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[From the Bulletin of the Torrey Botanical Club, 43: 1-16. 14 F igi6.J 



Physiological observations on Drosera rotundifolia * 



Henry D. Hooker, Jr. 



(with eleven text figures) 



CONTENTS 



PAGE 



1. Introduction i 



2. Material 2 



3. Pigment 3 



4. Habit 4 



5. Parasites 4 



6. Cultivation 5 



7. Mechanics of Movement 5 



(a) Normal Development 5 



(6) Experimental Method 6 



(c) Experimental Data 7 



(<f ) Discussion 19 



i. Bending 19 



ii. Unbending 21 



iii. Growth and Turgidity 22 



iv. Conductivity 23 



V. Second and Third Reactions 23 



vi. Naslic Reactions 24 



vii. Discal Tentacles 25 



8. Summary 26 



I. Introduction 



The object of the work, which this paper presents, was to 



determine whether the bending of Drosera tentacles was connected 



with a temporary acceleration of the rate of growth or with 



differences of turgidity; in physiological terms, whether the bend- 



* Contribution from the Osborn Botanical Laboratory. 



1 



