424 p. W. GAMBLE AND FREDERICK KKEBLE. 



The colonial habit o£ Con vo lata, which distinguishes it 

 from its allies, appears to be an indirect result of its tropisms. 

 In obedience to tropic stimuli, it becomes adept at vertical 

 movements, to the exclusion in very large measure of hori- 

 zontal movements. 



The lethargic state induced by prolonged light and pro- 

 longed darkness also tends to preserve groups of Convoluta 

 on the patch to which they belong. Gregariousuess is, in 

 this view, a negative quality. 



JUITERATURE. 



1SG9. CoHN,'_F. — " Uutersacljungen ueber die Eiitwickl. der Mikrosc. Algen 



u. Pilze," ' Verhandl. Leop. Carol.,' vol. xxiv, p. 103. (Discovery 



of the etiolating influence of sapropliylism.) 

 1872. Kleinenbekg, N.— 'Hjdra.' 

 1879. Geddes, p. — "Observations ou the Physiology and Histology of 



Convoluta Schultzii," ' Proc. Roy. Soc./ vol. xxviii, pp. 449 — 



457. 

 1879a. Geddes, P. — " Sur la Chlorophylle animale et sur la Pliysiologie 



des Planaires vertes," ' Archives de Zool. Exp. et Generale,' ser. i, 



vol. viii, pp. 51 — 58. 

 1879b. Geddes, P. — "Sur la Fonction de la Chlorophylle chez les Planaires 



vertes," 'Comptes Rendus,' vol. Ixxxvii, pp. 1095 — 1097. 

 1881. Geddes, P.—" The ' Yellow Cells ' of Radiolarians and Coelente- 



rates," 'Proc. Roy. Soc. Edin.' 

 ISSl. Entz, G.— "Ueber die Natur der Chloropliyllkorperchen der Thiere," 



' Biol. Centralbl.,' vol. i, pp. 646— G50. 

 1881. Ekgelmann. — " Neue Methode der Untersnchung. der SauerstofTaus- 



scheidung pflanzlicher und thierischer Organismen," ' Rot. Zeitung,' 



vol. xxxix, 1881, pp. 440—447. 



1881. Krukenbekg.— " Das Anlhea-Grun," ' Vergleich. Physiol. Studicn,' 

 1 Reihe, Abth. 5, pp. 38—42. 



1881. Brandt, K. — " Ueber das Zusammenleben von Algen u. Tliieren," 



' Verhandl. d. Piiys. Gescll. Berlin,' Kovtmber lllh. Republished 

 in 'Biol. Centralbl.,' vol. i, pp. 524—527. 



1882. Ray Lankkstek. — "On the Chloropliyll Corpuscles and Amyloid 



Deposits of Spougilla and Hydra," 'Quart. Journ. Micros. Sci.,' 

 vol. xxii, pp. 229—254. 



