74 ASA A. SCHAEFFER. 



EXPLANATION OF PLATES. 



The figures are camera lucida drawings of sample experiments taken from the 

 laboratory notes without alterations. The camera lucida was attached to the 

 right-hand tube of a long-arm Zeiss binocular microscope, which was used in con- 

 nection with the stage and condenser ot a compound microscope. Eyepieces 

 number 4 and objective as were used, giving a magnification of 65 diameters. A 

 scale by means of which the size of amehas and light beams can be estimated is 

 shown on Plate V. 



The figures are numbered serially from i on, for reference. The numbers are 

 placed inside the figures. They are to be looked upon as labels only. They have 

 no other significance. An x following a number, as 2ix, indicates the end of the 

 experiment illustrated by Figs. 10 to 2ix inclusive. A new experiment starts with 

 Fig. 22 and ends with Fig. 36xx, and so on. If a number is followed by xx, it 

 means that the next experiment was performed upon a different ameba. Thus 

 Figs, i to QXX represent the result of a single experiment upon an ameba. With 

 Fig. 10 a new ameba was employed, and so on. The order in which the figures were 

 drawn is represented by the serial numbers for all the figures in any one experiment, 

 and in nearly every case for all the experiments performed on any one ameba. 



The time of the beginning and the end of each experiment is given in hours and 

 minutes. In some case? the time of drawing of each figure is also given, and where 

 it is not given it may easily be computed the figures in such case being spaced 

 equally in time. 



The arrows show the direction of active protoplasmic streaming. The larger 

 arrow in the last figure of each experiment denotes the direction the ameba took in 

 moving away from the test object. 



The light beams, etc., are labelled in abbreviated form. See table of abbrevi- 

 ations on below. For quick and correct reference these test objects are connected 

 with the proper ameba by leader lines. These lines have no other significance. 



It will be noted that there are slight differences in the size and shape of the same 

 light beam or other test object as drawn in the figures of any single experiment. 

 The explanation for this difference lies in the speed with which the drawings had 

 to be made in order to catch important items of behavior. As a rule the parts of 

 the ameba lying nearest the test object received the most careful attention and 

 were drawn first ; the posterior parts of the ameba and the test object were drawn last. 



For detailed explanation of figures see pages 49-67 of the text. 



TABLE OF ABBREVIATIONS. 



B, blue light. LI, white light. 



CA, carbon. OL, orange light. 



D, dark beams. R, red light. 



G, globulin. V, violet light. 



GN, green light. Y, yellow light. 



