io8 Br acker . — Observations on Euglena deses. 
I take this opportunity of offering my best thanks to Dr. 0. V. Darbi- 
shire, under whose direction the work was carried out, and also to Professor 
Gamble, F.R.S., and Miss E. M. Lee, M.Sc., for valuable help and advice. 
Department of Botany, 
University of Bristol. 
Bibliography. 
1. Bohn : Sur les mouvements oscillatoires de Convoluta roscoffensis . Comptes rendus des Seances 
de l’Academie des Sciences, vol. cxxxvii, 1903, pp. 576-8. 
2. : Periodicite vitale des animaux soumis aux oscillations du niveau des hautes mers. 
Comptes rendus des Seances de l’Academie des Sciences, vol. cxxxix, 1904, pp. 610-11. 
3 . Dangeard : Recherches sur les Eugleniens, pp. 92-9. 
4. — : Ibid, p. 197. 
5 . Gamble and Keeble : The Bionomics of Convoluta roscoffensis . Quarterly Journal of Micro- 
scopical Science, vol. xlvii, 1903. 
6. Laurie : On the Bionomics of Amphidinium operculatum. Report of British Association, 1913. 
7. Wager : On the Effect of Gravity upon the Movements of Euglena viridis and other Micro- 
organisms. Phil. Trans. Royal Society, London, vol. cci, pp. 333-90. 
— : Movements of Aquatic Micro-organisms in Response to External Forces. The 
Naturalist, June and July, 1914. 
8 . 
