352 ASSIMILATION. 



921. Epiphytes, or air-plants, obtain their food-materials wholly 

 without contact with the soil. It is supposed that the ash materials 



ii. 290, also gives an account of Sarracenia, together with a description of its 

 digestive powers, and compares its hollow leaf to an animal stomach. 



1834. Curtis, in the Journal of the Boston Society of Natural History, i., 

 pp. 123-125, gives a description of the irritability of Dionaea, and of its mode of 

 action. 



1848. Benjamin : " Ueber den Bau und die Physiologic der Utricularien " 

 (Botanische Zeitung, vi., pp. 1, 17, et seq.). 



1850. Cohn : "Ueber Aldrovanda vesiculosa" (Flora, p. 673). 



1855. Greenland : " Note sur les organes glanduleux des Drosera" (Ann. 

 des Sc. nat. bot., ser. 4, tome Hi. p. 297). 



1855. Trecul : "Organization des glandes pedicellees de la feuille du 

 Drosera rotundifolia " (Ann. des. Sc. nat. bot., ser. 4, tome iii. p. 303). 



1859. Caspary : "Aldrovanda vesiculosa" (Botanische Zeitung, xvii. 

 p. 125). 



1860. Nitschkein Botanische Zeitung, xviii. p. 57, and xix., 1861, p. 145, 

 gives an excellent description of Drosera, and an account of simple but telling 

 experiments upon the sensitiveness of the leaves. 



1860. Darwin began his experiments upon Drosera, not published until 

 much later. 



1862. Botanische Zeitung of this year (p. 185) contains a second article on 

 the subject of Aldrovanda by Caspary. 



1863. Scott : "On the Propagation and Irritability of Drosera" (Garden- 

 ers' Chronicle, p. 30). 



1868. Canby published an account of experiments on feeding Dionsea, in 

 the Gardener's Monthly, p. 229. 



1872. Ziegler : "Sur un fait physiologique observe sur des feuilles de 

 Drosera" (Comptes Rendus, Ixxiv. p. 1227). 



1873. Treat : " Observations on the Sun-dew " (American Naturalist, vii. 

 p. 705). In this paper Mrs. Treat describes experiments relative to feeding 

 Drosera carried on in 1871. 



1873. A. W. Bennett : "On the movements of the glands of Drosera" 

 (British 'Association Reports, xliii. p. 123). 



1873. Stein : " Ueber die Reizbarkeit der Blatter von Aldrovanda" (Ver- 

 handlungen des bot. Vereins fiir die Prov. Brandenburg). 



1874. Burdon Sanderson : " Venus's Fly-Trap" (Nature, x. p. 105). 

 1874. Asa Gray : "Insectivorous Plants" (Nation, xviii. pp. 216, 232). 



An account of the observations communicated by Darwin, and a short resume 

 of the subject up to that date. 



1874. Mellichamp : " Researches on the pitchers of Sarracenia variolaris, 

 and the way in which insects are caught in them " (Nature, x. p. 253). 



1874. Hooker : Address before the British Association for the Advance- 

 ment of Science, published in full in the Report for 1874. This address gives 

 an excellent account of the digestive powers of various carnivorous plants, 

 especially Nepenthes. 



1875. J. W. Clark : "On the absorption of nutrient material by the 

 leaves of some insectivorous plants." This article gives the results of experi- 

 ments on the absorptive capacity of Drosera and Pinguicula, conducted with 

 the aid of the spectroscope. 



