INI1.KX' 1IOXS OF PROTOPLASMIC MASSES. IIJ 



A similar -eries of experiments were conducted between two 

 diverging lines of clone \Y. In this case seven observations were 

 made, extending through the eleventh generation, with the result 

 that cross-fu-ion took place in every instance. Further obser- 

 vations were ni.i'lt impossible on account of death in one of the 

 lines. In one case then, the time required for two related lines 

 to exhibit the negative reaction was greatly reduced, while in 

 the other death interfered with the determination of this point. 

 If standing alone, further evidence would certainly be necessary 

 before much emphasis could be placed on the significance of these 

 observations; but, since the conclusions drawn, from the experi- 

 ments dealing with different environments, were largely deducted 

 from later observations, it was decided to include these as they 

 stand without attempting to add more convincing proof. 



(b) w Per Cent, liny Infusion Containing I Per Cent. Sucrose. 



In these, and all succeeding experiments, the standard culture 

 medium was 10 per cent, hay infusion. After the first division 

 of the clonal parent, one of the daughter-cells was transferred to 

 a concavity containing 10 per cent, hay infusion plus I per cent. 

 sucrose, while the other was kept in the standard culture medium. 

 In every other respect the two lines arising from these individuals 

 were subjected to similar influences. In order to avoid possible 

 contaminations, a different pipette was used in transferring mem- 

 bers of these two lines to fresh culture media. The density of 

 the medium was, of course, increased ujxm the addition of sugar, 

 which resulted in the newly formed shells becoming smaller ami 

 smaller, so that it was considered advisable (perhaps necessary) 

 to remove the osmotic influence after six or seven days; conse- 

 quently, after having remained in the medium containing I per 

 cent, sucrose for approximately that length of time, tin organisms 

 were put back into 10 per cent, hay infu-i<>n. From thi- time on 

 both lines of a clone were living amid>t the -aim -urnuindings. 

 It was found that cross-fusion between the two line- continued 

 for five or six days, then for a period , ,|" -i\ , ,r --\vn days the 

 interactions were negative (even though the n-motic agent had 



ing reaction; o contact made but neither fusion M<>I -li.itii im^ !lln\viMl. The 

 number of symbols placed after a figure iiiilii.it<-- tin- munlx-i vatiohs made 



on that day. 



