180 ROBERT M. YERKES 



A large aquarium table, upon which any desired form of aquarium 

 may be placed, provides for the housing of amphibians and fishes. 



The writer's students' training course in animal psychology is 

 conducted in a class-room and lecture room on the third floor of 

 Emerson Hall. The space of the laboratory on the fourth floor 

 is, therefore, wholly available for research. 



The rooms of the new laboratory are supplied with water, 

 gas, compressed air, and a variety of electric currents. The 

 latter are conveniently delivered from boards located in each 

 room. In every room there are available 110 volt direct and 

 alternating currents, as well as currents from Edison storage 

 batteries which are located in the battery room of the main labora- 

 tory. A conveniently placed and well constructed switch board 

 (S. B. of Figure 1) in the corridor of the laboratory, provides 

 for the distribution of these storage currents. This board is 

 fitted with miniature Weston switch board voltmeter and am- 

 meter, and with taper plugs. 



Realizing the extreme need for apparatus in animal investi- 

 gations which shall, in a large measure, eliminate the experi- 

 menter from the situation to which the animal is expected to 

 respond, the writer, in planning this new laboratory, has attempted 

 so to arrange spaces that automatic setting, actuating and re- 

 cording devices may readily be placed in rooms adjoining those 

 in which the animal is responding. Heretofore, the majority 

 of students of animal behavior have deemed themselves com- 

 petent and able to observe and record accurately the doings of 

 their subjects. That this, however, is not the case is clearly 

 proved by numerous instances of misobservation and mis- 

 interpretation of reactions. We have, for example, twice dis- 

 covered in this laboratory that dogs which were presumably 

 responding to a definitely arranged experimental situation were 

 actually responding to certain unconscious movements of the 

 experimenter. The only safe and sure way to avoid such risks 

 is to provide mechanical recorders which shall at least enable the 

 experimenter to separate himself widely from his reacting 

 subject. 



We have striven for flexibility and adaptability in this new 

 laboratory of animal psychology while arranging for the devel- 

 opment, in designated spaces, of specific forms of apparatus. 

 So far as the conduct of experimental work under highly con- 



