142 J- PAUL VISSCHER. 



determine in large measure whether any living organism can or 

 can not be successfully captured. 



8. Specialized structures as, for example, the trichocysts of 

 Paramecium and the lorica of Euplotes, serve as protection against 

 the attacks of Dileptus. 



8. LITERATURE CITED. 

 Biitschli, 0. 



'80-89 Bronn's Thierreichs, Bd. I., Protozoa. Leipzig. 2035 s. 

 Calkins, G. N. 



'01 The Protozoa. New York. 347 pp. 

 '09 Protozoology. New York. 349 pp. 

 Claparede and Lachman. 



'85 Sur la reproduction des Infusoires. Ann. des. Sci. Nat., ser. 4, tome 



8, pp. 221. 

 Ehrenberg, C. G. 



'38 Die Infusionsthierchen als Vollkommene Organismem. Leipzig. 

 Entz, G. 



'88 Studien iiber Protisten. Auftrage der Konigl. Ung. Naturw. Ges., 



Budapest. 

 Hausman, L. A. 



'17 Observations on the Ecology of the Protozoa. Am. Nat., Vol. 51, pp. 



157-172. 

 Hertwig, R. 



'02 Nuclear Cytoplasmic Relations. Sitz d. Ges. f. Morph. u. Phys., Bd. 



18. s. 77100. 

 '04 Conjugation in Dileptus gigas. Sitz. d. Ges. f. Morph. u. Phys., Bd. 



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 Jennings, H. S., and Moore, E. M. 



'02 Studies on Reactions to Stimuli in Unicellular Organisms. Am. Jour. 



of Psychology, Vol. 6, pp. 223250. 

 Jennings, H. S. 



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 Khainsky, A. 



f iO" Morphologic und Physiologic einiger Infusorien. Arch. f. Protistenk., 



Bd. 21, s. 1-60. 

 Kent, W. S, 



'81 A Manual of the Infusoria. London. 3 vols., 894 pp., 52 pi. 

 Mast, S. 0. 



'09 Reactions of Didinium nasutum with special reference to the Feeding 

 Habits and the Function of Trichocysts. BIOL. BULL., Vol. 14, pp. 

 91-118. 

 Metalnikow, S. 



'12 Contributions a 1'etude de la digestion intra-cellulaire. Arch. de. Zool. 



Exper., tome 49, ser. 4. 

 Minchin, E. A. 



'12 Introduction to a Study of the Protozoa. London. 520 pp. 



