64 ASA A. SCHAEFFER. 



became for the moment the main pseudopod 427. After mov- 

 ing toward the globulin for a short distance a pseudopod was 

 thrown out on the right leading the ameba away from the test 

 objects 429-432. Presently however the main pseudopod 

 bent strongly to the left 433, 434 with the formation at the 

 same time of two pseudopods on the convex side of the main 

 pseudopod 434, 435. The pseudopod pointing toward the 

 globulin moved forward a short distance 436 but this pseudo- 

 pod was retracted as the other one of the two formed on the convex 

 side became reactivated leading the ameba away from the glo- 

 bulin and light. 



Since it was evident that the ameba reacted negatively to both 

 light and globulin when these substances stimulated the ameba 

 at the same time, two further tests were made on this ameba in 

 which each test substance was used by itself. 



The piece of globulin was laid some distance ahead of the ameba 

 438. The ameba moved toward the globulin a short distance 

 then threw out a pseudopod on the left 440 through which 

 the ameba moved forward with the globulin on the right 442. 

 A pseudopod was then thrown out on the right toward the globu- 

 lin while the tip of the main pseudopod turned strongly toward 

 the left 444. When the pseudopod on the right came into 

 contact with the globulin the main pseudopod was retracted 

 447, 448. The globulin was only partly surrounded 449. 

 One of several pseudopods formed on the right led the ameba 

 away, leaving the globulin behind. 



After a few minutes the beam of yellow light was projected in 

 front of this ameba 453. As the ameba moved forward several 

 pseudopods were thrown out on either side of the main pseudopod, 

 giving the ameba a very irregular shape. When the ameba came 

 nearer the light 458 it advanced definitely forward passing 

 the beam immediately to the right 459. The main pseudopod 

 then swerved a little to the side as two pseudopods were formed 

 on the right, through the lower one of which the ameba finally 

 moved away from the light. 



This ameba then reacted definitely positively to globulin but 

 much less definitely positively to yellow light, when presented 

 separately, but decidedly negatively when presented together. 



