INTERACTIONS OF PROTOPLASMIC MASSES. IOJ 



types of reactions were observed: (a) fusion and (6) failure to 

 attract, or if contact was made the fragment would be pushed 

 along for a while, without causing any apparent disturbance, and 

 then abandoned. 



During tin- course of this investigation, involving much more 

 extensive experiments, it was found that in some cases the 

 masses would readily attract l each other, but upon making con- 

 tact there would be a sudden contraction of the involved regions 

 as if violently shocked, while the protoplasm constituting both 

 the fragment and the organism's pseudopod (5) which had made 

 contact with it would be shattered into bead-like masses. See 

 Fig. i : A, B, and C. This type of reaction was observed so fre- 

 quently that it is referred to throughout this paper as the "shat- 

 tering" reaction. 



As the investigation progressed it seemed advisable to divide 

 the problem into three sections; and to study the reactions be- 

 tween organisms and fragments from related specimens under the 

 influence of three different conditions as follows: 



I . Similar environments. 



II. I >ilferent environments. 



III. Identical environments. 2 



Numerous methods have been employed in studying variations 

 among the proto/.oa, such as: rate of reproduction, measurements 

 of size, counting the number of spines, teeth, tentacles, etc., resis- 

 tance to poisons and to hiiji temperatures. In tin- Miuly, for 

 the first time, advantage has been taken of the property possessed 

 by certain organisms of fusing with their own or frav;inrin- lrm 

 closely related specimens. The superiority of this method lie- in 

 the fact that it affords a quick and definite means of di tci iniuin- 



1 In tliis, as in the previous paper, it was n ;mi.-.l why : 



were attracted to each other. When pn>ipl.i-n. t present the 



organisms would move about at random; but \\lu-n \- m wliii h liad 



been detached from themselves or from related individual- \\n- \\ ithin two or three 

 hundred micra of them, they would invariably ] irds the frag- 



ments. This statement is based on over liiu-rii liundn-d ob us. A series 



of experiments are being planned to ascertain, it ; nulus involved in 



these positive reactions. 



- The organisms comprising the two lines undi-r ol n were placed in the 



same concavity, or else, portions of the culture nn-diu v. uently exchanged 



tween the concavities containing them. 



