488 GENERAL CONSIDERATIONS [Cn. XIX 



perature or to chemical agents. It is to be observed that this 

 hypothesis is not an hypothesis to account for response to stimuli 

 or of the usual adaptive nature of that response ; but to account 

 only for that phase of "adaptation" which is seen in attunement. 

 The hypothesis is an attempt to explain an adaptive result 

 independently of selection, but rather as a necessary result of 

 the constitution of protoplasm. 



The adaptive acclimatized or attuned condition may be in- 

 herited. It has been shown that the acclimated condition 

 may long persist, only eventually apparently disappearing. It 

 may well be doubted, however, if the acclimated protoplasm 

 ever returns exactly to its primitive condition. If it does not, 

 progeny developed from the acclimated protoplasm will neces- 

 sarily be different and respond differently from their parents. 

 Individual attunement will initiate a race attunement. 



LITERATURE 



CIESIELSKI, '72. (See Chapter XIV, Literature.) 



CZAPEK, F. '95. Ueber Zusammenwirkung von Heliotropismus und Geotro- 



pismus. Sb. Wien. Akad. CIV 1 , 337-375. 



'98. Ueber einen Befund an geotropisch gereizten "VVurzeln. Ber. deut. 

 Bot. Ges. XV, 516-520. Jan. 1898. 



DARWIN, C. and F. '81. (See Chapter XIV, Literature.) 



HOGG, J. '54. Observations on the Development and Growth of the Water- 

 snail (Limneus stagnalis). Trans. Micr. Soc. London. II, 91-103. 



SEMPER, C. '74. Ueber die Wachsthums-Bedingungen des Lymnseus stag- 

 nalis. Arb. Zool.-Zoot. Inst. Wurzburg. I, 138-167. 



VARIGNY, H. DE. '94. Recherches sur le nanisnie experimentale. Contribu- 

 tion a 1'etude de 1'innuence du milieu sur les organismes. Jour, de 

 1'Anat. et Physiol. XXX, 147-188. 



WIESNER, J. '79. (See Chapter XVII, Literature.) 



YUNG, E. '85. (See Chapter XIII, Literature.) 



