196 ^- LEWIS NICKERSON, Intracellular canals in the skin of Phascolosoma, 



Literature. 



Andeews, E. a., 1890, Notes on the anatomy of Sipunculus gouldii 



PouRTALÈs, in: Stud. bid. Labor. Johns Hopk. Univ., V. 4, No. 7. 

 BoLsius, H., 1890, Recherches sur la structure des organes segmen- 



taires des Hirudinées, in: La Cellule, V. 5. 

 GiLSON, G., 1889, Les glandes odorifères du Blaps mortisaga, ibid. 



V. 5. 

 Lde, Manille, 1891, Glandes cutanées à canaux intracellulaires chez 



les Crustacées édriophthalmes, ibid. V. 7. 

 Zimmermann, K. W., 1898, Beiträge zur Kenntniss einiger Drüsen und 



Epithelien, in: Arch. mikr. Anat.. V. 52. 



Explanation of Figures. 



All figures were drawn with Zeiss' apochromatic lenses with the 

 aid of the camera lucida. 



C. d common duct o. a outer ampulla 



ep epidermis r. v radial vesicle 

 i. a inner ampulla sli sheath 



n. c nerve cell vac vacuole 

 n. sh nucleus of sheath 



Plate 12. 



Pig. 1. Section through an organ showing only those details seen 

 at one focal plane. The cuticula over the organ is not represented. 

 X 890. 



Pig. 2. Portion of the section shown in figure 1, combining the 

 details to be observed at different focal planes. X 1380. 



Pig, 3. Single gland cell showing vacuoles confluent with outer 

 sack. X 890. 



Pig. 4. Two cells from same organ, to show difference in character 

 of protoplasm of young and old cells. X 890. 



Frommannsche Buchdruckerei (Hermann Pohle) in Jena, — 1965 



