RELATIONS OF BURSARIA TO FOOD 39 



6. Congo red adsorbed by vitellin grains and fed to Bursaria 

 interferes With or prevents digestion of the parts of the vitellin 

 grain to which the dye has been adsorbed and causes an early 

 extrusion. 



7. Olein is digested and resorbed by Bursaria while paraffin 

 oil is not affected. Lipoids and fats play an important role in 

 promoting growth in Bursaria. No evidence was obtained for 

 the formation of stainable lipoid from pure vitellin. 



Starch or amylum grains are not digested. 



8. The time of extrusion is determined by the quality (chemical) 

 and the quantity or intensity (chemical, physical or both) of 

 the stimulus from within the vacuole by the substance eaten. 



9. The maximum tendency to respond by extrusion to the 

 stimulus from the vacuole contents, exists within a limited time 

 (4 to 6 hours with fresh yolk) after feeding. 



LITERATURE CITED 



Arrhenius, S. 1909 Die Gesetze der Verdauung und Resorption. Zeitschr. f. 

 Physiol. Chem., Bd. 63, pp. 323-377. 



Greenwood, M. 1894 On the constitution and mode of formation of 'food 

 vacuoles' in Infusoria as illustrated by the history of the processes of 

 digestion in Carchesium polypinum. Phil. Trans. Roy. Soc, London, 

 vol. 185-B, pp. 355. 



Lund, E. J. 1914 The relations of Bursaria to food. I. Selection in feeding 

 and in extrusion. Jour. Exp. Zool., vol. 16, pp. 1-52. 



NiRENSTEiN, E 1915 Beitrage zur Ernahrungs-physiologie der Protisten. 

 Zeits. f. allgem. Physiol., Bd. 5, pp. 435-510. 



1910 ■ Uber Fettverdauung und Fettspeicherung bei Infusorien. Zeits. 

 f. allgem. Physiol., Bd. 10, pp. 137-149. 



Staniewicz, M. W. 1910 Etudes exp^rimentales sur la digestion de la graisse 

 dans les Infusoires cilies. Bull. Intern. Acad, des Sc. de Cracovie> 

 S^rie B, pp. 199-215. 



