INTERACTIONS OF PROTOPLASMIC MASSES. 12J 



organ! -in- in the same concavity and removing the new individuals 

 as they appear. 



Method-, i and 2 were not undertaken, but both (a) and (6) of 

 method .> \\ere utilized. 



Four clones, J, K. Q, and R were started and each of these was 

 divided into two lines upon the first division. Individuals from 

 these lines were transferred to new concavities every other day, 

 and upon each transferral of the organisms a quantity of the 

 culture medium from the old concavity in which one line had 

 been growing was placed in the new concavity in which a specimen 

 from the other line was to be confined, and vice versa. Thus, each 

 time an organism was placed into fresh culture medium it brought 

 with it some of the bacteria from the old culture in which it had 

 been living; but in addition to this, bacteria from the old culture 

 in which its sister line had been growing were also introduced, so 

 that any difference in the flora existing in the two old concavities 

 were distributed to the new concavities alike. Tests were made 

 I >e i \veen representatives of the two lines as had been done in 

 former experiments, and it was found that cross-fusion did not 

 cease after twenty or twenty-five generations, but persisted as 

 ln^ as the experiments were continued; or in clone J until the 

 ) jd generation, clone K until the 47th, clone Q until the 65th, and 

 clone K until the 5Nth. After obtaining cross-fusion in clones J 

 and K for 42 and 47 generations respectively, Petri dish cultures 

 wen- made of the two lines in each clone by putting four indi- 

 \idti.ils in a IVtri dish containing 25 c.c. of to per cent, hay 

 infusion. These were placed before a window when- they re- 

 in. lined undisturbed from July 31 until August 25. 



Another series of experiments was begun in \\hich attempts 

 \\ere made to bring related specimens, that had been reacting 

 .itively towards each other's fragments, to a state in \\hii-h 

 cross-fusion would take place between them, 1>\ frequently ex- 

 changing small quantities of culture medium between the con- 

 cavities in which they were living. Three \ariatioii- of ihi- 

 system \vere employed: (a) by cro^-tran-ferring a small quan- 

 tity of culture medium from the old retvptarle "I "lie line to the 

 new container of the other each time the organi-m- \\ere con- 

 veyed to fresh culture medium thus bringing their en\ in mments 



