340 A. C. WALTON 



(1) In 55 per cent of the animals from conjugating lines and 

 in 85 per cent of the animals from non-conjugating lines tested, 

 there was increased rate of locomotion in response to increased 

 light intensity. 



(2) In 2 per cent of the animals tested the response to in- 

 creased intensity indicated inhibitory influence; the greater the 

 light intensity, the slower the locomotion. 



(3) In 40 per cent of the animals from conjugating lines, 

 there was no response, or at best a feeble one, to any change 

 in the light intensity. This fact points towards the conclusion 

 that the physiological state of Paramoecium at the time of 

 conjugation is such that the threshhold of light stimulation is 

 raised beyond the intensities used in these experiments. 



(4) No evidence was found that the amount of light to which 

 the animals had been exposed before the tests had any effect 

 on the subsequent response to the stimulus. 



(5) Responses to sudden changes of intensity in the light 

 were only gradually effected. 



(6) Paramoecium responds in essentially the same way to the 

 same intensity of stimulus, irrespective of the previous intensity 

 to which it has been exposed, provided only that it be given 

 time to adjust itself to the new condition. 



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