REACTIONS OF AMEBA TO PROTEINS 71 



it and then started to pass it on the left. An imperfect food 

 cup was then formed in a rather pecuUar manner, in which the 

 lactalbumin was ingested (723, 724). The ameba did not quiet 

 down after ingesting the lactalbumin but moved on as if inges- 

 tion had been a side issue. A little later (726) the ameba flowed 

 on through a new pseudopod formed on the right. The lactalbu- 

 min was excreted about three minutes after it was eaten. A new 

 piece of lactalbumin was then laid in the ameba's path (730). 

 The ameba moved forward and passed on the right of it. The 

 numerous small pseudopods at the anterior end (731) indicate 

 nearly a balance between negative and positive tendencies of 

 reaction. When the tip of the ameba reached the further side 

 of the lactalbumin, it swung to the left as if to encircle the lac- 

 talbumin. A food cup was then formed in which the test object 

 was eaten. The ameba did not become quiet but after throwing 

 out and retracting several pseudopods (735 to 737) moved off 135° 

 to the left and excreted the lactalbumin about four minutes after 

 ingesting it. The same piece of lactalbumin was again laid in 

 the ameba's path (740). After the ameba had moved into con- 

 tact with it, the direction of movement was changed slightly and 

 the ameba moved on avoiding the test object. A new piece of 

 lactalbumin was then laid in the path of the ameba (744), The 

 ameba moved forward and started to pass it on the right, but a 

 pseudopod was then sent out on the left and posterior to the 

 lactalbumin, which was then ingested with very little water and 

 without the formation of a definite food cup. The ameba moved 

 off without a period of rest and excreted the lactalbumin about 

 two and one-half minutes after ingesting it. The same piece of 

 lactalbumin was again laid near the ameba (754). The ameba 

 sent out a pseudopod into contact with it and kept on following 

 it as it rolled away while being pushed around by the ameba. 

 But the lactalbumin was laid for the third time in the ameba's 

 path (764). The ameba moved toward the test object and then 

 passed it on the right. A side pseudopod was sent out anterior 

 to the lactalbumin which was then followed around for a short 

 while as it rolled away from the advancing pseudopod. The 

 ameba finally moved off through a newly formed pseudopod, 



