ACCOMMODATION OF INFUSORIA TO CERTAIN SOLUTIONS. 



27 



be suitable to tbe life of tbis organism. Its body is bigbly metabolic, 

 so tbat no distinct change except tbe enlargement of tbe corpuscles 

 could be observed. 



Paramecium caudatum . 



Tbis organism was found to survive in 1-8% milk-sugar, 1-7% 

 cane-sugar, 1-5% grape-sugar, \-'à% glycerine, and T V— \% common 

 salt solutions, and experienced changes similar to those observed in the 

 case of Golpidium colpoda. 



Mallomonas sp. 



Solutions of 1-9% milk-sugar, 1-7% cane-sugar, 1-6% grape-sugar, 

 1-4% glycerine, and tV _ t % common salt were adapted to this organism, 

 and bad the usual effects. 



In general, when the concentration of the external medium increas- 

 ed, the bodies of the organisms contracted, and then their movements 

 which had hitherto been active became slower and slower until they 

 ceased entirely. In a few hours, however, the contraction of their bodies 

 gradually disappeared and they recovered their normal condition, accom- 

 modation to the new medium now beginning to take place. Similarly, 

 Fischer 11 found that 10-30% cane-sugar, which caused strong plasmo- 

 lysis on Spirillum, stopped its movement. Ewart' j) also observed that 

 Bacterium Termo, which moved actively in 10% cane-sugar or 5% 

 grape-sugar, lost its activity in 20% cane-sugar or 10% grape-sugar, 

 and finally came to rest in 30% cane-sugar or 20% grape-sugar. 



The higher the concentration of the solutions, the more difficult the 

 accommodation of infusoria to them became, and when it took place the 

 vacuoles or the corpuscles in the bodies of the organisms remained 



1) A. Fischer. Untersuchungen über Bakterien. Pringsh. Jahrb., 1895, Bd. XXVII, 

 pp. 39—40. 



2) A. J. Ewaet. On Assimilatory Inhibition in Plants The Journal of the Linuœan 

 Society, 1896, vol. XXXI, no. 217, p. 434. 



