a cylindric epithelium with not very high, 

 and indistinotly circumscribed cells. Radial dilatatory muscles are 

 connected with the oesophagal cuticle by fine fibres inserted 

 between the epithelial cells; the dilatatory muscles foran strong 

 muscle bands, and have their other end fixed to the external 



Textfig. IV. Transverse section of the oesophagus in Scalpcllum Strømii 

 [X 200], c. = cuticle; d. m. = dilatator3 r muscle; r. m. = ring muscle; 

 m. s. = undifferentiated sarc of the cells of the ring muscle. 



thoracic cuticle. Outside the epithelium, strong parallel ring 

 muscles build a sheath round the oesophagus; the ring muscles 

 almost seem to be stronger than the dilatatory muscles; they 

 consist of epithelial muscle elements with large bodies of undif- 

 ferentiated sarc fixed to the external side of the muscle sheath (pl. 

 V, fig. 25, textfig. IV, ms.). In longitudinal sections of the 

 oesophagus (pl. IV, fig. 17) we observe how the distal part of the 

 dilatatory muscles, or hetter the connective part between the 

 oesopihagal cuticle and the dilatatory muscle proper, exhibits a 

 more sinew-like structure; the connective pants seem to be arranged 

 in indistinct longitudinal rows, and are themselves connected b}' 

 cross-connections inside the sheath of ring muscles. As mentioned, 



