DR. HJALMAR BROCH [1918 



A study of the histological structures shows us ithat the 

 oesophagus is lined by a (rather thick cuticle (pl. I, fig. 3 — 4), 

 the direct continuation of the thoracic cuticle; it shows a pronoun- 

 ced affinity to bleu de Lyon. The cuticle is supported by a cylind - 

 rie epithelium consisting of small and narrow, but rather high 

 cells; the cells are, especially nearer the mouth opening, richly 

 furnished with grains of blackish pigment in their basal part. In 

 the hinder region of the oesophagus the pigment decreases little by 

 Little, and disappears wholly near the transition to the stomach. The 

 muscles of the oesophagus are extremely powerful and, especially 

 nearer the mouth opening, remarkably concentrated, the fibres 

 almost everywhere lying closely packed together. It is therefore in 

 most places impossible to deteot undifferentiated sarc, and only 

 between fibreis of the dilatatory muscles do small portioiis of undif- 

 ferentiated sarc seeni to occur a little outside of the oesophagal 

 epithelium, where the fibres havie not yet gathered into olearly 

 circumsoribed muscle bands. In this respect Anelasma evidently 

 occupies a higher stage of deivelopment in comparison with 

 Scalpellam as described farther below. Dilatatory muscles are 

 connected with the cuticle by fine threads running between the 

 epithelial cells (pl. I, fig. 4); these threads exhibit a pronounced 

 affinity to acid fuchsine, and thus strongly contrast with the muscle 

 tissues proper, which after treatment with van Giesson's staining 

 method attain a vivid yellow coilour, owing to the picric acid. On 

 the other hand, the connective threads in question, from their 

 indifference to bleu de Lyon, contrast with the cuticula. The 

 dilatatory or radial muscles gather into strong muscular bands, 

 connecting the oesophagal wall with the external cuticle of 

 the proboscis. Round the oesophagus indistinctly circumscribed 

 ring muscles form an almost continuous sheath; this is extraordin- 

 ally powerful nearer the mouth opening, but deoreases backwards, 

 and almost disappears at the transition to the stomaoh. 



The stomach proper is richly furnished with deep longitud- 

 inal folds, and covered by a rather delicate cuticle, the direct con- 

 tmuation of the oesopihagal cuticle. The cuticle of the stomach is 

 in Anelasma rather thick in comparison with that of Scalpellum, 

 and the transition to the cutiele-like lining of the intestinal 

 epithelium is somewhat abrupt (pl. I, fig. 5). The epithelium of 

 the stomach consists of high and narrow cells, and contrasts rather 

 markedly with that of the digestive intestine; on the other hand 

 it idiffers only slightly, if at all, from the oesophagal epithelium. 

 The stomachal epithelium is destitute of pigment. In comparison 

 with Scalpellum, the stomach proper of Anelasma is very indi- 

 stinctly bounded against the oesophagus, indeed no definite 

 boundary can be pointed out; the denomination of stomach is here 



