Il6 BRUCE D. REYNOLDS. 



among the members of a clone, without necessarily being accom- 

 panied by corresponding morphological differences, and that 

 these changes can be demonstrated by the cross-fusion method 

 within relatively short periods of time approximately 22 days. 

 Since both lines of a given clone were subjected to the same exter- 

 nal influences, the inference might be drawn that such proto- 

 plasmic changes are probably due to inherited variations and not 

 to the action of environmental factors. However, later experi- 

 ments show that this position is untenable. 



II. DIFFERENT ENVIRONMENTS. 



Having determined the time required for intra-clonal differen- 

 tiation under similar environments, it was now possible to subject 

 the two lines of a clone to different environments and observe 

 the relative effects such treatment would have on their behavior 

 towards each other's fragments. In carrying out these experi- 

 ments such factors were employed as might occur in nature, viz: 

 (a) 25 per cent hay infusion, (/?) sucrose, (c) saline, (d) acetic 

 acid, (e) sodium carbonate, (/) alcohol, (g) darkness, and (h) 

 temperature. The organisms seemed to thrive best in 10 per 

 cent hay infusion, and since this could be prepared by a given 

 formula, it was used in every case (except one) as the standard 

 culture medium: i.e., one line of a clone was grown in it at room 

 temperature in front of a window, while the other was altered 

 as desired. 



(a) 25 Per Cent Hay Infusion. 



An organism was isolated from a wild culture and placed in a 

 concavity containing pond water. Upon dividing, the new cell 

 thus formed was transferred to a receptacle containing 25 per 

 cent hay infusion and designated as clone H line h-Jiay, while the 

 individual remaining in the old shell was placed in a concavity 

 containing fresh pond water and now became known as clone 

 H line h. These two daughter-cells were then placed in the same 

 moist chamber, so that the only difference in their environments 

 was represented in the culture media. The usual tests for cross- 

 fusion between the lines were made with the following results: 

 on the second day after the beginning of the experiments +, 4th 

 + ,6lh +,8th--o,()th -o--. 1 



1 Tin.- significance of these symbols is as follows: + fusion occurred; shatter- 



