I 



Contributions to the Anatomy and Histology of Thalassema neptuni Gaertner. 565 



Fig. 11. Thalassema neptuni, dissected from the dorsal surface 

 to show the digestive system ; the segmental organs are coloured yellow, 

 the blood vessels red, the collateral intestine [c.i) green, and the ciliated 

 groove (c. g) brown ; v. r vascular ring (gut ring), d. v dorsal vessel, h. m 

 hook muscles, n nerve chord with ventral vessel, ph pharynx, oe, oe' 

 oesophagus, g gizzard, c. i collateral intestine, c. i. o origin of the same, 

 c. i. e end of the same, c. g ciliated groove, coe coecum, r rectum, a. v 

 anal vesicles. 



Plate 29. 



Fig. 1 2. Part of the intestine in the neighbourhood of the vascular 

 ring ; d. v dorsal vessel, n. i. a neuro-intestinal anastomosis, mes dorsal 

 mesentery, oe oesophagus, g gizzard, cr crop, p pre-intestinal constriction, 

 int intestine, c.gr ciliated groove, c.i collateral intestine. The ciliated 

 groove and collateral intestine are ventral, the mesentery and dorsal 

 vessel are dorsal. The piece of intestine is therefore twisted through 

 180", and the crop through another 180". 



Fig. 13. Hinder end of the collateral intestine (c.i); C.gr ciliated 

 groove. 



Fig. 14. Transverse section of the wall of the pharynx; ep.C 

 columnar epithelial cells, ep.n their nuclei, gl gland, b. c basal cells, 

 C. m circular musculature ; the outer longitudinal musculature is absent 

 in the pharynx ; p peritoneum. 



Fig. 15. Transverse section of the wall of the oesophagus; 

 ep. C, ep. n columnar cells and their nuclei, ep. c' thread-like inner ends 

 of the columnar cells , g\ gl. n gland cells and their nuclei , gV more 

 specialized, partly discharged gland cells with apparently effete nuclei, 

 gl. n', such as occur in the crop, c. m circular muscles, I. m longitudinal 

 muscles, p peritoneum. 



Fig. 16. Transverse section of the gizzard; c.t connective tissue 

 between the muscle fibres; other letters as in Fig. 14. 



Fig. 17. Transverse section of the wall of the crop, showing the 

 highl}'^ glandular nature of its walls; gl.C, gl.c', gl.c", gl.c'" four stages 

 in the history of the gland cells, which is characterized by the gradual 

 increase of the deeply staining secretion and disappearance of the 

 lightly staining plasma, these changes are accompanied by an equally 

 marked alteration (degeneration ?) of the nucleus, gl. n, gl. n\ Other 

 letters as in previous figures. 



Fig. 18. Transverse section of the wall of the intestine; ep.C 

 columnar cells, ep.n their nuclei, gl.c, gl.n the comparatively lightly 

 staining simple glandular cells and their nuclei, cm circular muscles, 

 i. I. m internal layer of longitudinal muscles, p peritoneum. 



Fig. 19. Horizontal section of the intestinal epithelium; ep.C 

 columnar epithelial cells, gl gland cells. 



Fig. 20. Horizontal section cutting the surface of the intestinal 

 epithelium ; ep. C the outer ends of the columnar cells, gl the pores of 

 the gland cells. 



