REFERENCES 285 



Parker, G. H., and Titus, E. G. 



1 916. "The Structure of Metridium (Actinoloba) marginatus 

 Milne-Edwards with Special Reference to Its Neuro- 

 muscular Mechanism," Jour. Exp. Zool., XXI. 

 Pike, F. H. 



1909. "Studies in the Physiology of the Central Nervous 



System, I," Amer. Jour. Physiol., XXIV. 

 1912. "Studies, etc., II," Amer. Jour. Physiol., XXX. 

 Fringsheim, E. G. 



191 2. Die Reizbewegungen der Pflanzen. Berlin. 

 Putter, A. 



1903. "Die Flimmerbewegung," Ergebn. d. Physiol., Jahr- 

 gang II, Abt. II. 

 Rand, H. W. 



1911. "The Problem of Form in Hydra," Science, XXXIII. 



191 2. "The Problem of Organization," Science, XXXVI. 

 Regel, F. 



1876. "Die Vermehrung der Begoniaceen aus ihren Blat- 

 tern," Jen. Zeitschr., X. 

 Reichert, E. T., and Brown, A, F. 



1909. "The Differentiation and Specificity of Correspond- 

 ing Proteins and Other Vital Substances in Relation 

 to Biological Classification and Organic Evolution. 

 The Crystallography of Hemoglobins," Carnegie 

 Inst. Publ. No. 116. 

 Retzius, G. 



1892. "Biologische Untersuchungen," Neue Folge, III. 

 Rhumbler, L. 



1905. "Aus dem Liickengebiet zwischen organismischer und 

 anorganismischer Materie," Ergebn. d. Anat. u. 

 Entwicklungsges . , XV. 

 Riggs, L. K. 



1919. "Action of Salts upon the Metabolism of Nerve," 

 Jour. Biol. Chem., XXXIX. 



RlTTER, W. E. 



1909. " Ilalocynthia Johnsoni n. sp. A Comprehensive 

 Inquiry As to the Extent of Law and Order That 

 Prevails in a Single Animal Species," Univ. Cal. 

 Publ., Zool., VI. 



1919. The Unity of the Organism. Boston. 



