Relation of the Nucleus to Movement. 



The movement of normal amebas in a suitable mediujn, 

 such as the dilute spring vater, when placed upon a glass 

 slide, was found to be of the limax type. The ameba is 

 attached to the slide by means of some sticky secretion, 

 and flows steadily forward, sending out pseudopods at the 

 anterior end, often from alternate sides. Frequently 

 araebas are found which are not attached to the slide, and 

 such amebas may project pseudopods in any direction, but 

 are unable to move from place to place. These animals 

 will in time, however, adhere to the slide, unless they 

 are abnormal or the medium is unsuitable. IVhen these 

 active amebas are stimulated roughly, as by pressure with 

 a glass needle, they retract into a more or less spherical 

 shape, and small droplets of protoplasm may be seen project- 

 ing from the surface. 



The effect of amputation of the nucleus upon the 

 movement of the cell may be seen from the following typ- 

 ical experiment: 



5:81 P.M.- An active ameba which was attached to the 

 slide was divided into two approximately 

 e^ual parts, the nucleus remaining in the 

 posterior half. Both parts went into the 

 typical condition of sli'iulation. 



5:25 P.i/:.- ooth pieces have put out pseudopods and are 

 active, but the non-nuclear part, which was 

 cut from the anterior end, is much nore active 

 than the nuclear and posterior oart. 



3:27 P.f,:.- Both pieces are moving in the typical limax 



(26) 



