NEPHRIDIAL TISSUES 357 



water bath will usually give the desired results. If this fail, one can be 

 sure of getting sections by the celloidin method, in which the difficulty 

 of brittleness does not emerge. 



In addition to the sections, it is very desirable 

 to control the results of sectioning by a careful 

 study of teased specimens. This method is 

 vastly preferable to the use of reconstruction 

 methods in the working out of long tubules, etc. 

 One should complete no comparative study of 

 the renal tissues without watching the live kid- 

 neys of a small annelid worm under the micro- 

 scope. Other nephridia may also be studied in FIG. 324. TWO basal cells 

 this way, in or out of the body. intheir na f ^ *f <>*> 



J ' J one superficial cell in the 



To determine the nature of a suspected ne- striated epithelium which 

 phridial cell or tissue it is often possible to watch lines the bladder of a mam- 



. mal. (After KOELLIKER.) 



the cells excrete some foreign material, as car- 

 mine, which has been placed in the blood or body cavity of the organ- 

 ism. This may even be seen in sections taken the proper time after 

 the material is injected. 



LITERATURE 



AWERINZEW, S. "Beitrage zur Kenntnis der maim Rhizopoden," Mitth. Zool. Stat. zu 



Neapl., Band XVI, S. 349-364, 1903. 

 JENNINGS, H. S. "A Method of Demonstrating the External Discharge of the Contractile 



Vacuole," Zool. Anz., Band XXVII, pp. 656-658, i fig., 1904. 

 BARTHELS, PH. "Notiz iiber die Excretion der Holothurien," Z. Anz., Jahrg. 18. 

 COTTE, JULES. "Excretion of Sponges," Bull. Scient. France, Belgique, T. 38, pp. 420- 



"573. 9%-. i9 4. 

 BENHAM, W. B. "The Nephridium of Lumbricus and its Blood Supply," Quart. Journ. 



Mic. Sc. (2), Vol. XXXII, p. 293, 1891. 

 FACE, Louis. "Recherches sur les organes segmentaires des Annelides Polychetes," 



Ann. Sc. Nat. Zool. (9), T. 3, pp. 261-410, 2 pis., 52 fig., 1906. 

 GOODRICH, E. "On the Nephridia of the Polychaetes," Part i, Q.J.M.S., Vol. XL, 1897 



(and other papers in same Journal). 

 HERNEBEL, M. A. "Observations sur le role des Amcebocytes dans le ccelome d'un anne- 



lide," Ann. Inst. Pasteur, T. 17, pp. 449-461, 2 pis., 1903. 

 CUENOT, L. "L'excretion chez les mollusques," Arch, de Biol., T. 16, 1899. 

 BOURNE, G. C. "On the Structure of ^Enigma cenigmata," Quart. J. Mic. Sc., N.S., N. 



202, May, 1907, Sec. p. 274. 

 GRIFFEN, L. E. "Renal Sacs of Nautilus," Memoirs of the Biol. Lab., Johns Hopkins 



University, Vol. V, p. 165, 1903. 

 HENSCHEN, F. "Zur Kenntnis der blasenformigen Sekretion," Anat. Hefte, Band XXVI, 



S- 573-594, 2 fig., 9, 1904. 

 BRENTY, L. "Contribution a 1'etude de 1'excretion chez les Arthropods," Arch. Biol., 



T. 20, p. 217-422, 3 pis., 1903. 

 HOFFMANN, R. W. " Uber den Ventraltubus von Tomocerus plumbeus, Z. und seine Bezie- 



hungen zu den grossen unteren Kopfdriisen," Zool. Anz., Band XXVIII, S. 87-116, 



19 fig., 9, 1904. 

 REGAUD, CL. "Demonstration relative au segment cile du rein de Petromyzon," Verh. 



Anat. Ges., 18 Vers., p. 181, 1904. 



