EXPLANATION OF PLATES 



The figures are camera lucida drawings taken from the laboratory notes with- 

 out alterations. The camera lucida was attached to the right hand tube of a 

 long arm Zeiss binocular microscope. Eyepiece 4 and objective 3,3 were used, 

 giving a magnification of 65 diameters. A scale by means of which the size of 

 amebas and of test objects can be estimated is shown on plate 3. 



The figures are numbered serially from 1 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 7x, indicates the end of the 

 experiment, illustrated by figures 1 to 7x inclusive. A new e.xperiment starts 

 with figure 8 and ends with figure 13x, and so on. If a number is followed by xx, 

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

 figures 1 to 152xx represent the results of a number of experiments upon the same 

 ameba. With figure 153 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 fig- 

 ures in any one experiment, and in nearly every case for all the experiments per- 

 formed on any one ameba. The figures were drawn in vertical columns whenever 

 possible. The work on the various amebas is not arranged in strict chronologi- 

 cal order. The given arrangement was decided upon in order that the experi- 

 ments on a given problem could be presented together. 



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

 and minutes. In many cases the time of drawing of each figure is also given, 

 and where it is not given it may easily be computed. 



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

 in the last figure of each experiment denote the direction the ameba took in 

 moving away from the test object. 



The test objects are labeled in abbreviated form. See table of abbreviations 

 below. For quick and correct reference the test objects are connected with the 

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



All the work was done facing a north window. All the figures were drawn in 

 the same position in the laboratory and on the plates. The top of each plate 

 therefore points toward the North. This is worth noting from the point of view 

 of the possible influence of light on the behavior of ameba. 



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

 same test object as drawn in the figures of any single experiment, even if the ob- 

 ject was not rolled around by the ameba. The explanation for this difference 

 lies in the speed with which the drawings had to be made in order to catch im- 

 portant 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 556 to 573 of the text. 



577 



