ACCOMMODATION OF INFUSORIA TO CERTAIN SOLUTIONS. 



25 



place. But then, to what extent would they accommodate themselves 

 to that medium '? And again, what change is brought about to the bodies 

 of these organisms ? Cohn 1 ' observed in his early investigations 'that a 

 sudden change of the concentration of the medium was injurious or fatal 

 to them. Fabre-Domergue 2) noted that the reserved materials found 

 in the bodies of infusoria appeared and disappeared according as the ex- 

 ternal conditions might be favourable or unfavourable to them. Bokor- 

 ny 3) found certain changes in their bodies when subjected to the action 

 of some basic substances. But a more detailed study on the effects of 

 the changed medium upon them has not yet been made. 



I began to investigate this subject from the spring of last year in 

 the Botanical Institute of the Imperial University, and will now make 

 a preliminary note of some of the results of my experiments. 



I selected milk-sugar, cane-sugar, 1 ' grape-sugar, glycerine, and com- 

 mon salt as the external media to be used, while the infusoria Golpidium 

 colpoda, Chilomonas paramœcium, Euglena viridis, Paramœcium 

 caiulatum, and Mallomonas sp. were chosen as bodies for the investigation. 



The experiments now described were made by a sudden transfer of 

 the organisms from the normal medium to an abnormal one, those in 

 which gradual change of the concentration of the medium is made being 

 still in course of investigation, and it may be proved to be the case that 

 the degree of accommodation given here is in reality much lower than 

 that when gradual change is made. 5 ' 



1) F. Cohn. Entwickelungsgesehichte der microscopischen Algen und Pilze. Nova 

 Acta Akad. Caes. Leopold., 1854, Bd. XXIV, Th. 1, p. 132. (Cited by True.) 



■J.) M. Fabre-Domergue. Recherches anatomiques et physiologiques sur les infusoires 

 ciliés. Annales des sciences naturelles, Zoologie, 1888, 7 me série, tome V, p. 135. 



3) T. Bokobnt. Einige vergleichende Versuche über das Verhalten von Pflanzen und 

 niederen Thieren gegen basische Stoffe. Pfliiger's Archiv für die gesammte Physiologie 

 des Menschen und der Tiere, 1895, p. 557. 



4) As our culture of infusoria contained bacteria it was necessary to test how long 

 cane-sugar was recognisable as such in the culture-water. After four days I found, by 

 means of Fehling's solution, that a little inversion of it had taken place. 



5) F. Eschenhagen, toe. cit. p. 34. Also B. Stange, loc. cit. Nr 18, p. 293. 



