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fatal to them. Fabre-Domeiigue 1} noted that the reserved materials 

 found in the bodies of infusoria appeared and disappeared according as 

 the external conditions might be favourable or unfavourable to them. 

 Bokokny 2) 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, 3 ' grape-sugar, glycerin and common 

 salt as the external media to be used, while the infusoria Colpidium 

 coljjj In, Chilomonas piramce :ium, Eug'ena viridis, l\iram:v<:ium caudatum 

 a:i ! Mdlomona.8 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 thau 

 that when gradual change is made. 4) 



The examination of each culture was made at the end of 1—5 days, 

 was repeated several times, and every time carefully compared with the 

 control-culture. 



Colpidium colpoda. 



In milk-sugar solution the organism was found to survive in 

 1—10^ concentrations. In 1 — 2o/ solutions nothing remarkable was 

 observed, but in a 4o/ solution the vacuoles increased in size and the 

 body enlarged itself and became somewhat rounded. In solutions above 

 6<?£ the vacuoles greatly enlarged and increased in number, giving the 



