METHODS OF EXHIBITING REACTIVE TENDENCIES 15 



the apparatus) connected by means of cords or wires with the 

 various entrance and exit doors of the apparatus, and so ar- 

 ranged as to enable the experimenter to unlock and open or to 

 close and lock any given door by a simple movement of a key 

 or lever; (7) a protected incandescent lamp in each of the boxes, 

 with the necessary switch and timing mechanisms for its satis- 

 factory use in connection with the Hunter method of delayed 

 reaction (lamps need not be installed in the twelve boxes, but 

 only in those which are to be used for the delayed reaction 

 method) . 



This apparatus may be built in three sizes: small, medium, 

 and large. 



The small apparatus is suitable for experiments with such 

 organisms as the toad, frog, lizard, tortoise, mouse, rat, spar- 

 row, canary, and other like-sized amphibians, reptiles, birds, or 

 mammals. The medium-sized apparatus is suited for experi- 

 ments with the tortoise (large), snake, dove, crow, domestic 

 fowl, cat, small dog, raccoon, rabbit, squirrel, marmoset, and 

 o her medium-sized reptiles, birds, or mammals. The large 

 apparatus may be used for various types of large-sized lower 

 vertebrates, and for such mammals as the cat (large), dog, pig, 

 goat, sheep, bear, monkey, ape, and man. 



The several figures indicate the general plan of the apparatus 

 and certain of the most important points of construction. 



Each reaction box, according to figures 1 and 3, and also 

 according to the measurements of table 1, occupies five degrees 

 of arc. The width of the box is therefore determined by its 

 distance from the center X (figures 1 and 3). By making the 

 boxes intercept six degrees instead of five, the advantage can be 

 gained of shorter distances between release door and entrance 

 door, but there results the serious disadvantage that the appa- 

 ratus is so spread out as to demand a considerable eye movement 

 for inspection of the twelve reaction boxes. There is the further 

 disadvantage, in the wider angle, that the large apparatus re- 

 quires for its installation a floor area of nearly thirty-six by 

 thirty-six feet. For these and other reasons, it has seemed 

 desirable to make use of the five degree angle in the designing 

 of this convertible apparatus. 



The alleys are, in each size of apparatus and throughout their 

 lengths, the same width inside as the reaction boxes are outside. 



