EXPLANATION OF PLATES 



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

 out alterations. They are all of the same magnification. A scale by means of 

 which the size of the amebas and of the test substances can be estimated is 

 shown on plate 3. 



The figures are numbered serially for reference. The numbers are placed 

 inside the figures whenever possible. They are to be looked upon as labels only. 

 They have no other significance. An x following a number, as 411x, indicates 

 the end of the experiment illustrated by figures 408 to 411x inclusive. A new 

 experiment starts with figure 412 and ends with figure 432x, and so on. A num- 

 ber with XX following it indicates that the next experiment was performed upon 

 a different ameba. 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 figures 

 were drawn in vertical columns whenever possible. The work on the various 

 amebas is not arranged in strict chronological order. The given arrangement 

 was decided upon in order that the experiments on a particular problem could 

 be presented together. Occasionally a figure as drawn in the laboratory records 

 is left out in these plates. Thus figure 428 does not appear in the experiment 

 illustrated by figures 412 to 432x because it does not add anything of importance 

 to the understanding of the experiment. Other figures were omitted for similar 

 reasons. 



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 alsogiven, and 

 where it is not given it maj' easily be computed, as the time of all figures where 

 it is not indicated are spaced equally in time, in any one experiment. 



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

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

 moving away when observations were terminated. 



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 too of each plate 

 therefore points toward the North. 



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 

 object was not rolled around by the ameba. The explanation for this differ- 

 ence 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 the figures see the text. 



The test objects are labeled in abbreviated form as follows: (For quick and 

 correct reference the test objects are connected with the proper ameba by 

 leader lines; these lines have no other significance.) 



A, aleuronat K, keratin 



F, fibrin L, lactalbumin 

 FC, food cup O, ovalbumin 



G, globulin Z, zein 



GG, grain gluten 



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