330 G. H. PARKER 



4. The stalk, proboscis, and tentacles in Corymorpha ex- 

 hibit great autonomy, in that each one possesses its own neuro- 

 muscular mechanism. 



5. Locomotion is extremely circumscribed and slow. 



6. Corymorpha is negatively geotropic and this response is 

 neuromuscular in its origin. 



7. In quiet water Corymorpha feeds by inverting the hy- 

 dranth and pressing the mouth and distal tentacles on the mud. 

 In running water the proximal tentacles entangle food and 

 transfer it to the distal tentacles and the mouth. 



8. The neuromuscular mechanism of Corymorpha is not 

 intermediate between that of the receptor-effector system of 

 actinians and the independent effectors of sponges. It re- 

 sembles a reduced actinian system rather than a primitive state 

 from which such a system could be derived. 



10. BIBLIOGRAPHY 



Agassiz, L. 1862 Contributions to the natural history of the United States 

 of America. Boston, 4 to, vol. 4, viii + 380 + 12 pp. 



Allman, G. J. 1863 Notes on the Hydroida. Ann. Mag. Nat. Hist., ser. 3, 

 vol. 11, pp. 1-12. 



1871-1872 A monograph of the gymnoblastic or tubularian hydroids. 

 London, 4 to, xxiv + 450 pp. 



Hadzi, J. 1909 Ueber das Nervensystem von Hydra. Arb. Zool. Inst. Wien, 

 Tom. 16, pp. 225-268. 



Lipin, A. 1909 Ueber den Bau des Slisswasser-Coelenteraten Polypodium 

 hydriforme Uss. Zool. Anz., Bd. 34, pp. 346-356. 

 1911 Die Morphologie und Biologie von Polypodium hydriforme 

 Uss. Zool. Jahrb., Abt. Anat. Ontog., Bd. 31, pp. 317-426. 



Loeb, J. 1895 Zur Physiologie und Psychologie der Aktinien. Arch. ges. 

 Physiol., Bd. 59, pp. 415-420. 



May, A. J. 1903 A contribution to the morphology and development of Cory- 

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Parker, G. H. 1910 The reactions of sponges, with a consideration of the 

 origin of the nervous system. Jour. Exp. Zool., vol. 8, pp. 1-41. 



1916 The effector systems of actinians. Jour. Exp. Zool., vol. 21, 

 pp. 461-484. 



1917 a The responses of hydroids to gravity. Proceed. Nat. Acad. 

 Sci., vol. 3, pp. 72-73. 



1917 b Actinian behavior. Jour. Exp. Zool., vol. 22, pp. 193-229. 

 Pearse, A. S. 1906 Reactions of Tubularia crocea (Ag.). Amer. Nat., vol; 

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