110 MOLAR AGENTS AND PROTOPLASM [Cu. IV 



results of contact upon protoplasm is modification of move- 

 ment, - - momentary quiet, followed by contraction. Rapidly 

 repeated shocks lead to a summation of responses called teta- 

 nus. Slowly repeated shocks may lead to acclimatization to 

 contact. Finally, the direction of locomotion is in some cases 

 controlled by contact ; many organisms move from the touch- 

 ing body - - negative thigmotaxis ; others may face the impact 

 of flowing water or keep close, as though attached, to the rigid 

 surface positive thigmotaxis. If the changed chemical con- 

 dition following contact be called the " response," then all 

 changes wrought by contact on protoplasm may be considered 

 as responses. 



i 



LITERATURE 



CHAMPION, P. and PELLET, II. '72. Sur la theorie de 1'explosion des com- 

 poses detonants. Compt. Rend. LXXV, 210-214. 

 DANTEC, F. LE '95. Sur 1'adherence des amibes aux corps solides. Compt. 



Rend. CXX, 210-213. 28 Jan. 1895. 

 DARWIN, C. '75. (See Chapter I, Literature.) 

 DEWITZ, J. '85. Ueber die Vereinigung der Spermatozoon mit dem Ei. 



Arch. f. d. ges. Physiol. XXXVII, 219-223. 29 Oct. 1885. 

 '86. Ueber Gesetzmassigkeit in der Ortsveranderung der Spermatozoen 



und in der Vereinigung derselben mit dem Ei. Arch. f. d. ges. Physiol. 



XXXVIII, 358-385. 31 March, 1886. 

 DUTROCHET '37. (See Chapter VIII, Literature.) 

 HOFMEISTER, "W. '67. Die Lehre von der Pflanzenzelle. Leipzig : Engel- 



mann. 664 pp. 1867. 

 HORVATH, A. '78. Ueber den Einfluss der Ruhe und der Bewegung auf 



das Leben. Arch. f. d. ges. Physiol. XVII, 125-134. 21 May, 



1878. 

 JONSSON, B. '83. Der richtende Einfluss strbmenden Wassers auf wachsende 



Pflanzen und Pflanzentheile (Rheotropismus). Ber. D. bot. Ges. 



I, 512-521. 



LOEB, J. '90. (See Chapter VII, Literature.) 

 MASSART, J. '88. Sur 1'irritabilite des spermatozoides de la grenouille. 



Bull. 1'Acad. roy. Belg. (3) XV, 750-754. 

 '91. La sensibilite tactile chez les organismes inferieurs. Jour, de 



Medecine de Bruxelles. 5 Jan. 1891. [Abstract only seen in Centralb. 



f. Bacteriol. XI, 566.] 

 '93. (See Chapter I, Literature.) 

 MELTZER, S. J. '94. Ueber die fundamental Bedeutung der Erschiitterung 



fur die lebende Materie. Ztschr. f. Biol. XXX, 464-509. 

 PFEFFER, W. '88. (See Chapter I, Literature.) 



