392 JOHN LINCK TJLRICH 



the problem may be accompanied by crouching. All these move- 

 ments that are completely performed are presented in a variety 

 of groupings, and this indicates that these fundamental move- 

 ments are somehow conjoined. They meet certain conditions of 

 the environment of the cage, and they reappear in the new en- 

 vironment of the problem. Here manifold stimuli, or the con- 

 figuration of the living cage, and that of the problem produce 

 similar responses. The only difference in these movements in 

 the two situations, that of the living cage and that of the prob- 

 lem, is that all movements in the problem are generally more 

 quickly performed, But this is not always so, for in some rats 

 movements may be performed slowly. A degree of reflex ex- 

 citability often accompanies greater activity. On the other hand, 

 at times fundamental movements are only partially or incom- 

 pletely performed. These incomplete movements consist of 

 reflex acts, such as ineffective scratching, biting, crouching, and 

 pushing the snout into the wire mesh of the door of the problem. 

 These movements are performed on hard resisting substances, 

 and as a consequence are ineffectively and incompletely pro- 

 duced. Being ineffectively performed, these movements are 

 usually accompanied by contraction of the extensor muscles of 

 the entire body. Pronounced contractions of the extensor mus- 

 cles produce posture for the performance of a definite act. Post- 

 uring is invariably seen in repeated crouching and setting of the 

 body in the performance of an exaggerated movement. In the 

 more active rats posturing is usually accompanied by a momen- 

 tary increase in reflex excitability. This increase in reflex excit- 

 ability indicates that widespread organic changes are taking 

 place in the organism. 



This division of all movements into complete and incomplete 

 is of use for descriptive purposes only, and either of these terms 

 used has no more fixed value than the other. The movements 

 that are completely produced show that an effective adjustment 

 to the outside of the problem has taken place, and those that are 

 incompletely performed show an ineffective adjustment to the 

 problem box. In many rats effective adjustment only to the 

 exterior of the problem box inside the hood takes place. As a 



