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HANDBOOK OF INVERTEBRATE ZOOLOGY. 



b. The oesophagus; a long, nearly straight, thin-walled, 

 elastic tube, much smaller than the pharynx, and extend- 

 ing from the eighth to the sixteenth segment (Fig. 84, c, d). 

 It is slightly constricted at the points where it passes 

 through the partitions between the segments, and its mus- 

 cular fibres are continuous with those of the partitions. 



(i.) In the tenth, eleventh, 

 and twelfth rings, the white 

 testes (Fig. 84, k), surmount 

 and overlap the oesophagus. 



(ii.) If these are carefully 

 displaced, three pairs of 

 high ly vascular pouches 

 (Fig. 84, e), the cesophayeal 

 glands, will be seen between 

 them, projecting from the 

 sides of the oesophagus. 



FIG. 84. The anterior end of the 

 earthworm, opened along the dorsal 

 surface, to show the digestive organs. 

 (From Lankester, Anatomy of the 

 Earthworm. Quar. Jour. Mic. Sc., 

 1864, P. VII., Fig. 5.) 



1, 2-19. The nineteen anterior 

 segments. a. Cerebral ganglia. 

 6. Pharynx, c. (Esophagus, d. Pos- 

 terior portion- of it. e. (Esophageal 

 glands. /. Crop. </. Gizzard. 

 h. Dorsal blood-vessel. L Aortic 

 FIG. . arches, k. Testes. I. Intestine. 



The first pair are a little larger than the others, and if 

 they are removed from the oesophagus, and opened upon 

 a slide, and examined with a microscope, they will be 

 found to contain solid crystalline bodies, which dissolve, 

 with active effervescence, when treated with acid. 





