AGAMIC REPRODUCTION AND REJUVENESCENCE 153 



Calkins, G. N., and Gregory, L. H. 



1913. "Variations in the Progeny of a Single Ex-Conjugant of Para- 

 mecium caudatum," Jour, of Exp. Zool., XV. 



Child, C. M. 



1910. "Physiological Isolation of Parts and Fission in Planaria," Arch. 



f. Entwickelungsmech., XXX (Festbd. f. Roux), II. TeU. 

 1911a. "Die physiologische Isolation von TeUen des Organismus," Vorlr. 



und Aufs. it. Entwickelungsmech., XL 

 191 16. "Studies on the D5rnamics of Morphogenesis and Inheritance in 



Experimental Reproduction: I, The Axial Gradient in Planaria 



dorotocephala as a Limiting Factor in Regulation," Jour, of Exp. 



Zool., X. 

 1911C. "Studies, etc.: Ill, The Formation of New Zooids in Planaria 



and Other Forms," Jour, of Exp. Zool., XL 



1912. "Studies, etc.: IV, Certain Dynamic Factors in the Regulatory 

 Morphogenesis of Planaria dorotocephala in Relation to the Axial 

 Gradient," Jour, of Exp. Zool., XIII. 



1913a. " Studies, etc. : VI, The Nature of the Axial Gradients in Pteana 

 and Their Relation to Antero-posterior Dominance, Polarity 

 and Symmetry," Arch. f. Entwickelungsmech., XXXVII. 



19136. "The Asexual Cycle in Planaria velata in Relation to Senescence 

 and Rejuvenescence," Biol. Bull., XXV. 



1914. Asexual Breeding and Prevention of Senescence in Planaria 

 velata," Biol. Bull., XXVI. 



Enriques, p. 



1903. "SuUa cosi detta' degenerazione senile' dei protozoi," Monitore 

 Zool. Ital., XIV. 



1907. "La conjugazione e il differenziamento sessuale negli Infusori," 

 Arch.f. Protistenkunde, IX. 



1908. "Die Konjugation und sexuelle Differenzierung der Infusorien," 

 Arch. f. Protistenkunde, XII. 



GOLDSCHMIDT, R. 



1905. "Der Chromidialapparat lebhaft funktionierender Gewebszellen," 

 Zool. Jahrhucher; Abt.f. Anat. u. Ont., XXI. 



Jennings, H. S. 



1910. "What Conditions Induce Conjugation in Paramecium?" Jour, 

 of Exp. Zool., IX. 



1913. "The Effect of Conjugation in Paramecium," Jour, of Exp. Zool., 

 XIV. 



Jennings, H. S., and Hargitt, G. T. 



1910. "Characteristics of the Diverse Races of Paramecium," Jour, of 

 Morphol., XXI. 



